the cooling circuit fig1 shows a variant of the cooling medium compensation container 301 according to the invention in contrast to fig1 the outlet opening 310 is arranged at the bottom of the cooling medium compensation container 301 in this way improved mixing of the cooling medium flowing into the collecting chamber 306 and a safer venting of the cooling circuit can be ensured the illustrated cooling medium compensation container 301 has moreover two covers a first cover 311 for removal and installation or exchange of the ion exchanger 302 and a second cover 312 for possible refilling or exchanging of the cooling medium or cooling fluid the cover 312 as shown in fig1 can have a spring 313 that acts onto the upper wall of the ion exchanger 302 in this way the ion exchanger 302 can be secured in addition to being secured by the mechanical means for locking in order to secure it even better with respect to sliding as a result of shaking or the like in all of the above described embodiments of the cooling circuit 10 of the compensation containers 20 301 of the ion exchanger cartridges 24 302 and of the radiator 218 the following modifications are possible inter alia the invention is not limited.