We've all been brought up in this hobby that once a LiPo has been drained below a certain voltage (3.0v - 3.5v), we may as well throw it away. I've always found this to be true (more or less). I recently left a battery plugged into a plane (absent minded) for almost a week. When I remembered where it was, I got it and tried to measure the voltage with my LiPo checker. The battery couldn't even power it up. The screen was blank. I bought two of these batteries and the "dead" one was slightly soft but not puffy while the "good" one was like new (firm). As an experiment, I decided to see if this "dead" LiPo could be brought back. I had nothing better to do. I put it on my charger (picture of battery and charger below - disregard what the display says as I'm charging other batteries for tomorrow's flying) and selected NiCAD. It defaulted to 1A charging and NiMH. I fired it up and monitored it for about 20 minutes as I watched the meter show the amps being added. It would not allow me to plug in the balance port, so left it unplugged. I took the battery off to check the volts. One cell read 1.0v while the other two were up to just under 3.0v. I put it back on, trying to bring all the cells to at least 3.7v. When that happened (the low cell was at 3.7, the others were just under 4.0v), I reverted back to LiPo balance charging at 0.5A and plugged in the balance port. Slowly, the 3 cells balanced and when it reached about 3.9v/cell, I charged it the usual way at 0.85A. All 3 cells reached 4.19 - 4.2v/cell. The softness remained the same. I've since used it for a flight in the intended plane and it flew just like it always did and was the same as the other battery of the same brand and size. I'll be very interested to see if this once dead battery will last the same as the other one that I bought at the same time for the same planes. Whodda thunk?
Had lunch with another flying buddy whose cousin left a battery (1300mah, 3s) in his plane for 3 months. He was about to throw it away but he'll give it to me next time we meet and see if that one can be resurrected. That will be an interesting experiment, too.
Had lunch with another flying buddy whose cousin left a battery (1300mah, 3s) in his plane for 3 months. He was about to throw it away but he'll give it to me next time we meet and see if that one can be resurrected. That will be an interesting experiment, too.
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