Best practice storing any of our lights to best protect the Li-Ion batteries inside is to do two things:

  1. Charge them fully - you can leave them on the charger indefinitely if you like, the light will protect itself and prevent overcharging, can sit there plugged in forever OR you can charge them fully, then unplug them and leave them off somewhere. Leaving them at low state-of-charge is the single most effective way to kill a Li-Ion battery of any kind. Full charge is the way to go.
  2. Keep them in consistent temperatures - basically just avoid large temperature swings, for example don't leave them in a garage that gets below freezing in the winter and 100 degrees in the summer, as that can fatigue batteries. Keeping them indoors where you maintain reasonably consistent temperatures is good.