Connection module

A connection module to be attached to an energy storage element group in which a plurality of energy storage elements including positive and negative electrode terminals are lined up, the connection module comprising:

• a plurality of bus bars that connects the positive and negative electrode terminals of adjacent energy storage elements of the plurality of energy storage elements;
• a plurality of bus bar holders that are lined up in a line-up direction in which the plurality of energy storage elements are lined up, holding the bus bars so as to be insulated;
• and
• a pitch adjustment coupler that is provided across adjacent bus bar holders of the plurality of bus bar holders so as to couple the adjacent bus bar holders, and the pitch adjustment coupler is configured to extend and contract in the line-up direction of the plurality of bus bar holders, enabling adjustment of a pitch between the positive and negative electrode terminals of the adjacent energy storage elements,
• wherein each of the bus bar holders includes a bus bar housing including an isolation wall that keeps the corresponding bus bars apart and insulated from one another, and
• the bus bar housing includes, on one side in the line-up direction, a free space where there is no isolation wall.