A power supply device for a motor vehicle, in particular a passenger vehicle, truck or motorcycle, comprises one or more storage cell modules, each of which includes one or more electrochemical storage cells and/or double layer capacitors that are arranged next to and/or on top of one another. The device includes a cooler block having a holder for the storage cell modules and a heat dissipating structure for dissipating heat emitted by the storage cell modules. The heat dissipating structure is provided on at least one side of the holder. The cooler block includes a clamping device operatively configured to generate a predefined force by which the heat dissipating structure can be pressed against a respective storage cell module.