Hi Mark,
I second what the others have said. Our batteries are very reliable. I have been flying electric planes for the past several years, hundreds of flights, and I have never had an in flight battery failure. I have blown up one battery due to a charger malfunction, and I have ruined one when I dropped it on a cement floor, it hit on it's corner (battery swelled up, not good, ..... dumb, and dumber ;-)
Here is a better example of reliability. When I fly at my club field in Las Vegas I get to fly with my friend Mark Leseberg. He flys his 37% IMAC planes with electric power, while we fly ours with gas engines. BTW: Mark's elec. flys just as good as our gas planes, his 3D flying is amazing. He has never had a battery fail in flight, and his batteries work harder than ours do. We turn 32 x 12 props! I'm sure Mark flys over 1,000 flights each year, and most of them are electric.
As Alan said, we should be really babying these things @$200 ea. ! Like most of the guys, I always use a balancer, and the TP data port feed back system, and keep a flight log of every flight, and every battery's charge info. from each flight. ..... I also mount my batteries surrounded by rubber matting material, under the Velcro, to help protect them during the shock of my landings. ;-)