mmmm, strange that i have yet to have any problems with atty's yet. I have big chuck at 3.7 now, but batteries and charger on way for 6v.
I got in a bind before owning my chuck and waiting on it---i had a hastily put together lightvapor that fell apart (my bad=as my mod building was sloppy). Anyway, basically trashed it.
I got couple of wire and soldered to connector from Radio shack, attached atty, a 901, cart and then just was touching wire to one of those big 6v flashlight batteries. Man, that was some vapin. Lot hotter inhale and throat, lung hit. Big vapor.
Even with that, atty's holding up to the punishment.
However, I did fry 2 of them when not paying attention when i laid it down and left the wires touching the battery contact. Once even the cart started to melt.
Everyone who saw me with the wires and that big battery sure thought it was funny.
Hope my luck keeps up.