• 03-02-2004
    spacoli
    Homemade Niterider batteries
    Has anyone made up there own batteries for there niterider lights?

    Has anyone every taken apart the waterbottle type batteries?

    I want to take apart my waterbottle battery and rebuild it with new batteries.

    How do these come apart? Do you have to cut them apart?

    Are there any tricks or advice on doing this?
  • 03-02-2004
    Speedub.Nate
    Metroid wrote a FAQ...
    ...but I don't know if it made it over to from the old forums.

    The bottle opens just below the "neck". It's sealed with a brittle adhesive that breaks apart easily if you have something pointy to jam in there.

    <img src="http://gallery.consumerreview.com/webcrossing/images/niteriderbattery.jpg">

    It's pretty simple to get 11 cells and solder them together, rewire the whole contraption and get it running again. Suggest you look to BatteryStation.com for the cells, and suggest you consider the highest capacity NiMH cells that'll fit.
  • 03-02-2004
    spacoli
    What size cells
    What size cells are they (c or d )?
    I'm not up to date on electronics.
    What do you mean buy highests capacity?
    What number relates to the capacity is it the ah?
    You just shouldn't go over the voltage (13.2) right?
    Shouldn't you try to match the original specs ( my battery specs 4.0 ah 13.3 volt)
    The battery specs on the battery staion are in mah, what is this?
  • 03-02-2004
    damion
    The FAQ is in the upper right hand corner of this page.
    It will answer all of these questions for you.
  • 03-03-2004
    Homebrew
    Like the others said, the DIY Light FAQ is in the upper right hand corner of in any General Discussion post, including this one. I'm going to be adding a good battery building post with pics next time I build some since this specific topic comes up so often.

    But to answer your questions...

    Cell size 4/3A or FAT 4/3A which are slightly larger.

    Capacity is rated in Amp Hours. That's the amount of time a cell can be run at a given current. It is often shown as milliAmp Hours. Milli means one thousandth of an Amp. 1 Ah = 1000mAh

    You should stick with the 13.2V. That's 11 individual 1.2V cells. The cells are run in series so the voltage additive and current is constant. This is already overvolting the rated voltage of the bulb (12V) by 10% to give the best balance between brightness and bulb life.

    If you go with the same capacity rating, you will get the same burn time. If you go higher, it will be longer, less and it will be lower. Although it may appear that going with the highest might be the best idea, however sometimes you can get lower capacity cells much cheaper. Also, the lower capacity cells are capable of producing much higher actual capacity. I've tested 3800mAh rated cells at over 5500mAh actual. The higher capacity cells aren't going to produce as much over their rated capacity as the lower capacity cells. If you get the 4/3 A cells, all eleven with fit nicely on the bottom of a standard waterbottle. If you get the FAT 4/3A cells, you might have to double stack them. Be sure to put some insulation between them if you do.

    I have a bunch of 3800mAh 4/3A cells because they were on sale for less than half the price of the 4500mAh cells. These give 2+ hours with a 20W at full power. This works just fine for me.
  • 03-03-2004
    spacoli
    Thanks to all.....great info.....nm
    no message
  • 03-03-2004
    cheetos316
    Can you use the original charge with this setup?
    Or do you have to get the chargers mentioned in the DIY FAQs page?
  • 03-03-2004
    Homebrew
    Quote:

    Originally Posted by cheetos316
    Or do you have to get the chargers mentioned in the DIY FAQs page?

    You can PROBABLY use the same charger. No guarantees though. With the standard trickle charger, battery chemistry and capacity don't really matter much. The hard part with these is trying to guesstimate how long to charge for. In the case of the NiteRider smart charger, you can use these for both NiCad and NiMH. It will charger higher and lower capacity cells just fine but the time it takes to fully charge will be different.
  • 03-03-2004
    Speedub.Nate
    No problem...
    Quote:

    Originally Posted by cheetos316
    Or do you have to get the chargers mentioned in the DIY FAQs page?

    If you've got the old style (constant current / "dumb" charger / wall wort) you've got to calculate a new charge time based on current output and battery capacity.

    For instance, if you build a 4000mAh pack and have a 300 mA constant current charger, you'll divide 300mA into 4000mAh (4000/300 = 13 hours) then increase that time by 40% to account for inefficiencies during charging (13 hours x 1.4 = 18 hours).

    If you have a Micro Brute or other Nite Rider "smart" charger, it detects charge level through a change in voltage as the battery peaks, and the charger will differentiate between NiCad or NiMH cells (peak behavior is different for each). So again, even if the new battery has a higher capacity than the old, the charger is oblivious and will simply take longer to complete.
  • 03-03-2004
    ctxcrossx
    Quote:

    Originally Posted by f*nætik
    If you've got the old style (constant current / "dumb" charger / wall wort) you've got to calculate a new charge time based on current output and battery capacity.

