What is a DC and AC current

AC / DC charging - what's the difference?

The famous hard rockers of the band AC-DC did not choose their band name for nothing, because behind the sweeping letters are the abbreviations for direct and alternating current. Even if fans can be electrified by the musicians, the AC-DC issue is especially important for charging electric cars. We clarify what the terms are and how it all relates to charging stations.

What is AC / DC?

AC is the abbreviation for Alternating Current and the English name for alternating current. DC stands for Direct Current and is the equivalent of German direct current. Alternating current (AC) changes polarity regularly. That means the current changes direction 50 times a second.
In contrast to alternating current, direct current (DC) is constant and only flows in one direction. The polarity remains the same.
Alternating current comes from German household sockets. However, since rechargeable batteries store direct current, the alternating current must first be converted into direct current for charging electric cars.

What kind of charging stations are there?

To make things happen quickly, electric cars should be charged at charging stations. There are AC charging stations (normal charging stations), which can be charged with a charging capacity of up to 22kW, and DC charging stations (fast charging stations), which can be used for charging with a capacity of more than 22kW.

AC charging stations emit alternating current. This is converted into direct current in the car. DC charging stations transform the alternating current through a rectifier in the station and then pass on direct current to the battery. DC charging stations have a much higher performance than the on-board devices of the car, so they can be used to charge a lot faster. Fast charging is usually associated with higher costs and is mainly used in public spaces, e.g. at petrol stations on the motorway. For this reason, DC charging is recommended for long journeys with only short stops. AC charging is well suited if you park for more than 20 minutes.

Which plugs fit which stations?

Normal charging stations (AC) can be used with household plugs (Schuko), CEE, Type 1 or Type 2 plugs. Fast charging stations (DC) are compatible with CHAdeMo or CCS plugs as well as the Tesla Supercharger.

There are more exciting eMobility facts in our knowledge portal, the reev Hub.