Pond Scum - Homebrew bike light instructions- Mtbr.com
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  1. #1
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    Pond Scum - Homebrew bike light instructions (not dial up friendly)

    Here are some quick instructions for DIY construction of a handlebar mounted bike light. Not a bunch of information on batteries, bulbs, bulb wattage and angle types as I figure there is already a whole bunch of information out there (search function).

























    Pond light $8.00
    Handlebar mount $10.00
    MR16 bulb $4.00
    14.4V Battery/Charger $70.00

    Total $92.00


    ****WARNING****
    Do not leave this light running unattended or for extended periods of time indoors. These MR16 bulbs overvolted to 14.4 volts produce a generous amount of heat and need some air flow to help pull the heat from the housing and bulb.
    Last edited by scar; 12-05-2006 at 05:56 AM. Reason: found out non-members can view pictures

  2. #2
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    For some reason, I'm not seeing the instructions... What format are they? I saw your idea in the other thread, and I'm planning on doing something similar. If you can't get the file to work, could you e-mail it to me? I'll PM you my e-mail...

    Maybe it was a work thing, cause I see them now at home.
    Last edited by dnlwthrn; 11-16-2006 at 08:07 PM.

  3. #3
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    Nice build I think I'll be stopping off at Harbor Freight on my way home from work.

  4. #4
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    Can you post a link to your bar mount? This is one of the slickest homebrews I've seen. good job!
    What, me hurry?

  5. #5
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    Miscellaneous parts

    Last edited by scar; 12-05-2006 at 06:02 AM.

  6. #6
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    clean, tasty little design...i'm gonna buy one fo those trick bar mounts.
    "He can make even a global summit meeting seem like a kegger." M. Dowd, NY Times, 19 July 2006

  7. #7
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    Scar,

    Were did you get your replacement battery? Would you recommend the 14.4 volt 5000 mah battery from battery space?
    Getting a dropper post is like getting a bidet. I didn't know I needed one until I get one and boy, does my ass thank me.

  8. #8
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    NMPhi767 - My original Jet battery pack was 13.2V. I went with the 14.4V 5ah C cell pack with charger from batterypace.com for brighter light output and longer run time at the price of bulb life. Build quality is great. I will be buying the 14.4V 5ah water bottle version to run the Pond Scum light. Be aware - these 14.4V 5ah batteries are not the lightest (12 C cells). I just consider them a training aid!

    The battery/charger combo came with the an extra male waterproof cable that matches up to the battery for splicing into your current set-up or if you are building one. I am sure the water bottle version is the same.

    All said for the entire light system - battery with charger, Pond Scum light head ~ $100


    14.4V battery pack and charger combo
    http://www.batteryspace.com/index.as...OD&ProdID=2302

    14.4V water bottle and charger combo
    http://www.batteryspace.com/index.as...OD&ProdID=2462

  9. #9
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    What kind of epoxy did you use?

  10. #10
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    kokothemonkey - I used JB Weld, but I am kind of disappointed with the result. The JB Weld did not attack the surface of the light fixture, but rather just hardened on the surface. I can already see it seperating from the fixture slightly. This weekend, I am going to chip off the JB Weld and try again with some Devcon Plastic Welder. Supposedly it has a solvent in it that helps it "melt" to the bond surface.

    It helps to keep a screw threaded in the nut during the epoxy stage to keep epoxy out of the threads. I just turned the screw by hand during the drying stage to insure that I wasn't gluing the screw to the nut.

    Final screw length is critical as well. If your screw length is too long, it will bottom out against the light fixture and "jack" the nut and epoxy away from the light fixture.

    I am also going to not only rely on the mechanical joint of the screw and nut, but I am also going to apply epoxy between the adapter and the light fixture and between the adapter and the bar mount. Should be rock solid. Just make sure you have everything fitting the way you want before epoxying everything together.

  11. #11
    Light freak
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    A couple of photos of light mounted....

    PHOTO #1




    PHOTO #2


  12. #12

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    Thanks for all that info Scar.... Have my parts on the way....

    BTW, for those of you who want a helmet mounted version, you can also get that mount on the batterspace.com website as well.

  13. #13
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    did you use the MR16/C 12V 35w or the MR16/C 12V 20W? and pics at night with the coverage of the light?

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    Don't see the switch.....bulb choice

    does the lite have a switch...
    do you plan on incoproartating one....
    is the lite dimmable...
    are the bulbs from batteryspace decent quality compared to the ones from JET

    newbie so all apologies if the above questions are ignorant

  15. #15
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    If you want a switch with dimming function, you'll need to get some sort of controller. You could build one yourself, or get something like the "Light Brain." http://www.trailheadlights.com

    I'm thinking of adding one of these to a 2 headlight setup similar to scar's. I'll probably fab a mount to hold both lights, using a spot bulb in one and a flood bulb in the other. Estimated total cost, not including the fabbed mount is $140 with battery... At the same time, I've been pondering switching to 6V bulbs so I can run a single light mounted to my helmet powered by RC car batteries (I have a pack or two at home that are in the 3000mAh range). So it may be an interesting project... But its definitely a score on the housing setup. Thanks scar!

  16. #16
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    ladracer –
    My next one will have the switch listed in the links above.
    Not dimmable – On or Off
    Don’t know about the quality of BatterySpace bulbs. Have a couple on order.


    Merkyworks –
    I am currently using a MR16/C 12V 20W (36 degree Flood). I went with 20W for light output, run time and temperature control. But I do have a MR16/C 12V 35w (12 degree spot) on order to play around with. Haven’t thought about or had time to do any nighttime “beam” shots. Maybe later.

  17. #17
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    Quote Originally Posted by dnlwthrn
    I've been pondering switching to 6V bulbs so I can run a single light mounted to my helmet powered by RC car batteries (I have a pack or two at home that are in the 3000mAh range). So it may be an interesting project... But its definitely a score on the housing setup. Thanks scar!
    I've got a bunch of these around, was trying to figure out how to use them in lights but they are the flat kind that match with contacts in the car. Baffled by how to make them work in the light without soldering wires to the battery -- this would make it impossible to recharge. Any ideas here or do you have different batteries?
    What, me hurry?

  18. #18
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    Go to your local hobby shop, you can pick up the mating connectors for cheap. Make up a loom to connect them to your lights: either use one pack for 6V system, or wire two in series for a 12V system (7.2V packs). You should be able to get a connector to plug into your light system (is the one available on batteryspace.com the same as some of the major light co's connectors?). Then you can swap out packs as they die... I was thinking real simple for a homebrew setup: single pack, 6V light, switch. Put pack in camelback, light on helmet, switch built into light housing.
    Make sense?

    Another option if you don't have a hobby shop nearby would be:
    Tower Hobbies

  19. #19

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    Please post some night photos that show this light in action. thanks

  20. #20
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    Quote Originally Posted by scar
    NMPhi767 - My original Jet battery pack was 13.2V. I went with the 14.4V 5ah C cell pack with charger from batterypace.com for brighter light output and longer run time at the price of bulb life. Build quality is great. I will be buying the 14.4V 5ah water bottle version to run the Pond Scum light. Be aware - these 14.4V 5ah batteries are not the lightest (12 C cells). I just consider them a training aid!

    The battery/charger combo came with the an extra male waterproof cable that matches up to the battery for splicing into your current set-up or if you are building one. I am sure the water bottle version is the same.

    All said for the entire light system - battery with charger, Pond Scum light head ~ $100


    14.4V battery pack and charger combo
    http://www.batteryspace.com/index.as...OD&ProdID=2302

    14.4V water bottle and charger combo
    http://www.batteryspace.com/index.as...OD&ProdID=2462
    So if I got the water bottle/charger combo, that would take care of the electrical side of things aside from a switch?

    Also you might try a product called Gorilla Glue instead of epoxy, that stuff is really strong, I used it for attaching a bracket in my engine bay to run my amp wires from the battery, and other random tasks and it holding.

  21. #21
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    Yes the battery/charger combo is all you need except for the light head. The Devcon Plastic Welder seems to be working great.

  22. #22
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    Pond Scum - Double Strength

    I decided to make a "dual" set of Pond Scum lights with switches this weekend. Here are a couple of pictures that I snapped with the lights installed.

    Double Strength





    Wiring Diagram



    Pond light (2x) $8.00 $16.00
    Handlebar mount (2x) $10.00 $20.00
    Switch (2x) $4.00 $8.00
    MR16 bulb (2x) $4.00 $8.00
    14.4V Battery/Charger (1x) $70.00 $70.00

    Total $122.00
    Last edited by scar; 12-04-2006 at 05:11 AM.

  23. #23
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    whats the life of the battery with 2 lights now? this is still with the 14.4V 5ah battery right?

  24. #24

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    why the switches? I would have thought you just pull apart the cable to turn it off? Also, how bright are the pond lights? night pictures would be nice.
    Last edited by Jarl; 12-04-2006 at 01:53 PM.

  25. #25
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    Merkyworks - The battery life is an unknown at this point. Here is what I am thinking.....
    Overvolted 12V bulb to 14.4V using 5ah battery should result in 2.75 hour run time. I was planning on just using one light for the uphill climbs and then switching to "Double Strength" mode for the downhills. Don't really see the need, but why not for an extra $20?
    If I use the two 20W lights full time on a fresh battery, I am calculating a run time of just under 1.5 hours.


    Jarl - The switches were installed so that I can run only one light on the uphills and switch to "Double Strength" mode for the downhills.

    I am sorry, but I don't understand your question about pulling apart the cables going into the battery.

    How bright do you want them? A 12V battery is going to give you yellow lights. A 13.2V battery will give you brighter, whiter lights, a little less run time, and a little less bulb life. A 14.4 battery will give you even brighter, whiter lights yet, even less run time, and even less bulb life. You have to weigh all of these variables in deciding how you are planning to use the lights and how much you want to spend on batteries.

  26. #26

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    Well in your lighting diagram you have the "water bottle", a coil of wire leading to a plug, then another plug leading to the lights. Couldn't you detach these two plugs to turn it off? (as they are in the picture)

  27. #27
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    Quote Originally Posted by Jarl
    Well in your lighting diagram you have the "water bottle", a coil of wire leading to a plug, then another plug leading to the lights. Couldn't you detach these two plugs to turn it off? (as they are in the picture)
    You could also cut them with some wire cutters, also carry a 12V soldering iron to solder the two ends together when you want them to light up again. Sure as hell improved my soldering skils! But on the other hand, a simple button/switch is pretty practical.

    @Scar: what chemistry battery are you using? Considering the price I'd say NiMH, but you never know...
    Nice looking light BTW! Always nice to see what people come op with and mod into bike lights. And with 2x20W (@14,4V thats 24W a piece!) you should have 'plenty' light!
    ps. Ever thought of upgrading your lights with a Lightbrain? Multiple levels for even longer runtimes and with a single controllerbutton it also cleans a the bit of the cablework out.
    Last edited by brum; 12-04-2006 at 04:52 PM.

  28. #28
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    Jarl - You are exactly right, you can make them without the switches and just plug/unplug them between at the cable end of the light and the cable end of the battery like I made the first one in the instructions above. I just wanted the ability to run one at a time on the climbs to conserve battery life, be able to switch them both on for the screamin' downhills, and the ability to switch them both off to enjoy the stars all with the just a push of a couple of switches!

    I agree, some "beam" shots at night would be nice. The only problem is that it has been extremely cold here since I have built these and I don't feel like venturing out just to take photos at night. Maybe once it warms up a little.

  29. #29
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    you could turn the lights out in the house/room and snap a shot

  30. #30
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    ****Warning****

    I added the following warning to the end of the instructions above.

    ****WARNING****
    Do not leave this light running unattended or for extended periods of time indoors. These MR16 bulbs overvolted to 14.4 volts produce a generous amount of heat and need some air flow to help pull the heat from the housing and bulb.

  31. #31
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    was this an after thought or did you turn them on and walk away and found out that they were on fire.

  32. #32
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    They suggest "cycling" your NiMH batteries by charging, discharging, charging, discharging for 3-5 cycles. I have been running my light in my cubicle to drain the battery and you can smell it when it starts getting hot. All it needs is a little air flowing around it to cool it down sufficiently. Even the housing on my Jet Phantom helmet light gets very hot when run indoors with no air moving around it.

    I built one for my friend at work who commutes everyday. The bike rack just happens to be outside of the window next to my cube. I was looking for him to pull up this morning. I ran out there to feel how hot his housing was getting on the commute. Not much heat at all. Just barely warm to the touch.

    Did you know that the majority of the MR16 halogen bulbs are designed so that most of the heat exits out the back of the bulb? Plug in a bulb outside of the housing and power it up and see how much light (heat) escapes from the back of the bulb. You will be amazed. This is because this type of bulb is used in retail and museums and they don't want the heat beating down on the customers or products.

    I played around a little bit with this issue this morning. I remember reading on candlepowerforums.com that some people were using aluminum tape to cover the backside of the bulb and stop the light (heat) from exiting the back. I did the same thing with one of my bulbs.


    This definitely stopped the heat from exiting the back of the bulb. I was able to leave the light plugged in much longer in my cube. Now, without any air flowing around the light, the o-ring starts to get hot.

    Like I said earlier, there is no issue with heat as long as there is some air flowing around the housing. This is no different than any overvolted halogen light that you can purchase from a manufacturer.

  33. #33
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    It does get really hot. I tested my pond light setup in office with a fan running and it still got super hot. For run time calculations, I ran mine with 12 AA powerizer batteries wired in series from batteryspace (2.5 aH) and only got an hour flat. I also cycled the batteries three times and still only got an hour. I am curious to see what the run times are with the pre-made battery.

  34. #34
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    i wonder if lithium-ion batteries would work better for longer life

  35. #35
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    kokothemonkey - I am not a "sparky" by any means but here are my questions.

    What kind of charger are you using for your battery pack? Are you sure you are getting a full charge? What is the voltage of the battery pack when you take it off of the charger?
    Last edited by scar; 12-06-2006 at 05:20 AM.

  36. #36

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    anyone see any problems with drilling holes into the back of the housing for hot air escape?

  37. #37
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    BassChop - I responded to your PM. Did you get it?

  38. #38
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    well if you drill holes then water/moistior could get in....thats all i could think of

  39. #39
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    Hey Scar, you have a PM.

  40. #40
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    rattpoison - I do not see another PM from you. I got your PM on Sunday and sent you a lengthy response Monday morning. Did you get my response? If you sent me another PM today, maybe I am just not seeing yet.

  41. #41
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    Quote Originally Posted by Merkyworks
    i wonder if lithium-ion batteries would work better for longer life
    Yes and no. Lithiums have an advantage because the same size li-ion battery as a Nimh or NiCd will have more voltage and/or more mah. So in that sense they would. However, if you get a li-ion battery that has the same voltage and mah as a nimh or nicd, it will give you the same run time. It will be smaller and lighter though. I really simplified that explanation so please forgive.

    What sucks about lithium and homebrews is that lithium becomes dangerous if you discharge too much energy from it and at best it will not recharge correctly either. Unless you put in a method of monitoring the current and turning off the light if the voltage dips to far into your homebrew, you could really mess up your battery.
    Getting a dropper post is like getting a bidet. I didn't know I needed one until I get one and boy, does my ass thank me.

  42. #42
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    Quote Originally Posted by BassChop
    Anyone see any problems with drilling holes into the back of the housing for hot air escape?
    I don’t see any issues in this case. I know of a manufacturer who does this. It looks to me like it’s pretty well made inside, with everything being covered by spaghetti insulation. I would just check to make sure things are nice and dry every now and then.


    Quote Originally Posted by NMPhi767
    What sucks about lithium and homebrews is that lithium becomes dangerous if you discharge too much energy from it and at best it will not recharge correctly either. Unless you put in a method of monitoring the current and turning off the light if the voltage dips too far into your homebrew, you could really mess up your battery.
    It sounds like you understand the issues, but I just thought I’d make things clear to everyone. To be honest I wouldn’t even bother building a home made Lithium pack unless you have read up and really know what you are doing. A quality battery protection circuit is absolutely critical with these cells. These devices protect the pack from over discharge, over charging, over current draw and usually have a thermal cut-out too.

