New LiPo defective
12-14-2011, 07:41 AM
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New LiPo defective
I received 2 ea. 2650 mah 4S 25C (Nano-Tech) batteries from Hobby King. I had the batteries stored for about a month waiting for an ESC and motor to arrive. I tried charging the batteries last week. One is fine; the other however will not get above 15.2 volts. Cell # 3 reads low, about .5v to 1.5v lower than the other cells while charging, balancing, storing, discharging, whatever, it's low. I have read that there are some ways to possibly get it going. I think I have tried everything in the normal method with no results. (discharging to 12V, charge at .2 amps, balance or store at very low rates and etc.) I have a safe metal can for charging so anything I do can't make it worst. It's not useable now.
Naturally they did not warranty it.
Any thoughts?
Thx
[&o]
Naturally they did not warranty it.
Any thoughts?
Thx
[&o]
12-14-2011, 07:50 AM
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RE: New LiPo defective
Isolate the low cell and charge it at .5C. Check it frequently to avoid overcharge. If you can get it to 4-4.2 volts, discharge it to 3.7v using again a .5 C rate and bring it back the average pack voltage; then cycle the whole pack and see what happens.
In my experience this rarely works, but every once in a while I can save a bad pack this way. I've never tried it on Nano-tec cells.
Walt
In my experience this rarely works, but every once in a while I can save a bad pack this way. I've never tried it on Nano-tec cells.
Walt
12-14-2011, 08:19 AM
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RE: New LiPo defective
Chop out the bad cell and use as a 3cell. You will need to replace the balcance lead with a 3cell one. It is for this reason that when my packs die (naturally or otherwise!) Ichop all the leads off and keep them.
You are probably better getting another pack- think hobbyking do warranty these for a month after they ship them, so you gotta be quick as you end up with a week to test them (also I think you have to add their serial number somewhere on their site. I'm in Scotland so they never arrive in time for me!)
Good luck
You are probably better getting another pack- think hobbyking do warranty these for a month after they ship them, so you gotta be quick as you end up with a week to test them (also I think you have to add their serial number somewhere on their site. I'm in Scotland so they never arrive in time for me!)
Good luck
12-14-2011, 03:19 PM
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RE: New LiPo defective
Two of four lipos I just bought from HK were defective... See this link for the thread I just started..
http://www.rcuniverse.com/forum/m_10859628/tm.htm
http://www.rcuniverse.com/forum/m_10859628/tm.htm
