Amazon.com: Replacement Battery for BACK-UPS CS 350 BK350 - UB1290 Universal Sealed Lead Acid Battery (12V, 9Ah, 9000mAh, F1 Terminal, AGM, SLA) - Includes TWO F1 to F2 Terminal Adapters - CP1500AVRLCD :
APC Back-UPS CS 350VA, 120V, 6 NEMA outlets (4 surge) - BK350 | APC USA