Busbar

A busbar having a plate shape and made of an electrically conductive material, the busbar being configured to be connected to terminals provided on one side in a perpendicular direction of two battery cells arranged in a predetermined direction, the perpendicular direction being perpendicular to both the predetermined direction and an up-down direction, the busbar comprising:

• a first connection portion configured to be connected to the terminal of one of the two battery cells;
• a second connection portion configured to be connected to the terminal of the other of the two battery cells;
• and
• a first through hole and a second through hole that are provided in a region between the first connection portion and the second connection portion and are arranged in the up-down direction,
• wherein a recessed portion recessed toward an opposite side from the second through hole is provided at an edge of the first through hole that is on the second through hole side.