This text is machine translated.
Useful information about charging stations, charging stations for electric cars
Those who think about electric mobility and want to buy an electric car must also think about the charging possibilities. Because there is no e-mobility without energy from the socket. But charging an electric car is absolutely no problem if basic things are taken into account. We will tell you why the power from the charging station is better for your car than the power from a 230 V mains socket.
-
What was an electric car charging station?
-
Why is a charging station or Wallbox required?
-
Which charging methods are differentiated?
-
How does a charging station work?
-
How to mount a charging station?
-
How is a charging station connected to the vehicle?
-
The smart charging station for taking along
-
Charge the electric car with solar power
-
State subsidies for charging stations
-
Frequently asked questions about charging stations Electric cars
What was an electric car charging station?
A few years ago, electric mobility and e-mobility were still in their infancy. But electric vehicles are now on the rise worldwide. Thanks to continuous further development, electric cars have enough energy to cover more and more distances with a battery charge.
But at some point the largest battery is exhausted and has to be charged. No owner would like to park his brand new e-car in a remote parking lot. Even if there is a free charging column for electric vehicles. No, the vehicle must also be able to be loaded on the company premises or in the domestic garage.
This requires a powerful charging station. In English, a private wall charging station for electric vehicles is also referred to as a "Wallbox", "Wall Charging Station", "Home Charging Station" or "Wall Connector". However, regardless of the name, the task is always the same: Wallboxes are the transfer point from the energy network to the electric vehicle.
For charging power above 3.7 kW, it is no longer recommended to simply connect or disconnect the connection plugs under load. Therefore, the charging station checks whether the electric vehicle is connected correctly and only then releases the voltage at the output. This ensures that the charging process is carried out with the greatest possible safety.
Electric cars with quick tank stop at charging stations.
Why is a charging station or Wallbox required?
Wall charging station with charging cable for domestic use.
The battery of an electric car has a considerable capacity, otherwise the current running performance of modern electric cars would not be possible. If such a high-capacity vehicle battery is completely empty, it could accept a very high charging current.
The socket as a power source would be quickly overtaxed. For this reason, the charging current must be adjusted or limited. However, the charging current should be high enough so that the electric vehicle can be used again quickly. On the other hand, the mains supply or the domestic electrical installation must not be overloaded.
The amount of current ultimately provided to the eMobil depends on which power connection is available. If the charging station is supplied with only 230 V AC, it can deliver far less power than if it is supplied with 400 V three-phase current over three phases.
A small example of calculation for illustration:
An electric vehicle requires approx. 15 to 20 kW per 100 km range. With an average charging power of approx. 10 kW, it takes about 2 hours to "fill up" electrical energy for 100 km range. If the charging is only done with approx. 3 kW, you need about 6 hours for the same amount of energy.
This shows that in order to recharge a car in a practical period of time, it is necessary to have a charging capacity of well over 3.7 kW.
As a result, a wallbox is required that can safely provide the vehicle with the required charging power. However, the Wallbox is not the charger! The actual charging process with the help of a charger takes place inside the vehicle.
Which charging methods are differentiated?
There are several ways to charge an electric vehicle. With the different charging concepts, it is crucial which voltage or power source is available. It is charged via alternating current (AC) or direct current (DC) with different power ratings.
Charging with alternating current
Earthing contact socket-outlet with 230 V AC current.
Alternating current is available at any standard household mains socket. However, with only one phase with 230 V and max. 16 A the power is max. 3.68 kW.
What was enough for household appliances like coffee machine, iron or fan heater, was rather weak for an electric car.
Depending on the capacity and charging status of the battery, the charging process takes ten or even more hours. If the vehicle is safely parked overnight in the garage at home, this is not necessarily a big problem.
Charging with three-phase current
CEE socket with 400 V three-phase current.
For domestic use, a charging station connected to three-phase current is the better solution.
In contrast to an alternating current with only one phase, 3 phases are available for three-phase current.
With a load capacity of 32 A per phase, this results in a calculated charging power of 22 kW.
This reduces the charging time considerably and the vehicle is ready for use again after a short time.
Some vehicle manufacturers often provide their vehicles with an in-cable control box (ICCB in Cable Control Box), in order to be able to charge the vehicle to a mains socket even outside the domestic garage or beyond the public charging columns in case of an emergency.
Charging with direct current
When charging with direct current, the charger is installed directly in the charging column. The charger is supplied either from the mains or from buffer batteries of a solar system.
In order to use this charging procedure, a DC connection must be provided on the electric car. The battery management in the vehicle then communicates with the charger in the column via the charging cable. Thus, the current strength can be adjusted perfectly and a switch-off takes place when the battery is fully charged.
With the direct current charging, charging power is possible far beyond the 22 kW and the charging times are very short. However, the prices of the DC charging stations are extremely high, which is why they are rather uninteresting for private use. Where fast charging with direct current makes sense, however, is on public charging columns such as on the highways. Here, the latch can be used immediately, in order to recharge the vehicle battery completely in less than an hour. But also for companies, quick-charge columns are a quite interesting investment. Especially when the purchase of electric vehicles is planned.
