Patent ID: 6953638

Claim:
A fluid-cooled battery pack system comprising: a battery pack case having at least one coolant inlet and at least one coolant outlet; a battery pack placed in the battery pack case and provided with a plurality of battery modules connected electrically in series or in parallel, each battery module including at least one cell and having edge portions with dimensions that vary in a thickness direction within a predetermined tolerance, and coolant flow paths formed for each battery module between the adjacent modules or between the module and a battery pack structure, the coolant flow paths allowing a coolant to pass from the coolant inlet to the coolant outlet, the width of the coolant flow paths being determined by the thickness dimensions of the edge portions; and a coolant transport device for introducing the coolant into the coolant inlet, allowing it to flow through the coolant flow paths, and releasing it from the coolant outlet, wherein a target width of the coolant flow paths is set so that a variation in temperature between the battery modules caused by the predetermined tolerance relative to the target width of the coolant flow paths is maintained within a predetermined range and all the battery modules have a predetermined temperature or less when the coolant flows through the coolant flow paths, and the thickness direction of the edge portions is parallel to the width of the coolant flow paths.