Hey,
I'm fully aware of the dangers of opening up a lipo.
I know that it might be safer to render it inert in saltwater and throw it away.
I understand that sometimes, charging a dead cell at 10mAh, might bring it back to life.
Any ideas on the best and safest way to do this?
Thanks,
DS
Replies
This really blows my mind. For what these batteries cost now a days, I can't fathom why someone would do this. Congratulations, you saved $50 on your $1000+ aircraft plus your house and family when it comes to charging and storage.
Thanks for all your tips, advice and concern.
Fly safe.
Step 1: Dispose of the battery properly.
Step 2: Order a new battery.
I can't see any reason at all why you would risk trying to recover a battery that has been damaged like this. It will eventually fail and you'll lose much more than the battery.
It seems more likely that zero volts is a wiring/connection problem than a dead cell. Dead cells generally read some abnormally low useless voltage. Not zero volts.
Yes, It's 0.0 and I tried the NiMh method, and the remaining 4 cells all charge fine.
Just have to figure out how to charge that cell with 10mAh only. And Safely.
Charge just that cell through the balancing plug :-)
Thanks...
So V+ on the balancing wire, and - on any ground?
Find the 2 balancing wires that are in each side of the cell in question. Make a cable that connects the + side of the cell to the + main port of the charger and the same for - . Charge as 1S with a low current.
A cell that has been completely discharged can be recharged. However it will never perform very well any more - internal resistance will have increased a lot. Lets hope that really is was just a balancer wire broken (happens often) that gave a false reading. Else the best solution is really to discharge the other cells to normal-empty (3V or so) for safety and then remove the dead cell from the battery.
Follow up:
Thanks for all your suggestions, very helpful. I ended up discovering that the cell in question was dead. I desoldered it from the pack for a charge attempt and it would not hold.
Thanks Søren, I removed the cell and turned my 5s into a 4s.
Note: I covered any exposed contacts with electrical tape to insure I would not accidentally short out the contacts during desoldering and voltage testing. Since I did the work inside my home workshop, I taped a 3 foot emergency carrying cord to the entire lipo pack and had my short escape route to the outside brick patio planned, (6 feet from my workbench), just in case the situation became inflamed.
In the early days of lipos, before balancing, I came home to my garage and there, on the cement floor, was black soot marks, extending a few feet in all directions, where my charging lipo had been.
Thanks and stay safe.
D
Hi David,
There is a way I have tried many times and it works! In such a situation, charge your LIPO under a different mode combinations with your Lipo charger. For e.g. charge under NiMH or NiCad or LiFe, etc. If your charger complaints try a different mode under your charger. (I used the standard Turnigy Accucel 6-charger from Hobbyking).
Use a lower voltage to charge with a low current. When the voltage comes up to about 2.8V per cell - switch back to LIPO charging for getting the 3.3V nominal voltage. If you battery has touched 0.00V/cell, it may have reduced lifetime of the battery by a bit - but that depends on how fast/ slowly you got it there. You can try the above procedure and report if that worked for you!
Good luck!
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