Battery holder

Battery holder for holding batteries having a central pole contact (36) at one end thereof, said battery holder comprising a cylindrical socket (28) having open ends and forming two spaces (35A, 35B) therein separated by an abutment (33) midway of the socket, for holding each a battery (13;

• 14) with the central pole contact thereof positioned at one and the other, respectively, of the open ends of the socket characterized in that the battery holder further comprises first and second caps (10, 12), clamping means (17, 39, 44) for holding the caps together with the batteries received in said spaces clamped therebetween, and contacts (15, 16;
• 24) on said first cap to be engaged by the poles of the battery received in the space closed by said first cap when the batteries are clamped between the caps, the socket being positioned selectively with one battery or the other engaging said contacts located on said first cap, that the socket (28) forms an outside circumferential groove (29) adjacent each end thereof and in each groove forms at least one slot (30) through the cylindrical wall of the socket, extending over a minor part of the circumferential length of the groove (29), and that an elastic O-ring (31) is received in each groove forming a straight portion (31′) extending through the slot (30) inside the socket.