Charger makes loud clicking, buzzing, or humming noises during operation.

Safety first: Turn OFF power before opening the charger. Do not touch internal components when energized.

• Identify noise source: Stand near the charger and note whether the noise is a single click (normal) or continuous buzzing/humming (abnormal).
• Check mounting: A technician should open the unit and verify that the main power contactor, transformer/inductors, and mounting brackets are tight.
• Inspect contactor: If the contactor chatters (rapid clicking), the coil may be undervolted or failing; the technician should test coil voltage and replace the contactor if needed.
• Monitor operation: If the noise is minor and no overheating or errors occur, it may be acceptable. However, increasing noise or any burning smell requires immediate shutdown and inspection.