Patent ID: 8231996

Claim:
A battery pack comprising: a plurality of battery cells each having a cylindrical housing with an anode at one end of the housing; a conducting plate disposed to make electrical contact with the plurality of battery cells; a first thermal interface material disposed between an anode end of each of the battery cells and the conducting plate to achieve thermal contact between the conducting plate and the plurality of battery cells such that the conducting plate provides thermal spreading to reduce temperature differences between individual battery cells of the plurality of battery cells; a sealed heat pipe containing a fluid that exists partially in a liquid phase and partially in a gaseous phase, the heat pipe having an evaporation section from which the liquid phase fluid evaporates and a condensation section from which the gaseous phase fluid condenses, the heat pipe further having (i) first and second flat surfaces disposed in thermal contact with first and second subsets of the battery cells, respectively, and (ii) a third flat surface adjacent the evaporation section; and a second thermal interface material disposed between the conducting plate and the third flat surface of the heat pipe to achieve thermal contact between the evaporation section of the heat pipe and the conducting plate.