Patent ID: 8435664

Claim:
A battery system comprising: battery blocks having a plurality of battery cells, which are rectangular batteries, stacked with intervening cooling gaps established to permit cooling gas to pass between the battery cells; ventilating ducts, which are supply ducts and exhaust ducts, disposed on both sides of the battery blocks to force ventilation through the cooling gaps and cool the battery cells; and ventilating apparatus to force cooling gas into the supply ducts, wherein cooling gas forcibly introduced by the ventilating apparatus flows from the supply ducts through the cooling gaps and into the exhaust ducts to cool the battery cells, wherein temperature equalizing walls are disposed in the supply ducts, and each of the temperature equalizing walls has a long narrow shape with a width and a length in a direction of flow that is greater than the width, and an upstream end of each temperature equalizing wall becomes gradually narrower towards the upstream end, and wherein each of the temperature equalizing walls is provided with a tapered region with a lateral width that narrows with increasing distance from each of opposing surfaces of the supply ducts.