    For instance, if you build a 4000mAh pack and have a 300 mA constant current charger, you'll divide 300mA into 4000mAh (4000/300 = 13 hours) then increase that time by 40% to account for inefficiencies during charging (13 hours x 1.4 = 18 hours).

    If you have a Micro Brute or other Nite Rider "smart" charger, it detects charge level through a change in voltage as the battery peaks, and the charger will differentiate between NiCad or NiMH cells (peak behavior is different for each). So again, even if the new battery has a higher capacity than the old, the charger is oblivious and will simply take longer to complete.

    If you have the dumb charger, can you upgrade to the smart charger? I have the Digital pro 12 (or whatever it is called, they grey one but with the blinking light guage). This has the old style connectors. I was told by a friend that some of the electronics for the smart charger were in the batteries. Is this true? Or can I just try to track one down on ebay or something? Thanks!

    Chris
  • 03-03-2004
    Speedub.Nate
    I *think* that...
    Quote:

    Originally Posted by ctxcrossx
    If you have the dumb charger, can you upgrade to the smart charger? I have the Digital pro 12 (or whatever it is called, they grey one but with the blinking light guage). This has the old style connectors. I was told by a friend that some of the electronics for the smart charger were in the batteries. Is this true? Or can I just try to track one down on ebay or something?

    ...the extra connector for the "smart" charger goes to a temp sensor in the battery. The temp sensor would act as a secondary cutoff, in case the battery gets over a certain temp while charging. *If* that proves to be the case, I don't know how difficult it would be to get the smart charger working. If you bypass the temp sensor, you're eliminating a safety mechanism that helps to ensure you don't burn your house down while you're sleeping.

    If you go with a Maha C777 Plus II charger, the temp sensor is external (it's attached to a separate lead off the charger and affixes to the outside of the battery). You'll still need to rig up a different connection method since the Maha only comes with generic connectors, but that's no sweat (just cut the leads off your old wall chargers, solder them on to pig-tails that connect into the Maha). The benefit of the Maha is that it works on anything from one to 12 cells, so you can use the same charger on multiple battery packs.

    <img src="http://gallery.consumerreview.com/webcrossing/images/maha(2).jpg">

    <img src="http://gallery.consumerreview.com/webcrossing/images/maha(3).jpg">

    <img src="http://gallery.consumerreview.com/webcrossing/images/maha(4).jpg">
  • 03-03-2004
    spacoli
    What diameter 4/3 A cells at the battery station
    What diameter 4/3 A cells did you use that fits perfect in a waterbottle?

    Are they the:

    4/3 A SIZE: DIA 17.0 mm X HT 66.0 mm

    PART NO MFR COMMENT MAH GRAMS OZ PRICE
    HR-4/3AUX Sanyo Ni-MH 3800 52 $ 4.50
    HR-4/3AU SALE w/tabs Sanyo Ni-MH 4000 55 $ 4.00

    VH-4000 SALE w/tabs Varta Ni-MH 4000 55 $ 4.00

    Or the:

    4/3 A SIZE: DIA 18.0 mm X HT 66.0 mm

    PART NO MFR COMMENT MAH GRAMS OZ PRICE
    HR-4/3FAU Sanyo Ni-MH 4000 62 $ 5.50
    HR-4/3FAUX Sanyo Ni-MH 4500 62 $ 5.95

    Seems like the 4000 mah are cheaper than the 3800 mah.

    Should I go with the larger capacity?
  • 03-03-2004
    Speedub.Nate
    Quote:

    Originally Posted by spacoli
    What diameter 4/3 A cells did you use that fits perfect in a waterbottle?

    I'd go with Sanyo, the largest capacity you want to afford.

    17 or 18mm really doesn't make too much of a difference.

    You'll appreciate a hot glue gun to construct your pack, something like so:

    - O - O -
    O - O - O - O
    - O - O - O
    - - -O - O

    That shape fits pretty well into the interior of the water bottle. You'll have to "connect the dots" so to speak, connecting positive to negative to create the circuit. To finish if off, after gluing and soldering the pack toghther, I used insulating foam in a spray can to fill the bottle.
  • 03-04-2004
    Homebrew
    I would just go with the Sanyo 4000mAh cells that are on sale unless you think the slight increase in burn time of the 4500mAh is worth paying 50% more per cell. Personally, I would look at that price increase as half way to another pack.
  • 03-04-2004
    Homebrew
    Quote:

    Originally Posted by ctxcrossx
    If you have the dumb charger, can you upgrade to the smart charger? I have the Digital pro 12 (or whatever it is called, they grey one but with the blinking light guage). This has the old style connectors. I was told by a friend that some of the electronics for the smart charger were in the batteries. Is this true? Or can I just try to track one down on ebay or something? Thanks!

