A connection module includes an FPC and a plurality of bus bars. The plurality of bus bars constitute a first bus bar row disposed along one long side of the FPC, and a second bus bar row disposed along the other long side of the FPC. The FPC includes tolerance absorbing portions each including a slit and a pair of deflection portions disposed with the slit interposed therebetween, and is divided into a plurality of wiring portion by the tolerance absorbing portions. The pair of deflection portions constituting the first tolerance absorbing portion can be deflected in a direction in which the two wiring portions that are adjacent to each other with the first tolerance absorbing portion interposed therebetween move toward and away from each other. The same description also applies to the second tolerance absorbing portion.