POWER SUPPLY FOR BATTERY PACK

The present disclosure relates to a power supply (100) of a battery pack. The power supply (100) may include: a first battery (120); a second battery (130); a DC/DC converter (150) for converting a first voltage output by the first battery (120) into a second voltage; a controller (110) for using the second voltage as an operation voltage; a relay (140) connected between the first battery (120) and an input terminal of the DC/DC converter (150) and controlling an electrical connection between the first battery (120) and the input terminal of the DC/DC converter (150); a first switch (SW1) connected between an output terminal of the DC/DC converter (150) and a coil (141) of the relay (140) and controlling an electrical connection between the output terminal of the DC/DC converter (150) and the coil (141); and a second switch (SW2) connected between the second battery (130) and the coil (141) and controlling an electrical connection between the second battery (130) and the coil (141).