The principle of the charger 12V\/24V switching is to detect the voltage of the battery through the electronic control unit (ECU), and then adjust the output voltage according to the voltage value. When the battery voltage is detected as 12V, the charger outputs the charging voltage as 12V; When the battery voltage is detected to be 24V, the charger outputs the charging voltage at 24V. This can be adapted to different types of vehicles and batteries for efficient charging.