BATTERY POWER SUPPLY DEVICE AND POWER CONTROLLING METHOD FOR SAME

A battery power supply device is provided. The battery power supply device includes: an input unit that receives external power; a battery power unit that is connected to the input unit to charge a battery with the external power; a current detection unit that detects a current that is supplied to a load and that provides the current to the battery power unit; and an output unit that provides the external power and battery power from one node to the load and that receives a load current from the battery power unit to adjust output of the battery power.