    If Lithium packs aren’t protected with a device like this they can get into thermal runaway, which cannot be stopped. The result of thermal runaway is a very, very nasty fire. These fires often burn at extremely high temperatures, and could more then easily burn your house down. Not to mention the highly toxic fumes that result. I’m not exaggerating in the slightest.

    If you’re not confident, or don’t want to spend the time to build a Lithium pack properly, go and buy a complete pack / charger solution from a reputable manufacturer.

    Dave.

  43. #43
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    well i was thinking of using


    or

    one 14.8V 4A
    http://www.batteryspace.com/index.as...OD&ProdID=2486

    i think these have all the protection that is needed, right????

    the thing is that it says that it cant run higher than a 15W halogen buld but i want to run a 20W halo. why does this matter?
    Last edited by Merkyworks; 12-13-2006 at 10:56 PM.

  44. #44
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    You are a phenomenon!!!!!!!!!

    Greetings - Saludos
    Warning!!! my english is very very bad, sorry.

    Easy DIY led light1
    Easy DIY led light2

    The Beast!!!

  45. #45
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    Quote Originally Posted by Merkyworks
    the thing is that it says that it cant run higher than a 15W halogen buld but i want to run a 20W halo. why does this matter?
    Because you will draw more than the battery is designed for and, for safety reasons, the battery protection will trip out and not let you turn the light on.

    But I run a 12 volt 20 watt using a 14.8 volt li-ion battery (which therefore draws 30 watts) and am able to get it light by using what someone described as ghetto softstart: switching the light on and off quickly a few time times. It usually starts on the third try. But you are better off building a proper softstart setup. There are quite a few directions here.

    Wombat

  46. #46
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    Or buy a battery from another manufacturer that will meet the power draw requirements that you need. Most Lithium Ion cells can deliver a fair amount of current continuously; often you will see cheaper packs bundled with cheaper, lower quality (cruder) protection circuits, hence cheaper performance.

    A mate of mine runs a 35 watt halogen, overvolted with a quality 14.8 volt Lithium Ion pack no problems at all.

    As Wombat mentions, a “soft start” circuit will often be enough to smooth the initial current draw that happens when a halogen globe is first turned on.

    Yet another alternative is to flick the power switch a few times which may be enough to trick the protection circuitry. I wouldn’t really want to keep on doing that in the long term however.

    Dave.

  47. #47
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    Quote Originally Posted by scar
    kokothemonkey - I am not a "sparky" by any means but here are my questions.

    What kind of charger are you using for your battery pack? Are you sure you are getting a full charge? What is the voltage of the battery pack when you take it off of the charger?
    The batteries and charger are from batteryspace, and the batteries get fully charged. When measured with a voltmeter, they read 16.8 volts coming from the batteries (12 AA in series), so I think that is my problem with the low run time. Anyone know why 12 AA at 1.2 volts each in series would give so much power when they should only be giving 14.4 volts?

  48. #48
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    Freshly charged cells will always measure a little higher straight off the charger with no load. If you were to hook your light up and measure the voltage across the pack after a few minutes I’m sure you would find that the voltage had dropped and settled.

    Your run time with a 2.5Ah pack overvolting a 12 volt, 20 watt globe sounds about right, considering you are running AA cells.

    I don’t care what people think, in my opinion AA cells are not a good idea in high current draw applications like this. You are much better off building a proper pack with larger cells like 4/3A NiMh cells.

  49. #49

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    Basic question : How does overvolting affect burn time/safety or anything else?

    Scar, How close to the 3.6hours (calculated) of burn time with your system?

  50. #50
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    Overvolting reduces burn time. In my case I overvolted a 12 volt 20 watt bulb by using a 14.8 volt li-ion battery. Using this battery means that the bulb now draws 30 watts (50% more than before). Burn time is reduced by (I think) about 1/3. Bulb life is also dramatically reduced: in my cases I now get only 10% of the original bulb life, but as my previous bulb
    lasted 5 years I am happy with this.

    Over volting also means that you may exceed the discharge rate for your battery: this is true of mine and it won't start unless I flick it on and off a few times to override the battery protection feature.

    Wombat

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    Wombat...thanks for your answer here and in the other thread!

  52. #52
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    BassChop - I have been using the formula previously mentioned that has you multiply the voltage of the battery (14.4V for example) by the amp hours (5ah) then divide it by the wattage of bulb to get an estimate on run time. If you are running a 20-watt bulb and overvolting to 14.4V, the bulb is running more like 25 watts.
    14.4 * 5 = 72 72/25 = 2.88
    Remember this is an estimate presuming everything is optimal, batteries degrade over time, I would multiply that final number by 75% and use that for a realistic run time guesstimate.
    2.88 * .75 = 2.16

    Here is a run time test experience from last weekend. I had only cycled my battery approximately 3 times. Took my battery with a full charge (just over 17 volts) and ran a single light until it went dim. Got 2 hours and about 20 minutes of nice bright light until it started to get very dim and yellow. I hope this might improve a little after a couple more full cycles of the battery, I don't know. Now if I add in another light I might get an hour of run time, don’t know, I didn’t have time to try it.

    Here is what I would expect for a run time using a 35W bulb (43 watts at 14.4V).
    14.4 * 5 = 72 72 / 43 = 1.68 1.68 * .75 = 1.26 hours run time.

    Another thing that I think factors into the reduced run times is the increase in wattage by overvolting. A 35W bulb runs at 35 watts using 12 volts. That same bulb runs at 43 watts using 14.4 volts. My battery pack measures just over 17V when freshly charged. Now what wattage is that 35W bulb running at? I am sure it figures into the equation, I just don't know how, so I use the old "multiply by 75%" rule. Seems to work.

    I saw in your post in another thread you mentioned the housing heating up. I am not sure if you noticed my post above about using aluminum foil tape on the backside of the bulb? It really works!

    Solution for right now - Just use any aluminum foil tape you can find at the home repair store. The glue on this tape is definitely not made to withstand the temperatures the bulb puts off so it will smoke for a while but it will eventually stop. The foil tape still is very effective in reflecting the heat back out the front of the bulb.

    Better solution - Find a source for 3M 433L aluminum foil tape. It uses a silicone adhesive made to withstand 600 degrees.

    Another soultion - Here is something you may want to consider. I have been looking at the Sylvania Tru-Aim line and noticed something on their product spec sheet. All of the versions of the Tru-Aim listed that they were designed to transmit heat out the back of the bulb (except one). These bulbs are used mostly in retail and photography where they don't want the heat "beating" down on the customer, products or subjects. The Tru-Aim Brilliant line uses an aluminized reflector to redirect the heat out the front of the bulb. I think this is the type of bulb we want for these housings seeing as they are sealed up and nowhere for the heat to escape except thru the housing body.

    Sylvania spec sheet




    Here is a great link with a bunch of info on Mr16 bulbs
    https://www.lrc.rpi.edu/programs/nlp...hatAreMR16.asp

    This page from the above link says it all
    https://www.lrc.rpi.edu/programs/nlp...edToKnow03.asp


    I have a couple of the Tru-Aim Brilliant bulbs coming in tomorrow; I will let you know how they work. I am also looking at some "energy saving" models to try to increase run time. Sylvania has an "IR" version that they say redirects the heat to the element to save energy. I have a couple of these coming with my order as well.

    Got any pictures of your light? I would like to see what you came up with.

  53. #53
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    Get The Heat Out Of Here!

    I thought I would try to emphasize why the Pond Scum housing or any other homebrew bike light using a MR16 bulb gets hot and how to reduce it. Like I have said earlier, the majority of these bulbs are used in retail, art galleries (check out the link I posted above for everything you would ever want to know about MR16 bulbs. Keep hitting NEXT on the bottom of the page for a wealth of information). The bulbs are specifically designed to transfer the heat out the back of the bulb.

    Check out this picture I took of a generic GE 12V MR16 20W bulb with a dichroic reflector powered up. This is the type of reflector the majority of the MR16 bulbs use. The bulb is pulled away from the housing.

    GE 12V MR16 20W 38 degree spot


    There is so much light (heat) coming out the back of the bulb you can't even see the bulb in the picture! The easiest way to mitigate the heat problem is to use aluminum foil tape on the backside of the bulb to help reflect the heat back out the front side of the bulb. I just used some foil tape I had lying around. The adhesive burned (smoked) off initially, but the tape is still adhered to the bulb. You will be amazed at how much difference this mod to the bulb will make.

    I just got some bulbs in today that are specially designed to transfer the heat out the front of the bulb. They use an aluminized reflector in place of the standard reflector. The difference is like night and day. Take a look at this photo; all of the light (heat) is coming out the front side of the bulb. You can even see the bulb in the picture.

    Sylvania Tru-Aim Brilliant 12V 20W MR16 8degree spot


    You can actually touch the backside of this bulb after it has been running for a couple of minutes. DO NOT TRY THIS WITH ANY OTHER BULB!!! I think I will probably use a little bit of the aluminum foil tape on this bulb around the base/socket area as there is a little bit of light (heat) leakage in this area. There is so much light (heat) coming out the frontside of this bulb, it is hard to hold your hand in front of it for any length of time without it feeling like it is going to burn a hole right thru it!

    Here is a link to where I found the bulbs. A little pricey compared to BatterySpace bulbs but I am hoping the light output is also greater on these bulbs. These are only these two options at 20 watts.

    Sylvania Tru-Aim Brilliant (#58569) 12V MR16 20W 8 degree spot
    https://www.lightbulbemporium.com/pr...asp?prod=58569

    Sylvania Tru-Aim Brilliant (#58570) 12V MR16 20W 36 degree flood
    https://www.lightbulbemporium.com/pr...asp?prod=58570

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    scar...thanks for all that info on the bulbs. I will get some pics up of my helmet mounted version shortly...Just need to make some final tweaks. I have done a couple rides with it, and have been very happy with the output of the light. It is very bright (using a 12v 20 watt, 38 degree flood light with the 14.4V/5000maH battery pack). Riding tight singletrack even down some steeps last night was no problem...have a mount for the handlebars, but not sure if I will bother to use two lights, doesn't seem necessary.

    Couple questions for you. I understand the calculations that everyone is using, except for one. How are you calculating the wattage when overvolting? Is this just a guess? It isn't critical, just curious.

    Reflecting the heat out the front of the unit seems to be a good thing, if that isn't going to melt the rubber gasket o-ring on the housing right behind the bulb or the housing in front of the light itself.

    Have you cycled through with the new bulb mounted in the housing? What were the results.

  55. #55
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    BassChop - I don't know where exactly I found this document but I happened to print it out. Lots of good information. Take notice how much the lumens go up in proportion to the voltage going up. I have been using these numbers for wattage of an over-volted bulb. I am sure someone will chime in with the formula for figuring this measurement out. Look forward to seeing your light design. I will be doing some run time test this weekend with a couple of different bulbs. I will let you know how it goes.


  56. #56
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    Quote Originally Posted by BassChop
    How are you calculating the wattage when overvolting? Is this just a guess? It isn't critical, just curious.
    Basschop

    You can use this site: http://www.angelfire.com/pa/baconbacon/page2.html

    Enter the original volts and watts (12v & 20 watts) and it calculates the amps and the ohms: 1.6 and 7.2. Then delete everything but the ohms (as these remain constant and enter in your new voltage (such as 14.8) and recalculate. Using 14.8 volts and 7.2 ohms you get 2.0 amps and 30.4 watts.

    Wombat

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    WOW!!!! Damn, I might actually have to try something like this. You make it look sooooo easy, scar.

    I was wondering about some cooling holes in that, too. I see that you have tape (reflective, i'm sure?) on the back of the bulb. Wouldn't removing that help the cooling side of the equation a little more than the extra light output? The heat could at least get "into" (absorbed by) the plastic easier and aid in cooling.

    Just a thought.
    I ..... need ..... DIRT!!!!!

    ... and cookies. :D

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    yeah...scar did make it look easy....and it was.

    Below are my pics of a helmet mounted version. I used the same Harbor Freight Housing, bulbs, wires, battery and charger (14.4Volt - 5000maH) and switch that scar mentioned above. My assembly is crude on this iteration. Wanted to make sure I was happy with result and get out on several rides with this before I went too nuts with the design.

    I ground off the bottom of the housing and epoxied it to a piece of hard wood (ebony in this case). Before adhering, I drilled a hole through to be able to use the thumbscrew through the helmet mount bracket. My thought with this was to determine what angle I would want in the light's final design, and have that adjustability as I tested. It doesn't need any as the angle is fine coming right off the helmet is right on, and for now I have just cranked down on the thumbscrew to hold it tight and flat. Most likely, I will cut off the little plastic screw ears from the helmet mount and epoxy the housing right onto that removeable helmet mount.

    I have taken this sytem out on 4 night rides this past week using a 20 Watt bulb (38 deg flood). Been very happy with the results. I find the light to be significantly more useful than an off the shelf unit I had purchased earlier this year for around $165.. I am riding tech single track in the thick woods, with plenty of up and down...but havn't rode in a situation where I am exceding 20mph down hill.


    I have been getting well over 2 hours burn time with the unit. I do run the battery way down even if it means turning it on and running it in the house till it is dead.

    Cooling...scar was right about the air flow when riding. It is adequate when riding....at least at this time of the year in New England. Most of my rides have been when temps are in the 20s - 30s. When I am buring the battery down in the house, I take the light out of the housing and let it dangle to keep the housing from melting

    Next stage is to figure out a headlamp style to use for cross country skiing...if we ever get snow in new england this year. I will most likely go for a bit less output or burn time and lighter batteries for that...
    Attached Images Attached Images

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    i just back from lowes and got a 20w 12v mr-16 bulb (flood) that is made by GE and it already has the back covering on it. I just tested it as well and it holds more light in than the Sylvania Tru-Aim Brilliant 12V 20W MR16 8degree spot.

  60. #60
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    BassChop - Great job on the helmet mounted version!! I am definitely going to order a helmet mount and copy how you mounted the switch, I like it. Have you tried running the foil tape on the back of the bulb?

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    Havn't done the foil...I am planning to get a bulb that has the reflector coating already on it. ...probably get the GE flood that Merkyworks got at HD.

    Merky and Scar ::: How has the rubber gasket held up with heat emitted through the front?

  62. #62
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    Quote Originally Posted by Wombat
    Because you will draw more than the battery is designed for and, for safety reasons, the battery protection will trip out and not let you turn the light on.

    But I run a 12 volt 20 watt using a 14.8 volt li-ion battery (which therefore draws 30 watts) and am able to get it light by using what someone described as ghetto softstart: switching the light on and off quickly a few time times. It usually starts on the third try. But you are better off building a proper softstart setup. There are quite a few directions here.

    Wombat
    I hope that you have some new and safe lithium ion cells. New ones can't explode because they turn off before they explode, but the olders just explode. One cell gives already a nice hot fire/explosion, I guess you have 12 cells...


    Would be a pity for your bike (and legs)

  63. #63
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    I've been bumming about the last month or so because its been getting dark right when I get home from work. I'm thinking of trying this out. I know how to solder and make battery packs from my R/C car days, so thats not a problem. I just have a few bike night noob questions. How long do these bulbs last when they are overvolted like this? Would one of these with a 20 watt bulb be good for light trail riding on trails I know, just to get some dirt miles down and stay sane? I don't expect to ride for more than an hour or slightly over an hour at a time, would a AA pack be okay? I don't know how many amps they are safe for, all my experience is with sub-c.

