Patent ID: 8173286

Claim:
A battery pack comprising: a lower case having a longitudinal direction; a battery stack supported on said lower case and arranged longitudinally thereon, wherein said battery stack has two longitudinal ends; a fan supported on said lower case and disposed adjacent to said battery stack on one longitudinal end of said battery stack, said fan having a fan opening for supplying and exhausting a medium of said battery stack; an upper case configured to cover said battery stack and fan, wherein said upper case joins with said lower case to enclose said battery stack and fan, and wherein a chamber space is formed between said upper case and said battery stack; and a junction duct for guiding supply and exhaust of said medium between said fan opening and said chamber space; said junction duct comprises a duct lower unit having a duct opening formed at a location facing said fan opening and a periphery of said duct lower unit extends to contact said upper case, wherein said duct lower unit periphery extends transversely to a width of said upper case and extends longitudinally from one of said longitudinal ends of said battery stack to an end of said upper case such that a duct space is formed between said duct lower unit and said upper case, and said duct space is connected to said chamber space.