APC UPS Battery Pack, for use with Smart-UPS SR1

The Schneider Electric Smart-UPS SR1 external battery pack (XBP) connects to select Schneider Electric Uninterruptible Power Supply (UPS) models. This Smart-UPS SR1 External Battery Pack provides extended protection to safeguard your computer and other valuable electronic equipment from utility power blackouts, brownouts, sags, and surges

The UPS and the external battery pack together provide continuous power from the batteries until utility power returns to safe levels or the batteries are fully discharged.
The external battery pack also provides extra protection while replacing the batteries in the UPS

APC Accessories