RE: Marine Battery
11. HOW LONG WILL A DEEP CYCLE BATTERY LAST ON A SINGLE CHARGE?
Discharging, like charging, depends on a number of factors such as: the initial state-of-charge, depth-of-discharge, age, capacity of the battery, load and temperature. For a fully charged battery at 70° F (21.1° C), the ampere-hour rating divided by the load in amps will provide the estimated life of that cycle. For example, a new, 72-ampere-hour battery with a 10-amp load should last approximately 7.2 hours. As the battery ages, the capacity is reduced.