Inter-battery connection device and inter-battery connection device assembly

An inter-battery connection device for connecting electrode terminals of a plurality of batteries comprises a housing, a bus bar attached to the housing, and a movable member attached to the housing. The bus bar electrically connects two electrode terminals of a pair of batteries adjacent to each other. The bus bar includes a pair of clips each contacting one electrode terminal and a coupling portion connecting the pair of clips. The movable member is movable between a temporary catching position attached to the housing and a final catching position attached to the housing. The movable member has a clip contact avoiding portion preventing contact between one of the clips and the electrode terminal in the temporary catching position and permitting contact between the clip and the electrode terminal during movement from the temporary catching position to the final catching position.