Energy efficient thermal and hydraulic performance analysis of a serpentine liquid cooled lithium ion battery pack for electric vehicles

Efficient thermal regulation of lithium ion battery packs is essential for electric vehicle safety, durability, and energy efficiency, particularly under high power operation. This study numerically investigates the thermal and hydraulic performance of a serpentine liquid cooled aluminum cold plate integrated into a 288-cell prismatic battery pack. A three-dimensional conjugate heat transfer model was developed in ANSYS Fluent to resolve coupled heat generation, conduction, and coolant flow behavior under a total thermal load of 2880 W. At a coolant flow rate of 9.84 L per minute, the proposed design-maintained cell temperatures between 298 and 308 K, with a maximum temperature of 315.3 K and temperature non-uniformity of plus or minus 4 °C. The pressure drop across the cooling channels was 15 kPa, while pumping losses accounted for only 4.2% of the total thermal energy removed. Compared with a conventional parallel flow cold plate, the serpentine configuration reduced peak temperature by 2.7% and improved temperature uniformity by 20%. The novelty of this work lies in the integrated quantitative evaluation of thermal performance, hydraulic penalty, and energy efficiency at full pack scale, providing design guidance for compact and energy conscious battery thermal management system.