A battery pack includes at least one battery module and a pair of pack end plates arranged to hold the at least one battery module therebetween in a predetermined direction. Each battery module includes a plurality of battery cells arranged in alignment with each other in the predetermined direction and a pair of module end plates arranged to hold the battery cells therebetween in the predetermined direction. Moreover, the strength of the pack end plates in the predetermined direction is set to be higher than or equal to a minimum required strength to hold the at least one battery module therebetween in a predetermined state where the battery cells of the at least one battery module have deteriorated. The strength of the module end plates of the at least one battery module in the predetermined direction is set to be lower than the strength of the pack end plates.