    Thanks

  64. #64
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    Quote Originally Posted by Stregone
    How long do these bulbs last when they are overvolted like this? Would one of these with a 20 watt bulb be good for light trail riding on trails I know, just to get some dirt miles down and stay sane? I don't expect to ride for more than an hour or slightly over an hour at a time, would a AA pack be okay? I don't know how many amps they are safe for, all my experience is with sub-c.

    Thanks
    stregone,
    double AA's would work. I've strung together the battery holders from radio shack to hold 12 rechargables (1.2a x 12 = 14.4) and run 12 volt 20w or 10w bulbs. Overvolt the 12 volts (to 14.4) and it'll run brighter and the life won't decrease that substantially. even so, a bulb costs less than 8 bucks normally so no big deal there. run time, you'll be fine, and you could even set up a 10w and a 20w and have over an hour of use (depending upon the ouptut of the batteries). if you decide to set up two lights, provide a switch on one or both and you can decide how much light you need based upon the conditions.

    coming from an rc background, you can pick up premade 7.2v rc packs at radio shack and use rc connectors in the wiring to make a 14.4 volt battery if you don't want to use AA's.

    have fun. post up when you've built your kit

  65. #65
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    BassChop - I have not had any problems with the o-ring heating up. I have just been leaving it running out in the garage while I am tinkering with some other things. Absolutely no air flow.

    Stregone - I am going to have to stay out of the battery debate as I am not experienced in this arena.

    Earlier in the thread kokothemonkey posted that he was using 12 AA's and getting a run time of 1 hour. I don't know if this has improved for him or not.

    Low-Rider expressed some concern about this
    AA cells are not a good idea in high current draw applications like this
    Moving on to bulb life, here is a link to a graph that tries to show the effects of overvolting these bulbs.
    http://www.myra-simon.com/bike/lights.html#overvolting

    Where all of the lines intersect at the center of the graph is 12 volts. When overvolted by 120% to 14.4V (Blue line) the light ouput (Green line) goes up by over 80% but the bulb life (Red line) is reduced by 90%. Sounds pretty bad, but these bulbs have a life of 3000-4000 hours. Reducing the life by 90% means a new estimated life of 300-400 hours. That comes out to equally about one hundred 3 hour night rides. Good enough for me! Just make it a habit to replace the bulb every season and you should have no problems.

  66. #66
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    I haven't posted any progress yet, as I haven't done anything with my lights yet... I got a pair of the harbor freight lights, and just yesterday ordered a battery pack (5aH from Batteryspace) and controller (Light Brain). I'm going to make a dual beam setup for bar mounting. I've got it almost all figured out, I just need to fab the bracket now. I'm hoping to get this done in the next two weeks or so (before classes start again).

    I'm liking the way this thread has developed! Anyone else have a version that they've come up with using these lights?

    One other question I have deals with the ring that clamps the bulb in place. Doesn't it cut down on the beam? It seems that with the MR16 bulb, the black ring would cut down on the width (diameter?) of the light beam, reducing any bulb to effectively a spot bulb. Am I correct in this? I don't have any bulbs to try yet, as I haven't picked them up either...

    Dan

  67. #67
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    Quote Originally Posted by Stregone
    How long do these bulbs last when they are overvolted like this? Would one of these with a 20 watt bulb be good for light trail riding on trails I know, just to get some dirt miles down and stay sane?
    When I first ran the 14.8 volt battery the bulb blew after about the second start. But it was 5 years old. The figures indicated that at this voltage the bulb should last for about 10% (a 90% reduction) of its life at 12 volts.

    The one bulb lasted through the winter just past, probably around a total of 100 hours, and I am still using it for an occassional night ride with my daughter now that it is summer.

    Wombat

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    This site mentioned here says that a 14.4v 20 watt bulb pulls 1.7amps, which is less than 1C for a 2500mah AA cell.

    According to this over at candlepowerforums AA can handle it.

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    I use a 38 deg flood with the HF housing...its still a flood...no complaints.

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    Scar ... thanks for the build info! Under $100 for a dual 20 watt light setup (including battery and charger)! You saved my marriage!!!

    BassChop ... I like the way you mounted the switch to the back of the light. How'd you attach it? Some type of epoxy or PVC cement?

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    dezmo...I used CA (cyanoacrylite) glue (aka superglue) and accelerator since I had it handy...Epoxy would work just fine.

  72. #72

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    Quote Originally Posted by Merkyworks
    i just back from lowes and got a 20w 12v mr-16 bulb (flood) that is made by GE and it already has the back covering on it. I just tested it as well and it holds more light in than the Sylvania Tru-Aim Brilliant 12V 20W MR16 8degree spot.

    Do you have a model number for this? I went to Lowes as well as HD and couldn't find one that had the back covering.

  73. #73
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    Variation to avoid the need for an adaptor

    Guys love this thread.

    was following the driections of scar and buiding the light with the button on the back like basschop when i broke the outside nutholder on the light assembly.

    necessity the mother of invention....i came up with this...





    no need for an adaptor

    simply grind off the nutholder thingy on the light drill hole for the bolt in the same area.

    grind off the quick release mount like the picture shows and then put bolt, flat washer on outside off lamp and lock washer and nut inside light housing.

    i also took the switch down a bit, no need for the button holders.

    hope you like it.

    many thanks to scar and basschop for thier ideas and hard work

  74. #74
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    what bulbs are you guys using, I have been looking for a spot beam, and its not easy. Are you using flood beams? and are they working ok for you. I hooked one up with the flood beam to my car battery and the visibility sucked.

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    20 Watt, 12Volt, 38deg Flood - MR16. I have both Flood and spot here, but prefer the flood. Visibility is great. You can get these at HD and Lowes.

  76. #76
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    Some real good stuff going on here! I have been off work shoveling snow and sledding with the kids for what seems like a month. I have been checking the thread, just haven't had time to respond so here it goes.

    dnlwthrn - The outer ring that retains the bulb does not seem to restrict the light in any way, if so, it is undetectable. Nothing to worry about here. Please post some photos of your light when you are done (even during the build would be cool).

    dezmo - I am glad that you appreciated the info. Please post some pics of your light when you have completed it.

    ladracer - Looks great! I knew when I posted this it would get the creative juices out there flowing. I like the way you expanded on BassChops' switch mounting scheme and ground off the tabs for the straps. I think I could get the switch and a cable holder squeezed together on the backside. Definitely going to give it a try on my next one.

    wake_100 - I have to confess that I have not even rode with this light on my bike yet except for a quick sprint around the neighborhood one evening about a month ago. I do have a product tester (a friend at work that I built one for who commutes year round) that has tested a couple of different bulb types, here is what he has said. The first bulb I gave him was a GE 20W 38 degree flood that I got at the grocery store. The first day he commuted with his light system, his comment was "that is one bright light". I then got in an order from BatterySpace and gave him a 20W 12 degree spot from BatterySpace. His comment was that this was the "mother" of all lights. Unfortunately he dropped his light onto the concrete one cold morning and killed the bulb. I then gave him a 20W 38 degree flood from BatterySpace. He really did not like the flood as he wanted the "beam" that the spot provided. I think the "spot" bulb really pierces the ambient light while the "flood" just appears to amplify the ambient light seen in front of him. I then gave him a Sylvania Tru-Aim Brilliant 20W 8 degree spot. He commented that he really likes the spot over the flood for commuting. He also commented that he thought the BatterySpace bulb was a brighter bulb and did not see any extra value to the Sylvania bulb. Remember this "testing" is being performed by a commuter that has some ambient light from streetlights at times and really isn't concerned about many obstacles. He wants to see what is coming up in front of him and wants to be seen. On the trail, my preference is a "spot" on the helmet and a "flood" on the bars. Also, remember your car battery is only 12 volts. Much of this thread has been directed at overvolting these bulbs to 14.4 volts. Overvolting these bulbs greatly increases their light output.

  77. #77
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    Scar,
    I'll post pictures as soon as I have something to photo... I'm working with a co-worker and the CNC right now to make bar clamps (I don't exactly like the style of the Batteryspace ones) and trying to figure out where/how to install/seal the controller. I'll try to post some in-process photos as soon as the chips start flying.

    To be more exact as to what I'm doing:
    2 Harbor freight light housings
    MR-16 bulbs (right now 1 spot, 1 flood)
    Light Brain Twin Plus regulated controller (http://www.trailheadlights.com/)
    Batteryspace 14.4V 5aH waterbottle batterypack and fast charger
    Custom clamp mout for the bars, allowing individual adjustment of the two beams.

    Should be interesting... Thanks for the idea, and thanks to everyone else for their versions of this homebrew!

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    scar I have noticed, I have 2 battery packs that are for a RC car that I played with and wired them differently to get double power or double voltage. I was using just the MR11 20W spot and I was amazed on the difference between 7.2V and 14.4V It lit up atleast 100ft when at 14.4V. I went for a test ride in the woods at 7.2V and worked rather well. Really yellow, no I'm working on the new battery pack. Its still in the imporovement stages.

  79. #79
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    Yay! The last part I needed (Light Brain) arrived today! Now its time to start wiring! I still have to figure out what I'm going to do for the switch, but that's just a Radio Shack away. Still working on the design for the bracket, so that may take a while...
    When I get things wired, I'll try to get some light output photos up (MR-11 v. MR-16 flood v. MR-16 spot).

  80. #80
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    Can someone get me the dimensions on the batteryspace mounting bracket? I need to know the distance between the ears...

    I've been working with a coworker on mounts, and we decided that it would be cooler to machine a complete housing. Hoping to do the CNC file today or tomorrow, then its just a matter of getting it cut out. I'm going to use the Battery space mount (like the QR capability), and ordered both the helmet mount and the bar mount. We'll see what happens. Its kind of frustrating sitting here at my desk with the battery, lights, lightbrain, etc. all staring at me waiting to be used, just for lack of a drawing...

    Oh well.

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    The distance is 3/4 inch for barmount 002. I had the same question 3 weeks ago and I sent them a mail and this was the answer.

    Mark

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    thanks... I sent them an e-mail as well, but I figured someone here would be quick to answer.

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    Scar ... thanks again for the build. Sorry that I have been a slackard. Anyway I got my system completed last week and took it out for a test with a buddy. He said to post that this system BLEW AWAY his 6v Marwi light (2 bulbs, 15w & 20w MR11). He ended up making me ride about 50 yards back since I was washing his light out so bad. Since he is good and I stink this was not hard.

    I ended up putting together a 2 light helmet mount system. I used a 20w flood and a 20w spot. My intention was to use the spot for the faster sections and turn it off when possible to preserve battery. I got (12) 5000 mAh 'C' cell solder tab batteries from Battery Space. Switches, connectors, and the cheapest charger I could find also came from Battery Space. I rigged up the brackets from stuff I had laying around. Total cost was $96.03 including tax and shipping. That's right ... less than $100 for an awesome dual light set up.
    Light Side.jpg

    Light Bracket.jpg

    How does it work? We weren't riding anything too tough but the light was great. I hit over 25 mph a couple of times and never worried about overrunning the light. Battery life? We rode 55 minutes and my friend's light was dying. I took mine home and burned it another 50 min! I'd guess that I had the spot on for about half the time. I'll probably try out a 10w spot because I don't need the challenge of reaching up to my helmet as I start a fast downhill.

    The light kit modified for the MR16 is great. The waterproof switches are nice and the 14.4 volt battery setup is good. My biggest issue has been the mounting. For the current set up I actually routed a slot in the tab of the light. I glued in a piece of plastic with a hole drilled. We'll see if this is sturdy enough (if not then I will drill a hole in the light and use an eye bolt). The bracket is made from some '69 Camaro sheet metal (don't ask) with a 1/4" bolt welded on each end.

    My biggest issue was the battery pack. If I was doing this again I would seriously consider a pre manufactured set up from Battery Space. I did not realize how thin the casing is and I shorted one of the batteries on assembly. I caught it pretty quickly and fixed the problem (sharp edge) with the Dremel. I'm just not sure it's worth saving $15 to sacrifice peace of mind. I used some heat shrink plastic sheeting to encase the battery. If everything keeps on working then I'll go ahead and plasti dip it. Oh yeah, I went cheap on the connectors. If I was doing it over I'd go with the nicer ones ... again $4 saved probably isn't worth the worry.

    One last thing before I end my rambling. Battery life and light power. Some of you guys are making this too hard. You need two equations to figure THEORETICAL life. You can then apply the safety factors you want.
    V (volts) = I (amps) * R (resistance in ohms)
    W (power in watts) = V (volts) * I (amps)

    For all practical purposes a light is a resistor so the first thing to do is calculate the resistance of your bulb. If you have a 20 watt, 12 volt bulb then:
    I = 20 watts / 12 volts = 1.67 amps
    R = 12 volts / 1.67 amps = 7.2 ohms

    So with a 5000 mAh battery you should get about 3 hrs burn time. Stay with me. Now lets say you are going to run this at 14.4 volts.
    I = 14.4 volts / 7.2 ohms = 2.0 amps
    W = 14.4 volts * 2.0 amps = 28.8 watts

    However you have cut your burn time to 2.5 hrs with the same battery. There are a lot of things that affect battery life like "how hard" you pull it down, more amp draw drains a battery faster. Also the voltage on a battery dc system is constantly decreasing which also effects light output and battery life. I don't mean for this to be the end of battery life and light discussion, I just wanted to put the science of it on the table.

    THANKS AGAIN TO SCAR, BASSCHOP, AND EVERYONE THAT HAS POSTED ON THIS THREAD!!!

  84. #84
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    Dezmo....

    1994 called. They want their helmet back! Vintage Specialized Sub 7 helmet. Where did you find one of those? I knew a guy who had two of them.... I need to see if he's willing to part with one.

    Seriously... nice light! I'm close to taking the homebrew plunge myself.

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    Dezmo...that looks good! Both of us have some old helmets...mine is from '97....

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    Basschop ... thanks, it works great!

    I seem to recall getting helmet from some pudgy kid trying to take his criterium success west in the early '90's. He had an old Astro cargo van full of these and rode an Eddy Merckx. Wonder whatever happened to him ....

  87. #87
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    dezmo - Great job! Gotta love the price too! Did you get your bulbs from BatterySpace? If not, what are running?

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    Yes, I got the bulbs from BatterySpace. I have to say that they were an excellent supplier. It took a week for the shipment to get to me but that is not their fault ... blame UPS. The 38 deg flood seemed to have a slight halo effect so I got a name brand bulb from Home Depot. It was a waste of money ... the generic BatterySpace bulb is every bit as good.

    Oh yeah, to anyone ordering from BatterySpace ... google BatterySpace and coupon. You'll find they generally have a 5% off discount code which helps offset the shipping cost.

  89. #89
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    Sounds like a good idea to use the Light Brain, although it's not obvious how to mount it. I am looking at 2 MR-16 20W spot bulbs with the controller. The cabling might be cleaner if the controller is located near the lights on the bars or stem, vs. near the battery in the water bottle cage. I'll be intersted to see what you come up with.

  90. #90
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    Just noticed...

    that Harbor Freight has the pond light on sale this weekend for $6.99. Can't help but get a spare to have on hand at that price. It is listed on page 2 in their "Parking Lot Sale" ad for March 2, 3, and 4th. Couldn't find it on their website to link??

    Also noticed that BatterySpace has new style of waterproof switch listed that I hadn't seen before (might not be so new).

    Waterproof Switch
    http://www.batteryspace.com/index.as...OD&ProdID=3213

    I know there has had to been a couple of more people building up lights this winter, come on, show us what you got!

  91. #91
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    dgwright,
    Yes, the Light Brain is best if its close to the bulbs (manual says 12" or less from controller to bulbs). If you're running a setup similar to scar's with two of the pond lights on the handlebars, you could pick up a cheap plastic "box" from radioshack to mount the Light Brain in. Mount the switch to it, run the wires through it, and you should be fine (if you're worried about water penetration, seal the wire holes with silicone caulk).

