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  1. #1
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    Tenergy charger issue

    I have a universal smart charger from tenergy that has setttings from 3.7-14.8V. I put a 3.7V battery on last night and it was on for over 6 hours w/ no green light. The charger was warm but not the battery. I topped off an 11.1 V battery this morning and it worked fine. I plugged in the 3.7v and measured current at 0.1A, no wonder.....It measured 0.5A when charging the 11.1 battery. Does this have something to do w/ the pcb protection circuit for the battery pack? I'm assuming I need a new charger for my 3.7v battery. And....yes I changed the switch on the charger to the appropriate settings for each battery.
    TIA, still learning all this magic electricity stuff.
    Andy

  2. #2
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    I have the same charger and have had no problems with it so far(many years).
    What capacity is your 3.7v pack? These chargers are very slow but good for the batteries in the long term, if it is a very high capacity pack it could take a very long time to charge from flat.

    The very nature of a lithium charger is to change current through out the charge cycle depending on what state of charge of the battery is in. Don't worry too much about that reading. 0.1A reading could be due to the charger going into the final part of charging. In other words you 3.7v is almost done.

    If it charges the 11.1v then the charger is fine. Let the 3.7v have a good 12 hours and if it still won't charge then it could be the battery.

  3. #3
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    After posting this morning, I left it on the charger for a few more hours and the indicator light turned green, wow, like you said just a long charging cycle. Can anyone recommend a reasonably priced faster charger? I noticed battery space has some that are 3A and 6A rated. Is that safe for the battery?
    TIA
    andy

  4. #4
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    Quote Originally Posted by Andy13
    After posting this morning, I left it on the charger for a few more hours and the indicator light turned green, wow, like you said just a long charging cycle. Can anyone recommend a reasonably priced faster charger? I noticed battery space has some that are 3A and 6A rated. Is that safe for the battery?
    TIA
    andy
    Andy, what YetiB told you about the charger is spot on. About the 3 and 6A chargers...No, those are not for Li-ion cells. There are different hobby set-ups that can deliver a fast charge but they are somewhat expensive. The cheapest one I know that is set up to fast charge single 18650's is the Soshine SC-S2. Another place to buy one ( that has a U.S. plug ) is from China goods.

    Anyway, according to the Soshine web site the SC-S2 should charge a single cell in about half the time. Two cells charged at the same time take about another hour.

    With a fully depleted cell, my own cheapo D/X chargers usual take about 6 hours. With that said, slower is better for the cells. Still, if you plan to ride in a race and need to get the cells charged ASAP...a fast charger is a must have item in my opinion.

  5. #5
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    I am using a pre-assembled 3.7v 7.8Ah pack so it is 3 X 2.6Ah individual 18650s w protection circuit. The info on the batteryspace's website states the minimum Ah rating for the charger to be appropriate. They have 1.5A, 1.8A, 3A and 6A chargers. The 6A charger says it is compatible w/ all 3.7v packs w/ >6000mAh rating, so in theory it should be OK for my 7800mAh pack. The 3A charger is compatible w/ packs >5000mAh. Thoughts?

  6. #6
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    I'd personally get a good hobby RC charger (AC6 etc). Upfront cost is much higher (~$60) but once you have it you can charge, discharge, balance, storage charge any battery of any capacity you want. It's what I did and I haven't regretted it for a moment.

    If not, then always aim to charge batteries at 1C (capacity in A) or less. Ideally 1/2C, to prolong battery life. So, a 3Ah battery would be charged at 3A (1C) or 1.5A (1/2C). In your case a 3A charger should be fine, but consider what batteries you might get in the future (eg. smaller lighter ones for local rides), so a 1.5A charger might be more use in the long run.

    Or just get a hobby charger

  7. #7
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    Thanks Matt.......Again.
    andy

  8. #8
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    no worries

    actually, I'd recommend this one that Savageman put me on to. I bought it and a LiPo charging sack for $50 and I've been very happy with it.

  9. #9
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    chargers and more,..
    Hi Andy13, definitely don't want the 6A charger , to dangerous.
    also your pcb might not take it ether.
    for chargers, the hyperion chargers are decent.
    Fast Charging:
    - don't recommend it ,
    unless you got experience and safety
    unless you have balance port on the pack
    unless you have quality cells,

    the weakest link / cell , is how strong your chain is.
    usually , for the multi-cells, in parallel, you want to be lower , then the max charger for the single cell .
    what happens, ... if One cell stays low on the charge voltage,.... the other ones,
    get to much, as such , the good ones get over charged and blow, especially with higher current , aka fast charging.
    regular packs , still don't have temperature sensor,... so they still pump power in , even after the pack is to hot
    better chargers, most of the RC chargers, have also a max time setting, to cut off power, after set time, to avoid this ,..
    have a fire-proof, charging place, lipo-bag, flower pot, ceramic dish, pyrex, etc,
    a bucket of sand,...
    even with good RC chargers, or intelligent chargers , or protection circuit,...
    had one lipo out of balance, charged with 5A,... a 4S 4000mah,
    ended up with 3.83V 4.27V 4.32V 4.29V ,... scared me,
    the chargers, pump in the current, and maybe afterwards balance the pack.

    So, best, to have balance connector on pack, so you can check.
    If you don't have it now on the pack, be nice to add.
    for a 2S = 2 cell, you only need 1 extra wire, and they don't have to be together,
    you can have regular 2-pin power, just the extra pins for measure or balance.

    ... there is a reason, they sell slow chargers,....
    ---
    recommendations:
    - RC / processor controlled charger with USB port and balance port
    - balance port on every battery pack or adapter cable
    - pcb protection circuit on every balance pack
    - balance checker, to check batteries, without going through the charger
    - fire-proof charging place + bucket of sand ,..
    - quality cells
    - waterproof pack
    - battery enclosure, protect from impact and harsh environment, and fail condition.
    ---
    think you had a 0.5A charger ,..
    don't go over 2A (2.5A max) , this should solve your charge time.
    for more current, have a balance port, charger, etc...
    for 2 cells, Lupine has very good chargers, and you could check their charge times,...
    ---
    need help too ! connectors, 3-pin ,4-pin, 5-pin ,.....
    any recommendations !?
    for bike battery packs, don't like two connectors, so want just one.
    can live with an adapter for the LED lamp, but only one connector for booth,
    also easier to seal one than 2, and balance connectors, are kinda cheesy fragile,..
    any suggestions ? thanks, Rob mtbl.robs-x

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