Patent ID: 8703317

Claim:
A battery pack comprising: (a) a battery chamber which houses a plurality of battery cells; (b) a cooling air chamber provided below said battery chamber; and (c) a fan which supplies cooling air into said cooling air chamber at a static pressure not less than atmospheric pressure; (d) an air discharge outlet provided above said battery chamber and configured to discharge air inside said battery chamber to an outside of said battery pack; (e) a bottom part that separates said cooling air chamber and said battery chamber, and on which said plurality of battery cells is placed, said bottom part being provided with air inlet holes which guide cooling air upward at positions corresponding to gaps between said plurality of battery cells wherein each gap between said plurality of battery cells has a plurality of air inlet holes; and (f) a straightening plate provided in said cooling chamber for diffusing kinetic energy of said cooling air and equalizing said static pressure within said cooling air chamber, wherein said straightening plate is provided above said fan with a clearance from said fan, and a planar shape of said straightening plate is formed greater than a planar outer shape of said fan and both said straightening plate and said bottom part are oriented orthogonally to the air flow initially resulting from the fan.