    Chris

    That charger is nothing more than a timed trickle charger. It is supposed to shut off after a set period of time (probably around 14 hours) after being connected. It doesn't care if you hook up a fully charged battery. It is still going to charge for 14 hours.

    With the old style connectors, there is nothing extra in the battery pack. Can't be with only two wires. A new fast charger will work fine as long as you get the same connectors. Jet Lites use the same connectors as the old NiteRider if you want to use one of their smart chargers or you can get a Maha and make your own connector cable like Nate did.
  • 03-04-2004
    jimjo
    Quote:

    Originally Posted by Homebrew
    I would just go with the Sanyo 4000mAh cells that are on sale unless you think the slight increase in burn time of the 4500mAh is worth paying 50% more per cell. Personally, I would look at that price increase as half way to another pack.

    did you use a regular soldering iron to put it all together? or an adjustable temperature one? did you use the batteries with or without tabs?
  • 03-04-2004
    Homebrew
    Quote:

    Originally Posted by jimjo
    did you use a regular soldering iron to put it all together? or an adjustable temperature one? did you use the batteries with or without tabs?

    I have a solding iron with two different elements, one is a regular 23W, the other is high power 45W. If using cells with tabs, the 23W works fine. Without tabs, you need to use a high power iron. The key without tabs is to rough up the surface, use flux and get it done quick.
  • 03-04-2004
    Speedub.Nate
    Quote:

    Originally Posted by jimjo
    did you use a regular soldering iron to put it all together? or an adjustable temperature one? did you use the batteries with or without tabs?

    Initially I bought batteries w/ tabs, but I didn't like them.

    I ripped the tabs off and cleaned the tops of the batteries with a Dremel & sanding wheel.

    Then I got a 40w (+/-) soldering iron with a chisel tip + required solder type (acid core? forgot which). Key is a hot iron for only a brief few seconds. Smaller irons will heat up the whole battery without getting the surface of the cell hot enough to complete the job.

    From my local RC store, I picked up some "battery braid" which is just flat ribbon cable to connect the cells. I pre-tinned those, then sandwiched the braid between the cell and iron for a 5-count and let the solder heat up, wick in. When pulling the iron away, use a wood popsicle stick to hold the braid to the cell for a few second while it cools.

    Lots of good references online from the guys that build their own RC car battery packs. Another key is to have the cells all glued together before beginning the soldering.
  • 03-04-2004
    jeffj
    A few words to avoid trouble.

    If you look at f*nætik's picture and see the cells with the metal casing that look as if they are touching each other, look again. You will notice that the cardboard has been cut away (for whatever reason) on the outside of the cells and they are not actually touching each other metal case to metal case. I have had cells short out this way if you don’t insulate them from each other. I know you can get heat shrink tubing that will fit sub-c cells easily and I imagine you can get it for all different sized cells. I have used electrical tape if I didn’t have any shrink tubing handy.

    If you can’t find the braided cable, you can use the type of wire sold in RC stores used to connect batteries to speed controls and motors. Novak and Deans are two companies that comes to mind that make a high quality wire suitable for this application. I use bars because they make them for the sub-c cells I have been using.

    I also have a jig made for assembling sub-c batteries in flat packs, but I put together two or three cells in a row using the jig and then finish assembling them in a 5 cell hump pack holding them together with a couple of winds of electrical tape. Note: Mine are 5 cell packs because I have 6v light systems. 12v systems use 10 cells at 1.2v each and 13.3v systems use 11 cells.

    The 4/3A cells seem like the power/price/size winner for bike lights. I use sub-c cells because I am so familiar (I have dozens of RC battery packs) with them and have the jig to help with assembly.

    Then I take a section of an old innertube and stretch it over the whole battery pack.

    Buy the “60/40” solder at Radio shack. It’s cheap and works perfectly (a half pound spool costs about $6 to $7). I like a ¼” chisel tip for good “on and off” in about three seconds soldering action that is still easy to maneuver. If you use a smaller tip, I find they don’t hold enough heat to do it quickly.

