Deceased battery?

[rdrunr11]

I have been flying helis for about 4 months now and have recently started flying airplanes. On Saturday, I lost an airlane due to unknown circumstanses (lost radio contact is what it seemed like) and after organizing a search party, we did not find the aircraft. I searched for the past few days and just found it today, 60 feet up in a tree. After recovering multiple pieces (battery, esc, servos, receiver) I went home hoping the battery is still ok. It is a Tenergy 3s 11.1 v 2200 mAh lipo that I fly in my helis. Do you think the battery is still ok after 2 days in the elements? This is a GREAT battery which I usually get around 12 mins of flying time in my Blade 400 and TREX 450. I just checked the voltage with a meter and it reads 4.7v. I assume the battery is trashed but I wonder if there is a way to save it and if so, how do I recover the lipo.

I have a Thunder Power 1010c charger with corresponding balancer.

Thanks!!

[BikeNBoatN]

I think the two days exposed in the elements is the least of your problems. The bigger problem is that it was left on for two days, which discharged the battery way down to 4.7V. If you really know what you're doing, and you're really careful, there's a small chance you might be able to save a cell or two. But if you don't, it would be a whole lot safer to consider it dead and not fool with it anymore. Give it a salt-water bath and consider yourself lucky to have found the pieces.

BTW, if you were flying a TRex for 12 minutes, you were way over-discharging that battery, so it wasn't going to be long for this world anyway. :(

[rdrunr11]

Good news!!

I charged the battery on slow charge for 6 hours and it brought the voltage up to around 11.4 and then put it on my TP 1010c with the balancer and after another 2 hours, it shows full charge and correct balance. I flew it with the Blade 400 for 4 minutes and it held great. I charged it again and put 750 mAh back into it (I think I said that right), balanced it again while charging, and then had a 7 minute flight with it!! I think the battery will be ok!! Thanks for all the tips and advice!!

BTW. Many heli pilots that I fly with are getting 10 to 12 mins on the Tenergy battery. I can't get that fly time with any other battery though. I average 8 to 10 on all of my other packs. I charge and balance EVERY time with the above charger / balancer. Battery never gets hot, just barely warm. I am slowly replacing all my other packs with the Tenergy battery.

Ralph