Patent ID: 7811699

Claim:
A battery pack, comprising: a plurality of battery cells, a housing substantially enclosing the plurality of battery cells, a cooling air intake port and a cooling air exhaust port defined within the housing, at least one cooling air passage extending between the cooling air intake port and the cooling air exhaust port, the at least one cooling air passage being at least partially defined by peripheral side surfaces of the battery cells and an inner surface of the housing, wherein the plurality of battery cells includes upstream battery cells located at an upstream portion of the at least one cooling air passage and downstream battery cells located at a downstream portion of the at least one cooling air passage; and at least one slope formed on a portion of the inner surface of the housing that defines the downstream portion of the at least one cooling air passage, each of the at least one slope locally-projecting from the inner surface of the housing towards a single one of the downstream battery cells and changing direction of cooling air flowing through the at least one cooling air passage towards the peripheral side surface of the single one of the downstream battery cells; wherein the at least one slope comprises at least two slopes, each of the at least two slopes projecting towards a same one of the downstream battery cells located at a furthest downstream position.