Lipo battery health can be a little mysterious, and seems unpredictable. I had some large ones die after on me recently after about 40 cycles, much too soon considering that they had not been severely mistreated and were a good brand. I suspect the reason they went bad prematurely was because I tend to charge batteries while they are fairly cold to the maximum voltage and then allow them to get warmer after they are fully charged. The temperature difference between my charging area and my car 50 degrees or more. It is common knowledge that temperature will affect battery output capacity during the flying phase, but you don’t hear very much about how temperature affects energy input capacity during the charging phase, or how the maximum safe charge level is affected by a battery temperature that has changed. I know there are some higher end chargers that can compensate for the ambient temperature during the charge, but I don’t have one. From now on, I think I will try to warm up my lipo batteries before charging them, then not let them get any warmer on the way to the field. Hopefully that will make them last longer.
If you want to dig deep into your Lipo battery’s health an article called, “What’s Really Going On Inside A Dying Lithium Battery” as well as this video about tracking your battery resistance may help remove some of the mystery.