In many EVs, the heating and cooling systems drain the battery and negatively affect the vehicle’s range. Comparing test results before and after a load change test on a function test bench can show how power consumption and performance change over the vehicle’s service life. The test object is connected to the power supply (low voltage 0-20VDC/5A) or high voltage (0-600VDC/150A) and the test media circuit. The test medium is circulated at a temperature of between -35°C to +100°C (-31°F to +212°F) and a flow rate of 1-50 l/min. The test can also be carried out in a climatic chamber at -40°C to +140°C (-40°F to +284°F) simulating changing ambient temperatures such as simulating ice-cold temperatures in Canada during Winter as well as dry heat around the Sahara desert.