BATTERY PACK

A battery pack includes: battery cells including first battery cells and second battery cells, each of the first and second battery cells including a first end portion and a second end portion that are opposite each other in a length direction of the respective battery cell, adjacent first end portions being arranged in a stepped manner; and a case providing an accommodation space in which the battery cells and a cooling fluid to cool the battery cells are configured to be accommodated, the case including a first cover covering the first end portions of the battery cells, the first cover being arranged along a height difference between the first end portions of the first and second battery cells and defining a height difference space, corresponding to the height difference, on an outer side of the first cover.