BATTERY PACK

Provided is a battery pack in which the cooling efficiency of a battery module is improved. A first cooling mechanism (40A) is provided with a first cooling medium flow path (41Aa) provided on the opposite side of the first battery module (11A) in the vertical direction with a bottom part (121) interposed therebetween; a second cooling medium flow path (41Ab) provided on the opposite side to the second battery module (11B) in the vertical direction with a bottom part interposed therebetween; and a connection flow path (41Ac) that connects the first cooling medium flow path (41Aa) and the second cooling medium flow path (41Ab) at one end in the front-rear direction and that extends in the left-right direction. A plurality of protrusions (61) are arranged at the bottom in a staggered mannerin the front-rear direction and the left-right direction. Each of the protrusions is a pyramid, one diagonal line of two diagonal lines (61a, 61b) of the pyramid is arranged so as to coincide with thefront-rear direction, and