A battery module includes a plurality of batteries stacked together, and a busbar. Each of the plurality of batteries includes a battery-side first structure and a battery-side second structure that regulate the connection of the battery and the busbar. The busbar has a busbar-side first structure and a busbar-side second structure that regulate the connection of the busbar and each of the batteries. If the battery-side first structures of the plurality of batteries are combined with the busbar-side first structure, and the battery-side second structures of the plurality of batteries are combined with the busbar-side second structure, each of the batteries is connected with the busbar. Alternatively, if the battery-side first structure of any one of the batteries is combined with the busbar-side second structure, the one of the batteries or another one of the batteries is not connected with the busbar.