Amazon.com: APC RBC110 UPS Compatible Battery : Health & Household
Amazon.com: RBC110 Compatible Battery Replacement for APC RBC110 by UPSBatteryCenter : Electronics
Mighty Max Battery 12V8AH for ES500 ES550 ES750G LS500 RBC110 PX12072 Rechargeable Sealed Lead Acid 1280 Backup Power Batteries in the Device Replacement Batteries department at Lowes.com