BATTERY PACK

A battery pack is provided with: a battery module having a cell stack configured by stacking a plurality of cells; and a cooling mechanism for cooling the battery module. The cooling mechanism is a refrigerant flow passage through which a liquid medium passes. The cell stack and the refrigerant flow passage are arranged with a bottom plate interposed therebetween. A plurality of protrusions are provided on the lower surface of the bottom plate. The plurality of protrusions are arranged in a staggered pattern along the stacking direction of the cells.