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  1. #1
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    The battery has no power

    Hi, I recently purchased three new 5000 mah NiMH batteries for my slash 2X4 but i ran into a little problem. I have two stock chargers that came with my two slash 2X4's. i plugged in all of the batteries into the two chargers and everything was fine. i had used the batteries and chargers a couple times before and they were fine until yesterday. One of the batteries was plugged in to the charger for a long time and the light on the charger was still red so i unplugged it and put it in my slash 2X4 to see if it would work but it didn't have enough power to move the car and the whole system just shut down after 10 seconds, so i plugged in the battery that was left over into the same charger thinking that it was the first battery that was the problem, but the same problem happened so i was almost positive that it was the charger that was the problem. I threw away the charger because i had another one and i knew this charger was working fine because the charger light turned green and it worked on my car perfectly.so i hooked up one of the batteries that were not working to the good charger and the light stayed red and the same problem happened for both of the bad batteries. But I know that the charger works fine because my other battery that was hooked up to it is working. So is it possible that the bad charger damaged and permanently ruined the two batteries?

  2. #2
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    What are the voltages of the batteries?
    Whatever it is I just said... I could be wrong.

  3. #3
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    they are 8.4v

  4. #4
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    Is that the measured voltage, or the voltage printed on the pack.
    Guide books aren't part of the packaging.

  5. #5
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    printed on the battery

  6. #6
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    I am currently in India so i dont know where i could find a voltage detector so i cant measure the voltage of the batteries sorry

  7. #7
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    Measuring voltages is how we can tell the health of the pack.
    Whatever it is I just said... I could be wrong.

  8. #8
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    With the batteries being new did you do a forming charge first.
    This is where you charge at 1/10C, for you would be 500mAh or 0.5A, Then let cool down.
    Then discharge at 1C or less until you get 1V per cell, in your case 7V. Then Let cool down.
    Repeat the process 2 or 3 times.
    Having a volt meter would be much easier to determine what's happening.
    Guide books aren't part of the packaging.

  9. #9
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    ok so if i have a lower voltage than 8.4 on the bad battery does it mean that the battery is broken?

  10. #10
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    I did not do a forming charge first i did not know we had to do this for new batteries

  11. #11
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    It's not required as it's normally done at manufacture. But if they have been stored, it should be done when they're bought. This gives the best performance out of the batteries.
    On low draining devices it may not be needed.
    But for power hungry equipment what we use, it is best to do that.

    But I have had a multi chemistry charger ruin two nimh packs with only 2 or 3 charges on each battery.
    Guide books aren't part of the packaging.

  12. #12
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    o okay thank you for the advice. I will try to find a voltage detector this weekend but i am not sure what to look for with the voltage detector, Are the bad batteries supposed to have very low voltages and the good battery 8.4's?

    sorry for all these questions i am only 13 and i do not have that much knowledge in all this electrical stuff

    Thanks

  13. #13
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    Under 0.9-1.1V per cell you start to damage the battery, or one of the cells. It's been a long time since i used nimh's.
    A voltage meter would look like this Click.
    You don't need an expensive meter or an accurate one, they'll all do what you need to test the battery.

    There is two must have tools for RC too keep everything running happy is, a multi meter and a temperature meter. Click
    Again doesn't need to be super accurate. We use a safe measurement for example 150 if the temp is 5 out, that's ok, because the limit is higher anyway. But it gives you a good figure to aim for.
    Last edited by trax de max; 11-07-2013 at 09:02 AM.
    Guide books aren't part of the packaging.

  14. #14
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    ok thank you

  15. #15
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    so i got my hands on a voltage detector and i was surprising. One of the two bad batteries had a voltage of 8 volts and the other bad battery had a voltage of 8.4 volts but the battery that works had a voltage of 9.6 volts (the good battery was charged if that changes anything?)

  16. #16
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    The charged voltage should be at least 9.8V. but i'm confused why the three measurements for the two batteries.
    Guide books aren't part of the packaging.

  17. #17
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    He has three measurements for three batteries.

    The two "bad" ones could probably be saved with a good charger... wall wart chargers are not good chargers.
    Whatever it is I just said... I could be wrong.

  18. #18
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    i just purchased a Traxxas 2933 EZ Peak plus 6 amp charger. is this good enough to save the two bad batteries?

  19. #19
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    it is going to arrive in 3 weeks

  20. #20
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    It may just do the trick. Do a little reasearch on form charging... that process may save the packs. All it is (I think) is a slow discharge followed by a slow charge a few times... just double check to make sure.
    Whatever it is I just said... I could be wrong.

  21. #21
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    ok thanks for all the help. but one last question, is there a certain way to discharge the batteries?

  22. #22
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    The RC will work... wire the voltmeter in parallel with the battery to watch voltage. Usually sticking the probes in the wire side of the battery connector works well.
    Whatever it is I just said... I could be wrong.

  23. #23
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    okay thanks

  24. #24
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    I lost track how many batteries was involved. Been a busy day.
    Guide books aren't part of the packaging.

  25. #25
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    haha thx for the help anyway

  26. #26
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    I have a question, how can you tell if a charger is not working because i tested the voltages on the bad charger and the good charger but they were turned out to be the same. any ideas?

  27. #27
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    Even if the voltage are the same on both chargers, It's how they detect a full battery that could show a bad charger. The easiest way is to just, charge a used battery up check the voltage of the battery. Then use the battery again and then charge with the other charger again checking the voltage of the battery. The more batteries you have the better information you have when you check the voltages of the battery for each charger.
    Write down the pack voltage on some paper and tape that paper to the charger so they don't get mixed up.
    Guide books aren't part of the packaging.

  28. #28
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    okay i get it thanks

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