Wallbox Guide 2022 - Model selection, funding, installation!

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Anyone who deals with electromobility will inevitably end up at some point with the topic of charging infrastructure. Especially in the private and business environment, the word "wallbox" comes up very quickly. It is supposed to be quick to install and comparatively inexpensive, the little saviour of electromobility in the home. In addition, there are regular headlines about wallbox subsidies and how quickly they are sold out. Basically, it is advisable to look into this topic if you are interested in buying an electric car. Good advance planning and analysis of the driving profile and the subsequent installation of the required charging infrastructure will ensure long-term enjoyment of the new electric car. But what exactly is a wallbox? We will explain which variants and equipment are available, which wallbox support you can use and whether you need to register your wallbox and obtain permits!

What is a wallbox and do I need one at all?

We recommend the use of a wallbox if you want to charge an e-car. Charging from a household socket only works to a limited extent. This is because the circuit must be designed for the corresponding continuous operation. Otherwise, there is a risk of uncontrollable fault currents in your household installation. We do not recommend that you build your own. A wallbox is one way of installing an appropriate charging infrastructure and has inherent protection against DC and AC faults. The wallbox is mostly used in private or semi-public areas, such as a company car park. In addition to the lower costs, the wallbox installation is also easier than with a charging pole, as simple wall mounting is usually possible. The charging power of wallboxes is up to 22 kW and is thus significantly higher than that of a conventional household socket (protective contact or Schuko socket) with a maximum of 2.8 kW (230 V, 12 A). This is also reflected in a significantly shorter charging time for e-cars. In addition, wallboxes offer some comfort functions such as smart charging management with integration of the smartphone app, the integration of a photovoltaic system by means of an energy manager, two charging points for simultaneous charging of two e-cars and an MID electricity meter to determine the charging amount for the vehicle, which make everyday life with the e-car much more pleasant. Not every driver of an e-car necessarily needs a wallbox; for some, the public charging infrastructure is sufficient. However, depending on the driving profile and one's own demand for comfort, it can be very helpful to have one's own small e-charging station in the garage.

How do wallboxes differ from each other?

In addition to performance, wallboxes differ primarily in price and additional functions. Since the selection is now very large, it is advisable to be clear about your own application profile at the beginning. Roughly speaking, wallboxes can be divided into simple wallboxes, mainly for private use, smart wallboxes with additional functions and wallboxes for commercial use, whereby the transitions are fluid. Which type of wallbox do you really need? SachsenEnergie will be happy to advise you on this topic and will continue to expand its online services in the future.

Wallboxes for the private sector

If the house installation allows it, a wallbox with a charging capacity of 11 kW is optimal. This charges the vehicle battery of an average e-car to a range of about 100 kilometres in two hours. Overnight, every e-car should thus be fully charged for the next day. A component with which the supply can be switched off in the event of is now already integrated in most charging devices. Some models also come with the minimum required type A residual current circuit breaker. If the charging device is supplied without the residual current circuit breaker, it must be retrofitted by an electrical installation company during installation. This is done by energy providers such as SachsenEnergie as part of the installation service package. For most applications, a wallbox with these basic functions is perfectly adequate. If you do without additional gadgets, you can save quite a bit of money. If you absolutely have to charge two electric cars at the same time, wallboxes with two charging points are also conceivable for this application.

In the existing power lines, only protective devices for alternating current are used (known as RCDs). If, for example, a fault occurs during charging in the DC mains, the fault currents can enter the AC mains and cause damage. Therefore, special protective devices (RCD type A) must be used that detect these fault currents and safely interrupt the charging process. As a rule, the RCD type A is installed by the electrician when the wallbox is installed, if it is not already present.

Smart wallboxes

The state of the art is that most wallboxes from different manufacturers are not compatible with each other due to different manufacturers' own load management systems. This can lead to problems depending on the application. A uniform, communicative, i.e. smart charging technology that can be integrated into a common load management system can help here. This is the only way to ensure that, with an increasing number of e-cars in a property, charging can continue to be carried out safely and efficiently and that no unnecessary costs or construction measures are incurred on the grid connection. Furthermore, some smart wallboxes offer an app with which you can conveniently see all information about your wallbox at a glance and also control it remotely. With the Mennekes smartphone app, for example, time-controlled and grid-controlled charging are also possible.

