Patent ID: 7217473

Claim:
A fluid cooled battery pack for a vehicle drive system, said battery pack comprising: a battery pack case, said case including at least one coolant inlet and at least one coolant outlet; a plurality of battery modules disposed within and arranged in a matrix configuration within said case, each of said battery modules including a plurality of battery cells, said battery modules positioned within said case such that said battery modules are spacedly disposed from other battery modules to form intermodular gaps between said modules, said intermodule gaps providing coolant flow channels between said battery modules; at least one coolant transport means, said coolant transport means causing said coolant to enter said coolant inlet of said case, to flow through said coolant flow channels and to exit said coolant outlet; and wherein the coolant flow channels are sized within a range: a) such that narrowing the intermodule gap between modules results in decreasing cooling fluid volumetric flow while increasing cooling fluid velocity; b) to maintain a temperature difference between said battery modules of 8° C. or less; and c) to maintain the maximum temperature of said battery modules to 65° C. or below.