Eindhoven University of Technology: TU Eindhoven students develop electric race car with very short charging time

Student team InMotion has presented for the first time its driving electric race car for endurance racing, with a very short charging time. Due to its self-designed cooling method, the racing monster is able to fully charge in 12 minutes. Jan Lammers, sporting director of the Zandvoort Grand Prix, Viaplay F1 commentator Melroy Heemskerk and rally driver Kevin Abbring presented the event surrounding the unveiling, which took place on the TU Eindhoven campus.

InMotion started building the race car three years ago, with a total of 35 students currently working on it. During tests at Circuit Zandvoort, the car already drove 225 kilometers per hour and according to models it can even reach 300 kilometers per hour. A special feature is the battery pack that has the same capacity as a standard Tesla Model 3 (58 kilowatt hours) but charges twice as fast, in twelve minutes. As far as known, this is the only electric car for long-distance racing that can do that. Meanwhile, the team is further developing the battery pack, with the aim of reducing the recharging time to a few minutes, a real pit stop, in other words.

The secret lies in the cooling of the battery pack, explains team manager Ewout Timmermans. “When charging a battery, heat is released. You can feel that, for example, when you charge a telephone; it gets warm. In the case of a telephone, you’re talking about a small battery cell, but during rapid charging of a battery pack with hundreds of cells close together, at least a thousand times more heat is released. The battery cells can’t handle that; above 45 degrees, they degrade pretty quickly. In other words; the capacity of the battery decreases. The car loses its range and needs to be recharged more often. In addition, the risk of short circuit and fire increases if the battery overheats.”

Therefore, the team developed a cooling method in which cooling plates filled with coolant are placed between the modules with cells. In this way, they extract heat from the battery pack so that the battery can charge faster without overheating. “In fact, we are now refining the technique by cooling at the cell level, which allows us to charge within minutes,” he says. Since there are about 360 cells in a battery pack, that’s quite a challenge,” Timmermans clarifies.

InMotion wants to challenge the current car industry with the very short charging time of its race car. By demonstrating that the charging time for electric cars can be drastically reduced – comparable to the time it takes to fill up a tank with gasoline – they hope to remove the threshold for electric cars and make the world a little greener. Timmermans: “In a race, you expose the car and battery pack to the most extreme conditions. If it is possible to shorten the charging time on a circuit durig a long-distance race, it must surely be possible on the road.”

According to Maarten Steinbuch, professor of Mechanical Engineering at TU/e, the students’ contribution is valuable for companies committed to green mobility. “InMotion is racing us towards a sustainable future in a steadfast and innovative way. Their technology and measurement models may be of interest to industry in the future, for example, to drastically reduce the charging time of electric trucks or airplanes.”

24-Hour race
The technology has been tested at research institute TNO, among other places. Professional drivers such as Kevin Abbring, Bas Schothorst and Christiaan Frankenhout performed the demo and test laps. The race car also meets the technical standards for LMP3, the entry-level prototype class of the 24 Hours of Le Mans, intended to allow young drivers and new teams to enter.

The dream is to eventually participate in this legendary 24-hour race. Timmermans: “But developing a race car does not yet mean that you have the knowledge to race it as a team, therefore we want to first complete a 1 hour race, to build from there. Hopefully we will then one day be at the start of this iconic race.”