There are many posts about battery failures but none of them seem to reflect the issue I am having, so here goes: I have a battery that has 45 charges on it. All cells are equal an look good. Occasionally, and that is the key here...occasionally, this battery drops from 20% to 5% instantly. Not all the time, but just sometimes. The battery has been calibrated from 100% to shutoff, then recharged to 100% on several occassions. It has not gone through the auto discharge function. So when I fly with this battery, I don't really do anything because I fear it will screw up on me under a normal flight. So the $200 battery is basically useless. Does anyone have a clue as to why this may be happening? Is it happening to others? I typically I fly with 5 batteries and this is the only one that shows this erratic behavior.