The Basement Watchdog battery is designed for standby use and will remain viable for 5 to 7 years. Special materials allow the battery to last for more years. More plates equate to longer run times. Accommodates battery fluid sensor included with all Basement Watchdog systems. The most common failure for other backups is a dead battery resulting from depleted water levels. Batteries are shipped dry. Vacuum sealed, bone dry batteries remain fresh until activated, this way the customer will always get a brand new fully charged battery. Batteries that are shipped wet can only sit on the shelf for several months before they begin to prematurely lose capacity. Makes shipping to the store easy and cost effective. Dry batteries are not considered a hazmat item. 6 quart acid battery pack sold separately, see Model No. ACID 6-QUART (SKU 453307).