by kaptain_zero » Sat Mar 10, 2012 5:09 am
No cell should be discharged below 3 volts for sure.... ( I can't remember the exact number). Do not let a battery sit at that voltage for any length of time or it's toast for sure. I would attempt to charge it carefully... if it comes back, you may be OK.
I have a battery tester/amp meter that tells me the current state of charge and the voltages of each cell and it can also balance a pack for me by simply discharging the high cells until they match the lowest voltage one. Of course the pack needs to be at a reasonable charge rate first, for this to work.
You should know that chargers such as the accucell 6 can only deal with a somewhat out of balance battery. If there is a large difference between some cells, it would take a very long time for such a charger to bring the cells back into balance because of the way it works.
I would try to save that pack and see if it behaves normally after that but if it keeps loosing charge on that one cell... it's toast. If it's toast, I would connect something like a brake light bulb or some similar load to the main connector, place it outside on a concrete surface or some such and let it go until the battery is completely dead and then you can safely toss it in the trash or send to to your local recyclers. Of course, if you purchased the battery locally, I'd take it back and see if they won't replace it as it would obviously be defective. If you bought from places like Hobby King, you got it so cheap that it's not worth the effort to try and get a replacement under warranty.
Don't leave any cell in your pack drop below 3V for sure (I try to avoid going below 3.5V myself) and don't leave your packs fully charged for more than a day or so.... keep them at the storage charge of about 3.8V per cell.
Bruce just released his lipo video on Youtube, check it out.
Christian
"I'd like to live as a poor man with lots of money."
-- Pablo Picasso