Charging power is measured in kilowatts, and three things determine it: voltage, current in amps, and the number of phases. Voltage × amps × phases = power. The European grid supplies 230 volts per phase, so single-phase at 16A gives around 3.7 kW, while the same 16A across three phases gives 11 kW.

The four common AC configurations are 1-phase 16A (3.7 kW), 1-phase 32A (7.4 kW), 3-phase 16A (11 kW) and 3-phase 32A (22 kW). UK homes are single-phase, so 3.7 and 7.4 kW are the figures that apply on your driveway. The three-phase ratings belong to public posts and commercial premises.

Actual speed is set by the weakest link: post, cable and your car's onboard charger. A useful rule of thumb is battery capacity divided by charging power, so a 60 kWh battery at 7.4 kW takes roughly eight hours from nearly empty.

One detail worth checking on your own car: most 11 kW cars draw 32A on a single phase and reach 7.4 kW, but some are strictly 3×16A and stay at 3.7 kW whatever cable you fit.

Rapid chargers bypass the onboard charger and feed the battery with DC directly, which is how they reach far higher figures.