A battery and capacitor assembly for a hybrid vehicle includes a plurality of battery cells, a plurality of capacitor cells, a cooling plate, a pair of end brackets, and a housing. The plurality of capacitor cells are arranged adjacent to the plurality of battery cells such that the plurality of battery cells and the plurality of capacitor cells form a cell stack. The pair of end brackets are disposed at opposite ends of the cell stack and are attached to the cooling plate. The pair of end brackets compress the plurality of battery cells and the plurality of capacitor cells. The housing is attached to the cooling plate and encloses the cell stack and the pair of end brackets.