Battery kit for APC Back UPS ES 350 replaces APC RBC29
APC Back-UPS ES Compatible Replacement Battery BE350G
Amazon.com: APC Back-UPS ES 350 BE350R Battery - Replacement UB1234 Universal Sealed Lead Acid Battery (12V, 3.4Ah, 3400mAh, F1 Terminal, AGM, SLA) - Includes TWO F1 to F2 Terminal Adapters - Also