CONTROL UNIT, BATTERY PACK, AND POWER SUPPLY DEVICE

A battery indicator estimates a remaining battery capacity when a controller instructs a driving power source to start the power supply based on a battery voltage detected at a timing when the controller instructs the driving power source to start the power supply. The controller instructs the driving power source to stop the power supply after the discharge of a secondary battery by a charge-discharge circuit is ended and at a timing when a battery voltage being measured by a voltage measurer is stabilized.