6 May 2026

Single-phase or three-phase? Choosing the right charging power

3.7, 7.4, 11 or 22 kW: the numbers are simple arithmetic, the choice depends on your fuse box, your car and how long the car sits still.

The power figures are not marketing but arithmetic: voltage times current times the number of phases. One phase of 230 volts at 16 amps delivers around 3.7 kW, at 32 amps around 7.4 kW. Three phases at 16 amps deliver around 11 kW, at 32 amps up to 22 kW. Which of those four you get at home is set by the weakest link in the chain: the grid connection, the circuit in the fuse box, the charger and what the car itself accepts on alternating current.

That last limit is forgotten most often: many cars charge at a maximum of 11 kW on AC, and some models no more than 7.4 kW. A charger that can do more than the car accepts does not charge faster — you pay for capacity that stays unused. So first check the AC charging specification of your (upcoming) car before choosing a charger; an installation quote with advice is free and without obligation.

Then the fuse box. For 11 or 22 kW you need a three-phase connection plus a heavier dedicated circuit; on a single-phase connection it stays at 3.7 to 7.4 kW. If your box has no room or no three phases, a fuse box upgrade or extension (€ 350-950) is the first step — and note: upgrading the grid connection itself goes through the grid operator, with its own rates and lead time, outside the installer's quote.

The sober question is: how much hurry does the battery have at night? A car that sits at the charger from evening to morning also adds a solid share of battery at 3.7 kW — roughly 150 to 200 kilometres of range in a night, depending on your car and consumption. If you drive average distances, single-phase is often simply enough and you can keep the upgrade money in your pocket. If you drive a lot, the car sits still briefly or a second EV is coming, three-phase at 11 kW is the future-proof choice. Set both variants against the price index and have the installer calculate during the survey what your situation really needs.