A growing number of electric cars is produced every year. This trend is driven by the need to reduce carbon print from personal vehicles. Also, sports electric cars started to appear, mainly because of high torque that can be exerted by the electromotor. The main problem in electric car implementation is energy storage limitation. In that regard Li-ion cells give the best results. But, during the process of charge and discharge cycles they release a lot of heat that produces unwanted side effects. The side effects can be managed with battery thermal management systems (BTMS). BTMS that are already being used in car industry are air cooling, cold plate cooling and immersion cooling. All those principles have disadvantages regarding peak heat flux, temperature uniformity and efficiency. In this thesis, to overcome those disadvantages, test equipment for new BTMS technology is developed, in collaboration with company Rimac automobili.