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  1. #1
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    Magic Shine and LiPo batteries

    After reading another thread in which one explains one can use a LiPo battery to power one's magic shine while one patiently awaits a new battery, I decided to go out and purchase a 5200mAH lipo battery and a charger for it.

    Long story short, I got my stuff in yesterday and wired it up to a female end piece for my magic shine. It works! Mostly sorta at least.

    It doesn't seem to want to go off.. or change modes. It stays in high and will not turn off unless I disconnect the battery. Is this normal? Is there any way I can change any of this? I'd at least like the off switch to work (and it seems I may have to throw a spst switch on there..), although all the options would be groovy as I tend to do our long climbs in a low mode.

  2. #2
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    Can you post specs on the battery? Where it is from and the PCB it uses?
    I'm assuming it is 7.4v, yes?
    I WANT TO BUY YOUR MAGICSHINE LIGHTS! Working or not.

  3. #3
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    Hi! This is the battery I bought:
    7.4v 5200mAh 20C LiPo 2S 7.4 Volt RC Akku Battery WF - eBay (item 150463964023 end time Aug-29-11 03:35:51 PDT)

    I honestly have no idea about the PCB... I am pretty new to this whole battery game.

  4. #4
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    Do you have a multimeter handy? That battery may not have a PCB if it's designed for RC use. Check the voltage using a multimeter. Are you charging it with the standard MS charger?
    I WANT TO BUY YOUR MAGICSHINE LIGHTS! Working or not.

  5. #5
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    So its a 2 cell Li Po and quoting 5.2 ah
    each cell is then 3.7 volt 5.2 AH and for $18 ish

    If something seems too good to be true it probably is

  6. #6
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    I'm using a lipo charger.

    Okay, since it has no PCB, is it safe to use with my magic shine still? I really don't mind being on high all the time.

  7. #7
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    One would avoid the situation you're in with your Li-Po.

    It is not working as it should and as I'm sure you are aware, it could burn your house down whilst on charge.(not saying it will, but it could).

    To quote Troutie: You will not get a decent 7.4v 5.2 AH Li-Po for that sort of money (otherwise we would all buy 10).

    In theory you are correct and it should all work. Just replace a 7.4v battery with another 7.4v & if it's a different chemistry then get the correct charger.

    I don't think it will do any harm to your light, although it should work just the same as the old one if it is actually 7.4v. Just don't like the Idea of you charging it as it is not working as it should.

    Does the battery have balance leads and is the charge a balance charger?
    Last edited by yetibetty; 08-12-2011 at 05:27 PM.

  8. #8
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    I have a balancing charger, so I am pretty sure my lipo is okay to charge. For now, I can't afford any other type of battery or charger. I am pretty damn broke and I don't see my battery coming in from Geoman any time soon seeing as how I finally sent it in (haven't been using it, nor any other battery since the recall).

    Would adding a pcb, such as the one that is currently on the old battery packs (I recycled only the battery portions) or like this: All-Battery.com: Protection Circuit Module (PCB) for 7.2V Li-ion 18650 / 18500 Battery Packs 3.5A Working (5A cut-off) w/ Gas Gauge port make it safe to use?

    Why do I even need a PCB in the battery pack in the first place?

    I know the risks of fire and charged the battery pack with my LiPo balancing charger in a terracota/cement brick container in the garage.

  9. #9
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    Quote Originally Posted by MrBaker View Post
    I'm using a lipo charger.

    Okay, since it has no PCB, is it safe to use with my magic shine still? I really don't mind being on high all the time.
    The setup you describe should work as per normal. The fact that it does not says you have a problem. If I was in your shoes I would not use the light until I figured out what the problem was, and hopefully fixed it.

    It could be as simple as the driver in the light head has stopped working. The fact that it has started to fail suggests that it might fail completely. I would not be leaving it plugged in when not in use and if the light stops working for any reason I would recommend disconnecting the battery immediately.

    In relation to safety, that is the entire purpose of a pcb - to prevent a dramatic incident caused by over discharge of the cells, over charge of the cells, too high a current or the cells being significantly out of balance. Not having one means you do not have a safety backup & you are relying upon the light and charger. A fault in either one can seriously damage the cells & create a hazardous situation.

