AC charging — the slow kind, and the one you use most
AC charging supplies alternating current that the car's onboard charger converts to direct current; it is limited by that converter rather than by the wall.
A fast charger does the conversion itself and pushes direct current straight into the pack, which is why it can be so much quicker. A home wallbox or a public post does not: it delivers alternating current, and the car has to convert it with hardware it carries around.
Why it matters when buying
The consequence is that the car, not the installation, usually sets the ceiling. Paying for a three-phase supply achieves nothing if the onboard charger is single-phase, and this mismatch is the most common wasted expense among new electric-car owners.
Three-phase supply is normal in domestic housing across most of continental Europe and rare in others, so the value of a three-phase onboard charger is genuinely market-dependent — the same car is a better or worse buy depending on the wiring in the country it is sold in.
Since the overwhelming majority of charging happens at home or at work overnight, this unglamorous specification affects daily life more than peak fast-charging power, which most owners meet only on long journeys.
Related: onboard charger · CCS2 · V2L
Updated Aug 21, 2026