Our wallbox offer for you:

Mennekes AMTRON Compact

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Wallbox SachsenEnergie

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Find a wallbox!

An offer for East Saxony.

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Wallboxes for the commercial sector

When converting to an e-mobility system for your company or in an apartment building, in addition to vehicle procurement, the required charging infrastructure must also be evaluated in the form of a detailed charging concept. As with the planning of the inventory based on the mobility analysis, sound and detailed planning can also save considerable costs here. It should answer the following questions in particular:

Depending on the determined usage profile of the e-vehicles, the charging points can then be selected and installed. If the journeys are such that one battery charge is sufficient for all journeys of the day and can be charged overnight, a low-cost charging point up to 11 kW (on the company premises or at the employee's residence) is usually sufficient. However, if the vehicles are used for shorter and longer distances and the battery is discharged 70 to 80 per cent per single trip, it should be ensured that the charging infrastructure is adequate for the use case. To achieve this, it makes sense to install more powerful charging stations with 22 kW. In addition, it should be taken into account whether charging processes are to be charged at all or selected charging points, for example for charging private employee vehicles. If this is the case, charging technology that complies with calibration law should be used. In order to be able to implement the billing and technical management simply and conveniently, it usually makes sense to use a service provider.

SachsenEnergie advises commercial customers on the use of charging technology and offers operational management as a service in Dresden and eastern Saxony.

How do I bill the employer for the consumption of a wallbox?

If a company car is to be charged at home and the charging current in kilowatt hours is to be

There are various possibilities for delimiting household electricity. Of course, these must always be agreed individually with the employer.


  • In the simplest case, the mileage of the e-car is sufficient. This is multiplied by the average consumption in kilowatt hours and the electricity price and serves as the basis for the reimbursement.

  • in addition to the wallbox, a separate electricity meter or a sub-meter is provided to delimit the electricity. The transmission of the consumption to the employer is then the responsibility of the employee. When a new meter is installed for the charging station, the employee receives an electricity bill once a year, which can be transmitted to the employer.

  • A communicative wallbox for the delimitation of the charging current, which complies with calibration law, enables a maximum digitalised implementation. The employee authorises himself with an RFID charging card provided and charges the vehicle as usual. The back-end integration of the wallbox now enables the automated transmission of the charging data to the employer, which serves as the basis for reimbursement.

  • For most employers, however, an extract of the charging data created with the smartphone app of the wallbox manufacturer (if available) is sufficient. The advantage: With this solution, there are no ongoing costs for the back-end integration and the RFID charging card via an external service provider.

Wallbox costs: What can you expect?

The price range for wallboxes is relatively wide. Depending on the model, you can expect to pay 400 to 2000 euros or more for the purchase alone. Especially powerful 22 kW models are often rather expensive. You can also expect a higher price (from 1,600 euros) for a wallbox with calibration conformity for charging billing. Simple models are already available from 500 euros. For KfW funding for a wallbox, communication capability is required. Models start at 800 euros. You can find the list here.

You also need to plan costs for the wallbox installation. In some cases, modifications are necessary or the cables have to be laid, so the effort required is very individual. Again, you can roughly calculate between 500 and 2000 euros. If you would like a separate electricity meter and there is no free meter field available in your meter cabinet, you will need to extend the meter cabinet. You can expect additional costs of about 1,000 euros for this. In any case, we recommend a consultation with your regional energy provider. A final factor is the Wallbox subsidy. It is worth being informed about this, as you may be able to offset a good portion of the costs.

Wallbox promotion

You have probably heard about various sources of wallbox subsidies. In addition to the nationwide subsidies such as the KfW Wallbox subsidy, there are also various regional subsidy opportunities in municipalities and federal states that you should keep your eyes open for. In Saxony, for example, there was a funding guideline for storage systems from the SAB for a very short period of time, but the number of applications meant that it was discontinued after a very short time. The 3.8 million euros made available by the state legislature were exceeded within a few hours. So it is always worth looking around for current funding at short notice.

