Battery kit for APC Smart UPS 1500 replaces APCRBC133
How To Replace & Upgrade Your APC Smart UPS Battery
Amazon.com: APC UPS Battery Replacement, RBC7, for APC Smart-UPS Models SMT1500, SMT1500C, SMT1500US, SUA1500, SUA1500US, SUA750XL and select others, Black,1 Count (Pack of 1) : Electronics
Amstron Replacement Backup Battery for APC RBC55 (Blue Connector)
APC Replacement Battery Cartridge 6 UPS battery 1 x battery lead acid black for PN SMC1500IC SMT1000I AR SMT1000IC SUA1000ICH 45 SUA1000I IN SUA1000J3W SUA1500J3W - Office Depot