APC RBC133 Battery Cartridge, part# 911-0133
Compatible w/ SMT1500R2-NMC, SMT1500R2X122, SMT1500R2X180, SMT1500RMUS
Condition: 2x New In Box, 1x New but taken out of the box
Price: $40 new in box, $25 no box
https://excessups.com/apc-911-0133-compatible-replacement-battery-cartridge
https://www.apc.com/us/en/product/APCRBC133/apc-replacement-battery-cartridge-133-with-2-year-warranty/