KfW Wallbox funding for residential buildings - Extremely popular and unfortunately out of stock

Probably the best-known funding option for wallboxes is the KfW Wallbox Grant for Residential Buildings (KfW 440). This subsidy supported the purchase and installation of charging stations at parking spaces and in garages that belong to residential buildings and are only accessible privately. The prerequisite was the exclusive use of electricity from renewable energies for the subsidised charging station. Since the end of last year, the funds for this subsidy have unfortunately been exhausted. The new federal government must decide whether to continue it. This decision is not foreseeable, but as mentioned before, it is worth keeping your eyes open. In any case, we will keep you up to date on umschalten.de!

Commercial customers still benefit: KfW Wallbox subsidy

The pots of funding for private residential buildings have already been exhausted due to great popularity, but as a commercial customer you can still benefit! The funding Charging Stations for Electric Vehicles - Subsidy for Charging Stations in Businesses (KfW 441) subsidises the purchase and installation of charging stations with up to 22 kW at parking spaces that are not publicly accessible. You can thus receive a grant of 900 euros per charging point, provided your charging station is eligible and the total cost per charging point is at least 1,285.71 euros. This is therefore a subsidy of 70 %. The maximum grant per location is 45,000 euros.


Is my wallbox eligible for funding?

To find out whether the wallbox of your choice is eligible, you should always take a close look at the website of the desired subsidy. There you will find a list of all eligible wallboxes and you can easily search for your model. These lists are constantly updated, so it is advisable to go back to the primary source as far as possible. If you are interested in KfW funding for commercial customers, you can find the current list here. In addition, KfW provides a suitable fact sheet for each funding scheme, which explains step by step how to apply and what to bear in mind.

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Wallbox installation

After deciding which wallbox is necessary for your own application, comes the implementation. We explain to you what you need to bear in mind during installation!

Wallbox registration - Which permits do I need?

The installation of a charging system should always be carried out by a certified electrical contractor. In the process, the house installation is expanded to include protective devices such as the type A residual current circuit breaker and, for example, the available power is checked. The electrician also registers the wallbox with the grid operator. If it is planned to install charging technology with a total power of more than 12 kVA (approx. 11 kW) at the connection, the approval of the grid operator must be obtained beforehand. Depending on the grid operator, additional costs may be incurred for this approval.

In the case of single-family homes, a wallbox is usually the most favourable charging option. However, contrary to what the name suggests, the wallbox does not necessarily have to be mounted on the wall. Wallbox manufacturers also offer elevations, foundations and protective roofs for the installation of wallboxes outdoors.

Wallbox installation service: everything from a single source

If the decision has been made to install charging points for the electric vehicle fleet, the first step should be to check whether the existing connection capacity is sufficiently dimensioned or whether an increase in the connection is possible. Coordination with the respective grid operator is necessary and even prescribed in the Low Voltage Connection Ordinance (§ 19 para. 2). Any installation of charging technology must be notified to the grid operator. If it is planned to install charging technology with a total power of more than 11 kVA at the connection, the approval of the grid operator must be obtained beforehand. At this point, it is advisable to look for a comprehensive wallbox installation service in order to save yourself the work of registering the wallbox. Often, the local grid operator such as SachsenEnergie offers such an installation service, which also takes care of the necessary wallbox registration or application with the grid operator SachsenNetze.

Charging at home - simple and safe with a wallbox!

If you are planning to purchase an e-car, it is highly advisable to also take care of the appropriate charging infrastructure. A household socket is not suitable for continuous operation, offers no additional functions and charges much more slowly than the wallbox. You should analyse in advance exactly which wallbox is right for you. You can expect to pay between 400 and 2,000 euros for the wallbox and between 500 and 2,000 euros for the installation, depending on your individual situation. Depending on the installation effort (number of wall openings, etc.), possible meter cabinet extension for an additional electricity meter. You can save time and nerves by using a wallbox installation service. In any case, it is worth keeping your eyes open for possible subsidies. These are sometimes sold out very quickly, so it pays to be quick.

If you have any further questions or comments on the topic, please contact us at frag@umschalten.de!

A contribution by Eric Wegner

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