I had my 14500 high drain battery in my pocket today (never had a problem w/ them loose like this) but somehow the battery made contact with the change in my pocket and my pants almost caught fire (no joke). I felt the heat and started emptying my pocket rather quickly...all my money and my battery were ultra hot. Thought I had ruined my AW IMR but it was fine- charged up to 4.29 volts aftewards!! Anyway, this is a lesson learned. Either put your batteries in a plastic bag or get a case for them- don't carry them loose with your change- they or you might be in for a huge, bad surprise! No joke!