Thermal Performance of EV and HEV Battery Modules and Packs

Abstract

Thermal issues associated with electric vehicle (EV) and hybrid electric vehicle (HEV) battery packs can significantly affect performance and life cycle. Temperature variations from module to module in a battery pack could result in reduced performance. As part of the U.S. Department of Energy's Hybrid Propulsion Systems Program, the National Renewable Energy Laboratory (NREL) works with automobile and battery manufacturers on thermal analysis and management of valve-regulated lead-acid battery packs for HEVs. We use fundamental heat transfer principles and finite element analysis tools to predict the temperature distributions in cells, modules, and packs. We use infrared photography and liquid crystal thermography to obtain thermal images of the surface of battery modules under HEV charge/discharge profiles. In this paper, we provide an overview of related literature on battery thermal management, along with non-proprietary results of some of our work.