Charging electric cars: Everything you need to know

25. Apr 2023 | Industry + More

It is well known that electric vehicles can be charged at various locations, such as at home, at public charging stations or at quick-charging stations along motorways. During this process, electrical energy is transferred from the mains to the vehicle's battery via a plug connection.

Charging at home: Socket or wall box

A household socket is probably the easiest and most cost-effective way to charge an electric car. Here, the car is connected to a normal protective contact socket via a cable. However, this charging method is relatively slow and there may be problems with overloading the power grid. The charge loss is also quite high.

The wall box is a faster and safer option that was specially developed for charging electric vehicles. The wall box is usually installed by an electrician and is connected directly to the power supply. It offers a higher charging capacity and is safer than a household socket. It can also be connected to smart home systems to enable the charging process to be controlled more intelligently.

If you want to charge your electric car at home, you must, of course, have an adequately secured power supply at the charging location. Before buying an electric vehicle, it is important to learn about the specific requirements to ensure that charging at home can be carried out safely and efficiently.

Public charging stations and quick-charging stations on motorways

How the charging process works

With the wall box, for example, alternating current (AC) flows first, which is converted into the direct current (DC) required for the vehicle by the electric vehicle charger. The direct current then flows into the vehicle battery.

The battery management system of the electric vehicle monitors the temperature and charge level of the battery during the charging process. When the battery is almost fully charged, the battery management system reduces the charging speed to prevent the battery from overcharging. The charging curve decreases the closer the battery is to being fully charged. The charging process stops automatically when the battery is fully charged. With some electric vehicles, the charging capacity and the desired state of charge can also be set. On the motorway, for example, it makes sense to only charge in the area if the highest charging capacity is available.

The charging time depends on various factors, such as the battery capacity, the charging capacity of the charging station or wall box, the battery type and the temperature. The higher the charging capacity of the charging station or wall box, the shorter the charging time of the battery. Some electric vehicles have a quick-charging function that can be used to charge the battery in a short time.

The matter of the plug

Unsurprisingly, public type 2 charging stations have a type 2 charging socket. This is an internationally standardised plug used for charging electric vehicles with alternating current (AC). These charging stations, which are often found in public places such as parking spaces, supermarkets, petrol stations and other strategic locations, offer electric vehicle owners a convenient way to charge the vehicle while they do other things.

Most public type 2 charging stations can be started and stopped with an app or an RFID charging card, in rare cases only one of these two functions may be available. Newer charging stations can also be activated with a bank card or credit card, but in this case, higher amounts are often blocked and billing takes place later accordingly.

Electric car drivers need to carry their own charging cable for these charging stations, as charging cables are not permanently mounted on these stations. Don't worry, the charging cable cannot be stolen: The cable is protected against unauthorised removal while the vehicle is charging.

In Germany, only new electric vehicles with a CCS connection are now launched on the market. CCS stands for Combined Charging System, which is an international standard for charging electric vehicles with direct current (DC). The CCS system combines a type 2 plug for charging with alternating current (AC) and additional contacts for charging with direct current, so that an electric vehicle can be charged at a CCS fast charging station with a single connector. The vehicle can communicate with the charging station via the additional contacts.

CHAdeMO stands for "Charge de Move". CHAdeMO is a Japanese standard for charging direct current electric vehicles (DC) and is used by some car manufacturers, particularly Nissan and Mitsubishi. In contrast to the CCS system, ChaDeMo uses a separate plug for charging with direct current. A type 2 charging socket is provided on so-called "triple chargers", in addition to a CCS and a ChaDeMo charging cable.