Please check the operating frequency of the electrical devices before using P2001. If the frequency does not match, it may pause P2001 discharging. Frequency switching operation methods: Option 1, long press the AC button for 3 seconds, the 50Hz or 60Hz icon on the screen starts to flash, short press the AC button to select the 50Hz or 60Hz frequency, after selecting the appropriate frequency, the icon flashes for 3 seconds and stops, indicating that the switch is successful. Option 2: Use the standard home wall outlet to charge P2001 once, and it can automatically adjust to the output frequency of the wall outlet. The output voltage of the P2001 AC port is 100V-120V. Press the AC button 10 times in succession to switch the AC voltage between 100V and 110V.