Mobility has to be CO2-neutral in future and vehicle technologies have to ensure that eco-friendly, efficient and quiet vehicles will be on our road. Therefore, the future belongs to battery electric vehicles (BEVs).

However, there are still certain challenges to be overcome so that the many advantages of the electronic powertrain can be leveraged. One challenge is the thermal management system in BEVs.

In contrary to ICE vehicles, the electric motor in BEVs produce little (waste) heat which is a challenge for BEVs at low temperature. It means that additional heating is required to warm the passenger compartment and this comes at the cost of reduced available range since it increases the efforts for the battery management.

Additionally, the ability to fast charge has been a big driver for thermal management. Many network providers offer DC fast charging stations with up to 350kW of power now. As a consequence, batteries need to be at an even narrower temperature window than general operation to make the most of the available charging power. This requires pre-heating or cooling the battery. As cells charge faster, there is a greater requirement for thermal management. If greater power than 350kW start to be adopted, then this could bring emerging thermal management strategies to the fore.

Therefore, thermal management system plays a critical role in BEVs. The thermal management system is responsible to keep the electric motor, the power electronics and the battery at right temperature while ensuring the passenger comfort in the cabin. For instance, a failure of thermal management will result in demagnetization of magnets, aging of the insulation materials, decrease of efficiency, shorter lifetime and even burnout of electric motors. Also, an efficient thermal management system helps to increase the longevity of the battery cells but is also a major safety feature to prevent thermal runaway.

The overall thermal management system comprises various thermal circuits which need actuators like the electric compressor, coolant pumps & fan motors, valves and flaps, HVAC control modules and electric heaters. Additionally, integrated thermal management systems are more commonly used by OEMs who converge to liquid-based battery cooling strategies.