The APC Back-UPS Pro External Battery Pack consists of a unit of four 9Ah batteries that plugs into the rear panel of the 1500VA Back-UPS Pro model. The 1500VA Back-UPS comes with two standard 9Ah batteries. To triple the normal amount of runtime provided by a Pro unit, connect it to an RS Battery Pack. The battery recharges automatically through the unit's internal charger.
Reviewed by 2 customers
Makes a great product even greater. If you've already purchased the UPS, and need to add capacity, the External Battery Pack is a good solution. You keep the value of your earlier purchase, while getting the capacity increase you needed.
BOUGHT MY FIRST EXTERNAL BATTERY FOR MY SECOND APC PRO 1500. WORKS LIKE A CHAMP. I LIKE THE GREATER BACKUP TIME I GET.