The APC by Schneider Electric Smart-UPS RT external battery pack, the SURTA48XLBP, connects to the APC by Schneider Electric Smart-UPS RT uninterruptible power supply (SURTA1500XL and SURTA2000XL, or SURTA1500XLJ). Together these units provide extended protection against blackouts, brownouts, sags and surges reaching your computers, servers, and other sensitive electronic equipment.