What should you do if you plan on storing your device for an extended period? The normal instinct is to full charge the device, but I've found that only charging it up partially – around 50 percent – is the best way. Storing a battery in the discharged state can push it to the point where it won't recharge, and storing a battery fully charged can shorten its life.
Long-term storage is best done as close to room temperature as possible. So avoid really cold rooms or keeping the device next to a radiator.