AbstractTraditional automobile exhaust contains a large amount of thermal energy. Thermoelectric generators (TEGs) can store recovered electrical energy into battery packs and supply to vehicle‐mounted electrical equipment. A reasonable battery pack structure is designed to facilitate stable vehicle operation based on the actual conditions of the vehicle. This paper presents investigation on thermal performance of air‐cooled li‐ion battery pack in different arrangements. Taking the AVIC (Aviation Industry Corporation of China) lithium battery as the research object, a battery pack model based on T‐type parallel ventilation structure is established in Fluent, and the accuracy of the model is verified through experiments. In the same battery module, there are three typical arrangements of forming battery cells into an equal arrangement, an increasing arrangement, and a decreasing arrangement. The changes of the temperature field of the battery pack under different discharge rates and wind speeds are studied, respectively. Studies have found that battery pack arranged in decreasing order has the best temperature consistency and the temperature difference is reduced by 14.82% and 6.21%, respectively, at 1C and 2C discharge rates, compared to the equally spaced arrangement.