emobility umlaut energy interoperability


Charging made simple: Interoperability in EV charging

Charging is a major issue in the adoption of electric vehicles. umlaut expert Christian Sussbauer on complex standards and simple solutions.

Christian, you have been testing charging infrastructure for years. Assume I want to travel around the world with my electric vehicle. How many charging plugs or adapters would I need right now?

The situation always reminds me of the early days of mobile phones. There were all kinds of different charging plugs worldwide, which was driven by the manufacturers. In the EV space, OEMs in the car producing countries came together and defined types, which also resulted in different solutions. In North America, for example, we have a J1772-Type 1 plug for AC charging, and CCS-Type 1 for DC charging as well as CHAdeMO, which is the Japanese solution and not compatible with the others. And there is also Tesla, which covers both AC and DC in a separate solution. In addition, Europe and China use their own plugs, and the rest of the world adapted one or the other of the standards. So you would probably need to have all of these plugs and adapters in the trunk for your round trip.

Is there a perspective to solving this fragmentation?

We slowly see that happening. In Europe for example, there is more and more CCS around, which stands for Combined Charging System meaning AC and DC charging sits in one plug. Tesla seems to be transitioning there, too. CHAdeMO seems to be phasing out in North America – which could lead to one standard in Europe and North America. So we feel that fragmentation will go away at some point, but it will definitely take a while. Regulations would be beneficial to speed this process up, and avoid newer market participants to develop their proprietary and exclusive solutions.

What is the incentive for manufacturers to get rid of different plugs and standards?

There is a common goal: To make it as simple as possible for EV drivers. User experience is crucial to support the adoption of EVs. We have been benchmarking UX in the US and just released a report for DC charging infrastructure, which compares major charge point operators (CPOs) based on their user experience journeys. This knowledge is key to eliminate many issues before they can cause frustration for drivers.

Except for the actual plug, which other aspects do you have to cover to make sure charging works?

Sometimes very simple things can go wrong, for example, when cables are just not long enough to reach all the inlets of different EVs. Maintenance is also a critical item on the list, that charging stations are simply out of order for a long period of time. Most of the interoperability issues come in during digital communication between the EV and the charging station. Often the charging communication cannot be established, leading to charging errors. There can also be charging interruptions because there are wrong limits set for voltage, current or timeouts in the software of the two components.

Isn’t there a standard for the communication between EV and the charging station?

The communication is described in a standard, but the standard is very complex, and the interpretation is open to whoever writes the software. So, OEMs and charging station manufacturers all interpret the standard a little differently and sometimes this makes them incompatible. Which leads to a shutdown of the charging session.

All of this is highly relevant for the industry, but as a customer, I just want to charge my car. What is the easiest way to do this right now?

There is a solution we implemented for first movers in the US and Europe, called “plug & charge.” Which means no unnecessary steps, no app, no interaction with the display at the charging station, no authentication, no payment – you just simply plug in and charge. It is based on the ISO 15118 standard and all the necessary steps like identification and payment are happening in the background.

Until this becomes a reality everywhere – how do you test all the combinations of infrastructure that exist right now?

We can test many features in the lab. For example, communications only – without power flow or connector – is called conformance testing and covers most of the issues described before. We also have the possibility to build up actual charging stations in the lab and simulate tests with different EVs, or emulate the different grid standards in different regions.

Do you still need the actual vehicle for testing?

As part of testing, before the launch of a new car, it makes sense to test with the actual vehicle at real, public charging stations, using break-out-boxes by umlaut to access data and simplify the validation process. But we also developed a solution called “truck in a box,” which means we pack the working EV components of a truck or a bus together and bring them to different stations for testing. This approach is still much more effective than driving around with an actual truck.

EVs and charging stations will be integral parts of smart power grids. How does this affect your work?

We have supported many OEMs and other companies globally for many years now, so we also support them when it comes to the transition from mobility to energy ecosystem providers, including topics like energy storage or bidirectional charging. Right now, e-mobility is getting established, so innovations and ideas pop up for integration and improvements. They often go towards the energy sector. umlaut has a strong energy department as well, in which we have teams for eMobility, battery, and power grids, so there are a lot of synergies.

Christian Sussbauer

Christian Sussbauer

Manager eMobility


+1 248 302 0190