Successful HPC charging test in the All Electric Society Park Electric bus put to the test for High Power Charging

Founded in 1882, Swiss family-owned company and vehicle builder HESS manufactures innovative electric buses for local transport. These include the Swiss eBus plus.
Nicolas Amacker, Project Manager for Swiss eBus plus and Head of Traction Hardware at HESS, was enthusiastic about this innovation project: “This is a lighthouse project, it’s called Swiss eBus plus and that’s also the name of our new generation of electric buses. They can drive a good 300 to 350 km in all conditions and can therefore replace a diesel bus.”

HESS implemented the project together with ETH Zurich and Bern University of Applied Sciences. It is supported by the Federal Office of Energy in Switzerland as a pilot and demonstration project. Within the project, both universities carried out research work in the fields of thermal management and battery technology. Overall, the Swiss eBus plus provides impressive new technologies with regard to heating, air conditioning, insulation, drive, and charging technology.

To fully test the innovative technologies in the e-bus, Nicolas Amacker and Carlo Rindlisbacher, System Developers at HESS, traveled from Switzerland to Germany with the Swiss eBus plus. First, they made a stopover in Marburg, where the bus passed a climatic chamber test. The bus was cooled down to minus 20 degrees to test its innovative thermal insulation. This ensures that the bus achieves particularly efficient energy management through lower thermal losses.

After successfully completing the test in Marburg, the journey carried on to Phoenix Contact and its All Electric Society Park.

The collaboration between HESS and Phoenix Contact was established by our Swiss colleague Stefan Staiber. As a system consultant, he was able to support the innovation project with the new CHARX connect universal CCS vehicle charging inlet. The project was also supported by the product managers responsible for vehicle charging inlets, Linda Cam, Mefer Dogan, and Rik Stellbrink from Phoenix Contact E-Mobility headquarters.

“It was back in spring that I visited HESS in Switzerland, along with my colleagues Stefan Staiber and Rik Stellbrink, to find out more about the project,” explained Mefer Dogan. “Even then, it was impossible to think that we would all be carrying out a charging test here in the All Electric Society Park.”

“This is the first time we have installed a High Power Charging inlet in this bus, which now enables us to charge with very high charging currents,” explains Carlo Rindlisbacher, System Developer at HESS.

And it was precisely these high charging currents that were to be put to the test at the DC charging station in the All Electric Society Park.

The new type 2 CCS vehicle charging inlet from Phoenix Contact is installed in the electric bus. With DC conductor cross-sections of 120 mm², this charging inlet enables battery charging with a charging current of up to 400 A. In Boost Mode, charging currents of up to 700 A can even be achieved for a limited period of time during the charging process. The charging power that can actually be achieved depends on a number of factors, such as the vehicle, outside temperatures, and the cooled charging infrastructure.

And that was exactly what the team was looking at when the Swiss eBus plus underwent the two-day charging test in the All Electric Society Park. Nicolas Amacker and Carlo Rindlisbacher wanted to find out whether the charging power tested in the laboratory could also be achieved in practice – under real conditions and in warm weather – when the charging inlet, other vehicle components, and charging infrastructure interact.

The aim was to charge the battery at 80% with a constant charging power of 350 kW. Another test was aimed at Boost Mode, because HESS wanted to find out whether the vehicle could be charged with 500 A under real summer conditions.

“For previous projects, the typical charging times were 3 to 4 hours,” says Nicolas Amacker. So he was all the more delighted with the charging times achieved during the test: “The vehicle was charged from 30 to 80% in around half an hour, which is a pretty impressive time.”

Carlo Rindlisbacher was also pleased with the charging test: “Right now we’re drawing power from the charging station at 500 A, which corresponds to around 350 kW. And what's more: We’re charging with 350 kW at a very good temperature.”