Optimization Strategy for Battery Electric Vehicle (BEV) DC Fast Charging (FC) in Cold Environments

BEV fast charging in cold weather is severely limited by slow kinetics, high impedance, and degradation concerns in the lithium battery. This paper presents an offline open-loop optimization approach that considers the electrical and thermal behavior of the battery, including its thermal management system. This scalable approach is experimentally validated at cold temperature in a custom thermal chamber on a single Tesla Model 3 battery module using a Battery Assisted DC Fast Charger with four parallel-connected 25 kW DC-DC converters.