The Zoeller DC emergency pump system requires a good quality, 12 volt battery to obtain maximum pumping time during a power outage. A deepcycle, 12 volt, 105 amp-hour marine battery or larger is recommended and will provide approximately 7� hours of continuous pumping time in a sump pump installation with 8' of head pressure. In most installations the pump runs intermittently and the battery life is extended accordingly. Batteries with top terminals are recommended for ease of installation.