had the same problem yesterday, center pin nonsense. again. last time managed to lift it and was fine but yesterday all went to hell and now that battery is in pieces waiting to be built into another tube with a spare 510 connector i had lying around. but enough about my woes, have also read about people using a small o-ring to wedge it under the pin to lift it. didn't work for me. my idea that i want to ask about is this : could a small copper disc be soldered to the top of the ego type
batteries center pin? or just a blob of solder stuck on there and sanded flat? seems to me if the center pin keeps on falling down, leave it and build up from there?