Until now, using an elec­tric vehicle to travel long distances on vaca­tion has often meant long stops at rest areas or service stations to charge the vehicle. For many people, this was also coupled with the concern that they would be unable to find a charging station on their journey and could actu­ally break down with an empty battery. However, long charging times and long distances to the next charging station should soon be a thing of the past. As a result of inno­v­a­tive new tech­nolo­gies, compa­nies like ef cooling are shaping the future of elec­tro­mo­bility and making it more conve­nient and compat­ible with everyday life. This not only applies to cars. Elec­tric ships and ferries are already in use and could be joined by planes as well in the not too distant future. In logis­tics as well great advances are being made in terms of the perfor­mance and range of elec­tric trucks.  

“The goal in the future is to be able to recharge elec­tric cars to at least 80 percent capacity far faster than at present -  in just ten minutes. And it should be possible to recharge elec­tric trucks to their full range of 800 to 900 kilo­me­ters during a stop of just 40 minutes.” This is the vision described by Daniel Bärtschi, CEO of ef cooling. “In order to achieve this, we already need more high-perfor­mance, high-power charging (HPC) stations.” The Swiss company employs 70 people and supplies heat exchangers for liquid-cooled ­cables that ensure the effi­cient cooling of this kind of charging station. Daniel Bärtschi explains: “Around 95 percent of our heat exchangers are exported, espe­cially to the Asian market and the USA, where elec­tric vehi­cles are already more widely used than in Europe. However, I am convinced that effi­cient and fast tech­nolo­gies will enable us to achieve the same here as well.” 

Effi­cient cooling for demanding elec­tro­mo­bility

ebm-papst offers cooling solu­tions for all systems related to elec­tric vehicle charging. 

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Heat exchangers for liquid-cooles cables

The main chal­lenge presented by HPC stations is that the charging points over­heat at peak periods. In order to charge an elec­tric vehicle more quickly, a higher charging current is neces­sary. During the charging process, this gener­ates more heat, which must be dissi­pated by the charging station. The voltage can be as high as 920 V. The process is not made easier by the weather condi­tions to which HPC stations are exposed throughout the year. Whether it is snowing and – 10 degrees Celsius or it is 50 degrees Celsius under a scorching sun, the charging point has to be ready to go from standby to deliv­ering a full charge at any time.  

In 2017, ef cooling was commis­sioned by a charging station manu­fac­turer to develop a proto­type that ensures the avail­ability and effi­ciency of HPC stations. “An oil circu­lates in the charging cable and cools the copper wires,” says Bärtschi, explaining the cable cooling concept. “Oil may not exceed a maximum temper­a­ture of 30 degrees Celsius. An absolutely reli­able solu­tion is needed for the heat exchanger that is used to ensure this.” ef cooling began searching for a suit­able compact fan. “The oil cooling can’t func­tion without the heat exchanger, so the HPC station can’t func­tion either,” empha­sizes Daniel Bärtschi. “That’s why the choice of compact fan was a crucial feature of the proto­type.”

Cool charging cable thanks to compact fans  

The copper wires in the charging cable are surrounded by a sheath. The oil used as the cooling medium is pumped back­wards and forwards through this sheath, first to the plug and then back to the heat exchanger once it has heated up. This cools the oil using three compact fans supplied by ebm-papst, emit­ting the heat to the ambient air. “The higher the outside temper­a­ture, the more diffi­cult it is to cool the cable,” explains Daniel Bärtschi. “That’s why we chose a robust and very high-perfor­mance compact fan.” As the HPC stations are used all over the world, it was impor­tant to ef cooling that the fans were able to easily with­stand envi­ron­mental influ­ences such as extreme heat or cold. Samuel Schlit­tler, a member of the sales team at ebm-papst in Switzer­land, explains: “This was the reason for choosing fans with an IP68 rating for the HPC stations. As a result, the compact fans are resis­tant to splashing water, salt spray and other weather influ­ences.” 

A lot of effort and thought 

Along­side the tech­nical require­ments, the design of the charging point also played a major role. The appear­ance of the HPC charging station was as impor­tant to the manu­fac­turer as its internal work­ings. “The charging point was to be slimmer and taller, reducing the amount of space for the heat exchanger. Suddenly, the dimen­sions were too tight and we had to come up with some­thing new,” says Daniel Bärtschi.  

“Ulti­mately, we – like ebm-papst – are a supplier that works to imple­ment our customer’s wishes as best we can.” That is why ef cooling devel­oped a new unit in which the heat exchanger and the pump func­tion inde­pen­dently of each other. “This was a true feat of engi­neering. There were actu­ally crit­ical voices within the company that doubted it was even possible,” recalls Daniel Bärtschi. “However, it was soon clear that we were building some­thing that not everyone on the market is capable of.”  

The oil cooling can’t func­tion without the heat exchanger, so the HPC station can’t func­tion either.

Daniel Bärtschi, CEO ef cooling Ernst H. Furrer AG

Reli­able suppliers matter

Reli­able suppliers are key to such a special high-tech solu­tion. “In this project in partic­ular, the people behind the product were impor­tant. We wanted a compe­tent partner that could help us when a problem came up,” empha­sizes Bärtschi. “We found a great partner in ebm-papst.” He goes on: “In addi­tion to the high-end tech­nical product, we were espe­cially impressed by the efforts made by ebm-papst to reli­ably supply the number of compact fans needed, despite the diffi­cul­ties of the coro­n­avirus pandemic. For me, that is defi­nitely an addi­tional mark of quality.” Samuel Schlit­tler from ebm-papst recalls: “At peak times last year, we deliv­ered 1,200 compact fans each week to ef cooling. They were used to equip a total of 400 cooling units weekly.” 

The project has been running contin­u­ously since 2019 - and it remains exciting. Until now, every elec­tric vehicle manu­fac­turer has had its own plug for HPC charging stations. Now, after years of uncer­tainty, there is a global shift to the uniform NACS plug. It remains to be seen how e-mobility will evolve. In the future, elec­tric aircraft, ferries, and even container ships could be trav­eling the globe.