Patent ID: 7709137
Filing Date: 2010-05-04
Classification: H01M,Y02E

Abstract:
1. An electric power source comprising: a plurality of batteries; and a battery case including a holder case containing the plurality of batteries stacked in more than three tiers, wherein the holder case is divided into a first sub holder case and a second sub holder case disposed in a direction of stacking the batteries, the batteries being contained in a larger number of tiers in the first sub holder case than in the second sub holder case, wherein the battery case comprises an intermediary duct for transfer of cooling air therethrough, the intermediary duct being provided inside the holder case between the first sub holder case and second sub holder case, wherein the battery case comprises an outer duct which comprises a first outer duct disposed outside the first sub holder case and a second outer duct disposed outside the second sub holder case, wherein the first sub holder case and the second sub holder case are disposed between the first outer duct and the second outer duct, and the intermediary duct is disposed between the first sub holder case and the second sub holder case, so that the batteries contained in the holder case are cooled in such a manner that the cooling air is allowed to flow from the intermediary duct through the holder case into the first and second outer ducts for exhaustion, or alternatively the cooling air is allowed to flow from the first and second outer ducts through the holder case into the intermediary duct for exhaustion, and wherein the second outer duct is designed to experience a larger pressure loss than the first outer duct, so that the cooling air is blown into the intermediary duct and the outer duct to cool the batteries contained in the holder case, wherein an inside width in the second outer duct is made narrower than an inside width in the first outer duct so that a pressure loss in the second outer duct is larger than a pressure loss in the first outer duct, and wherein the batteries are contained respectively in “m” number of tiers in the first sub holder case and in “n” number of tiers in the second sub holder case, such that a ratio of the inside width in the first outer duct to the inside width in the second outer duct is m:n.