The largest and most powerful Basement Watchdog battery. This standby battery will last longer and perform better than automotive or deep-cycle batteries when used with a battery backup sump pump system. Unique construction allows it to run the sump pump longer (for more hours per charge) and to last from five to seven years in standby service. The only brand that accommodates the battery fluid sensor, which is an important feature of the Basement Watchdog battery backup sump pump systems. Will run the Basement Watchdog A/C-D/C system and the Basement Watchdog Special up to 7.5 hours continuously, and will run the Basement Watchdog Emergency system 12 hours continuously. It's shipped without acid to remain fresh until you activate them. Filling it is done easily and safely with a 6-qt. battery acid pack (sold separately).