This on-line, double-conversion central inverter provides computer grade power quality for any lighting system, including incandescent, magnetic and electronic fluorescent ballasts, high power factor compact fluorescent, high intensity discharge (HID), high pressure sodium (HSD), and metal halide (MH). In the event of an AC power failure, the Staco Energy Products Co. FirstLine 924 automatically transfers to battery power, providing a continuous power supply for 90-minutes. When power returns, the FirstLine 924 automatically recharges the batteries in preparation for the next power disturbance. A front panel LCD includes two by 24 character display which shows system status and alarms. The user-friendly control panel located on the front of the freestanding NEMA 1 enclosure allows remote monitoring through an RS232 connection.