BATTERY PACK

A battery pack is provided with a check valve including a cover body that is attached to a housing accommodating battery cells and a valve main body that is provided at an inner side of the cover body. The check valve exhausts gas discharged from the battery cells to outside the housing. The valve main body includes a moving portion disposed at an upstream side of the cover body. The moving portion is urged by an urging member to separate to the upstream side from the main body portion. When an internal pressure of the housing is at least a threshold value, the moving portion moves to the downstream side in opposition to urging force of the urging member. Plural stopper portions of the moving portion abut against the main body portion and limit the movement to the downstream side. Interstitial flow paths for the gas are formed between the stopper portions.