Abstract: A charger in the form of a primary switched rectifier and transformer charges a battery and carries a load when the operating voltage is available to a sufficient extent. When a voltage drop or break in voltage automatically disconnects the battery from the charger, the load is supplied with voltage from the battery. The battery voltage is chopped into square wave form and transformed up via the secondary side of the transformer to the voltage required for the load. A diode is connected between the load and the battery allowing the battery voltage to act directly on the load as long as this voltage is sufficiently high.