In various embodiments, an electronic device may include: a connection terminal configured to connect to an external power supply device; a switching circuit including an input terminal connected to the connection terminal, a first output terminal, and a second output terminal; a first battery and a second battery connected to the power supply device in series through the first output terminal and physically separated from each other; a charging circuit configured to adjust a voltage or a current of power received through the second output terminal and output the adjusted voltage or current to the first battery and the second battery; a monitoring circuit configured to monitor a voltage of the first battery and a voltage of the second battery; a protection circuit configured to monitor a current charged to the first battery and a current charged to the second battery and to suspend charging of the first battery and charging of the second battery; and a processor connected to the switching circuit, the charging circuit, the monitoring circuit, and the protection circuit, and connected to the power supply device through the connection terminal. The processor may be configured to: control the switching circuit to connect the input terminal to the first output terminal or the second output terminal; select one of the first battery and the second battery as a first sensing object based on data indicating the voltage of the first battery and data indicating the voltage of the second battery, the data being received from the monitoring circuit; output a first control signal causing suspension of charging of the first sensing object to the protection circuit on the basis of a result of monitoring of a current output from the first sensing object; select another one of the first battery and the second battery as a second sensing object based on the suspension of the charging of the first sensing object; and output a second control signal causing suspension of charging of the second sensing object to the protection circuit based on a result of monitoring of a current output from the second sensing object.