I've been getting the check battery message in my mod, changed the battery a couple of times and it worked for a couple hours each time. Had a pain in the face with it so bought another kit. I dunno why but I much prefer the tank in my original one (the one that says check battery). I put the tank from original one onto new mod and puff the check battery message pops up on my new mod. Maybe it was never the battery could it be the tank?? Has this happened anyone else?