    I'm still sitting on my stuff. I've got everything I need, I just got picky about the setup. We've got a housing designed in AutoCAD, now I need to sit down with the machinist and get tool paths run. Once we get that, chips will fly! I'll try to get pictures of the process. The plan right now is to make it out of aluminum (we have a "scrap" block that's just about the right size). Once I decide whether or not I like the idea, I may remake it out of ABS, depending on cost.

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    scar wrote: "I know there has had to been a couple of more people building up lights this winter, come on, show us what you got!"

    I'm new here, I'm overwhelmed by the vastness of this forum. Admitedly I probably posted in the wrong threads, at least my DIY light anyway. The reality of "a kid in a candy store" is, he can't eat it all. Though I try, I can't read it all. Instead of adding duplicate content to the forum here is a couple of links to them.

    scar - Your homebrew pond scum light is brilliant. Great name too. I sort of did the same thing using the head and end cap of a D cell maglight w/MR16. It was bulletproof. Something bugged me about it though. It was too bulletproof. Probaly survive a iraqy IED.

    You know when your finished when your done tinkering and I had to do some more. I ran a dual light setup too, until I made my current DIY light. This light kicks over them all. In fact its too bright for the streets with traffic. I finally stood about 100 feet in front of it tried looking at it. and ya its damn bright, even at a 45 deg. angle from the beam. This is what I run now. 12v 20w MR16 8deg. beam, 5000hr avg life over volted to 16.5 volts (12 AA's in series X 2 or 3 parallel, ie., 24 or 36 AA's total) These AA's are the 2500mah NiMh kind, and can be used in a 15 minute charger. I think these AA's are so good at holding lots of power and releasing lots of power I went heavy into the 15 minute chargers. With 5 (4) bay chargers one can go from no power to out the door with full power in 45 minutes. Thats 52 AA's (36 for the halogen 3+hrs runtime and 16 for my helmet light 4+hrs runtime) which is my setup for a night epic.

    Honestly I've tried to stay out long enough to run out of power a few times and thats why the plus signs in the runtime numbers. I really don't know much past the hours givin. I do know that when I use it as needed (intermittently) it will last all night.

    So overvolting that high may give me 2000 hours from it. 10x longer than some of those tweaky expensive bulbs. Been running it for almost two years. Forget about any MR16 over 13deg beam spread, Trust me, the tighter beams reach farther and still spill enough area light. On the streets I have a 6v high pressure xeon $20 flashlight head mounted with 1/16"dia. shock cord and a 5.2v battery pack to run it. And of course, cateye LED blinkers front and rear.

    I need to learn not to be so long winded. Really I'm just trying to share my experience with DIY'ers. I enjoyed your posts and hope you can get something from my posts.

    Light setup:
    http://forums.mtbr.com/showthread.ph...tpost&t=269251

    Battery:
    http://forums.mtbr.com/showthread.ph...stpost&t=52685

  93. #93
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    UrbanPounder - Great looking light, very clean. That battery is intense, very clever use of PVC. A total of 52 AA's (helmet and bar light)-that is incredible. The PVC battery holder looks very large in the picture by itself, but I am sure it is not that big. Does the 36 battery module fit right in your Camelbak or mount on your bike? Just curious. Once again, great job on the light and batteries. Bring on the night time!

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    Thank You Scar and everyone else who has posted in here, lots of great ideas.

    My parents picked up a couple pond lights for me last weekend, and it will be a couple weeks before they return from Florida. So I have a question that would be easily answered if I had the light in front of me.

    Why use MR16 bulbs? I have a bunch of MR-11's from other projects, and was hoping to keep using them. Also, all my batteries are 7.2v, so it would be nice to stay with 6v bulbs. Will a MR-11 with glass cover not fit in the light without modification?

    Thanks

  95. #95
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    [QUOTE=dnlwthrn]dgwright,
    Yes, the Light Brain is best if its close to the bulbs (manual says 12" or less from controller to bulbs). If you're running a setup similar to scar's with two of the pond lights on the handlebars, you could pick up a cheap plastic "box" from radioshack to mount the Light Brain in. Mount the switch to it, run the wires through it, and you should be fine (if you're worried about water penetration, seal the wire holes with silicone caulk).

    I'm still sitting on my stuff.

    dnlwthrn,
    I'm still waiting on my stuff to arrive . . .the plan is to mount the Lightbrain on the stem, and run a double light setup similar to Scar's. I would like to mount a switch that I can hit with my thumb, but I haven't found the right switch yet. I'm looking at some momentary right-angle tact switches, but they are so small, I'm not sure how they will work in practice. Found a few larger switches in Mouser, Digikey, etc. that may work. None of the batteryspace switches appear to be momentary. Another option is to mount the switch on the Lightbrain board. Since that would be located on the stem, it would be awkward to change light levels. I need to talk to Lightbrain. As I have never ridden trails at night, I don't know whether I will be changing light levels all the time, or 1-2 times in 2 hours. Look forward to seeing your housing fabrication.

  96. #96
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    The only downside I see to mounting the switch in the same housing as the light brain is that you'd have to take your hand off the bar to adjust light. That, and to dim the light you need to hold the button down for a sec or so... I haven't been able to find many momentary switches either for our application, so right now I'm just using a simple one from radioshack that will be mounted in the housing.
    I'm trying right now to get some basic photos of the setup (from my phone, so they'll suck) as well as a quick video showing the way the light brain works (also from camera phone). Maybe this will help to clear things up a little... Will post them when I get them uploaded.

  97. #97
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    Here's a quick video showing how the lightbrain works with my setup.

    <embed width="430" height="389" type="application/x-shockwave-flash" wmode="transparent" src="https://s147.photobucket.com/player.swf?file=https://vid147.photobucket.com/albums/r288/dnlwthrn/030607_11291.flv"></embed>

    And here's a photo of the same:


    Sorry for the poor quality, all I had to work with was my cell phone...

    The video stopped right as I was turning th light off. If you haven't looked into the Lightbrain, here's how the chip works: You press the button to turn it on (lowest power), then press momentarily for each step up to full power. To turn down/off, you hold down the button till it reaches the desired state. To turn off, you press and hold the button again after it gets to the lowest power setting.

  98. #98
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    Baulz - The outer diameter of the MR11 bulbs are quite a bit smaller than the inside diameter of the housing. The plastic lens that comes with the light has a "pocket" that holds the MR11 bulb in place. Without the plastic lens the bulb will be able to move around a lot. With the plastic lens at 14.4 volts, it will start to melt with the heat produced by the MR11 bulb and no water (i.e. pond) covering it to cool it. Without the plastic lens, the outer ring will have nothing to seal up against. You could always try just replacing the MR11 bulb with one of yours and use the plastic lens, might not get that hot at 7.2 volts. Hope that helps.

  99. #99
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    Quote Originally Posted by scar
    Baulz - The outer diameter of the MR11 bulbs are quite a bit smaller than the inside diameter of the housing. The plastic lens that comes with the light has a "pocket" that holds the MR11 bulb in place. Without the plastic lens the bulb will be able to move around a lot. With the plastic lens at 14.4 volts, it will start to melt with the heat produced by the MR11 bulb and no water (i.e. pond) covering it to cool it. Without the plastic lens, the outer ring will have nothing to seal up against. You could always try just replacing the MR11 bulb with one of yours and use the plastic lens, might not get that hot at 7.2 volts. Hope that helps.
    Thanks Scar. Have to order a few things from batteryspace so will be adding some bulbs as well.

    Would probably get the same amount of heat with 7.2v as it is still a 20% over-volt. I have melted plastic with bulbs before, so would prefer to avoid a repeat.

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    scar - Concerning the size of the battery pack.......Layout 6 AA's end to end then add a inch or so. I carry it in my nomad pack and drape the chord over my shoulder. The switch just kinda hangs in front. Used to have a bar mounted switch, but when it comes to riding around with wires dangling, a little as 2 inches too long or short of chord can really suck. I may have a better solution to a battery pack. I made the mistake of clicking a link to that online battery store. The 10,000mah D cells are out now. ( its been over a year since I checked.) Thats like 4 AA's, so I will order 4 to relpace my helmet pack and if they can deliver the amps like the AA's can, man, that would be good. It then would take 12 D cells to replace the halogen pack because you need 12 inline for the voltage, and that would be like 48 AA's, some serious runtime. Serious weight too, though. Oh well, seeing on a dark trail is more important to me than lugging around the batteries. I'm leaving now on a small epic.

    dnlwthrn - Thats one clean setup you have. Love the connectors to the bulbs I could never find. Great video too. I must take a que from you and copy that. You did that with your phone? I can IR to my PDA with special software I need to find. Then from PDA to computer, easy. Anything special I need to know? Because as simple and even low quality your video was, it was great. Oh, a great source for those DC coiled stretchy wires is your local thrift shop, 2nd hand store, or whatever. Mine is Value Village with tons of car adapters for 99 cents each. That Light Brain may even fit in a gutted shell of some adapter you may find.

    Now the video won't play for me....I did this AM. I swear, software is like a new chain with a old cassette, works for a sec then chain jumps, works for a sec then chain jumps, and so on.
    Sorry about the subject change in the thread. Now I'm gone riding.
    Last edited by UrbanPounder; 03-07-2007 at 10:34 PM.

  101. #101
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    UP,
    I got the connectors (along with extra bulbs, handlebar mount, helmet mount) from Batteryspace.

    The video was shot with my RAZR (Verizon) and then uploaded to my pc by sending it to my e-mail. I've got software to upload it straight from the phone (hard to do with Verizon, won't go into details), but for some reason it didn't recognize the 3GPP2 format (cell phone video format) until I e-mailed it to myself. It seems that Quicktime has a plugin for the format...

    If you're looking for ways to interface with your phone, and it has IR or Bluetooth capability, google "P2K" and see what you can find. It took me a LONG time to get things to work, but I've been able to get everything from my phone (except for the video) without problems now.

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    dnlwthrn - Thanks for the info. I don't want to start up e-mail on my phone, got too much at work and home to deal with, let alone, be charged for more of it. I can now watch movies on my PDA, just need it to reconize a IR'ed 3GP file. Still looking.

    dezmo - "'69 Camaro sheet metal" (I won't ask, but I know the process). I just wanted to suggest not to get too technical with the helmet mounting. Small diameter shock cord and maybe some sort of plastic shims for aiming the lights is all that is needed. Just tie off a circle of cord the correct size and feed it thru the helmet holes so to loop the front and rear of the light housing. Have fun at night riding.

  103. #103
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    I should have been more clear... I sent the video to my e-mail as a TXT message (or whatever Verizon calls it when you send a picture or video via text message). Did you know you can send them to e-mail addresses instead of phone #'s?

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    I really liked your post, I built two of these Harbor Freight pots into a light set up, using two three watt Led MR 16 bulbs, they were a bit larger than a halogen, had to get rid of the o ring, even after the dremel tool work, use silicone, the front aluminun lip on the bulb is thicker, its a tad longer, had to dremel the male tabs on the front of the pot where the front ring screws on, no room on the bar on my cross bike, so its a heavy rig on a nashbar mini rack, since its a mix of trail and bad road, I just want to thank you for this post. I posted about this on the forum, with two NMIH 2000 mah packs ganged I get very good run time, but I use one xenon 20 watt, my run time with that is only one hour with the two leds on as well. Your Pond Scum Lights got me started.

  105. #105
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    Great job Roger. Looks like you have no problem seeing where you are going!


    Here is the link to Rogers' light set-up
    http://forums.mtbr.com/showthread.php?t=280444

  106. #106
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    Ride test results

    Well I have been out trail riding with the Pond Scum lights twice now and I am very happy with their performance. The first time out I rode with a buddy that didn't have any lights so I loaned him my Jet helmet light and a 14.4v battery pack. That left me with one 14.4v water bottle battery so I ran a single Pond Scum light mounted to the bars. Used a BatterySpace 20W 12 degree spot bulb. Nice bright, long beam. Rode again, but got to use all of my lights this time! Ran the Jet helmet mounted light (20W 18 degree Jet bulb) with the 14.4v battery pack stuffed in my Camelbak. I made a "Y" connector so that I can run two Pond Scum lights off of one battery. Ran the BatterySpace 20W 12 degree spot bulb in one light and a Sylvania Tru-Aim 35 degree flood bulb in the other light. Got the flood light pointed down just ahead of my front tire and the spot light pointed out well in front of me. I have gotta say I think I have enough light! I have read some people complaining about BatterySpace light bulbs but I have to say that they are quite good. The Jet spot light and the BatterySpace spot light actually blend right together when pointed at the same spot. I really can not tell any difference. Just my opinion. I am going to bring my camera with me next ride so that I can get some beam shots. For just slightly over $100 I have a dual handlebar mounted light system that I would put up against any high dollar, mass manufactured halogen light system.

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    Good job scar. Fire on the bar!

    My LED Pond Scum build is pretty modest on the light output. Runtime is amazing, but the light is felt as good, not outstanding.

    Two 3 watt luxeons do about 20 watts of nice white light, set about six inches on center apart, since I am on a cyclocross bike, its on a rack, I have a halogen high beam, but I am going to try a Cree XLamp MR 16, spot, three one watt crees in one bulb to replace my 20 watt bulb for more runtime and I think about 180 lumens of light. The two threes are at best 65 lumens each, and are floods. New, not a lot of tests on them.
    If it puts out the low end of what its rated four, its a good light to run alone in economy mode, with a helmet light and a blinkie.

    I am making some new Pond Scum versions for my MTB, using two of the Cree XLamps, for a more compact rig, and less monster cross funk. First tested as a spot on the cross bike.

    Never made bike lights before, my mind connected to rally lights on an old MG. Now, I just want a lighter rig.

    Its hard to beat this kind of build for the money.

  108. #108
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    Let us know how the Cree Xlamps compare in light output to the standard halogens. I've been wanting to play with them as a way to greatly improve run-time, but would like to have similar light output to the 20W halogens...

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    I have three of them on order, Some sites rate them at 240 lumens, I do not buy it. A friend has one says its easily better than a three watt by double. I have no pictures yet. I know two three watt luxeons are NOT near as good as one real good 20 watt halogen or xenon bulb overvolted. However at 12 volts, it gets close. The more sane sites rate them at 180. If they make 160 lumens with 70% of it in the center spot, then two of them would be gravy. That would be in the 20 watt range plus a bit. Take a couple of weeks to get back to you guys. I want to compare it to two 3 watt luxeons side by side. If it wins by whatever, I will subtract the hype, eat whatever crow I have to, and post.

  110. #110
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    Beam Shots (finally)

    Well I finally got around to trying to take some beam shots. First time for taking night photos so we will see what you think. Did White Ranch this morning at 5:15 a.m. Very slight mist, about 34 degrees. Started spitting snow as we got to the Long Horn Intersection. These beam shots are of only the one light listed running by itself. I didn't think to take a photo with all three running, next time. Can't give much info on run times as the ride was only about hour and a half. Let me know what you think.

    Pond Scum flood


    Pond Scum spot


    Jet Phantom helmet mounted

  111. #111
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    Scar, excellent light!!!!!!!!! I'm like

    Greetings - Saludos

    msxtr
    Warning!!! my english is very very bad, sorry.

    Easy DIY led light1
    Easy DIY led light2

    The Beast!!!

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    scar - Great photos. Good job. Maybe you will come to the same conclusion I did with a three light setup. The bar mount flood only duplicates the helmet mounted light. And to me (who likes lots of light) the bar mount flood was not worth carrying the power needed to run it. Look at that beam.....the 20 watt overvolted mr16's are the best. You could even lift that beam slightly and see ahead even farther. Need a good helmet light though, and you have one. I love night ridding, cutting through the dark like a train

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    I got three of the 'turbo' looking ones and did tests, the ones that are touted as 240 lumens, or more honestly 180, with what looks like 3 10 degree optics in the center area, under one lens cover, the Cree XLamp 1x3 bulb, posting reviews, and will use them in some lights to replace 3 watt luxeons, It was said on all sites that it put 'most' of the light in the center spot. That is not true. It is good light, one bulb is brighter than two 3 watt luxeon 30 degree MR 16's ganged and run with the beams crossed. It is bright, but the optics are sloppy. I knew it would be a mix, but at twice the brightness, its certainly a better flood in one or two config than the two luxeons maxing out at 100-110 lumens. One bulb maxing out at at least 160 with some loss of light around the edges, maybe useful as foot dab light, its a sloppy but VERY bright dog named Spud, not named Spot.

