APC BACK-UPS CS 500 BK500 Battery - Replacement UB1280 Universal Sealed Lead Acid Battery (12V, 8Ah, 8000mAh, F1 Terminal, AGM, SLA) - Includes TWO F1 to F2 Terminal Adapters : Amazon.ca: Health
RBC2 Battery Replacement for APC BackUPS CS500 - YouTube
APC Back-UPS CS 500 | eBay
Battery kit for APC Back UPS ES 500 replaces APC RBC30