Wallbox 11 kW or 22 kW: which one is right for you?

Wallbox 11 kW and 22 kW compared

An 11 kW wallbox charges at three-phase 16 A, a 22 kW wallbox at three-phase 32 A, so twice as fast if the car accepts the power. The calculation is simple: energy divided by charging power gives the charging time.

If you come home in the evening and leave in the morning, you often have ten hours or more. In that time even large batteries are full again at 11 kW.

Why the car's on-board charger decides

When charging with alternating current, the charger built into the car (on-board charger) determines how much power actually flows. Many models are limited to 11 kW. ADAC points out that not all vehicles support the higher charging power, in which case a 22 kW wallbox brings no benefit.

Check "AC charging power" in your car's specifications. If it says 11 kW or less, an 11 kW wallbox is the right choice, also for your next car as long as it charges at 11 kW too.

Registration: notification up to 12 kVA, approval above

Under § 19 of the German Low Voltage Connection Ordinance (NAV), all charging equipment for electric vehicles must be reported to the grid operator before it is put into operation. If the total rated power exceeds 12 kVA per electrical installation, the grid operator's prior approval is also required. The operator must then respond within two months of receiving the notification.

What counts is the total, not the individual wallbox. Two 11 kW wallboxes on one house connection add up to about 22 kVA and therefore need approval, just like a single 22 kW wallbox. Double garages and families with two electric cars should plan for this from the start.

§ 14a EnWG: what controllable means

Wallboxes with a connected load above 4.2 kW that went into operation since 1 January 2024 count as controllable consumers. According to the Federal Network Agency (Bundesnetzagentur), the grid operator may reduce their consumption to as little as 4.2 kW when needed; this minimum must always be available.

In return grid fees are reduced. There are three options:

• Module 1: a flat reduction of 110 to 190 euros a year depending on the grid area, according to the Federal Network Agency (as of 2023).
• Module 2: a percentage reduction of the grid energy price; requires a separate meter.
• Module 3: time-variable grid fees since April 2025, only in combination with module 1.

Cable and residual current protection

Every wallbox needs its own circuit with overcurrent protection and its own residual current device. Under DIN VDE 0100-722 this is at least a type A RCD combined with disconnection for DC fault currents above 6 mA, or a type B RCD. Many wallboxes already have the 6 mA detection built in.

If you install 11 kW now and may switch to 22 kW later, the cable and protection can be sized for 32 A from the start. That saves a new cable run later, but the grid operator still has to approve 22 kW.

When 22 kW is still worth it

A 22 kW wallbox makes sense mainly where vehicles must be ready again quickly. ADAC names workplaces with electric vans or company cars as a typical example.

• The vehicle has a 22 kW on-board charger.
• Parking times are short, for example for care services, trade businesses or delivery vehicles.
• Several vehicles charge one after another at the same charging point.

Whether an 11 kW or 22 kW solution suits your house depends on the house connection and the meter cabinet. What a wallbox installation in Neuss includes is summarised on our service page.