I am having a similar problem. I have 3 batteries and many tanks. my ego type cheapo tanks work fine on my ego/510 batteries. I also have a Protank 3 and a Drunker tank. If I attached either of those 2 tanks to the ego batteries, the light on the battery flashes, which I assume is a short. sometimes if I back the topper off a turn or so, it will fire. this adjustment is super critical. there is only a very fine line where the tank will fire. Go to far and it wont work again. I just tried pulling the battery pin up. didnt make any difference. Any ideas? Makes no sense to me.