I bought IB's last season. when I was returning to the RC racing. I didn't like the mess with those cells. 2 of 12 cells went dead after ~10-15 cycles. I don't remember having any problems like these when we had Sanyo 2000 mAh cells, we cycled them several times a day, several years and no cell venting. This season I decided to go with EP, as I read there that they are more stable. Got them from ProMatch.