METHOD AND APPARATUS FOR PROVIDING UNINTERRUPTIBLE POWER

An uninterruptible power supply for providing power to a load, including a bypass input selectively coupled to the output to provide output power from a bypass power source, the uninterruptible power supply being arranged in a bypass mode of operation to control an inverter circuit to convert AC power from the bypass power source at the output of the inverter circuit to DC power at the input of the inverter circuit, further comprising a battery charger coupled to the input of the inverter circuit to receive DC power and provide power to charge the back-up power source in the bypass mode of operation and a power supply separate from the battery charger and coupled to the input of the inverter circuit to receive DC power and arranged to provide DC power to components of the uninterruptible power supply in the bypass mode of operation.