System requires a 12-volt battery. Sealed Lead Acid (SLA), deep cycle marine, or automotive style batteries can be used. A tether switch is included in the system and will automatically start the pump when power or the main pump fails. Removes up to 2880 Gal per hour. 40 VA charger maintains battery with computer controlled 2-step charge for improved charging performance. Audible alarm alerts homeowner that the back-up system is operating. LED on control box indicates battery condition. Includes tethered float switch.