How long is the typical shelf life of an unused backup battery?Adam
An unused solar backup battery can last well over a year if properly taken care of. Like any battery, one that is left depleted will eventually lose its ability to hold any charge at all. To combat this it is strongly recommended to use a trickle charger to slowly keep a battery charged part way to full. This should be done as often as possible but at minimum once a month to help ensure the life of the battery stays as long as possible.