The CyberPower BP240VL3U01 rack/tower convertible Extended Battery Module (EBM) extends UPS runtimes during power outages. Designed for select Smart App Online UPS systems, this EBM takes 3U of rack space and can be installed in a rack or tower configuration to match the UPS form factor. It also has a built-in battery charger, providing Fast Charge Technology to quickly restore the backup power supply from 0-90% in four hours. Up to ten EBMs can be connected in a daisy-chain to the UPS. The BP240VL3U01 typically has a UPS charging time of four hours regardless of whether one or ten EBMs are installed when Fast Charge is connected. The BP240VL3U01 is compatible with OL6KRT, OL6KRTF, OL8KRT, OL8KRTF, OL10KRT, OL10KRTF, and OL10KRTHW. With a three-year warranty, you can trust CyberPower's commitment to the quality of the BP240VL3U01. Easily replaceable by the user In terms of cost per watt hours, it is an inexpensive choice providing efficient power Power your UPS safely without causing hazards with 12 V DC battery