A battery adhesion-fixation structure includes battery cells, a holder, an adhesive agent, bus bars, and an insulator. The holder includes holder holes for holding the battery cells therein. The adhesive agent adheres the battery cells with the holder within the holder holes. The bus bars electrically connect the battery cells with each other. The insulator intervenes between the bus bars and the holder. The bus bars include a bus-bar hole, and a terminal tab. The bus-bar hole faces face-to-face to an electrode terminal of the battery cells. The terminal tab projects into the bus-bar hole to be electrically connected with the electrode terminal. The insulator includes a face, and a dent opening in the face. The face opposes to the holder. The dent opens in the face, and accommodates the adhesive agent overflown toward the insulator therein.