When using a car to charge the device, the output voltage must be 12.2V-50V. When charging with a voltage higher or lower than this range, P2001 will automatically protect from charging, the LCD screen has no power display, and the charging voltage exceeds 50V When the device is broken down, it will cause the damage and P2001 cannot work. The voltage of common cars is 12V, and the truck is 24V. The charging current of 12V-16V car charging mode is 8A, the maximum power is 100W, and the current is greater than 8A, and the device is automatically protected. Note: Only charging P2001 when the car engine is working for avoiding the car battery being depleted and unable to start the car.  The charging current of 16V-24V car charging mode is 10A, the maximum power is 240W. If the current is greater than 10A, P2001 will be automatically protected. Note: Only charging P2001 when the car engine is working to avoid the car battery being depleted and unable to start the car.