    Reality check time. Its NOT a spot, I like to think of it as a 20 watt flood, 30-35 degree plus, with a big soft bright center spot, about 20 degree at best in focus, at 70 ft its 8-9 ft in diameter, its between 160 and 180 in lumens. Its a big bright dog named SPUD. Maybe 20 lumens are lost on the edges, and no more than 30% of the light is in the center spot.

    A SPUD, its not a spot, its a flood with a big soft spot in the center. We need to call it what it is, a 'Spud Light'. It is at least 20 watts of light, its a good flood, and for a one light solution on the cheap with a good helmet spot, its not a bad flood at all. Two of them, tested off the bike, playing with the beams ganged, was an amazing WAD of light out there, the center Spud, finally bright enough to get out to 90 ft with good range. With over 300 lumens, its has range more on total light flow, rather than good optics. Its good optics for a track light. Good build quality, solid metal, heavy, needs some sealing on the front around the lens in those stupid 'turbo' slots. It never got hot enough to feel more than warm, good heat sink.

    Can it replace a 20 watt halogen flood? Sure, running at 3.6 watts it would be good, can it replace a 20 watt spot, no. Is it as bright as an over volted halogen 20? No. It was better than a 20 run at normal voltage. A lot of light is lost up and to the extreme sides. I have a dense yard with a path that is rather like an 80 foot single track section, its easy to see what it is pretty fast. It is not a race level downhill speed bulb, its a vast improvement over existing led floods in MR 16, but it is what it is....I have a single NiteHawk Emitter, tight bright spot, at ten watts, dim to grim around the small spot, this light is much more comforting as a one bulb solution, or the flood end of a two light rig.

    A bare bones build from the ground up, with good optics for a spot, or existing halogen is kind of the end game on a spot, but I want an all led rig for mixed dirt and road touring. However, for long run time and ease of construction, as long as you know its a Spud, and know to have a tightly focused helmet light, for longer range, its useful as a Pond Scum flood or one light or two ganged super bright SPUD light. Said with a wry smile.

  114. #114
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    Roger Palmer - Thanks alot for the information on these bulbs. I have been eyeballing some of these bulbs on E-bay for a while also. Never could come to pull the trigger at that price. Does the casing of the bulb get hot when lit for a while? Can't wait to see some photos of it in the Pond Scum housing and some beam shots.

  115. #115

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    Eliteled.com, 35 bucks. No, not hot at all, heavy cast aluminum that is chromed, open frame, sealed guts, fins meld with the core for one big heat sink.The front with the slits is open around the edges of the sealed lens to duct air around the fins. Held it in my hand for ten minutes, wired up outside, heat is not an issue, the 3 watt luxeons I was running got hotter. It appears to be the same size as an MR16 halogen, do not know exactly what the dremel work will do yet, but it looks about the same as your build in issues except for using some plumbers putty in the front vent slots. Wax paper over it and some smoothing. It appears it was designed to be a track light run front side down, in a pot, so cooling in that situation and 'style' was an issue. On a bike, with some wind on the pot, and due to its cool running nature, its not an issue. The main thing is the 30 to 40 degree flood, with the central 20 degree Spud of light, that is big enough, but not tight enough for a lot of distance. However, two of them in combination, one on the bar one on the helmet, or one on a compression plug or star nut under the fork arch and one on the bar or helmet, I did rough tests on two combined, put out so much light it has enough do it all throw decent speeds short of downhill mayhem. Road fast downhill, good shoulder and front of bike flow, but down range above 20mph, well....ideal? no...but...

    I have to laugh, I rode with a lead acid system long ago, that was worse, than one of these, and I did not know better. I ride dirt and limerock and single track and back country roads that are often nasty but fairly flat, major issue is having enough light to watch out for pot holes, washouts, hog holes, fallen trees. Volume is king. I will have to build the Spud Light.

  116. #116
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    Pond Scum helmet mounted (my version)

    Well I got around to building a helmet mounted version of the Pond Scum light for my buddy this weekend. Used the battery space helmet mount and a piece of Delrin for the adapter between the light head and the helmet mount. Mounted the power switch to the back of the light like BassChop came up with and ground down the switch like ladracer did. Here are some pictures

    Battery Space helmet mount
    https://www.batteryspace.com/index.a...OD&ProdID=3098



    Pond Scum helmet mounted









  117. #117

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    Nice job scar. I keep whacking head lights on the low brushy and vine strewn tropical woods, Caught one on the over hang after one cane season, and it dropped me by my head. My fault for riding after the wind. I have been using tiny low streamlined lights now, like the K2 LED from Target, previous lights, a Princeton Tec etc. Not as bright, or as integrated a system. Safe, on a Cyclo cross, there is a lot of jinking on and to the side of the trail, close to the woods to get around and over stuff in tight spots, I have too much brush on my head often. Still thinking about a steamlined light that cannot catch a vine. The cheap K2 puts out 60 lumens, but its not much more than 10 watts, of halo eq, better than the old Princeton Tec. If I want a smaller bright head light, close to the hat, the addiction continues I guess. I still have two pond scum pots...uh oh. I should know better but..Maybe a cow catcher on a pond scum light...ha ha. Thanks for the pic.

  118. #118
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    Pond Scum commuter

    Just finished another Pond Scum light for a coworker. He just bought himself a bike this summer to commute into work on. He wanted to position the light so that it was mounted on top of the handlebars and the power switch to be mounted on top of the handlebar mount. Worked out really well.

    Pond Scum commuter


    Just a heads up to anybody ordering battery packs from Batteryspace. It appears they have just recently changed the style of waterproof connector they are supplying on their 14.4V NiMH battery pack/charger combo. It used to come with this waterproof 2 pin lockable cable set https://www.batteryspace.com/index.a...OD&ProdID=2898. They are now coming with the Trail Tech waterproof coaxis lockable cable set https://www.batteryspace.com/index.a...OD&ProdID=3234. Seems to be a comparable cable set, just different than the ones shown in the photos earlier in this thread.

  119. #119
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    I am working on 2 lights, both using 14.4 -3.6 ah batteries from allbatteries.com (made for a robot vacum cleaner) both will use 20 GE bulbs, spot on the helmet and flood on the bars.
    I am using an old housing for the helmet mount and PVC for the bars.
    the batteries are only about $35 bucks with free shiping
    I should get about 1.5 hours from each light.
    wish me luck I should have 2 good lights with batteries and charger for under $150

  120. #120
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    Hey guys, Great tutorial/posts in this thread. Thanks a lot.

    Well as the summer hours start to dwindle and the light disappears I've found myself looking for a light to help illuminate my way.
    I really don't feel the need to drop 2-300 dollars on a light system so this looks especially wonderful.

    But anyways, I have a few questions:
    Question 1: Compared to anything else in the 100-120 dollar range would this come out on top in terms of light output/battery life? I'm really not too concerned about weight. The only thing I'm timid about here is the 2.5hr battery life. I might need a little more juice than that on my rides. Any suggestions on how I could extend that?

    Question 2: Everyones always talking about lumens this and lumens that.... anyone have an estimate on about how much this light puts out?

    Question 3: If later on I decided I wanted to build an LED setup, would I be able to transplant the battery and charger over to that system? Seeing as the battery is really the most expensive bit here, I want to make sure that I get my moneys worth in that department.

    Question 4: I know led technology has really improved as of late and I was also wondering whether i may be better off just building an led setup now or if this would be a better starting point. I'm leaning towards the latter because the halogen is easier to wire and it fits so well in the housing. But I figured I'd ask anyways.

    Thanks in advance for any advice/input!
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    I built an LED setup, using an mr16 1x3 cree xlamp, that fits into the pond scum casing, using a build like the builds in this threat. I tried the halogen, but use the led version on a Cyclo Cross frame set up for trail and rough road, on longer rides. The Cree bulb was advertized as 'most of the light is in a 10-15 degree spot'. No, it puts out at least 30 watts of halo level light, but 60 percent of it is wide flood, 40 degrees, the rest is 30 degree with a small center spot. Not a spot at all. Bright yes, for a flood. Its a garden or pot grade bulb. I used one of these with two ganged 2000 mah batteries, 2.5 hours is not out of the range, go for two 2200, etc, you can use extra connectors, make an Y adaptor so you can gang two together. The bulb, the bright one, has 3 1.2 cree xlamps in a rather poor optic. and I needed at least 10 watts of good spot good to at least 75 feet on the hat. Cheap solution is a Target 1.2 River Rock brand headlight, at least 12 watts of good spot, uses one K2 led, works well as a spot. For 24 bucks, it runs for four hours on 3 AA batts. I do have a friend who runs one K2 on the bar, one on the helmet, but its such a small spot, its poor as a close in flood, he sets the one on the bar 8 ft out, the helmet a bit more, about 22 watts of halo like light, for 45 bucks and a bike reflector with the K2 JB welded to it. Best low cost rig, marginal for speed, but he just leaves it on the bike, ok, its a bit dim for my old eyes, but hey, I used to live with 10 watts of halo. Good luck. Cost wise, the battery and charger are not cheap, small parts, connectors, switches, its not so much saving money, its a project.

  122. #122
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    Welcome Popper252-

    Question 1- I originally chose the NiMH pack to keep the cost down. After using the light for almost a year now I wish I would have gone to Li-Ion because of size and weight. To get longer run times you will need more amp hours which costs more money.

    Question 2 - Take a look at this table Overvolted Halogen Data Shows a 20w 12V bulb overvolted to 14.4 volts is 1555.5 lumens!!

    Question 3 - Battery is transferable. Think about going Li-Ion from the start.

    Question 4 - You are exactly right about the minimum parts and ease of the PondScum. I have been playing around with some LED's and the "R&D" and/or "learning curve" is steeper and more expensive. Build a light that you can ride with now then start playing with a LED version.

  123. #123
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    Nice!

    BTW, $10 from harbor freight:

    http://www.harborfreight.com/cpi/cta...emnumber=47604

    I may try to adapt this for helmet use.

  124. #124
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    Check out the last page of this thread - helmet mounted version.

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    Scar, you are right on the LED learning curve and cost, it adds up, I found I did not save money, but I learned a lot, the NMIH batteries work fine, but I have had some dead cells in the NMIH, re soldering the things is tricky. The big thing is run time, if you are out for three or four hours, LEDs are good, but the best MR16 bulbs cost 35-40 bucks, require sealing, are are all wide floods, with a few exceptions that are medium floods with a hot but small center spot. The halogen versions are very inexpensive, but run time was a BIG issue. The lower end LED commercial rigs are marginal at best, I have some commercial versions, they cost 100 plus bucks, and were not much better than the Target K2 for 24 bucks, except in build quality and a glass lens. The higher end ones are very good, my home built cree pond scum is in the middle, powerful, but sloppy. When I do LED again, I will hand build up from the basic bits, choose the optics, and get more power and less wasted light. That will not be cheap, you get into designing heat sinks, using PC thermal epoxy and PC chip set heat sinks, housings. It gets interesting. Cheap, not, fun, sure. For an easy flood, for long run time, I like the cree 1.3 LED mr 16 in a pond scum HF pot. On a long run on mildly technical single track or a bad dirt road I can just use that and save power, however I would like a SPOT that is more like HID, or over volted halogen on the helmet. An on demand little sun on the head for the nasty bits or a long range look downhill. I think for what I have spent playing, I could have bought a 300 buck pro LED rig. However, I have bike lights for three bikes, in HF pots and had fun. If cost is the issue, and you want lumens for less, I think you are right about over volted halogen. Most people are not out that long, but if you have a cross/commutter, dirt road ride, run time is king. After running LED, I still like it as the basis for a long night ride, as flood, not so happy with it for a long range spot.

  126. #126

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    What would happen if you put an 18V battery to a 12V Halogen? Is this doable or what?

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    ask SCAR, the resident guru of Pond Scum Lights, but 14.4 seems to be overvolted to the nice level, you will have some problems with bulb life if it works long at all.

  128. #128
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    Ok well lets see....
    So far I have the pond light, a bulb, and some nuts and bolts.

    I also ordered the water bottle battery/charger, handlebar mount, and switch from batteryspace earlier today. Can't wait for that stuff to get here.
    BTW use coupon code Batteryspace for 5% off your total order.

    Tomorrow when I go into work I'll be able to fabricate some plastic for the mount as well as make use of a dremel tool.

    So far all I've been able to do is cut away the o-ring lip with a razor blade and chop off the bottom suction brackets with a wire cutter.
    It all looks really sloppy but until I get my hands on a rotary tool and some sand paper that's as good as it'll get.
    At least i got the light bulb to fit and I have to admit it looks really cool.

    I also had a question.
    Would adding an inline fuse to this system be a good idea? In case the bulb were to break or something along those lines.
    I think the battery may have something along the lines of a over volt protector so I don't know if a fuse would just be redundant.

    And finally I was wondering if anyone knows where I could get some 20 watt bulbs with a 25 degree beam width. That seems to be the sweet spot btwn a pure flood light and a spot. I know they make them but I just can't seem to find any.

    Thanks!
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    I tried a lot of Home Depot halogen, the best bulb was a Home Depot xenon bulb, cheap, white light, good flood. A 25 degree is to me ok as a one light solution, if you have something on the helmet for a narrower spot, past about 30 ft the cheap halogen bulbs are more of a 'spud' than a spot. I did like the xenon light, brighter, but the depot lights are pretty much floods. I went to LED MR16 after that, not totally happy with it, but it was interesting. The best builds in LED are ground up. The xenon bulb was super bright while light, two for ten bucks, run time was short, when it died it died. I would take a back up LED, maybe on the helmet, when the halogen dies, it dies fast. Ten watts of halo eq in a Target K2 river rock, mounted on the hat will save you when the big light goes out. I hate promoting a low end light, but the immigrants in my area die monthly with no bike lights at all on BMX bikes, and I keep learning enough Spanish to push a headlight since they never wear helmets. Got addicted to pushing the painfully bright pin point of LED as a cost effective solution. Good luck.

  130. #130
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    [email protected] - I have heard of people running a 12V bulb at 18V. Seems a little too much overvolting for me. Gonna create extra heat and reduce bulb life faster.

    Popper252 - Adding another connection point for an inline fuse is just another area that could fail while you are out on the trail. I like to keep my solder joints/connections to a minimum.

    Here is a part number for a Sylvania 20W 25 degree bulb and a link. It is one of their IR models. The inside of the reflector is coated with an "infrared reflective coating" to help redirect the heat out the front of the bulb. 20MR16/IR/NFL25/C Thanks for keeping us updated!

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    Built my light today - questions...

    I just couldn't wait any longer. I built my Pond Scum and took it out for a test ride. A couple of things that I did differently. I left in the original light to see how well it would work and I also used an 18v Ryobi battery pack (it was laying around and available). I was able to get about 45 minutes of run time out of it. How can I increase the run time? Does the 18v decrease the run time or just the bulb life. Does the MR16 bulb have any effect on that? Would it give me a longer run time? Just curious.

    Currently I am only running one light on the handlebars and would like to add on a second but am afraid that will really effect my run-time.

    Any help would be appreciated.

    Thanks

  132. #132
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    To approximate the run time of a halogen system you can multiply the voltage of the battery by the amp hours of the battery then divide by the wattage of the bulb.

