PFPower's BATT1500-EXT Battery Pack offers extended run-time for the F1500-UPS. This 2RU battery pack aesthetically matches the F1500-UPS and can be rack or tower mounted. The heavy gauge power cord is adapted with plug-n-play DC connectors for easy installation. The all metal enclosure safely houses the 8 (eight) 12V 9Ah batteries which are connected via 2 strings of 4 in serial. 19 in W x 17 in D x 4 inH. Weight 67 lbs.