US Patent 7782015 Electric power system

A system and method produces electrical power for a load. First and second battery banks are provided, as is an inverter bank, which produces three phase. A switch alternately connects one of the first or second battery banks to the load and to the inverter bank with the other of the first or second battery banks being disconnected from the load and the inverter bank. A motor is connected to the output of the inverter bank. The motor drives an alternator bank, which alternator bank is electrically connected to, and recharges, the other of the first or second battery banks. A timer periodically alternates the battery banks between a load mode and recharge mode.