    18V (your battery) * 1.7 (what I found listed for a Ryobi 18V battery) / 30 (estimated watts be pulled by a MR11 or MR16 at 18V) = .9 hours (with a battery fully charged)

    To increase your runtime you need to get a battery with more amp hours as well as decrease the wattage of the bulb. At 18V's you are 40% overvolted which is producing about 30 watts at the bulb. That is pulling on that battery very hard.

    MR16 and MR11 20w bulbs pull the same wattage just different size housing. Here is a useful chart with overvolted halogen info. Overvolted halogen info

    A second light hooked up to the same battery will halve your run time. I usually run 2 lights on the bars. Run only one on the uphills and run both on the down hill when I really need the extra light. Helps with run time. The Sylvania IR MR16 bulb I linked to earlier might help a little. They tout the IR version as "energy saving" as it redirects the heat to the fillament therfore reducing the amount of energy consumed to keep it at optimal operating temperature. Here is a link to their IR product line PDF Sylvania IR MR16 PDF

    I am curious, how well did the original plastic lens hold up to that MR11 overvolted at 18V's? It had to get very hot and start to bubble. It is originally designed to be submerged under water so the plastic lens stays cool.

  133. #133

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    Thanks, that helped alot. This formula will help me in the future.

    As far as the plastic lens, nothing melted or bubbled. It was warm but never too hot to touch. I checked it often for that very reason. Everything ran fine.

    Thanks for putting all this info on the web. I am not tech savvy enough to build an LED system and I did not want to invest the money in to a store bought system, but I wanted to get out and try this on the trail.

    Thanks for the help.

  134. #134
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    When you overvolt a bulb, the efficiency improves a lot (for light versus consumption) but the bulb life really suffers, and some overvolts just will flat out kill the bulb in the first half second (depends on bulb quality mainly, but I accidently put a pack to a 5.5V rated vistalight screw-in bulb that was meant to go to a 6V MR11 in a different light housing and burned it). Basically if you learned to do powers and exponents in math class yet, and have a scientific calculator... you can do this....find the y to the x button on your calculator... this becomes important later.

    - The lumens output jumps to the power of 3.5. So in the case of a 10% overvolt, its 1.1 then y(x) then 3.5 then the equal button... and you get 1.3959 so effectively a 10W bulb puts out the light of a 13.959 watt bulb. A 20% overvolt gives 1.8929 times the light, a 30% overvolt gives 2.5049 times the light, a 40% gives 3.246 times as much, and 50% gives 4.133 times as much. From this you start to see the light jumps in larger increments as the overvolting goes up. This is why in one of my lights I run a 100% overvolt (6V-5W MR11 running off a 12V pack) as it gives over 11 times the light as running it at regular voltage (so the equivalent of over 50W of light, it literally looks like I have an HID when its on). Another one I ran before which I can't find right now (maybe I burned it out, I don't remember if I did or not) was a 6V-10W bulb, which meant half the runtime but twice the light (so literally, picture the light of two car headlights on high beam... I cast shadows past people running HIDs ahead of me that their lights couldn't fill in the darkness of)

    - the power consumption however squares (so the power of 2)... which means on that 10% overvolt its 1.21 times as much amperage, the 20% is 1.44, the 30% is 1.69 and so on. The 100% over is 4 times the power consumption (which is why my 2.65Ah battery pack only gives me about 45 mins of "high beam" endurance. But the battery pack only weighs 11.7 ounces so its not too bad.

    - the bulb life on the other hand goes to the power of -10... so a 10% overvolt gives you 1.1 then y(x) then -10 = 0.3855, you then multiply that by the manufacturer's estimated bulb life (for most halogens its anywhere from 2000 to 5000 hours) and get on the low side 771 hours, which is still a LOT for a $5 bulb. 20% overvolt gives 0.1615, 30% gives 0.0725 and so on... my 100% over puts the bulb life in terms of 5-10 hours. But for the 10 night rides a season I do... that's fine with me.

    Currently since I'm making packs using Duracell 2650mah AA size NiMH batteries (4 cost me $15, and I've got a charger that can recharge them in under 3 hours per 4) its easy to rig up packs to overvolt with off the shelf AA battery holders from TheSource/RadioShack. I've got 6 cell ones to run my 5.5V Vistalight VL430 at 7.2 (31% over), a 10 cell setup for a 6V light (100% over), and a 12 cell for a 12V helmet light (20% over).
    Last edited by DeeEight; 09-21-2007 at 01:12 PM.
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  135. #135
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    Keep in mind on the overvolting question, most manufacturers only hold the "powers" rules as accurate up to a +/- 20% or so change in design voltage, beyond that (especially for lifetime calculations) they say you are on your own (as mentioned, going beyond that often results in an instant "pop", so make sure you have a spare bulb or two when seriously overvolting.

  136. #136
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    The guys I ride with have had luck running 18v through GE -MR 16 bulbs (the higher end series not the cheap ones) The light seems a bit more white but not really that much brighter than mine run at 14.4. Just be careful not to light your helmet on fire ; )

    They do constrution work and use thier 18V drill batteries, with runtimes at about 45 minutes to an hour.

  137. #137
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    Quote Originally Posted by christexan
    Keep in mind on the overvolting question, most manufacturers only hold the "powers" rules as accurate up to a +/- 20% or so change in design voltage, beyond that (especially for lifetime calculations) they say you are on your own (as mentioned, going beyond that often results in an instant "pop", so make sure you have a spare bulb or two when seriously overvolting.
    THe main reason they only hold it accurate up to +/- 20% is because that's the range they use for over/under volting themselves and the last thing they wanna get into doing is an escalating arms race as it were to see who can come up with the most efficient (light/runtime anyways) overvolted setup with a reasonable bulb life (aside from commuters, nobody is really gonna complain about 200 hours of bulb life unless the bulbs cost $20). Vistalight's trick was to spec these pricey bulbs made just for them that were rated as 5.5V - 1.67Ah for example, and use 6V battery packs (originally these 3-Cell Cyclon SLA battery packs, each was 2V-5Ah, so in series you got 6V-5Ah). The battery packs were like $100 to replace and they "claimed" the lights were 10W bulbs and yes the power consumption was close to 10W but they were brighter than say, BLT's 10W lights which basically used the same screw-in bulb type (except actual 6V-1.6A ones) of the same time period.

    The ones with multiple outputs like PlanetBike Insight and Alias models with their 15-12-9 watt outputs were using a 6V-2.5A bulb and 6V pack. At 100% voltage its 15W... but they undervolted to get the 12 and 9 watt settings but the run times clearly didn't match the wattage numbers in the lower settings so while the light was like a 12 or 9, the consumption was higher. That's the thing with the powers formula... you quickly see that undervolted really gives lousy efficiency. A 10% undervolt gives 31% less light (so that 15W turns into a bit over 10W for example) but only reduces the power consumption by 19% (so you're still using 12W of juice). Meanwhile bulb life increases 2.86 times (so using 2000 hours like my previous examples, that's over 5000 hours of bulb life).

    Undervolting is something most people encounter daily if you run those "reduced" wattage energy saver lightbulbs. Ya know the ones that claim to be like 31W instead of 40, or 51 instead of 60W bulbs. They're using undervolting to do that. Which is why the light levels are so much lower yet the energy savings is hardly any better. Really you'd be better off running fewer regular strength bulbs.

    Another thing to remember is multi-cell battery packs start out slightly higher voltage than the nominal battery rating when fully charged. My 12 cell AA pack is nominally 14.4 but fully charged it starts out at about 17.28. The DuraCell 2650mah AA's peak out at about 1.44V each, whereas my energizer 2100mah ones peak out at about 1.41 each and my 2500mah ones at 1.33 each.
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  138. #138

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    That is what I am running. My 18v battery from my Ryobi drill. Do you know how they connected the wires to the battery packs?

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    OK. This is wierd. I ran my pond light with 18v battery and the stock light with no problem. I set my sons up the same way and his burned dimmer than mine and melted the lens. The only thing different between the two is the fact that I cut the lamp socket wires on the inside of mine and wired it in direct, bypassing whatever is under the black epoxy in the housing...

  140. #140
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    They soder the wires to the heads of broken off screws and tape the whole setup to the battery pack. Its not pretty but it seems to work ok.

    Quote Originally Posted by [email protected]
    That is what I am running. My 18v battery from my Ryobi drill. Do you know how they connected the wires to the battery packs?

  141. #141

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    That is basically what I am doing as well. Not pretty, but is cheap and works well. Once I am certain I want to invest money in this I will buy a battery that is lighter and has a higher aH.

  142. #142
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    Ok, so a week after ordering everything I got a knock on the door and sure enough it was Mr. UPS.

    I tore the box open and layed everything out nice and neat.
    My first impressions of the mount is that it's built really well. Some of the plastic is a little flimsy but overall pretty good.
    The battery is sealed in expanding foam, which is then all housed in the water bottle. The top is then also sealed off with glue as to prevent water from leaking in.
    The charger is a charger. Nothing too exciting there. It's doing its job right now and so far no hiccups.
    The switch. It switches

    Alright so I suppose I have one or two questions before I put everything together.

    1st. What would be the best way to connect the wires? Should I solder them, tape them, or use chewing gum to hold them together?

    2nd. Whats a good way to manage the cables coming out of the battery? Even with pretty much no slack at the light, it still feels like i have way too much cable. I suppose I'll just have to velcro strap the excess. Anyone have any other solutions?

    3rd.Whats that little red cable that's hanging off the battery do? I see that it plugs into the charger. But when I'm running the light is it supposed to just be dangling there?



    4th. And finally is this schematic right?



    Thanks guys!
    Last edited by Popper252; 09-26-2007 at 04:12 PM.
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    Glad to see your light stuff has arrived. I built two last week and can remember what it was like when I got the supplies. Of course, I did not order from the web, I just purchased the items locally. My setup is similar but different. It is one thing for sure....very clean and tidy...

    As for your questions, I can answer a couple from my own experience. This maybe different than what someone else recommends, but it works for me...

    1. I use solder any chance I get and heat shrink around the wires to make it clean.
    2. I did not go with a straight cable from the battery to the switch. I took and old guitar amp chord that was laying around and used it. It is a coiled wire and allows me to keep tension and not sag. Then I just velcroed it up to the frame with a couple of straps. Again, very clean.
    3. Not sure, I don't use that battery.
    4. It looks like you are set to go.

    Hope that helps...

  144. #144
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    Thanks for the reply buddy.

    I figured as much as for the soldering. It means I wont' be able to put it together until Monday but the stronger build up will be better for the long run. I figure take my time and build it right rather than be caught in the dark in the middle of the woods.

    I also have the heat shrink tubing all cut up and ready to go. Like your set up, I'm trying to go for a clean professional look.

    As for all the slack, I'm going to cut the light wire a little shorter and then just use velcro to keep the wires close to the frame. It should turn out nicely.

    Thanks again.
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  145. #145

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    Quote Originally Posted by Popper252
    Ok, so a week after ordering everything I got a knock on the door and sure enough it was Mr. UPS.

    I tore the box open and layed everything out nice and neat.
    My first impressions of the mount is that it's built really well. Some of the plastic is a little flimsy but overall pretty good.
    The battery is sealed in expanding foam, which is then all housed in the water bottle. The top is then also sealed off with glue as to prevent water from leaking in.
    The charger is a charger. Nothing too exciting there. It's doing its job right now and so far no hiccups.
    The switch. It switches

    Alright so I suppose I have one or two questions before I put everything together.

    1st. What would be the best way to connect the wires? Should I solder them, tape them, or use chewing gum to hold them together?

    2nd. Whats a good way to manage the cables coming out of the battery? Even with pretty much no slack at the light, it still feels like i have way too much cable. I suppose I'll just have to velcro strap the excess. Anyone have any other solutions?

    3rd.Whats that little red cable that's hanging off the battery do? I see that it plugs into the charger. But when I'm running the light is it supposed to just be dangling there?



    4th. And finally is this schematic right?



    Thanks guys!
    I just finished making mine and took it for a night ride last night. I hacked together my own lighthousing->mount connection, and that needs a little work. And I barely got an hour of burn time, but I think I need to cycle the battery a few times.

    1) I soldered, heatshrunk the individualt connections together, then taped it all up.

    2) I velcroed the excess to the water bottle.

    3) The small pair of wires is for thermal protection while charging. If the battery is getting too hot, it will cut off the charger. For the battery pack and charger I have (the 5000mAh +1.8A charger you probably have too), it is recommended to use it. When it is on the bike, it is not needed.

    4) That is basically what I did, but the leads to the push button are longer and it is mounted to the back of the light housing.

  146. #146
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    Found this thread a couple of weeks ago, nice work everyone.

    I've been running a pair of lmaps very similar to this for the past two years and on the whole they've been pretty good.

    I got a couple of pond lights from B & Q here in the UK and 14.8v 4000mAh Li-ion battery from batteryspace. I've been running Osram Decostar IRC bulbs (similar to Philips masterline series). The osrams are great becasue they reflect the heat back to the filament making them much more efficent. The blurb says a 20w is equivelent to a 35w standard, I'll take that with a pinch of salt but they are definietly better than the norm.

    The battery was pretty good but I never got the runtime I'd initially expected, it runs under 2 hors with the 20w lamp. That prompted me to add a second lamp lower wattage lamp. I've never been able to find a 10w mr16 so I resorted using a 10w mr11. The nice thing about the pond lights I have is that they come with a glass front. I made a reducing collar out of an old jam jar lid, the lid sits in place of the mr16 and the mr11 sits in the lid. The glass front then holds the mr11 in place.

    I also suffered the battery cut out when starting a cold 20w bulb and had to "kick start" it by flicking it on and off as already described by others. The other thing which was not quite sorted was the battery when it was flat. The protection circuit would shut the battery down without warning; not so funny when your running down a tricky section at full chat!

    They are certainly the brightest set in my club by far and have served me well. Until the other day that is...

    The battery died a death so I got myself a new one. This time I've gone for an 18.5v 5200 mAh from battery space. It's much better than the last one, it's got a decent connector and cabling and doesn't trip when starting a cold bulb. This also prompted me to finish my pwm regulator project (based on a picaxe PIC) that's been sat on the shelf for the past two years. It's basically like a lightbrain but it will work with any battery pack on the fly. I can reprogram it at will by plugging it into the usb port on my PC to change brightness levels and / or features. So far I've got soft start, three light levels, low (~9v), high (~15v) and turbo (~18.5v) and low battery warning (~15 v). I'm hoping the plastic case will arrive tomorrow so I can package it up in time for my Thursday night club ride.

    My light hasn't been cheap but it's definitely been fun. LEDs next me thinks.

    Keep up the good work.

  147. #147
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    Alright so tonight I took my maiden voyage with the new light. Let me just say that night riding is a pretty amazing experience.

    So anyways I hit the trails at about sundown. It was raining and pretty humid but the light performed flawlessly. No issues whatsoever with the water.

    The mount and everything else worked wonderfully.

    To get to the meat of my post, here are some beam shots of my setup. I had bought a few different light bulbs to see which i liked better.

    The first of which were these in both 10 and 36 degree patterns:


    And then I picked up some Feit Xenon bulbs from homedepot. These were only available in a flood version.


    And These are the beam shots:
    These were all taken with 1 second shutter delay at ISO80 (because I forgot to change it to 800) on a canon sd600. No tripod... just my wobbly hands.

    Here is the 10 degree phillips 20w spot:


    36 Degree phillips 20w Flood:


    38 degree Feit Xenon 20w Flood


    My favorite was the 10 degree spot. While the xenon was brighter, I liked how the spot sent light further down the trail. I think the perfect light would be a Xenon spot, but I have yet to find one available at any retail stores in my area.

    Here are some shots of everything mounted up on my bike:







    As you can see im still trying to get the cable management down. I'll figure something out eventually.

