Patent ID: 7029787

Claim:
A power supply unit comprising: a battery assembly in which a plurality of rod-shaped battery modules having a plurality of batteries connected together in series and having a positive electrode at one end and a negative electrode at the other end are arranged so that axes of the battery modules are parallel to each other and, in a plane intersecting these axes, points of intersection of the axes and the plane are aligned in both a vertical direction and a lateral direction relative to the axes, the battery assembly having positive/negative electrode groups that are formed from a plurality of positive electrodes and a plurality of negative electrodes and are disposed at axially opposite ends of the battery modules; an insulating ring disposed directly between and in direct contact with two opposing ends of adjacent batteries of each battery module, the insulating ring having annular recesses into which the two opposing ends fit, a connection between a positive electrode and a negative electrode being in a region surrounded by an inner peripheral surface of the insulating ring; each battery module running through and being retained by a plurality of plate-shaped members that stand on a base plate and are parallel to the plane; each plate-shaped member being kept vertical by a gantry-shaped frame member that has an upper linking portion abutting against an upper end face of the plate-shaped member and has legs fixed to the base plate; each plate-shaped member being an assembly of a plurality of grommets formed from two split halves, the two halves having a semi-annular recess that opens on a split surface and is fitted around a semi-circumferential portion of an outer peripheral surface of the insulating ring; and a plurality of through holes into each of which one of either the positive and negative electrode is fitted and a plurality of bus-bars that are each connected to the positive or negative electrode fitted in the through hole being provided in each bus-bar plate facing each positive/negative electrode group of the battery assembly, wherein the connection between each bus-bar and the positive or negative electrode is movable toward and away from the positive or negative electrode.