Why are there AC and DC chargers?
A charging hub at a motorway junction. Four slim AC charge points stand in the car park of the hotel next door, two large DC chargers by the slip road.
A service technician starts the monthly inspection. Both kinds of equipment charge the same cars.
The questionWhy do they look so different?
Guess firstA 300 kW DC charger and a 22 kW AC charge point stand side by side. Which one contains the larger power converter?RevealHide
The DC charger. The AC charge point contains no converter for the battery at all: the car converts the current itself, with its onboard charger.
- Gridalternating current
- Charge pointswitches and protects
- Onboard chargerconverts, in the car
- Batterydirect current
- Gridalternating current
- Chargerconverts to DC
- Car inletpasses it through
- Batterydirect current
The battery always stores direct current. The only question is where the conversion happens.
The converter moved out of the car
With AC charging, the in the car turns alternating current into direct current. It has to fit into the car, so its power is limited, often to 11 or 22 kW. For a car parked for hours, that is enough.
A DC charger carries the converter itself. Outside the car, it can be large, heavy and cooled, so the power can be much higher. The battery then sets the limit.
EU law draws the line at 22 kW: up to that, a charge point counts as normal power, above it as high power.
Most public charge points are AC, placed where cars park for hours; DC sits where time matters.
Each one where it fits
- AC charge points stand where cars park for hours: at home, at work, in town, at hotels. They are compact, because they contain no converter for the battery.
- DC chargers stand where stops are short: along motorways and in hubs. They bring the converter, the cooling and the grid connection for high power.
Where electric cars charge most often is the subject of eMobility and EV basics, stop 07.
Check your understanding
3 questions. Answer all of them to complete this stop. Each answer explains itself.
Where is the current converted during AC charging?
An AC charge point switches and protects; the onboard charger in the car converts the current for the battery.
Why can a DC charger deliver much more power than an onboard charger?
Size, weight and cooling limit what fits into a car. A charger standing outside has none of those limits.
From which power does EU law count a charge point as high power?
AFIR defines normal power recharging points as up to 22 kW; everything above is high power.
- Onboard charger The converter in the car that turns AC from a wallbox or public AC charger into DC for the battery; its rating limits AC charging power. eMobility and EV basics, stop 04 Glossary
- U.S. Department of Energy, Alternative Fuels Data Center: How do all-electric cars work?. https://afdc.energy.gov/vehicles/how-do-all-electric-cars-work. Checked 09 Oct 2026.
- EUR-Lex: Regulation (EU) 2023/1804 (AFIR), Articles 2, 5 and 20 and Annex II. https://eur-lex.europa.eu/eli/reg/2023/1804/oj. Checked 09 Oct 2026. © European Union, reused under Commission Decision 2011/833/EU.
- emobility.directory: Charge point operators in Europe, from national registries of 8 countries and OpenChargeMap; Switzerland, Greece, Luxembourg and Poland left out, data as of 28 Sep 2026. https://emobility.directory/. Checked 28 Sep 2026. Charging data: Bundesnetzagentur.de (CC BY 4.0); IRVE, transport.data.gouv.fr (Licence Ouverte 2.0); NDW (CC0); DGT (CC BY); Fintraffic / digitraffic.fi (CC BY 4.0); Via Lietuva (CC BY 4.0); NOBIL by Enova (CC BY 4.0); Open Charge Map contributors (CC BY 4.0), including public sector information licensed under the Open Government Licence v2.0; combined and calculated by emobility.directory.