    So all in all.
    Am I happy with the light?
    Extremely.
    Would I do it again?
    Absolutely.
    Would I do anything different?
    Yes, I would have gotten a Li-ion pack instead of the NiMH pack. Yeah I know you all suggested that I get the Li-ion right off the bat. But at the time I didn't want to spend the extra money. I didn't think I'd notice the extra weight. But man that NiMH pack is really heavy and I could feel it the whole way. Other than that though, I'm totally happy.
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  148. #148
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    New question here.

    I've been loving this thread everyone, thanks for all the info!

    That Batteryspace site is huge and I spent some time surfing it with the goal of finding the most amp hours per dollar when I came upon this http://www.batteryspace.com/index.as...OD&ProdID=3233

    (8.4 volts @ 5 Ah. and the weight seems decent)

    I'd like to run a 10w and 15w on the bars with one battery. Using that battery would require overvolting 6v bulbs. I think I would still get a decent runtime even with periods of both switched on if need be.

    Is that a reasonable or excessive amount of overvolting?

    What about 7.2 v batt? I don't see a 5Ah in 7.2...

    Can you guys see any holes (gaping or otherwise) in this plan?

    Is there a better option for "most amp hours per dollar"?

    Thanks in advance for the feedback.

    Chris E.

  149. #149
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    8.4V is a 40% overvolt so hmmmm, 3.25 times the normal light of whatever bulb you use (run a 5W, it'll be as bright as a 16.25W would be running 6V), the bulb life will cut to about 1.8% of normal (so if its a 2000 hour mininum bulb, expect that new mininum to be 36 hours, I'd track down a 5000 hour rated bulb myself, they won't cost much more and they'll obviously last longer, you'll save money in the long run), and as to current draw, if GE's halogen light table is to be believed and is reliable enough to be extrapolated from (they only give numbers up to 10% over/under) you'll be pulling about 22% extra current to drive that bulb (so with a 5W bulb which normally pulls 0.83A of current, it'll now use about 1.01A).

    I'll know tommorow if GE's figures really do extrapolate out in a linear scale for higher overvolts, as I'll be running two 20% overs and a 100% over on a night ride tommorow that should last more than an hour of darkness (so if my 100% over lasts the full ride, it'll definitely be a different result than the formula I've been using to date would tend to suggest).


    Anyways, on a side topic, I'm doing a couple budgetbright light setups myself right now, one with a MR11 and the other an MR16. The housings and mounts I'm building allow for relatively quick bulb changes, and fairly quick mounting/removale, and each light unit is running a whopping $15 in parts maybe. My battery packs are actually costing more for a change than my lights do.
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  150. #150
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    Popper252 - Welcome to lunacy of night riding. It opens up a whole new world as every trail you know like the back of your hand is a brand new trail at night. I find that I can actually make extended climbs better at night as I am only focussing on the area directly in front of me where during the day I can catch a quick glimpse of how much more climbing I still have to do and I end up kind of "psyching" myself out, telling myself how tired I already feel. Kind of weird. Great job on the light. Now you just got to turn on some of your friends to the fun of night riding. I find everyone thinks you are nuts to ride at night, until they try it once then they are hooked.

  151. #151
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    My PoopLight is coming together, all the housing & wiring is ready, I just need to pickup the clamps I'm using from HomeDepot in a bit, and then drill the housing for the clamp and to pass the MR11/16 leads thru and its all done. The bulbs you can figure out the pricing on yourselfs, the mr11 leads were scavenged from a cheap driving light whose bulb i burned out (and I can't find replacements for it, and you need EXACT replacements to fit it properly so otherwise the housing is useless as it won't accept standard mr11 bulbs), the red/white wire with the black plastic ends are trailer-hitch light quick-disconnects (cost about $6), the tubular male/female wire connectors I run on most all my battery packs and light leads now, and I build all my AA battery packs around either double 9V connectors (to take different battery housings, so an 8 cell and 2 cell gives me 10 total) or I wire a 4-cell in series with a 9V connector (so I can do 6, 12, etc). The plastic housing for the lamp is a 1 1/4" ABS Pipe (commonly used for the sewer/waste out pipes of your house, hence PoopLight) trap adapter pressed into a 1 1/4" to 1" pipe adapter that comes with a white plastic compression seal. They're mainly used to adapt a PVC pipe to an ABS (the glue's for the two aren't the same). The seal fit the base of the bulb perfectly, and the top cap screwed down tight and automatically centered the bulb and locked it solid. No rattling around. The two pieces cost about $5 in the plumbing section of most hardware stores, and gives a waterproof seal around the bulb. The wire leads I'm using into the lamp housing has a rubber gasket seal, and the only other hole into it will have a screw in it for the clamp.

    <img src="https://yoda.densan.ca/kmr/bikes/pooplight1.jpg">

    <img src="https://yoda.densan.ca/kmr/bikes/pooplight2.jpg">

    <img src="https://yoda.densan.ca/kmr/bikes/pooplight3.jpg">

    <img src="https://yoda.densan.ca/kmr/bikes/pooplight4.jpg">

    I'll post up beam shots later tonight probably, my camera can do the same adjustments as the last guy so its not a problem to have a scene comparable to his. Also because the bulb end screws down, I can quickly change this setup from a 6V to a 12V MR-11, and any wattage I want to run. My different battery packs can thus be configured as either straight 6/12V or overvolted 7.2, 13.2 and 14.4 setups if I so choose (I have a LOT of battery packs). The base trap end of the thing with the square wrench part sticking out is where the clamp for the bar will go probably, as I could then unscrew it quickly if needed to remove the whole lamp from the bike when its not needed.
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  152. #152
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    Took my lights out for the first tmie tonight with my new battery. I took my camera too with the intention of taking some beam shots. Unfortunately my camera is a little too basic and won't allow me to set it manually, at least I don't think it will. Maybe I'll rtfm and try again tomorrow night.

    I have got some shots of my lights though

    N.B. even though the stick on my battery says NiMH it is in fact a Li-ion battery.








    It was a real shame I couldn't get the beam shots because.......this set up is totally awesome!

    It was a club night ride this evening and I guess there must have been about 20 of us out. It's really a social club first and a cycling club second. There are varying degrees of seriousness amongst the group and most of the riders ride on the road. Well, there's this new chap who turned up and he'd bought himself a L&M arc HID. I don't think any of the others had seen a hid light before and didn't realise people were prepared to spend that kind of money on a light. He was telling all the other guys how bright his light was and how, although it was very expensive, he was really pleased with it. They were all very impressed. I rolled behind him with the 10w mr11 on and was chucking out pretty much the same amount of light as him. Then I flicked the switch on the 20w mr16 and it just blew his light away. I swear, you could bearly tell his L&M was even on. It was all a bit childish on my part but man did it make me chuckle!

    The 20w is like driving with a car headlamp on your bike, I'm well pleased with it.

    I had intended to take my regualtor out for a run too but I fried the ADC input on my pic when a transfered the circuit from my bread board to a bit of strip board. Doh! Must pay a bit more attention next time.

  153. #153
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    Putting a 50% overvolt to a light tends to do that. Put 100% to a 10W bulb and it totally drowns out several HID's at once. You go from 200 lumens to more than 2000. Mind you yer bulb will only last 10 hours but hey, at $4 a bulb you're still talking what, maybe 50 bulbs before that HID setup becomes cost effective. I dunno about you, but I maybe do 50 hours of real night riding a year at most.... so that's 5 bulbs. At this rate I'm good for 10 years.
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  154. #154

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    Quote Originally Posted by scar
    Popper252 - Welcome to lunacy of night riding. It opens up a whole new world as every trail you know like the back of your hand is a brand new trail at night. I find that I can actually make extended climbs better at night as I am only focussing on the area directly in front of me where during the day I can catch a quick glimpse of how much more climbing I still have to do and I end up kind of "psyching" myself out, telling myself how tired I already feel. Kind of weird. Great job on the light. Now you just got to turn on some of your friends to the fun of night riding. I find everyone thinks you are nuts to ride at night, until they try it once then they are hooked.
    Good summary of night riding...that uphill phenomenon is spot on. Many times at night I'm at the top of a hill before I even realize where I am on the trail. Here in Michigan, we often reverse the trail direction at night also, which makes every trail a new experience and some of the lame bits much more exciting.

  155. #155
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    You're quite right about bulb life. I've never even considered it as a factor to be honest.

    The way I see it is unless you are wanting to drive your bulbs to extremes you don't really need to consider bulb life. If you still have a little bit of niggling paranoia about being left in the dark on the trail, carry a spare.

    I had a thought about my beam shots; I'll see if I got exposure lock on my camera. I could then set up the shot using the 10w bulb and then flick over to the 20w for the actual pic. If I get a chance tonight I'll give it a go.

  156. #156
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    I did it...

    You guys gave me the motivation to go ahead and try this diy bike light... This has been one great thread an imo, should be made a sticky. I've learned tons about lights and this is an ideal first time diy project.

    I ordered two pond lights from Harbor Freight, and picked up an MR16 bulb from Traget, and went to work with my dremel. One motivating fator was that I had two HF gift certificats burning a hole in my wallet for the past 1.5 years! So anyway, I found with my bulb I had to open up hte hole in the bezel/twist on part. The glass is thick in the front, but thins a bit at the edges. Also, the bulb I got is one that has the whole back side siver-ized, metal-ized, whatever.. So, I'm thinking it's one of the kinds that focuses the heat out the front. All I need now is a battery setup, charger, and a handlebar clamp. The dremeling only took aobut 15mins. It's amazingly easy, and looks pretty good too...

    I might keep my eye open though, for one of those 25 degree narrow floods...

    BM
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  157. #157
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    Quote Originally Posted by bmadau
    You guys gave me the motivation to go ahead and try this diy bike light... This has been one great thread an imo, should be made a sticky. I've learned tons about lights and this is an ideal first time diy project.
    BM
    I agree 100%

    I saw this and I was instantly inspired to go ahead and build my own. It's straight forward, fairly easy to do, and works great!

    I read through a bunch of DIY threads and the led ones seemed a bit more complicated and I wasn't sure if I wanted to spend that much money on an led kit. So this was the ideal way to start my ventures into night riding. If i find that I really enjoy it, maybe later on down the road I'll be more inclined to build my own led system but for the time being this setup is awesome!

    Good luck on your build and be sure to post some pictures of it if you can.
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  158. #158
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    Halogens are simpler to diagnose when you flip the switch and there's no light. Or the light goes on and then dies (too much voltage for that brand bulb) in 1 second.
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  159. #159

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    narrow flood 24degree

    Been looking for a narrow flood, maybe i missed it on this thread. This seems to be to be the only one i can find http://www.1000bulbs.com/Front-Glass...ht-Bulbs/8896/. Will this work, or am i missing something again ? awesome thread by the way!
    Cheers!

  160. #160
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    That bulb would be perfect. Cheap too!

    Kind of a low bulb life, but at that price it doesn't really matter.

    Honestly I'd go buy a spot light and a flood from a local store and see if either of those would work for you. If you're not happy with either one then I'd buy the bulb online.
    Just my thoughts.
    You happen to know how much shipping is?
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  161. #161
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    24 degrees isn't very spot... most spot beams are 10deg and floods are around 30deg.
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  162. #162

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    Well i have a flood that i love on the trail Vs my brothers CygoLite DualCross ( spot ). But would like it better if it was a tad more focused, and thought the narrow flood would be perfect. Yeah its a nice price for the bulb, but shipping is where they get you
    Subtotal: $ 1.48
    Shipping: $ 9.50
    Total: $ 10.98.
    I will prob order one tomorrow, and post a review as soon as i get it going.
    Unless someone knows of another cheaper place i could get one.
    Cheers!

  163. #163
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    If you buy 12 it comes out to about $1.90 a bulb
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    not really looking for a spot.. most spots i have seen are 8 - 12 and floods are 36 - 38.. this is a narrow flood...

  165. #165
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    My Pond Scum Light

    Well, I started my project. I bought two lights with some Harbor Freight gift certificates that I've been sitting on for over a year (litterally, they've been in my wallet), I got an MR16 bulb, and did all the requisite dremelling. Now, all that's the same as what everyone else has done, but I did something different with the mounting of it... I went by lowes today and picked up a few M5 x 0.8 x 16mm long hex head screws, nylock nuts, flat washers, and a tube of epoxy and went to work.

    First, I had to slim down the head of the screw ot fit in the slot on the light, about 1 min with my cheapo belt sander did the trick:


    Close up:


    You can see it's a real snug fit. Almost doesn't need any epoxy at all:


    Here's the epoxy I bought. I got the 5 mins stuff because I'm not in that big of a hurry, and I don't think I quick enough to beat the 1min setup time of the faster stuff. It says it'll bond wood, metal, tile, ceramic, glass and plastic- yup, metal and plastic- got it covered.


    I got a little out of control withe epoxy. It's a bit more runny than JB Weld. A lot of what you see here ran out while it set up, before it fully hardened I used my pocket knife and peeled off the excess. When it was still wet, it cleaned up nice with rubbing alcohol.


    and:


    This finished project:


    For power I won a dozen 2500mAh batteries on Ebay last night, for $13 w/shipping. I'll have to get a soldering iron and learn how to make a battery pack. I've already done some internet research on the subject. I know I'm pushing the max current drain rate of the AA batteries. I intend to make a 2nd pack and wire them in parallel to make a 5Ah total supply, which should be good for two hours, I think, maybe a little more. I've found that AA batteries are the best for mAh per gram of battery weight. Sub C's have far higher max drain rates, but per gram they are lower in mAh. I don't need a 50A drain rate, I want a light pack... Eventually I'll try to go wiht LiIon batteries, same power for 1/2 the weight, but over twice the $$. There's no free lunch when it comes to batteries.

    BM
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  166. #166
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    Unless you have a smart charger capable of doing a 14.4 NiMh battery pack you're better to go to TheSource and get some AA battery pack holders (they make them in 4, 6, 8, 10 cell sizes, some with wires and some with 9V battery tabs on them) and you can come up with all sorts of wired in series combinations with 9V leads and so on) and then use an off-the shelf charger for AA batteries. Most do 4 or 8 cells, but the quick-chargers will do 2500mah ones in 3 hours or less, so figure 9 hours total to do 12.
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  167. #167
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    I like it. However, I bought a NiteRider MiNewt X2 Dual a week ago because I wanted something nice and mindless for night riding. Nicely done. Oh, and the comment about how climbs go quicker in the dark is dead on. I have ridden a particular trail at least 100 times and it's still a surprise to hit my main marks for difficulty.
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  168. #168
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    Ok, got some light shots.... First four are 1 sec exposures, 80 iso with my Kodak Z7590 and last two I bumped the iso to 400. Both are built to my PooperLight housing designs, 12V-20 watt bulbs in both cases with a 20% nominal overvolt using 12 2650mah AA Duracells, fresh batteries so the initial (no load) voltage is closer to 15.8V which is how the pictures were taken. Camera's on a compact tripod that lifts it about a foot above ground level but at least is stable. Unfortunetly while I scored a GE Edison Constant Colour 15° spot beam for the MR16 I'm unsure what my more generic Globe MR11s are but I THINK they're a 30° Flood. I'll check next time I'm at the store what the packaging says and edit this post if its different.

    MR11 bulb, held same height as lense about 1 foot left of the camera, and the hedge is about 20 feet away.

    <img src="https://yoda.densan.ca/kmr/bikes/mr1120-144-80a.jpg">

    MR16 bulb, identical position as above but I think I pointed it downwards a bit more

    <img src="https://yoda.densan.ca/kmr/bikes/mr1620-144-80a.jpg">

    MR11 bulb, this time in another part of my yard and the hedgeline this time is about 40 feet away. Also the light is being held in line with lense but now two feet above it.

    <img src="https://yoda.densan.ca/kmr/bikes/mr1120-144-80b.jpg">

    MR16 bulb, otherwise as above but what's funny is the mr11 bulb's light seems to be whiter on the grass close to the camera at the edge of the flood pattern in these two shots.

