1. Check the power environment: Ensure that the power socket is stable during charging, without looseness or unstable voltage, as voltage fluctuations may cause abnormal sounds from the charger.
2. Check the connection between the charger and the battery: Confirm that the charger is firmly connected to the electric vehicle battery, and poor contact may also be one of the reasons for the noise.
3. Check the inside of the charger: If all the above are normal, it may be due to loose or faulty internal components of the charger. Stop using it and contact the manufacturer or professional maintenance personnel for inspection or replacement.