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  1. #1
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    geomangear battery problem.

    I own a 6ah battery pack from geomangear, i couldnt get power from the pack. so i dis assembled the pack, and tested the battery voltage. it showed 8.4volts before the small board. but no power going to the connector, so i guess the small board is shot.

    My question is could i solder the connector directly to the battery, bypassing the board? im not very knowledgable about electronics. hope someone could help me out

  2. #2
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    Some battery protection PCBs trip if the battery is shorted and are reset by connecting to a charger for a moment. Otherwise you should really replace the PCB. batteryspace.com among other places sells them.

  3. #3
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    but is there a danger by making a direct connection?

  4. #4
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    Yes, some level of danger. The PCB protects the battery from overcharging (battery catches on fire or explodes), overdischarging (kills the battery), and short circuits (wires melt and battery could catch fire).

    A careful and knowledgeable user can minimize the risks of using an unprotected battery. I would recommend that you try to reset your protection PCB and failing that, source a replacement protection PCB.

    Look at it this way. There is enough risk that even the cheap Chinese made bike light battery packs have a protection PCB. If anyone was going to try to save a few bucks on their product they would be the ones. They don't, you shouldn't either

  5. #5
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    If you discharge the Lithium cells below 2.8 - 3 volts, you're damaging them. That can severely impact their lifespan.

    the PCB in that pack was supposed to function in one of 2 ways, depending on how fancy it was -1) it sensed the individual voltage in each cell and shut down if any one fell below a certain threshold, or 2) it sensed the whole pack voltage and shut down if the pack fell below a certain voltage.

    If you replace your board, make sure you get one that can sustain ~6A current or so would be my guess.

  6. #6
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    I had the same issue and after buying a PCB from batteryjunction (or similar), my pack still did not work. I think one or more of the cells was bad.

    I would seriously question the value of attempting to fix or bypass this pack and just get a new light setup. Yeah, you already paid for the light head and all, but you can get a newer and better one on Amazon for $40 if you still want to go cheap, or another option is to spend more $ to get an integrated battery light (see Lezyne Super Drive XL, Niterider Lumina 650) or similar money for a flashlight w/ battery, charger and mount.
    Last edited by diylighter; 10-25-2012 at 05:12 AM.

  7. #7
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    I rebuilt one of those packs about a year ago( magic shine) and was able to reuse the pcb. On the other hand, I just got a NR lumina 650 from amazon. It's easily as bright as my old magic shine. I was gonna use it as a helmet light but its a bit heavy and the helmet mount it came with is kinda sub par compared to the bar mount, so now the lumina is going on the bar and the magic shine will be my helmet light.

  8. #8
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    Another thought (that I am planning to persue) is to unsolder the pack and use the 18650 batteries in flashlights or cordless bike lights like the lezyne Super Drive XL that accept single cells. That is, until they give out as well.

    All battery packs will die eventually, which is why in hindsight I would value higher the time it took to repair the pack (unsuccessfully, in my case) vs a new pack and/or light kit. Just trying to give the OP a little tip. Everyone has their own priorities.

  9. #9
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    Quote Originally Posted by dunkinx View Post
    I own a 6ah battery pack from geomangear, i couldnt get power from the pack. so i dis assembled the pack, and tested the battery voltage. it showed 8.4volts before the small board. but no power going to the connector, so i guess the small board is shot.

    My question is could i solder the connector directly to the battery, bypassing the board? im not very knowledgable about electronics. hope someone could help me out
    If this is one of the new style (hard shell with slot for velcro attachment) batteries, there's a good chance that nothing is wrong with the pack. I have one of these 6.0 Ah new geomangear packs and exactly the same thing happened to me. Once I plugged in the charger, even for a minute, I could use the pack again.

    Like Vancbiker mentioned the PCB can automatically shut the pack down. This occurs if the current limits or voltage limits are either too high or too low. The only way to reset the pack is to plug in the charger. I thought my pack was dead too. I couldn't figure out why absolutely no power was coming from the pack.

    In my case, I'm running a light that is much larger and drains more current than the pack was designed for. I kept tripping the PCB when I ran my light on high. On high I'd only get half the calculated run time. When I ran the light on medium or low, then I'd get full run times. I have two lights, a 16 watt and 30 watt. The PCB is not designed for lights that draw this much power.

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