Wall charging station

Simple wall charging station with (covered) connection for type 2 charging plug

A wall-mounted charger for charging electric cars is called a wall charging station . Tesla called charging station or Wall Connector and BMW uses it as a term his word mark "wallbox" ( English Wall Box ). The wall charger is not only the connector for the charger cable and connect to the AC power grid is available as a wall outlet, but also additional functions, in particular communications to the current intensity, which otherwise in charging cables through an in-cable control box is provided (ICCB).

In contrast to charging stations , wall charging stations have a simpler structure with comparable technical functionality (only alternating current) and are designed for use indoors or in protected outdoor areas (carport). As a rule, they are not public and do not offer any payment options.

The term is not standardized and can cover the entire spectrum from the installation of a simple power socket in the garage to a networked charging connection that communicates with home and vehicle electronics. As a rule, the "wall charging station" provides a connection option in accordance with IEC 62196 for charging electric vehicles. This version is shown in the article.

Emergence

In all currently available electric vehicles (exception: factory Renault ZOE 2013 without ICCB cable ) the drive battery can be charged at "normal" low-voltage mains - domestic sockets. However, these can only transmit relatively little power (single-phase, 230 V / 10 A; 2.3 kW), which means that the charging process takes between 6 and 12 hours, depending on the battery capacity. With the Nissan Leaf , this charging option is therefore referred to as "emergency charging".

Another problem is that household sockets are not designed to be permanently exposed to very high currents for several hours. The CEE connectors according to IEC 60309 offer higher charging capacities . But because there are different CEE connectors (depending on the performance), older electric vehicles have to carry the appropriate adapter.

Various charging plugs have therefore been developed to simplify the charging process . In the EU, the type 2 charging connector, developed by the Mennekes company according to specifications from RWE and Daimler AG and presented in 2009, is introduced as the standard. Practically all wall charging stations sold in Germany have such a connection.

Wall charging stations are offered by accessory dealers, but they are also available directly as vehicle accessories from most car manufacturers.

Versions and connected loads

Wall charging stations have either a type 2 built-in socket for the vehicle-side charging cable or a mounted charging cable with a cable socket for the vehicle-side type 2 built-in plug .

The wall charging station serves as an interface to the upstream network installation and communication with the car. The box informs this of the current intensity with which the car can now charge from the existing power source. The charger is integrated in the vehicle when charging according to IEC 62196 Mode1-3. The wall charging station is therefore a very intelligent on / off switch with many security levels (“intelligent power switch”).

The smallest available wall charging station is connected on the mains side to the 230 V / 16 A “ household network”. These wall charging stations can only be charged in a single phase with up to around 3.6 kW, which results in a very long charging time. Although several car manufacturers only equip their electric cars ( VW E-Golf , BMW i3 ) with such a small charger for the lighting network as standard and many plug-in hybrids have built in these small chargers, the installation of such a wall charging station only makes sense if it can be ensured that no electric cars are to be charged with more powerful chargers in the future. Often the models of the charging stations are marked as "Eco" or "Basic".

Many wall charging stations for private use are connected to 400 V / 16 A three-phase current (11 kW maximum charging power). Almost every household has this connection option , as electric stoves , for example, also use this connection strength. A recharge with 11 kW allows charging times of one to two hours (depending on the size of the battery) with the appropriate charger. More powerful chargers are automatically throttled to this connection value accordingly. The simple structure of these wall charging stations is advantageous, as in addition to three-phase charging, the standard on-board chargers with 230 V (max. 3.6 kW) can be operated on one phase without any further protection.

Single-phase chargers with> 3.6 kW (6.6 kW / 7.4 kW) represent a special case. Since the distribution networks on the low-voltage level to the houses in the Asian and American markets in particular are single-phase, car manufacturers around the world often only use a universal charger installed. In order to be able to charge these electric cars more quickly, appropriately sized and secured supply lines are required. A stronger wall charging station for three-phase current is usually recommended, which then also provides a higher output on one phase. Legally, the network operators in Germany must observe the limits set by the network operators for unbalanced loads - from a technical point of view, charging is unproblematic.

Larger wall charging stations are connected to 400 V 32 A (22 kW) or 63 A (44 kW) and enable significantly shorter charging times if correspondingly powerful chargers are available (standard on Renault ZOE ). The performance of the built-in on-board charger ultimately determines the realizable charging capacity. The maximum achievable charging power is determined by communication between the electric car and the charger. Lower charging capacities can usually be selected in the settings of the electric car. The technical implementation with the more powerful components makes these wall charging stations more expensive.

Mobile type 2 charging box with setting options from 6 to 63 A mains current

Mobile charging box

Mobile charging boxes have been developed in order to be able to charge vehicles with type 2 plugs in addition to the charging options at charging stations using normal 400 V three-phase sockets. With the same functionality as a wall charging station, these offer the additional advantage of mobility through feet and a carrying handle and generally the option of setting the maximum power consumption according to the power source available. If the current setting on the charging box is too high and a correspondingly powerful on-board charger is used, the protection of the upstream installation would be triggered. With a lower setting, the on-board charger reduces the charging power accordingly, which increases the charging time required. This can be useful if other consumers are operated on the upstream (house) installation. In addition, a residual current circuit breaker (particularly safe: all-current-sensitive FI type B) can be integrated, which is part of the house installation in the stationary wall charging station. This provides comprehensive protection against electrical accidents . The mobile charging box has a type 2 socket on the car side for the standard charging cable. On the mains side, the connection to the power grid is established via a standardized CEE plug connection (mostly 32 A CEE plug). Using an adapter, all power connections (weaker than the speaker connection) can be charged. The number of possible usable charging points increases significantly as a result.

Approval process

Certain approval procedures may have to be passed through for the construction of wall charging stations.

Austria

In Austria there are various building and trade regulations that must be observed when setting up charging stations. A distinction is made between businesses and private individuals. The regulations are not the same in all federal states . Whether the construction does not require a permit, requires notification or a permit can also depend, for example, on whether the charging station is to be set up outdoors or in a garage or building , whether a foundation is required or what electrical connection power (maximum charging power) is sought.

literature

Klinger, Jürgen: Charging infrastructure for electromobility in the private and semi-public sector: selection, planning, installation. VDE-Verlag, Berlin, Offenbach 2018. ISBN 978-3-8007-4417-6 .