A battery protection circuit device, comprising: a first voltage divider circuit comprising a first resistor electrically connected between the positive terminal (C+) of a charger and a first node (m), a second resistor electrically connected between the first node and a first terminal of a diode, the second terminal of the diode being electrically connected to the negative terminal (C-) of the charger; a first FET having a drain terminal and a source terminal that are respectively electrically connected to a battery and the positive terminal (C+) of the charger to receive a charging current from the charger and supply the charging current to the battery, the gate terminal of the first FET being electrically connected to the first node, the first FET being turned on or off based on a magnitude of the voltage at the first node (m); a second voltage divider circuit comprising a third resistor electrically connected between the positive terminal (C+) of the charger and a second node, a fourth resistor electrically connected between the second node and a first terminal of a second diode, the second terminal of the diode being electrically connected to the negative terminal (C-) of the charger; and a second FET having a source terminal electrically connected to the positive terminal (C+) of the charger, a drain terminal electrically connected to the first node and a gate terminal electrically connected to the second node, the second FET being turned on or off based on the magnitude of the charging voltage of the charger, wherein each of the first diode and the second diode is a Zener diode connected in a reverse direction between the positive terminal and the negative terminal of the charger. a first voltage divider circuit comprising a first resistor electrically connected between the positive terminal (C+) of a charger and a first node (m), a second resistor electrically connected between the first node and a first terminal of a diode, the second terminal of the diode being electrically connected to the negative terminal (C-) of the charger; a first FET having a drain terminal and a source terminal that are respectively electrically connected to a battery and the positive terminal (C+) of the charger to receive a charging current from the charger and supply the charging current to the battery, the gate terminal of the first FET being electrically connected to the first node, the first FET being turned on or off based on a magnitude of the voltage at the first node (m); a second voltage divider circuit comprising a third resistor electrically connected between the positive terminal (C+) of the charger and a second node, a fourth resistor electrically connected between the second node and a first terminal of a second diode, the second terminal of the diode being electrically connected to the negative terminal (C-) of the charger; and a second FET having a source terminal electrically connected to the positive terminal (C+) of the charger, a drain terminal electrically connected to the first node and a gate terminal electrically connected to the second node, the second FET being turned on or off based on the magnitude of the charging voltage of the charger, wherein each of the first diode and the second diode is a Zener diode connected in a reverse direction between the positive terminal and the negative terminal of the charger.