We could start by modifying the charging line. Fast charging is conditional, one is the output voltage and current size of the USB, one is the charging voltage of the mobile phone battery and the maximum charging current size to be consistent. The cell phone battery cannot be changed, only from the charging power supply to change. However, the existing 36VUSB does not change, and can only be achieved by installing a step-down current limiting resistor on the charging line according to the voltage and charging current of the mobile phone battery.