What do Mode 2, Mode 3 and Mode 4 mean for EV chargers?

The modes are defined by the IEC 61851 standard and describe how the vehicle connects to the power supply and what protection exists along the way. There is also Mode 1, a direct connection to a socket with no communication, which is essentially no longer used for cars.

• Mode 2: charging from a standard Schuko or industrial socket, with a cable that has a built-in control and protection box. From a household socket the power is low, so it suits mainly occasional use.
• Mode 3: AC chargingGlossary · EV chargingAC ChargingCharging with alternating current, where the vehicle's on-board charger converts it to direct current to fill the battery. from a fixed station, such as a wallbox or a public AC charger. The station communicates with the vehicle and supplies power only when the connection is correct.
• Mode 4: DC fast chargingGlossary · BatteriesFast ChargingA charging method that restores battery capacity quickly without damage by controlling current, voltage and temperature., where the charger is inside the station and the cable is permanently attached to it.

Mode 2 protects the user, but it relies on a household socket that is not designed for a continuous load over many hours. The common mistake is charging every day with a Mode 2 cable from an old socket or an extension lead, where the contacts may overheat. For regular home charging, the right solution is a Mode 3 wallboxGlossary · EV chargingWallbox (home wall charger)A wall-mounted EV charger that charges with AC from its own circuit in the panel and communicates with the vehicle for safe charging. on its own circuit from the distribution board, with suitable protection.