A power management circuit for a battery cell is provided. The battery cell is coupled to a load through an output terminal. The power management circuit includes a current detection circuit, a loading determination circuit, and a voltage determination circuit. The current detection circuit detects a discharge current of the battery cell when the battery cell is discharged through the load to generate a discharge-current signal. The loading determination circuit determines a loading value of the load according to the discharge-current signal to generate a loading signal. When the battery voltage of the battery cell drops to the cut-off voltage, the power management circuit terminates the discharge of the battery cell through the load.