    I could ramble on and on about chargers for way too long just to get you to this conclusion that is the logical choice for most people looking to upgrade from the simple low powered “brick” style chargers:

    Unless you are willing to spend some substantial coin, just simplify your life and get one of the Maha chargers that will handle the voltage for your system. They are THE most simple, cost effective, relatively quick charging (mine charges @ 700mah) units available for nicd and nimh cells. Now, 700mah is not super quick (I have chargers that will charge at safely at 5500mah), but they are far better than the 200mah units that come with many light systems. AND they will cycle your packs as well. I’m going to stop now…

    One other thing about making your own battery packs… It’s kind of addicting and hard to make just one.
  • 03-04-2004
    FM
    I got a related question....

    Can I use my newer micro-brute charger (came with a storm HID) to charge my older 12v battery pack I made for my classic dual-beam?

    I made this pack just like f*naetik's with Sanyo 4000mah's. The battery works great, but I don't get consistent charges with my old nite-rider "dumb charger" - mainly just becuase I'm never in one place long enough to give it a full charge. Understand I will need at least some sort of adaptor- does nite-rider sell this, or any tips on fabricating one?

    Thanks a ton!
  • 03-04-2004
    piercebrew
    13.2V can I make it from 11+ batteries?
    I know that to build a replacement for my 13.2V NR classic battery, I need 11 1.2V batteries. Could I set it up so I have 13 or 14 batteries, and add the last two or three in parallel or a series, which ever way as to not increase the voltage but to increase the burn time on my NR light?
    Forgive me for not knowing the technical terms.
    Thanks.
  • 03-04-2004
    Speedub.Nate
    Ooohh, I should point out...
    Quote:

    Originally Posted by jeffj
    If you look at f*nætik's picture and see the cells with the metal casing that look as if they are touching each other, look again. You will notice that the cardboard has been cut away (for whatever reason) on the outside of the cells and they are not actually touching each other metal case to metal case. I have had cells short out this way if you don’t insulate them from each other.

    ...that the batteries in the picture I posted of the open water bottle are the original Nite Rider batteries that I had already hacked at with a razor blade in the process of breaking the pack appart.

    Those are C cells soldered end to end. I constructed my pack out of 4/3A cells which did not require stacking; the follow the side-by-side diagram illustrated in my O - O - O diagram in one of the previous posts.
  • 03-04-2004
    spacoli
    Niterider battery plugs ends
    Where could I get plug ends (old style niterider) that come from the battery and plug into the light cord / charger port of my old digital 12.

    I want to build more than one replacement of my old battery?
  • 03-04-2004
    Albuquerque Rockhopper
    1 Attachment(s)
    I make RC battery packs all the time for my other hobby (electric RC airplanes), and found that these plugs work really well. They are press-fit plugs that also pull apart with just a bit of intentional force (good if your battery departs from your light), and they are designed for up to 80 amps of juice (maybe more, but thats the most I have put through them). Cheap for a set too.

    I am going to set up my batteries to use these plugs so I can charge my standard NiMH niterider batteries from my computerized peak detecting charger.

    http://www.wsdeans.com/products/plugs/ULTRA-PLUG2.jpg
  • 03-05-2004
    spacoli
    battery plugs
    Where could I get plug ends (old style niterider) that come from the battery and plug into the light cord / charger port of my old digital 12.

    I want to build more than one replacement of my old battery?
  • 03-05-2004
    Homebrew
    Quote:

    Originally Posted by FM
    I got a related question....

    Can I use my newer micro-brute charger (came with a storm HID) to charge my older 12v battery pack I made for my classic dual-beam?

    I made this pack just like f*naetik's with Sanyo 4000mah's. The battery works great, but I don't get consistent charges with my old nite-rider "dumb charger" - mainly just becuase I'm never in one place long enough to give it a full charge. Understand I will need at least some sort of adaptor- does nite-rider sell this, or any tips on fabricating one?

    Thanks a ton!


    Absolutely. You can use the new Microbrute for your old Classic battery. You just need a connector adapter cable available from NiteRider.

    http://www.niterider.com/Merchant2/m...ry_Code=Access
  • 03-05-2004
    Homebrew
    No
    Quote:

    Originally Posted by piercebrew
    I know that to build a replacement for my 13.2V NR classic battery, I need 11 1.2V batteries. Could I set it up so I have 13 or 14 batteries, and add the last two or three in parallel or a series, which ever way as to not increase the voltage but to increase the burn time on my NR light?
    Forgive me for not knowing the technical terms.
    Thanks.

    In theory parallel pairs would give you more burn time, there is absolutely no advantage to this. It will not charge properly. Besides, you get the same burn time from 2 separate packs and they are much easier to deal with. Just use the 11 cells.

    If you are interested in using a higher voltage battery (more cells in series) you would need to build or buy some type of voltage regulator to feed a constant voltage to the light.
  • 03-05-2004
    Homebrew
    Quote:

    Originally Posted by spacoli
    Where could I get plug ends (old style niterider) that come from the battery and plug into the light cord / charger port of my old digital 12.

