BATTERY MODULE

A plurality of battery cells are arranged side by side in a first direction and each have a prismatic shape. A case accommodates the plurality of battery cells, and supports the plurality of battery cells in at least a first direction, and forms a unit including the plurality of battery cells. The case includes a first end portion and a second end portion arranged side by side and facing each other in a second direction orthogonal to the first direction. The first end portion is provided with a biasing portion that is deformed, when one battery cell of the plurality of battery cells is inserted into the case, to bias the battery cell toward the second end portion of the case. The second end portion is provided with a reference surface to position the battery cell in the second direction.