The 5 Minute Quick Guide of Electric Car Charging

Driving a car is a comfortable way of getting around: just get in and drive off. This also applies to electric cars. A major difference between burners and electric cars, however, is the shop, here come to the electric car driver a few special features. Different connector types, charging power and charging times - eco mento has teamed up with The Mobility House, an expert in charging infrastructure, to summarize the key points.

With what maximum charging power can I charge?

The maximum charging power of an electric car basically depends on three factors: the charging power of the electric car, the charging station, and the charging cable. How quickly loaded determines the weakest component.

The biggest factor: the charging technology

Basically, a distinction is made between direct and alternating current. The difference is important because electric cars store only direct current (DC) in the battery. Almost all sources of energy that we encounter in everyday life (household and industrial sockets as well as most charging stations) give off alternating current (AC).

Charging, therefore, requires the conversion of alternating current into direct current - and there are two possibilities: either the onboard charger in the vehicle (AC charging) takes over the conversion into direct current and charges the battery. Or the rectifier in the charging station (DC charging) converts the power directly and then charges the battery of the electric car. Depending on the type of charge, the connectors also differ.

AC charging

Each electric car is capable of being charged with alternating current. The vehicle's onboard charger converts the alternating current into direct current. Depending on the charger installed, the AC charging capacity may vary. A VW e-up! For example, it only charges 3.7 kW, whereas a current Renault ZOE charges up to 22 kW and is recharged much faster. To secure and communicate with the vehicle you now need an AC charging station. This ensures usually at home or in semi-public places (company premises, parking garages, etc.), a safe and comfortable charging of electric cars. The connector types in the overview:

DC Download

Some electric cars have a faster alternative to AC charging: the DC or DC charging station. The electricity is charged directly into the battery. The expensive and heavy rectifier is installed directly in the charging station. These so-called fast charging stations allow high charging power. For example, up to 50 kW for the Nissan LEAF, up to 70 kW for the Hyundai Ionic and currently up to 120 kW for Tesla. However, DC charging stations are significantly more expensive than AC charging stations and are therefore used mainly in public areas. The plug types for fast-charging stations in the overview:

Which other factors influence the charging performance?

In addition to electric car and charging station, there are other factors influencing the maximum charging power. The battery management system always monitors the temperature of the battery. If this is not optimal, ie too low or too high, the charging power is reduced to protect the cells. This plays a big role in winter. We, therefore, recommend always to charge directly after a long drive and not just the next morning with a cold battery.

Another influencing factor is the battery charge level (SoC - State of Charge). The fuller the battery, the slower it will charge. The 80% rule serves as orientation: Until then, the electric car will charge with high charging power and then reduce it successively. This is similar to filling a glass of water. In the beginning, you can pour heavily, but the fuller the glass, the amount must be reduced, so that nothing overflows.

How long does a charge take?

The duration of a charge depends on two factors: the maximum charging power (kW) and the battery capacity (kWh). If you divide the capacity by the charging power, you get the approximate charging time in hours. The actual charging process usually takes a little longer, because the charging power is reduced as already mentioned with increasing charge level. Almost all vehicles indicate the remaining duration of the charging process in the info display or via the app.

Charging time (4 h) = battery capacity (85 kWh) / charging power (22 kW)

With this basic knowledge, you are well equipped for electromobility. Even easier is the understanding if you just tried it. With more than 25,000 public charging points, experimenting should not be too difficult.