    I want to build more than one replacement of my old battery?

    Digikey recently added a good single ended cable to their catalog.

    2.5mm x 5.5mm right angle connector with 18 AWG cable part # CP-2200-ND

    http://dkc3.digikey.com/PDF/T041/0253.pdf

    While you are ordering, you might want to pick up some resettable fuses as well. I would probably use one of these:

    part # SRP350-ND or part # SRP420-ND

    http://dkc3.digikey.com/PDF/T041/1130.pdf
  • 03-05-2004
    alibi
    Good eye Homebrew....
    That's a handy cable that, as far I know, has been previously unavailable anywhere (except those Radio Shack car lighter plug-ins that quickly disappeared).

    Do you know of the existence of the female counterpart to that cable? or even a panel mount style? I cruised the Digikey catalog +/- a few pages form the one you referenced, but didn't see anything.
  • 03-05-2004
    Homebrew
    Quote:

    Originally Posted by alibi
    That's a handy cable that, as far I know, has been previously unavailable anywhere (except those Radio Shack car lighter plug-ins that quickly disappeared).

    Do you know of the existence of the female counterpart to that cable? or even a panel mount style? I cruised the Digikey catalog +/- a few pages form the one you referenced, but didn't see anything.

    For the female, depends on the application. If you just want a panel mount, I picked one up at Radio Shack. BTW, this one fits PERFECTLY jammed up into the bit valve of a water bottle just remove the stopper in the middle of the valve.

    http://www.radioshack.com/product.as...Fid=274%2D1576

    If you need an inline connector, I'm sure Digikey has them you just have to dig around. I don't have time right now. Here is another source though...

    http://www.action-electronics.com/acadaptr.htm

    These folks have the cable with the proper connector as well but I was unsure of the gauge wire used. Looks okay but you never know.
  • 03-08-2004
    cheetos316
    Difference in 12V and 6V systems?
    Was just looking at the Niterider site at the battery packs and noticed that they sell difference packs for different systems. There are 12V and 6V packs. Does it matter? According to the information from above, seems like everyone is just throwing 11 of the 1.2V 4/3A batteries together and getting the 13.2V. Would the 13.2V short out the systems that should take 6V. I have the old Digital Evolution and the site says that it should get the 6V battery pack.... Can I go for the 13.2V battery pack version? Would this affect the bulb life?

    Thanks!
  • 03-08-2004
    Homebrew
    Quote:

    Originally Posted by cheetos316
    Can I go for the 13.2V battery pack version? Would this affect the bulb life?

    You can't do this. You will blow your bulb immediately. As you can see from the chart below, as you increase voltage over nominal value, you exponentially decrease bulb life. They didn't go past 20% voltage increase in the chart because bulb life is already decreased about 90% at that point. Technobabble blah blah blah. Bottom line, just don't do it. Use a 6V battery for a Digital Evolution. The other folks were talking about the Nite Rider dual beam lights which take 13.2V batteries. The good news is the 6V packs are cheap. You can build a 5 cell 4500mAh pack for about $35 which will give about 2 hours burn time with a 15W bulb.



    http://www.myra-simon.com/bike/lights.html#overvolting
  • 03-11-2004
    cheetos316
    Couple more Q's
    I think I'm starting to understand this all..... a couple of things I'm confused about though - so when you put the batteries together, the voltage adds up? A 6V battery will be made of 5 1.2V batteries and a 13.2V battery will be made of 10 1.2V batteries? When you put the batteries together, the capacity doesn't add up? The 5 4000mAh batteries will not be 80000mAh but is still 4000 mAh? On batterystation.com I see there are D batteries that are 9000mAh. Could I use 5 of those to make a 6V battery? I'm thinking this would give me twice the burn time as opposed to 5 4000mAh batteries, but would it work?

    As for the battery pack itself, where can I get the 2.5mm x 5.5mm right angle connector with the cable? On digikey.com, they only sell the connector, but it would be great if I can get the connector with some cable attached to it, preferably in coils too. What are the resettable fuses for? Where do they come into play?

    Thank you so much for your help!
  • 03-11-2004
    darkmatter
    Quote:

    Originally Posted by cheetos316
    I think I'm starting to understand this all..... a couple of things I'm confused about though - so when you put the batteries together, the voltage adds up? A 6V battery will be made of 5 1.2V batteries and a 13.2V battery will be made of 10 1.2V batteries? When you put the batteries together, the capacity doesn't add up? The 5 4000mAh batteries will not be 80000mAh but is still 4000 mAh? On batterystation.com I see there are D batteries that are 9000mAh. Could I use 5 of those to make a 6V battery? I'm thinking this would give me twice the burn time as opposed to 5 4000mAh batteries, but would it work?

