I use a Triton Jr. charger with a cheap RTF balancer and store them in a .50 cal ammo box.
I am working on a heat activated Co2 dispenser for The box as well
Best to store them at a storage charge only (learned at the cost of 3 batteries). They will not last if stored fully charged or fully discharged.
The danger of fire or explosion does not exist except when charging or discharging unless you puncture
the battery or expose it to severe physical trauma.