I would agree that if all of them have failed, there is something in common with all of them that is causing the failures (whether it's the charger or something shorting on the vehicle). I have been using Lectron lipos and I had one puff up on me after only a few uses. I contacted Lectron about it. Not to complain, but to try to understand what I did wrong for that one to fail but not the others. They said it was likely a manufacturing defect and replaced it. However, having all of yours fail, that's not likely to be a manufacturing defect.