    As for the battery pack itself, where can I get the 2.5mm x 5.5mm right angle connector with the cable? On digikey.com, they only sell the connector, but it would be great if I can get the connector with some cable attached to it, preferably in coils too. What are the resettable fuses for? Where do they come into play?

    Thank you so much for your help!

    It all depends on how you wire the batteries. If you wire them in series you will be adding voltage and 5 1.2v 4000mah batteries will add up to 6v at 4000mah. If you wire them in parallel you will get a cell that is 1.2volts but will supply 20000mah of power.

    Series is [- +}[- +}[- +}[- +}[- +} Then wires out to light from either end 6 volts 4000mah

    Parallel:
    |[- +}|
    |[- +}|
    |[- +}|
    |[- +}| 1.2volts 20,000 mah
    |[- +}| Wire out of the positive and negative terminal on the last battery here

    Series parallel
    |[- +}[- +}[- +}[- +}[- +}|
    |[- +}[- +}[- +}[- +}[- +}|
    | | 6Volt 8000mah

    I am also interested in where the coil cable can be purchased.
  • 03-11-2004
    piercebrew
    making a 13.2V battery
    I had an idea for making an easy battery pack for my old NR classic, couldn't I just put 11 in a row in a PVC pipe the plastic water pipes with a spring at the bottom. Just like a big mag light?
  • 03-11-2004
    Speedub.Nate
    Yes, that would work...
    Quote:

    Originally Posted by piercebrew
    I had an idea for making an easy battery pack for my old NR classic, couldn't I just put 11 in a row in a PVC pipe the plastic water pipes with a spring at the bottom. Just like a big mag light?

    ...just the same as those VistaLite Nightsticks, only really long.

    <img src="http://www.vistalite.com/vistalite_03/NSC25.jpg">
  • 03-11-2004
    EBasil
    I just put my home-built battery arrays into a widemouth water bottle, the type with the threaded lids. Performance sells them for 2 bucks at their "sales", usually. Ream the drink spout out with a drill bit, run the wires right through there and then seal off the top of the battery pack with spray foam.
  • 03-11-2004
    Homebrew
    Kirchhoff
    Voltage is additive in series but current stays constant. Current is additive in parallel but voltage stays constant. Capacity is just the rating of current over time.

    For a quick electronics lesson...

    http://www.physics.uoguelph.ca/tutor...ohm.intro.html
    http://www.physics.uoguelph.ca/tutor...Q.ohm.KVL.html
    http://www.physics.uoguelph.ca/tutor...Q.ohm.KCL.html

    For 13.2V, you need eleven 1.2V cells not ten. And if you read my previous post, Digikey does sell the 5.5x2.5 connector on an 6 ft 18awg cable...

    2.5mm x 5.5mm right angle connector with 18 AWG cable part # CP-2200-ND

    http://dkc3.digikey.com/PDF/T041/0253.pdf (bottom of the page)

    While you are ordering, you might want to pick up some resettable fuses as well. I would probably use one of these:

    part # SRP350-ND or part # SRP420-ND

    http://dkc3.digikey.com/PDF/T041/1130.pdf
  • 03-11-2004
    darkmatter
    Kirchoffs Rules or Ohms Law
    Quote:

    Originally Posted by Homebrew
    Voltage is additive in series but current stays constant. Current is additive in parallel but voltage stays constant. Capacity is just the rating of current over time.

    For a quick electronics lesson...

    http://www.physics.uoguelph.ca/tutor...ohm.intro.html
    http://www.physics.uoguelph.ca/tutor...Q.ohm.KVL.html
    http://www.physics.uoguelph.ca/tutor...Q.ohm.KCL.html

    For 13.2V, you need eleven 1.2V cells not ten. And if you read my previous post, Digikey does sell the 5.5x2.5 connector on an 6 ft 18awg cable...

    2.5mm x 5.5mm right angle connector with 18 AWG cable part # CP-2200-ND

    http://dkc3.digikey.com/PDF/T041/0253.pdf (bottom of the page)

    While you are ordering, you might want to pick up some resettable fuses as well. I would probably use one of these:

    part # SRP350-ND or part # SRP420-ND

    http://dkc3.digikey.com/PDF/T041/1130.pdf

    Hey Homebrew,

    Thanks for the digikey tip, I found it in a previous post but was being a numbnuts about digging through their catalog. I am interested in the fused switch you add. Is this to avoid shorting out your battery or will it possibly throw when your battery is charged and begins to get hot due to increased resistance. It says that it provides noncycling protection but I am not really sure what that is. You seem very knowledgable on the subject; what is your background? I am a High School Physics teacher so I know the electricity stuff but I have limited practical experience.

