Battery thermal management comparison for orthogonal arrangement of battery modules in an EV battery pack

In recent years, environment concerns led to rise of electrification of vehicles across the globe. OEMs started adopting hybrid and battery electric vehicle technologies and even found the economic viability for their usage. Electric vehicle batteries, which contains lithium-ion chemistry, requires specific operating temperature range for effective power and energy output. The battery operating range is generally considered between 25°C to 35°C depending on battery internal chemistry. Thus, it necessitates use of battery thermal management which refers to heating and cooling of batteries by various methods such as air cooling - both active and passive strategies, liquid cooling and refrigeration cooling [1]. This paper describes performance comparison between air and liquid cooling for a prototype battery box based on specific parameters such as temperature variation within cell and within pack, rate of temperature drop and parasitic losses during their operations. Based on the comparison, it is found that liquid cooling meets most of the battery thermal requirements. Also, a simple control logic is elaborated which then can be use for triggering of liquid cooling during vehicle running conditions.