of peltier units 18 and a heat exchanger 19 is also provided the heat exchanger 19 is arranged in the housing of the test cell 3 and is connected by its inwardly directed side to the peltier units 18 in this case the peltier units 18 are constructed in the form of a pyramid and each comprise peltier elements which are respectively placed flat against one another the structure in the form of a pyramid results in a multi stage cooling system the last stage being connected to the heat exchanger 19 in the exemplary embodiment shown the second cooling apparatus 17 is connected to one end of the battery 2 alternatively however it is also possible for the second cooling apparatus 17 to only be connected to the battery in an emergency this can be achieved for example in such a manner that the second cooling apparatus 17 is arranged on a linear supply arrangement and if an emergency is detected the second cooling apparatus 17 is moved linearly until it is in contact with the battery 2 in order to dissipate heat from the battery otherwise this exemplary embodiment corresponds to the first exemplary embodiment and so reference can be made to the description given there it is also noted in this case that only a.