    You have been extremely helpfull on this subject and I would like to extend my gratitude.
  • 03-11-2004
    jeffj
    One thing to add on the coiled wires: An issue I have with them is that if I run them with lights of 20w or less they work fine, but if I try to run mine with both the 20w and the 15w lights running at the same time, the wire is not large enough to handle the demand for 35w of light output. The lights dim to the point of them both being about as bright as the 20w light by itself. If you are going to run more powerful lights, you need to find some heavier gauge wire (probably 16 or 14).
  • 03-12-2004
    Homebrew
    Quote:

    Originally Posted by darkmatter
    Hey Homebrew,

    Thanks for the digikey tip, I found it in a previous post but was being a numbnuts about digging through their catalog. I am interested in the fused switch you add. Is this to avoid shorting out your battery or will it possibly throw when your battery is charged and begins to get hot due to increased resistance. It says that it provides noncycling protection but I am not really sure what that is. You seem very knowledgable on the subject; what is your background? I am a High School Physics teacher so I know the electricity stuff but I have limited practical experience.

    You have been extremely helpfull on this subject and I would like to extend my gratitude.

    The fuse is for overcurrent protection (shorts). The ones I mentioned are specifically designed for rechargeable battery packs and all comercial packs have them. They reset themselves after the overcurrent condition is gone. They don't have anything to do with charging. You could add a thermistor to your pack but your charger would need to be setup for delta T charge termination and then you would need a 3 pin connector. Some chargers like the Maha universal chargers have a thermistor external to the pack to prevent overcharging but mainly use other voltage detection methods for termination.

    I spent 6 years as an electronics technician in the Marine Corps. I have since moved on to engineering, although industrial engineering not electrical. Then I spent too much time reading about this stuff on the internet while bored at work. It satisfies my technogeek urges and applies to bikes. What more can one ask for?
  • 03-12-2004
    spacoli
    Power inverter size for charging 2 batteries
    Since it seems like your the tech here, I got a question.
    I would like to charge batteries from my truck while camping.
    What size power inverter would I need to charge two 13.2 (at the most) batteries at once?
  • 03-14-2004
    jeffj
    No need for an inverter IMHO
    Why bother with an expensive power inverter?

    The better battery chargers (not necessarily made for bike lights) run off of 12v anyway.

    Here is one that I think might suit you well that runs about the price of an inverter ($65) and runs off of AC or DC and will charge 2 battery packs at once up to 14.4v each. I'm told that the 2500mah limit is not really so, but check it out for yourself.

    http://www.hobby-warehouse.com/wapfduacpech.html

    There are many others out there. A good hobby store should be able to help you.

    Even the Maha can use a cigarette lighter adaptor.
  • 03-15-2004
    Homebrew
    Quote:

    Originally Posted by jeffj
    Why bother with an expensive power inverter?

    The better battery chargers (not necessarily made for bike lights) run off of 12v anyway.

    Here is one that I think might suit you well that runs about the price of an inverter ($65) and runs off of AC or DC and will charge 2 battery packs at once up to 14.4v each. I'm told that the 2500mah limit is not really so, but check it out for yourself.

    http://www.hobby-warehouse.com/wapfduacpech.html

    There are many others out there. A good hobby store should be able to help you.

    Even the Maha can use a cigarette lighter adaptor.


    Inverters don't cost that much especially on eBay (maybe $20). The RC DC chargers are setup to attach directly to a car battery and not the cig lighter through the cars wiring. The Maha may have a cig adapter but it doesn't charge higher voltage batteries with it. The simple voltage regulator it uses only allows you to charge the higher voltage packs with a 18V-22V input. The NiteRider 13.2V Microbrute has a buck-boost switching regulator to allow it to charge higher voltages with the standard 12V input. That's why the 13.2V cost about $20 more than the 6V.

    Anyway if you want to go the inverter route, you really don't need anything too powerful even for 2 chargers. Most chargers only draw 1Amp-hour. It's kinda funny that all chargers actually run off DC so you would be converting the DC battery to AC then through a AC to DC wall wort to a DC charger. It's not the most efficient method but might be the simplest.
  • 03-15-2004
    jeffj
    I have made a couple of cigarette lighter cords for my chargers so I can charge while driving. I use Deans plugs to connect them to the lighter cord. Make sure that the plug and wiring is designed to handle the amp load regardless of whether you use an inverter or a 12v charger. I have found plugs rated as high as 10 amps with integrated fuses. If you run a 10amp plug at 10 amps, it will get hot and possibly fail. My point being that you should get a plug rated at least 30% higher than the demand you will place on it. I can run two of my chargers at 3 to 3 ½ amps each with the 10a plug and it will only get a little warm at most. If I run them at 8 to 10 amps, they get hot, REAL HOT at 10 amps (don’t do it).

