Tripp Lite's BP240V400 External Battery Pack offers extended battery runtime when used in conjunction with compatible Tripp Lite UPS systems. Requires BP240EXTNDR15A to connect to UPS. Cabling for additional battery packs is contractor supplied.COMPATIBLE UPS SYSTEMS: SU20K3/3, SU30K3/3 and other Tripp Lite UPS systems specifying the use of this battery pack- Offers extended-run UPS operation when used in conjunction with compatible Tripp Lite UPS systems- Multiple battery packs can be daisy-chained through each other to the UPS for even longer extended run operation- Internal DC disconnect- 10 year design lifespan