    Like BKruahnndon said, you should check the battery voltage, both total and of each cell, both now and after every charge & discharge - it only takes a moment. Look at the three wire plug - its a balance port. The voltage between the red & black wires should be between 8.4v and say 7v (some people discharge lower, but that is the limit I am comfortable with). The voltage between the red & centre wire (hard to tell in pic but may be blue) & between the black & centre wire should be between 4.2v and 3.5v. Both voltages should be fairly close.

    I would be amazed if your battery has a pcb - RC uses very high discharge rates which PCBs are not rated for. The battery you have is claimed to have a continuous discharge rate of 15C.

    What that means is that the battery is meant to be able to cope with going from fully charged to fully discharged in 4 minutes. Assuming that it has the claimed capacity, that is 78 amps and the reason why the battery has such chunky wires. Most PCBs for 8.4v batteries have a rating of 5-10 amps.

    Your light has quite different requirements to RC - the light will run for something like 2 or 3 hours on high and consume more like 2-3 amps. You can pick up a pcb for about $5-$10. It's cheap & easy to install & it might prevent a dramatic incidient

  10. #10
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    Quote Originally Posted by find_bruce View Post
    The setup you describe should work as per normal. The fact that it does not says you have a problem. If I was in your shoes I would not use the light until I figured out what the problem was, and hopefully fixed it.

    It could be as simple as the driver in the light head has stopped working. The fact that it has started to fail suggests that it might fail completely. I would not be leaving it plugged in when not in use and if the light stops working for any reason I would recommend disconnecting the battery immediately.

    In relation to safety, that is the entire purpose of a pcb - to prevent a dramatic incident caused by over discharge of the cells, over charge of the cells, too high a current or the cells being significantly out of balance. Not having one means you do not have a safety backup & you are relying upon the light and charger. A fault in either one can seriously damage the cells & create a hazardous situation.

    Like BKruahnndon said, you should check the battery voltage, both total and of each cell, both now and after every charge & discharge - it only takes a moment. Look at the three wire plug - its a balance port. The voltage between the red & black wires should be between 8.4v and say 7v (some people discharge lower, but that is the limit I am comfortable with). The voltage between the red & centre wire (hard to tell in pic but may be blue) & between the black & centre wire should be between 4.2v and 3.5v. Both voltages should be fairly close.

    I would be amazed if your battery has a pcb - RC uses very high discharge rates which PCBs are not rated for. The battery you have is claimed to have a continuous discharge rate of 15C.

    What that means is that the battery is meant to be able to cope with going from fully charged to fully discharged in 4 minutes. Assuming that it has the claimed capacity, that is 78 amps and the reason why the battery has such chunky wires. Most PCBs for 8.4v batteries have a rating of 5-10 amps.

    Your light has quite different requirements to RC - the light will run for something like 2 or 3 hours on high and consume more like 2-3 amps. You can pick up a pcb for about $5-$10. It's cheap & easy to install & it might prevent a dramatic incidient
    Thank you! That was quite helpful.

  11. #11
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    PCBs keep your cells from over charging and discharging. Two things that lipos greatly dislike. They can also help regulate a discharge. What you ideally need a PCB for is the over discharge feature to keep the cells from draining too far.
    Was this the first time using the new battery? Or have you used it, drained it, charged it and now this is the problem? I would still check the voltage of everything, I've seen this happen and it was a battery issue.

    *cough* I have extra MS batteries to sell *cough*
    I WANT TO BUY YOUR MAGICSHINE LIGHTS! Working or not.

  12. #12
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    Quote Originally Posted by BKruahnndon View Post
    PCBs keep your cells from over charging and discharging. Two things that lipos greatly dislike. They can also help regulate a discharge. What you ideally need a PCB for is the over discharge feature to keep the cells from draining too far.
    Was this the first time using the new battery? Or have you used it, drained it, charged it and now this is the problem? I would still check the voltage of everything, I've seen this happen and it was a battery issue.

    *cough* I have extra MS batteries to sell *cough*
    First time using the battery. I noticed it right away. Unplugged it and posted this.

    I just tried the battery again, seems it wasn't on high mode at all. Seems to be stuck shooting a very low light. I think it might even be dimmer than my 120 lumen vega.

    I will check the new battery tomorrow. I need to locate a multimeter first though.

    New plans: order PCB
    with next pay check, purchase quality battery and nicer, digital charger that will tell me how my batteries are doing.

  13. #13
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    [QUOTE

    New plans: order PCB
    with next pay check, purchase quality battery and nicer, digital charger that will tell me how my batteries are doing.[/QUOTE]

    Smooth move. Good luck.

