Couple of notes about batteries, chargers, and LR atties.
LR atties and cartos do not always play well with protected 14500 and smaller batts. They seem to trip the discharge protection on the circuit. This is why IMR batteries are usually recommended for LR applications, they have a higher C rating and can handle the additional current required to effectively operate LR atties/cartos.
IMR batteries have a lower internal resistance than standard LiIon batts, some chargers can overcharge them because of this, have a multimeter handy and check them often when they come off the charger. My AW IMRs come off my TR-001 at 4.21v every time, the safe limit on them is 4.25v.
That being said, don't leave batteries on the chargers once they are fully charged, you can reduce the chance of an event happening this way.
IMR batteries are LiMn chemistry batteries, they less volatile than LiIon batteries and don't require a protection circuit.
That being said, if abused, mishandled, misused, over charged or over discharged any battery can fail and possibly experience thermal runaway, leading to venting (the expulsion of hot gasses.)
Treat all batteries with respect, and only use them for their intended purpose...oh and for the love of all that is great about vaping and particularly mods...make sure there are vent holes in your metal mods...you don't need to be holding a grenade under your nose if anything bad were to happen.