Amazon.com: Beiter DC Power APC-UPS Backups RS1500 These Batteries are High Performance, Rechargeable (2)12V9ah Replacement for APC RBC109 : Automotive
Amazon.com: POWERSTAR Replacement Battery for Compatible with APC Back-UPS RS 1500 - Pack of 2-3 Year Warranty : Electronics
APC Back-UPS Pro 1500VA 10-Outlet/2-USB Battery Back-Up and Surge Protector Black BN1500M2 - Best Buy