    Also make sure that any charger you use is designed to run at 12v and at up to 15v because your car’s alternator will put out up to 14.6v while it’s running and some chargers will not operate at voltages significantly higher than 12.0v.
  • 03-15-2004
    cheetos316
    Pointes on soldering?
    Batteries are on order and now I need to get me a soldering iron. I've looked around on ebay. Does it matter what kind of soldering iron I get? The cheap ones are the pencil type with about 30 watts and the more expensive ones are the gun type with trigger feed. What kind of solder should I be using? I got batteries with and without tabs. How do I use the soldering iron? I'm assuming I should practice on something else before trying to solder the batteries together.... Also, how do I attach the wires to the batteries? By soldering as well? If so, do I have to protect or cover the joint between the wire and the tab with something like electrical tape?

    Thanks again for the wonderful help!
  • 03-16-2004
    Homebrew
    For soldering directly to cells, you want a higher than standard iron but a gun is not necessary. I have the type that is just the handle with replaceable elements. For this type of work, I use a 45W with a 1/4" chisel tip. You will want to rough up the surface of the cells to get good solder adhesion. It doesn't work very well on the smooth chrome plating. A few strokes on some sandpaper is fine. For solder, any electronics solder will work (I wouldn't recommend plumbing solder). Silver solder will be a bit stronger. Rosin core is easier to use. You might want to get some additional liquid or paste rosin flux. I would stay away from the acid flux (very corrosive) and stick with rosin though.

    The key to soldering is good heat transfer. Everything should be clean, keep your tip clean, tin your leads, flux is your friend. Don't hold the iron on the cell too long. If it doesn't melt right away, it's not getting good heat transfer. Clean everything and try again. Good solder joints should be clean and smooth. You might find that you don't have enough hands to do this. I use a vise to hold the cells and forceps to hold the wire so I have my hands free to solder.

    Depending on how you arrange your pack, you may or may not need to wrap the cells. You just want to make sure the cells aren't going to touch each other.

    You might try to google up on soldering techniques before trying on your cells.

    Good luck.
  • 03-16-2004
    airman
    More Info...
    Lots of really good info in this thread! A couple of suggestions for stuff I didn't see mentioned:

    Protection - if you are making your own battery packs they need physical, electrical and thermal protection. The physical may be tape, heat shrink, waterbottles etc., but you may also find some other products useful. Really thin gasket paper is tough enough to insulate when soldering and prevent shorts. Parchment paper will also work. Electrical protection may be old-style fuses, or the resettable kind. Thermal protection is required to prevent cells from overheating and exploding. Two types of thermal protection are commonly used - one is resettable and the other self-destructs (before your battery does...). The thermal reset and overcurrent protection is available in a single package from various manufacturers, but I like to use the Texas Instrument Klixon type set at 70 deg. If you intend to rapid charge without cell temperature detection make sure you have the thermal protection! They cost about 2 bucks each, and you should order them when you purchase your batteries...

    Build on...

    :cool:
  • 03-30-2004
    JimSpokes
    Will the 2.5mm x 5.5mm plugs work on the old 6v NR lights also?
    Quote:

    Originally Posted by Homebrew
    Digikey recently added a good single ended cable to their catalog.

    2.5mm x 5.5mm right angle connector with 18 AWG cable part # CP-2200-ND

    http://dkc3.digikey.com/PDF/T041/0253.pdf

    While you are ordering, you might want to pick up some resettable fuses as well. I would probably use one of these:

    part # SRP350-ND or part # SRP420-ND

    http://dkc3.digikey.com/PDF/T041/1130.pdf

    Will the 2.5mm x 5.5mm plugs work on the old 6v NR lights also?
  • 03-30-2004
    alibi
    Yes...
    The right angle male connector with twin wires fits perfectly into older NR lightheads, such as the Cyclops, Trail Rat, Digital Pro 6 etc. It would be all you need to wire up to a new homemade battery pack, as it's about 6 feet long.

    Since this is bumped up, I'll take the opportunity to say "thanks Homebrew" for that Action Electronics link. They sell the same right angle connector with wires (the wire is 18 gauge; a little fragile, but probably OK), and they also have a few different styles of female connectors that are very handy for homemade setups.