Charging is very slow compared to expected rate, but no error codes are shown.

Safety first: Do not increase current settings beyond the rating of your electrical installation.

• Check configuration: Use the Mercedes-Benz wallbox app or internal selector to verify the maximum current setting. Adjust only if your circuit and cable are rated for the higher current.
• Review load management: If connected to a home energy management system, check whether other loads are causing the wallbox to reduce current.
• Measure actual current: An electrician can measure the charging current on each phase to confirm the wallbox is delivering what it advertises.
• Environmental factors: Ensure the wallbox is not overheating due to direct sun or poor ventilation, which can cause automatic derating.