  14. #14
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    I think you have a issue with your light.

  15. #15
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    So its a 2 cell Li Po and quoting 5.2 ah
    each cell is then 3.7 volt 5.2 AH and for $18 ish

    If something seems too good to be true it probably is
    Not to harsh your buzz too badly Troutie, but there are some pretty decent hardcase LiPos coming out of China, such as: HobbyKing Online R/C Hobby Store : ZIPPY Flightmax 5000mAh 2S1P 20C hardcase pack (USA Warehouse) for $21. Not sure if they have a warehouse in your Kingdom, but you can order direct from China. The killer on total cost is the price of shipping, but if it lets you get around the VAT it might pan out.

    I've been using the 3 cell version of the above to power some of my lights with no complaints. I usually put a PTC resettable fuse in line with the battery. You can also find nice little buzzer warning boards (plugs into charging lead) that squeal when the voltage on any cell in the battery gets too low. Not as foolproof as a a well designed 18650 battery pack with a PCB, but then I'd never tout the MS batteries as well designed.

    I don't trust the hardcase all by itself. I pack the battery in foam inside a plastic case that I strap to my frame. The whole thing winds up being heavier than a MS pack, but I can stash a few charged replacement batteries in the truck and I'm good a whole night of riding.

    Mark
    Nimium est melior!

  16. #16
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    Quote Originally Posted by yetibetty View Post
    New plans: order PCB
    with next pay check, purchase quality battery and nicer, digital charger that will tell me how my batteries are doing.

    Instead of spending money on that why not just do the $25 upgrade at Geoman for a battery you know will work.
    Last edited by jhymel; 08-13-2011 at 02:48 PM.

  17. #17
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    OK I will stand corrected but have only heard bad stories about cheapie fleabay batteries .
    and it is good to hear a knowledgeable guy recommend a battery

  18. #18
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    I got my lipo's from hobby kings german warehouse..
    HobbyKing Online R/C Hobby Store :

    A quick ebay you can get a 14.8v 4500mah for 45 Turnigy 4500mAh 4s/14.8v 30c-40c LiPO - hardcase | eBay
    I bought a turnigy 14.8v 5800mah and a 7.4v 5800mah delivered for $10364
    Shipping was GLS Express Courier 2kg (Germany to UK) $14.98
    ..at the time i was looking at around 65 just for the 14.8.v 5800mah

  19. #19
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    I use my cheap eBay 7.4v batteries for both my MS LEDs with no issues. I do use a fireproof charging bag when charging.
    _______________
    1x10 IS SO FINE on my 21.9 lbs IBIS SL-R
    11-36 XTR in the rear, 36T wide-narrow upfront

  20. #20
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    Quote Originally Posted by troutie-mtb View Post
    OK I will stand corrected but have only heard bad stories about cheapie fleabay batteries .
    and it is good to hear a knowledgeable guy recommend a battery
    Don't know about the LiPos from fleabay, but hobbyking has been good so far. I wish they would stock cheaper chargers and accessories like the low voltage beepers in their local stores, you have to order from China and the shipping adds a bit to the price, and can take a while depending on time of year.

    The usual disclaimers about LiIon batteries apply to LoPos: don't charge your battery in the cold, charge it someplace fireproof (I use a metal bucket with a chunk of aluminum stock on top), don't overdischarge it, don't beat it up too badly (hence my foam padded case), etc.

    One advantage of the beeper board that warns of low voltage is you can always decide to ignore it for the 5 minutes you have left to get back to the car and not worry about your lights suddenly cutting out.

    I would never sell a setup using a LiPo to just anybody. I usually sell them to friends who are looking for a system that lets them buy cheap replacement packs.

    Mark
    Nimium est melior!