Important!
When charging with alternating and three-phase current, the charger is located in the electric car. For this reason, it is important to know exactly how high the charging capacity of the integrated charger is. If the vehicle can only cope with 7 or 11 kW of maximum charging power, it makes little sense to install a charging station with 22 kW or more.
How does a charging station work?
The maximum charging current depends on the power connection.
When installing a charging station on alternating or three-phase current, the maximum permissible current is set in the Wallbox.
The maximum amount of current depends on the performance of the electrical connection and not on the requirements of the electric vehicle.
This information is transmitted to the charger in the vehicle during the charging process. The charger in the vehicle then adjusts the charging current so that the electrical installation of the power connection is not overloaded.
The charging station uses current transformers to record and check the current current value. If it is too high, the charging station can interrupt the power supply for the charger in the vehicle.
In order for the charging station and the charger to interact in the vehicle, the charging cable contains two additional connection lines called CP (Contact Pilot) and PP (Proximity Pilot or Plug Present).
By changing the resistance at the PP connection, the charging station detects the connection of the charging cable to the electric car.
The respective states for the charge enable are detected via resistance changes on the CP connection.
At the same time, the charging station emits a pulse-width modulated signal at the CP connection to transmit the maximum permissible charging current to the charger in the vehicle.
The two smaller contacts of the charging plug are for CP and PP.
Other special functions
, since the charging station continuously records the current consumption, faults and malfunctions can be detected immediately. In extreme cases, the charging station interrupts the charging process and disconnects the electric car.
Likewise, the charging station can also guarantee the access authorization of the users. This can be implemented by means of a key switch, pin code or RFID technology. However, comprehensive evaluations for energy management or real-time monitoring are also possible with many charging stations.
How to mount a charging station?
Define the installation location
The charging station must be in direct proximity to the vehicle.
Suitable installation sites should therefore be chosen preferably in the garage. In outdoor areas, a charging station must withstand the weather conditions. Therefore, the weather-protected area of a carport is recommended.
For completely free-standing charging stations, the IP degree of protection must be correspondingly high.
Electric connection
If the installation location is fixed, the electrical connection must be made. In many cases, this is a massive interference in the electrical installation. Therefore, the installation must be carried out by an electrician who is familiar with the relevant regulations and procedures.
No additional loads or sockets may be connected to the power line that leads from the fuse box to the charging station. In addition to the necessary cable routing, a line fuse (LS switch) and a residual current circuit breaker (FI switch type A EV or type B) must also be installed. If the charging station already has a DC fault current sensor, a standard fault current switch (FI type A) is completely sufficient.
Important!
If a charging station has more than 12 kW charging capacity, a permit from the network operator must be obtained prior to installation or commissioning.
Programming the charging station
Many charging stations have extensive setting and programming and reading options.
The correct setting is just as important as the professional connection to the mains.
This is the only way to ensure that the electric vehicle is quickly charged without overloading the electrical installation.
How is a charging station connected to the vehicle?
There are different plug systems for the charging cables, which have become more or less well established depending on the manufacturer and country. For this reason, before purchasing a charging column or a charging station, you should find out which charging plug is required for your vehicle.
Type 1 charger plug
The Type 1 charging connector is widely used in Asia and North America.
The charging plug with its five contacts is designed for charging power up to 7.2 kW.
For trucks sold in Germany with type 1 plug system, a connecting cable is usually included, which is suitable for charging stations with type 2 plug-in socket.
The type 1 charging plug has 3 large contacts, which are assigned phase (L1), neutral (N) and earth (PE). The two smaller contacts are for the signal lines CP and PP.
Type 2 charger plug
The type 2 charging plug has established itself in Europe.
The connector, also known as Mennekes plug, is supported by all major car manufacturers in Germany.
The maximum charging power for private wall boxes is 22 kW, with public charging stations transmitting up to 43 kW.
The type 2 charging plug has 5 large contacts that are assigned to phases L1, L2 and L3 as well as the neutral conductor (N) and the protective conductor (PE). The signal lines CP and PP are connected via the two smaller contacts.
CCS plug
The Combined Charging System connector is a further development of the Type 2 charging connector. Two additional contacts in the lower section of the plug enable quick charging with direct current (DC+ and DC-).
The charging socket on the vehicle is designed in such a way that either type 2 charging plug or CCS plug can be connected. The CCS2 plug has now become established in Europe. In the USA the combination CCS1 is used, in which a type 1 charging plug with DC contacts is extended.
Fast charging stations with CCS connections support a charging capacity of up to 125 kW.
Mode 2 charging cable
A Mode 2 charging cable is often included with the electric vehicles and enables the charging at a commercially available 230 V mains socket.
