Amazon.com: Apc Industrial Panel And Din Rail Ups With Standard Battery - Ups ( Din Rail Mountable ) - Ac 120 V - 325 Watt - 500 Va - Rs-232 - 1 Output Connector(S) : Electronics
Amazon.com: Replacement for APC Back-UPS CS 500 BK500 Battery - Replacement UB1290 Universal Sealed Lead Acid Battery (12V, 9Ah, 9000mAh, F1 Terminal, AGM, SLA) - Includes Two F1 to F2 Terminal Adapters
Amazon.com: PowerStar 12V 7.5AH Compatible with APC Back-UPS ES 500 VA, BE500C, BE500U UPS Battery : Health & Household