  21. #21
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    rattle the chain !?
    there is no free lunch !
    had a bunch of lipos, just because I did not had to solder some cells,...
    and one pack, seam to take longer to charge,...
    found out the hard way, that the $250 buck charger, still ignores the balance port,
    till the battery is juiced up, happen, that one cell stayed at 3.91, guess what the other ones where ?
    4.32V !? you got to keep en eye on it all the time with charging lipos,....
    -> USB and graph, balance prior to charging.
    thought the LIFE ones be better,... did not use it for 1/2 year, and they developed gas,
    like a little too much mexican beans. the square pack was now round, worked fine,
    just I did not feel comfortable with the new look......
    ---
    recommended:
    - balance port on all packs, I mean all of them
    - EOS sentry - > easy and fast, check balance and charge capacity
    - cell-log, programable cut-off and warning , cheap pcb still no good for lipos, lipos don't like to be rundown to 2.5V,
    max at 3.0V 3.15V is good
    - calibrate measure, your fancy charger, might not be on the same voltage,...
    ---
    everybody can cook, and blow up the kitchen.
    what defines a chef, is that he can repeat the recipe to the dot, and that he has a fire-extinguisher .
    .... do like the pyrex dishes to cook my lipos,..... and a bag of sand
    cheers, Rob
    oh, forgot to mention, the fleabay GTL cells are a waste of time and dough
    Last edited by rschultz101; 08-15-2011 at 06:17 PM.

  22. #22
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    I use these SkyLipo batteries from HobbyPartz.com for my RC planes: Sky Lipo 5000mAh 7.4V 20C

    I have the 3S 40C units for high amperage and discharge rates, so it seems like these would work great for running the magicshine light head. The only danger, as people have mentioned, is over-discharging. From what I've read, the red light comes on at 6.8V correct?

    EDIT: 3S 11.1v batteries will NOT work...voltage too high. I purchased some cheap 2S 7.4v batteries and soldered up some Deans->MS connectors.

    If that is the case, then it is safe to discharge to that point with these batteries and even a bit further (3.2v per cell). And at 20C, the output amperage is many times that of the maximum used by the light head on high.
    Last edited by TwoHeadsBrewing; 09-05-2011 at 10:49 AM.
    "Got everything you need?"

  23. #23
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    You could use one of these to warn you before you kill your batteries. You might be able to find somethiong similar on ebay.

    HobbyKing Online R/C Hobby Store : On Board Lipoly Low Voltage Alarm (2s~4s)

    If the Magicshine cuts off the light, or warns you with a red light @6.8 volts, the LiPos from HobbyKing or Hobbypartz would be an ideal replacement as you could almost double your runtime on the cheap.

    Just keep in mind, care must be taken, especially when charging. If you must charge unattended, use an ammo can, or similar, and use a balance charger.(also available inexpensively from HK,or HP)

  24. #24
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    Quote Originally Posted by TwoHeadsBrewing View Post
    I use these SkyLipo batteries from HobbyPartz.com for my RC planes: Sky Lipo 5000mAh 7.4V 20C

    I have the 3S 40C units for high amperage and discharge rates, so it seems like these would work great for running the magicshine light head. The only danger, as people have mentioned, is over-discharging. From what I've read, the red light comes on at 6.8V correct?

    If that is the case, then it is safe to discharge to that point with these batteries and even a bit further (3.2v per cell). And at 20C, the output amperage is many times that of the maximum used by the light head on high.
    I just reread your post.The Sky Lipo 7.4v batteries would be fine with your MS. The "3S 40C" will not. 3S is 11.1v not 7.4. I don't know what the voltage range of the MS is, but it would probably fry it. Even if it will run the light, if you discharge a 3S LiPo to 6.8v, you have killed it.

    I think you are talking about the 2S 7.4v battery, just making sure.

    I just ordered a 5000mah 7.4v hard case battery from HobbyKing for $18.
    HobbyKing Online R/C Hobby Store : Turnigy 5000mAh 2S1P 20C hardcase pack (ROAR Approved)
    I also purchased one of the $44 MS lights. I might break apart the MS battery, and use them in my flashlights.

    Here's another neat little device from Hobbyking.
    HobbyKing Online R/C Hobby Store : Battery Monitor 2-6S

    It will tell you the voltage of each cell in a pack, and the total voltage. It requires a balance plug, which is on most LiPos. It's only $2, and can usually be added to an order without incurring any additional shipping charge.

  25. #25
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    Caution;  Merge;  Workers Ahead!

    you will fry your Lipo's with MS !!!
    only the Gemini light, does actual cutoff properly, at 5.9-6V !
    discharging Lipo's below 3.2V per cell is not good !
    Lipo's don't like water or shock, hardcase a must.
    MS discharges to 5.5V, as such, your battery be toast in no time.
    a pcb or a cell-log programmed be good.
    there are plenty of assembled packs available with pcb,... add your connector, viola!
    charger, get one with a microprocessor, and balance port !
    convert all packs, to have balance ports .
    easiest, to just buy a ready pack from geoman ,...

    need something you can't buy, give me a buzz ,...

    cheers, Rob

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