    <img src="https://yoda.densan.ca/kmr/bikes/mr1620-144-80b.jpg">

    Now the MR11 again but at 400iso and now it becomes clearer the different in beam patterns and light output.

    <img src="https://yoda.densan.ca/kmr/bikes/mr1120-144-400.jpg">

    And finally the MR16 at 400iso

    <img src="https://yoda.densan.ca/kmr/bikes/mr1620-144-400.jpg">
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  169. #169
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    Also since I was bored I decided I'd do beam shots for three of my other lights that are just different MR11 bulbs in existing light housings. First three shots are 1sec/80ISO and second three are 1sec/400ISO and same camera/light positions as the shots in the previous post in the same section of yard. All are running from the same 12V pack built using 10 2650mah AA Duracells.

    Specialized Helmet light (think they were called Solo or something, I got the thing on clearout years ago, its small, fits my helmet snug and has an easy to reach/work switch), 12V-10W Globe bulb about a 30 degree flood as I recall

    <img src="https://yoda.densan.ca/kmr/bikes/mr1110-12-80.jpg">

    Nitehawk Mirage light, 12V-12W Nitehawk bulb and its a 10 degree spot as I recall.

    <img src="https://yoda.densan.ca/kmr/bikes/mr1112-12-80.jpg">

    Nitehawk Nomad light, 6V-5W-10 degree spot Nitehawk bulb (yes this is one of my infamous 100% overvolt godlights)

    <img src="https://yoda.densan.ca/kmr/bikes/mr115-12-80.jpg">

    Specialized Helmet light at 400ISO

    <img src="https://yoda.densan.ca/kmr/bikes/mr1110-12-400.jpg">

    Nitehawk Mirage light at 400ISO

    <img src="https://yoda.densan.ca/kmr/bikes/mr1112-12-400.jpg">

    Nitehawk Nomad light at 400ISO

    <img src="https://yoda.densan.ca/kmr/bikes/mr115-12-400.jpg">
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  170. #170
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    I plan on getting a 14.4v smart charger from Batteryspace. I also plan to put a thermister in my battery pack, and when it's all said and done dip it in plasti-dip. I'm going for the cool professional look. We'll see how close I get...

    Thanks for the suggestion on the batter holders though. I have actually thought about that. The #1 downside, I think, is how do you seal up 12AA's in battery holders?

    BM
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  171. #171
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    Ziplock bag...section of rubber innertube...waterproof compact camera bag...waterbottle with a screw-on lid...etc
    I don't post to generate business for myself or make like I'm better than sliced bread

  172. #172
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    Dee,

    Could we get a picture of your light showing the mount set up please?

    Thank you,
    Chris

  173. #173
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    Gotta love this time of year, everybody is building lights again. Great job to everybody that are building the Pond Scum Homebrew!

  174. #174
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    Ok, the MR11 size PooperLight as assembled and the parts that make up the mount clamp for the bar...

    <img src="https://yoda.densan.ca/kmr/bikes/pooplightmount.jpg">
    <img src="https://yoda.densan.ca/kmr/bikes/pooplight11a.jpg">
    <img src="https://yoda.densan.ca/kmr/bikes/pooplight11b.jpg">
    <img src="https://yoda.densan.ca/kmr/bikes/pooplight11c.jpg">

    And the parts being used to build the MR16 sized one. Everyone should recognize the metal pipe clamp bracket and its inner rubber compression seal. The seal has several lips inside which perfectly match the edge of the MR16 bulbs and produce a tight centered fit for them. The rubber seal also fits tightly around 1 1/2" ABS Pipe trap adapters which lets me use my mount brackets. I haven't drilled a hole in the side of this one yet to pass the wires thru though.

    <img src="https://yoda.densan.ca/kmr/bikes/pooplight16parts.jpg">
    <img src="https://yoda.densan.ca/kmr/bikes/pooplight16parts2.jpg">
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  175. #175
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    Dee,

    Thank you! A P clamp, lol, I never even thought about that!!!!! All th etimes I have used them with wiring jobs around the house, car, & trailer wiring, NEVER even thought about it for a lamp mount.

    Great idea!!!!

    Chris

  176. #176

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    Guys, I'm building a pond scum light and using a 5200mAh Li-Ion battery to power a 12V 20W MR16 lamp as per instructions. Would 18gauge wiring be OK to use as wiring from the battery to the lamp switch?

  177. #177
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    18 gauge is fine.
    I don't post to generate business for myself or make like I'm better than sliced bread

  178. #178
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    Using Li-Ion 14.8 battery

    I am getting parts together to make a pond light and the question of using a li-ion battery keeps poping up . Battery space does not recommend using a li-ion 14.8 on an HID bulb . The current calculates out ok . Is there a problem with starting the sucker due to hight initial current draw? I read about hillbilly soft starts. Is that necessary? What experience have others had?

  179. #179
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    These aren't HID bulbs, these are only halogen so you should be fine
    09 Giant Anthem X3
    07 IBEX Trophy Comp X7

  180. #180

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    runtime?

    Over the weekend I finished building a 2 light pondscum setup, thanks for the idea and all the great posts!

    There is plenty of good light with just one running however, after my 4th full drain and charge cycle, running one 20w bulb with a 14.4V 5000mAh NiMH Water Bottle Battery (new before my 4 charges) only yields 1 hour and 20 minutes of light.

    From what I have read on this thread, it should be getting 2+ hours runtime, correct?

    Any thoughts?

    Thanks again!

  181. #181
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    For two lights that sounds about right. The lights draw approx. 2000mA (aka 2A) each. So, two lights - 4000mAh = right about 1hr 20min...

    BM
    "I've come to believe that common sense is not that common" - Matt Timmerman

  182. #182

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    I am only running one 20w light for the 1 hour 20 minute runtime.

  183. #183
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    Bear_Murph - It has been quite awhile since I used my PondScum set-up, you are right, that run time sounds low. Have you been able to measure your battery after a full charge, should be ~17V. I remember mine starting out at about that run time, but then got better after depleting and charging the battery multiple times, just as you have said you have done. Has it gotten progressively better or stayed the same at 1 hour 20 minutes of runtime? Which bulb are you using?

  184. #184
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    wow, i was looking at building another LED flood light but this is MIGHTY tempting for this price... and i could always use more lights for my broke technically inept friends...

    great idea and find, scar!

  185. #185

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    Scar,

    It started out @ 1 hour and has slowly gone up to 1:20. I am using one of the Sylvania bulbs that is advertised to be more energy efficient. I don't have a way to measure the battery output.

    Heading out for my first trail ride with the lights in a few minutes. My fingers are crossed the battery will hold out :-)

    Thanks for the reply!

  186. #186
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    That's a fantastic build for the price. It's simple in design so those wanting more light but don't want to spend a fortune can easily have it. Great explainations of the problems that can happen too. You covered this build in nice detail. Now, when are you going to modify this to an led light source? It would be interesting to see your detailed process using this housing in an led application. Thanks for all you've done here. Good job.

  187. #187

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    Bear_Murph,

    I don't think that the efficient bulbs use less power but they give you more lumens per watt. I get 1:30 with time to spare and I am using a 20w flood constantly and a 20w spot about half of that time. I made my own 14.4v 5000mAh battery pack using (12) C cells from battery space with the solder tabs. One thing I noticed putting them together was that the covers are somewhat fragile. I nicked one of them and got a short which cost me one cell. Like Scar said, check the full charge voltage. If it is not around 17v then you might have a dead cell. It also could be a problem with the charger. I got a bad charger from Battery Space on the first go round (they were great and replaced it right away ... no hassles). Good Luck!

  188. #188
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    I got a couple pond lights and a GE 20w flood to try it out with. I don't have a switch or nice mounts yets, but i'm going to ride w/ it tonight using some old parts i have kicking around and duct tape.


  189. #189
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    Went out w/ a pond light last night. It was quite bright, but the flood bulb i had it in it had only like 25ft of throw. It was very wide though. It was a 40degree flood. Thats the widest flood i've heard of, but it was all they had at Lowes.

    Overall the light was more full than the LED's id say. The LED (3xluxIII) has a great throw and a really piercing hot spot, but the halogen was just bigger and more full all over. This could of course be due to the optics. I have very tight optics on the LED and very flood on the halogen.

    I'm going to try and find a spot and a tighter flood for the two halogens. The two combined should work out really well. I almost like these more than the LED. cheaper, easier, simplier, and seemingly just as bright. Just a little power hungry.

    Btw, i almost got attacked by a herd of deer last night out there. :crack:

  190. #190
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    Mee too

    Wow! Scar et al, thanks for the inspiration to build a pond scum set up.

    Here’s how my project went: Ordered two lights from HF. Immediately broke the bezel of one just messing around – the plastic is pretty brittle, people. So built one pretty straight forward from the unbroken pond light for my helmut. Just by luck found a really small track light fixture at the thrift store for a buck. Used pvc parts for a mount and a radio shack on-off switch. This was just luck: the pvc clicks into place on my monkey bars and stays put all by itself, haven’t needed any wrap around to retain it at all, even in the stutter bumps!

    I went straight 12v for my batteryspace batts. It saved me a little money and a little weight. Both bulbs are 20W, flood on bars, spot on top. Everything works great! After my 4 “conditioning” charges, I am getting 2.5 hours from each light.

    I am totally satisfied with this lighting set up and I am loving the night rides. It feels more “flowy” when you’re not distracted by the periphery and there’s always a background adrenaline drip as this is big cat/grizzly country. Not to mention a mother moose who would gladly stomp you!

    Thanks you guys! Without this thread I doubt I would own lights as the retail costs are just so high. It was a really fun tinkering project too!
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  191. #191
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    Mods, How about making Pond Scum a sticky? Totally worthy, look at all the hits it gets!
    Thx, Chris E.

  192. #192
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    Scar,

    Thanks for the info in the PM you sent me. This thread is amazing, and has me totally inspired to try this myself! The clear directions and links to the parts, as well as others' input is what just I needed to decide to do this myself. I've got some more questions that I'll get to in a few days, but just wanted to say thanks to you and the others that contributed to this thread. THIS is MTBR at it's best!

    Why isn't this thread a sticky???!!!!

  193. #193
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    Quote Originally Posted by kapusta
    Why isn't this thread a sticky???!!!!
    I wonder the same thing...

    BM
    "I've come to believe that common sense is not that common" - Matt Timmerman

  194. #194
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    Question about bulb wattage

    Question about bulb wattage choice:

    Burn time is a real concern for me. When I look at a) the that chart dealing with overvolting, b) the formulas DeeEight has presented for voltage-lumen-bulb life estimations and c) Scar's explanation of estimated burn times, it looks like a 20w MR16 will put out around 15,000 lumens. That sounds insanely bright, but with a 5Ah battery, my estimated burn time is just shy of three hours, though I'm sure that in reality it is less (my current battery/lamp combo gives me about 75% of the formula's predicted burn time)

    My thought is to go with a 10w MR16. DeeEight's formula as well as that chart show a 20% overvolt giving out something like 750 lumens. Is this for real? That's as bright as decent HID's, right? Am I missing something here other than bulb life?

    Just curoius if anyone has gone with lower wattage MR16's for longer burn time.

    Also, are these lumen estimations realistic?

  195. #195
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    I made one last night and rode over 1.5 hours with plenty of juice left but Im running a 12 volt battery I came across. its a little bigger than what you guys are running. I store that big battey in my camel back Mule .

    Not pretty but works awesome. Im using a light housing I picked up at Lowes a 20 watt M-16 flood. Im thinking Ill maybe try the spot bulb later.

    I highly reccomend this setup.
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  196. #196
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    An observation and question for those using high-efficiency/energy-saving bulbs. I picked up two, an 8 degree spot and 36 degree flood, both 20 watt varieties, supposed to put out the same light as a 35 watt bulb.

    http://www.bulbs.com/eSpec.aspx?ID=1...=Halogen+Bulbs

    http://www.bulbs.com/eSpec.aspx?ID=1...=Halogen+Bulbs

    I compared them to a regular 15 degree GE bulb (my favorite) and A Ushio 24 degree bulb. Both GE and Ushio are rated with a lower color temp – 2900K, versus the 3150K of the Philips bulbs. I expected higher color temp and more brilliance (higher lumens per watt) but was sadly disappointed. I’ve read that the energy savers use the heat to somehow increase the output but I didn’t see it. I confess, however, that I only ran them for about 5 minutes a piece. Does anyone know if the energy-saving bulbs get brighter/whiter the longer they’re on? Maybe I should’ve let them run for another 10 minutes or so.

    http://www.bulbs.com/eSpec.aspx?ID=1...=Halogen+Bulbs

  197. #197
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    My turn!

    Harbor Freight ought to pay Scar royalties! I`m getting ready to build one too and I`m wondering about a few things.

    First, I`ve seen references to 10W MR16s but so far no reports. I plan to order a 10W (none available locally) to supplement my 3W dyno when needed. I want to keep it small if possible since I`m going to run it off a dozen AA NICADs that I picked up on sale. At 2650mAh each, it`s a nominal 3.2 Ah- a good bit smaller than the rest of you have. I already have a universal smart charger on order and I`ve already Dremeled out the housing.

    Second- nobody mentions fuses. Even if it isn`t absolutely necessarry, I`d feel better about fusing my system as long as that won`t cause any unexpected complications. If I do put in an in-line fuse, it can go anywhere in the system can`t it? Does it matter which lead?
    Recalculating....

  198. #198
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    I don't know about the 10w bulb, but I wonder too for a dual light setup, a 10w low beam, and 20w high beam for three possible brightness (and battery killing) options.

    BTW, I just finished my pondscum light. I only have a 40 degree bulb in it but it's still way bright. I need to order a 25 degree bulb since none of the hardware stores around me carry one. It's sweet. I also went with the dozen AA's, at 2680 mAh each, from ebay for like $1.99 + $12 shipping from hong kong. Let's see how they hold up! I'll post pics of my build and carnge (yes, there's a casualty) tomorrow, since it's like almos 1:30 in the morning now!

    BM
    "I've come to believe that common sense is not that common" - Matt Timmerman

  199. #199
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    bmadau- You`re already running a 20W on 12 AAs? I was a little concerned that it might not light at all. Hope that concern was unwarranted. Carnage pics on the way?
    Recalculating....

  200. #200
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    Alright- got it all wired up and working last night! Soldering the battery pack was a lot easier than I expected, but time will tell if I did any kind of internal thermal damage to the battery pack.


    The bracket is designed to be able to run two lights side by side. I like the idea of maybe getting a 2nd 10w bulb as a low beam. With 12AA's, I can only run one light at a time or probably hurt the batteries, so I'll probably wait until I have better batteries before I go for a dual light setup.




    I epoxied the switch with the same stuff I used for the screw. Seems to hold pretty strong.


    Here's the battery pack. I used a 40W soldering iron from radio shack. It did the trick just fine. I bought a spare pointed tip and ground it to a chisel point with my little belt sander. You need the wide surface area of contact to quickly transfer heat to the batter terminals. It literally only took no more than 2 seconds to get the ends of the batteries tinned. Then it only took no more than one second to attach a previously tinned wire to the end of the battery. I also built a thermistor into it for the soon to be coming smart charger. The wires attach to the bottom side of the pack, and pass through the middle of the pack (between the batteries, and out the top, heavily hot glued along the way so there's no worry of pulling the wires off the ends of the batteries.


    I was using hot glue to hold the pack together, and I accidentally stuck it together the wrong way and quickly pulled it apart before the glue set, but stuck my finger in the hot glue. It was late.


    Then after I was done I left the room for a minute and the stupid soldering iron tipped off it's stupid little useless stand and burned my table. I'm pissed about this one... It's solid oak, no plywood or vernier, so I hope it could maybe be refinished at some time. It's a bit deep though...


    Now I'll be building lights for my riding partners so I don't have to ride at night alone!

    Thanks Scar!

    BM
    "I've come to believe that common sense is not that common" - Matt Timmerman

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