However, the charging times are correspondingly long. The communication with the charger in the vehicle is carried out by a control box (ICCB in Cable Control Box), which is integrated in the cable. This ensures that the charger in the electric car does not overload the power supply.
Mode 3 charging cable
To connect the vehicle to a public charging station, a Mode 3 charging cable is required.
An integrated control box (ICCB) is not required because the charger communicates directly with the charging station in the vehicle.
Mode 3 charging cables are equipped in Europe with two type 2 charging plugs each.
Mode 4 charging cable
Mode 4 charging cables are used when charging with direct current and high power. Due to the high charging currents, these cables are permanently connected to the charging station. A CSS plug is mounted on the vehicle side of the charging cable.
The smart charging station for taking along
Mobile charging stations with different socket adapters.
A mobile charging station combines maximum charging power with maximum flexibility. The function is identical to that of a Mode 2 charging cable, but the possible charging power is much higher.
Depending on the type of mains socket, charging power from 3.7 kW to 22 kW is possible. This means that drivers of electric cars can "refuel" at almost any socket.
A wide range of adapters are available for easy socket connection. And by coding the plug adapters, the charging station automatically detects how high the available power connection may be loaded.
Back in the domestic garage, the mobile charging station is simply hung in the wall bracket and connected to a CEE socket. Now it works as fast and reliable as a permanently installed Wallbox.
Charge the electric car with solar power
Constantly rising costs and ever lower feed-in remuneration are linked to the cost-effectiveness of photovoltaic plants.
Instead of selling the self-generated electricity to electricity grid operators at a low price, the cost-effective solar power should be better used for own consumption.
The charging of an electric car is a perfect solution. Apart from the fact that the energy production for the operation of an electric car is absolutely emission-free, one can also save money.
Charge with solar energy cost-effectively and drive without emissions.
Here is a small example:
With an annual driving power of approx. 25,000 km and an average energy consumption of the electric car of 16 kWh/100 km, this results in an annual energy consumption of approx. 4,000 kWh.
The energy costs for mains power (26 – 30 ct/kWh) then amount to 1,040,- to 1,200,- Euro.
The energy costs for solar power (11 – 14 ct/kWh) then amount to 440,- to 560,- Euro.
This results in an annual saving of around 600,- Euro!
The purchase of an electric car is even more interesting if the existing solar system already exists for a longer period of time and the feed-in fee contract has expired or will expire in the foreseeable future. In this case, the PV system has paid for itself and only minimal maintenance and maintenance costs are incurred. As a result, the solar power is almost free of charge.
Unidirectional and bi-directional loading
In unidirectional charging, the solar power flows from the PV system to the electric car via the charging station. If the solar system generates more electricity than is currently needed in the house, the excess current flows into the vehicle battery.
With bi-directional charging systems, the energy stored in the vehicle battery can be used to supply the consumers in the house in the evening or at night. The vehicle battery serves as a buffer and there is no need to buy expensive network energy. However, bi-directional charging stations are still in the development or test phase.
For more information on the electronic shop, please visit our advisory page on sustainable technologies for building installation.
State subsidies for charging stations
Funding can be requested from the Federal Administrative Service Office for the establishment of public loading points in customer parking spaces. Further interesting information about the current funding programs can be found on the website of the Federal Institute.
Frequently asked questions about charging stations Electric cars
Why do the last 20% of the charge take much longer?
The reason for this is the charge voltage limitation. For lithium batteries, the charging voltage must not exceed a certain value per cell. The batteries would otherwise be damaged. When charging an empty battery quickly, the voltage increases continuously to allow a permanently high charging current. When the maximum charging voltage is reached, the rechargeable batteries are not yet 100% full. The charging voltage is now kept stable at the maximum value and the charging current slowly decreases. The charging current is now determined not by the charger but by the rechargeable battery. Only when the charging current has reached a minimum value at the maximum charging voltage is the lithium battery charged to 100%.
Is slow charging better for the battery than quick charging in 30 minutes?
A charging process in which 80% is charged in 30 minutes places a considerable load on the battery than a charging process lasting between 2 and 4 hours. On the other hand, charging with low current for 12 or more hours is not optimal. The battery temperature is always important when charging. °Lithium batteries feel the most comfortable in the range of 20 - 40 C. When charging quickly, the battery temperature can°quickly exceed 40 C without proper battery and temperature management.
What was the cause of premature aging of the vehicle batteries?
The batteries with which a manufacturer equips his vehicles are easily able to absorb and deliver high performance. Nevertheless, the batteries are subject to a certain calendaric aging. Another criterion is the frequency of use and the service life between the uses. However, the greatest negative influence is the very high performance at very low and very high temperatures.
Where can ich find public load points?
The charging infrastructure is constantly being expanded, so that the owners of electric vehicles find power stations throughout the entire area. Meanwhile, there are also apps for the smartphone, where all the charging points of a region are clearly displayed.