I think I know the answer but just wanted to confirm my battery status. One of my original Mavic batteries is about 15 mos. old. It has been charged about 60 times. The voltages seem good and the cells are within +/- 0.02 volts of each other during the entire discarge cycle. On this battery, the membrane on the bottom of the battery is puffing out slightly. You can feel it as it is slightly inflated. I tested on a short flight today at about 93 deg.  and I landed with about 40% of the battery remaining. I immediately brought the battery inside and the bottom is puffed out even more and is not squishy at all as it seems to be pressurized. It looks as though the bottom is puffed out beyond the plastic housing. As it cools, the swelling goes down somewhat but is still quite evident. I fear this battery will fail, or expand enough to unseat it from the clips in the aircraft.

I have another battery of the same age and charge status that is ever so slightly puffed up and is barely noticeable.  Funny thing is, these both started displaying this on the same day. Do you think these batteries are trash?

P.S. I have had LiPo batteries in cell phones that have been charged every day and have lasted at least 2 years, some 3. What's the difference here?

have you tried running them down to below 8% and then fully charging them up and see if it makes a difference, doubt it but wort a shot.

Suren Posted at 2018-6-2 12:12
have you tried running them down to below 8% and then fully charging them up and see if it makes a difference, doubt it but wort a shot.

No, I have not. I guess I was assuming the blowing up was a failure mode and was a little wary of doing this, Do you think this would let the pressure go down?