APC BACK-UPS RS BR900 900VA/540W UPS System (Discontinued by Manufacturer) Output Power Capacity: 540 Watts/900 VA Nominal Output Voltage: 120V Output Connections: 3x NEMA 5-15R (Surge Protection) Audible Alarm: Alarm when on battery; distinctive low battery alarm; configurable delays Typical recharge time: 8 hours