Abstract: A battery charging system includes a first battery charger configured to charge a first battery, a second battery charger configured to charge a second battery, a third battery charger configured to charge a third battery, a first switch circuit configured to open and close an electrical connection between the first battery and the second battery, a second switch circuit configured to open and close an electrical connection between the second battery and the third battery, and a system controller configured to control operations of the first battery charger, the second battery charger, the third battery charger, the first switch circuit, and the second switch circuit. During a charging mode, the system controller is configured to open, by the first switch circuit, the electrical connection between the first battery and the second battery and open, by the second switch circuit, the electrical connection between the second battery and the third battery.