Myers Model MBSP 12 Volt Battery Standby Pump System, 30 GPM The Myers® MBSP battery operated back-up sump pump is designed to back up primary residential sump pumps in case of pump or power failure. A must for those installations where an inoperative sump pump can not be tolerated. Separate float switch and built-in alarm automatically starts back-up system and activates warning buzzer to protect against high water damage and warn of primary pump failure