Energy Efficient Battery Heating in Cold Climates
In cold climates batteries in electric and hybrid vehicles need to be preheated to achieve desired performance and life cycle of the energy storage system and the vehicle. Several approaches are available: internal core heating; external electric heating of a module; internal electric heating in the module around each cell, internal fluid heating around each cell; and external fluid heating around each module. To identify the most energy efficient approach, we built and analyzed several transient thermal finite element models of a typical battery. The thermal transient response of the battery core was computed for the first four heating techniques, which were compared based on the energy required to bring the battery to the desired temperature in a given time. Battery core heating was the most effective method to warm battery quickly with the least amount of energy. Heating the core by applying high frequency alternating currents through battery terminals is briefly discussed.