AC / DC charging – What is the difference?

The famous hard rockers in the band AC-DC had a good reason for choosing their band name, because the punchy letters are actually the abbreviations for direct and alternating current. Even though the musicians certainly electrify fans, the notion of AC-DC is particularly relevant when it comes to charging electric cars. We explain what the terms mean and how the whole thing relates to charging stations.

What is AC / DC?

AC is the abbreviation for alternating current. DC stands for direct current. Alternating current (AC) changes its polarity at regular intervals. This means that the current changes direction 50 times a second.
In contrast with alternating current, direct current (DC) is constant and only flows in one direction. Its polarity remains the same.
Alternating current comes out of household sockets. However, since batteries store direct current, the alternating current must first be converted into direct current for charging electric cars.

What kind of charging stations are available?

Electric cars should be charged at charging stations in order to be charged quickly. For this purpose, there are AC charging stations (standard charging stations), where charging occurs with a charging power of up to 22kW, and DC charging stations (rapid charging stations), where charging can be carried out using power of over 22kW.

AC charging stations emit alternating current. This is converted to direct current in the car. DC charging stations transform the alternating current through a rectifier that is already present in the station and then pass on direct current to the battery. DC charging stations have a much higher power output than the car’s on-board units, so they can be used to charge much faster. However, rapid charging is usually associated with higher costs and is mainly used in public places, such as motorway service stations. For this reason, DC charging is recommended for long journeys with only short stops. AC charging is well suited when parking for longer 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. Rapid charging stations (DC) are compatible with CHAdeMO or CCS plugs as well as the Tesla Supercharger.

More exciting eMobility facts can be found in our knowledge portal, the reev Hub.