Patent attributes
A fluid-cooled battery pack system can maintain the variation in battery temperature in a battery pack within the permissible temperature range even when the variation in the gaps between battery modules is considered. A plurality of battery modules are each provided with a plurality of convex portions and concave portions on the sides thereof, where the connections to other battery modules are made. When the battery modules are connected by bringing the opposite convex portions into contact with each other, coolant flow paths, through which a coolant flows, are formed. The target width of the coolant flow paths is set so that the variation in temperature relative to the target temperature of each battery module is maintained within a predetermined range when the coolant flows through the coolant flow paths; the variation in temperature is caused by a fabrication tolerance relative to the target width of the coolant flow paths between the battery modules.
