Dürr Somac filling technology used by electric vehicle manufacturers around the world

Stollberg, December 2017 – The battery is the heart and the largest cost item of every electric vehicle. To ensure a long life and optimal range, the battery must not overheat and must be cooled reliably. The cooling systems of electric cars have various designs – several manufacturers in Europe, China and the United States use Dürr Somac systems for filling the cooling systems of batteries and power electronics.  

One of the benefits of Somac technology is that the filling systems and adapters are flexible to use. And they can even be used in mixed production for cars with conventional drives, although their filling processes sometimes differ from those of electric vehicles. "We can thus offer carmakers the right solutions for their systems", says Guido Kämmer, Account Sales Manager at Dürr Somac.

Somac systems are used for safely and accurately filling, for instance, ABS brakes, power steering, clutches and radiators with fluids, and air-conditioning systems with the gases R134a, R1234yf or R744 (CO2). The usual process is that of vacuum pressure filling, where the adapter is clamped to the media container and sealed. During an overpressure leak test, pressurized air is pumped into the containers to identify any leaks where the air might be escaping. Then all the air is extracted and an underpressure leak test is performed. The medium is subsequently inserted under pressure and extracted into the compensation tank until the right level is reached. The lighter generation of G³Blue adapters enables continuously adjustable filling heights for many different types of vehicle.

For complex battery cooling systems in electric cars, activating thermal control valves in the vehicle's cooling circuit may be required for the filling process. These control valves are important for regulating the battery temperature, preventing it from overheating. The valves must be switched to a suitable position prior to filling.

Larger volumes for electric cars

The volumes of filling media required for electric cars are considerably larger than those used in the conventional cooling circuits of combustion engines. This extends the process time for creating the vacuum in the cooling system and prolongs the filling process. In fact, the processes involved may be longer in any case, for example the filling of brakes or air-conditioning systems in a combined system. Therefore Dürr Somac always configures the filling system on a project-specific basis.

The company has thus equipped assembly lines not only for large quantities of renowned electric vehicles worldwide, but also for several thousand units of the Streetscooter made by Deutsche Post. Dürr Somac provides the filling systems for the brake and cooling systems used in this electric parcel and mail delivery vehicle.

"Thanks to a wide range of projects, we already have a wealth of experience in the production of electric cars", reports Guido Kämmer. "Regardless of planned unit volumes and increasing requirements, our filling technology always enables us to offer a perfect, customized solution."

VW also uses Dürr Somac filling systems for the production of its e-Golf in Dresden.