Abstract: An expansion tank for a battery cooling system may include a tank housing having a first lid and a second lid, a dryer cartridge screwable onto a threaded nipple of the first lid, a vacuum valve arranged in the first lid, and a pressure relief valve arranged in the second lid. Fresh air from an environment may enter the expansion tank via the vacuum valve and the dryer cartridge when there is a vacuum in the expansion tank. Air may be released from the expansion tank into the environment via the pressure relief valve when there is excess pressure in the expansion tank.