A battery pack and method of cooling a battery pack. In one form, the battery pack is an assembly made up of numerous battery cells arranged within numerous modules. Cooling channels that receive cooling fluid from a ducted supply are placed between adjacent cells or cooling plates within each of the modules. The ducted supply includes beads or related area-increasing undulations that are designed to improve both the stiffness of the ducting as well as the uniformity of the flow rates of individual cooling channels within each of the modules. In one form, the pressure-enhancing beads are placed in an inlet portion of the ducting that is adjacent a forward portion of one or more of the sequentially-encountered modules in order to promote a more equitable distribution of the cooling fluid between the various cooling channels within each of the modules.