A Multi‐Component Thermoelectric Modeling Framework for Electric Vehicles' Air‐Cooled Battery Packs

Battery systems, which play a critical role in the proliferation of large‐scale electric vehicle adoption, still face challenges related to their temperature control. Many studies already present modeling approaches for the thermal phenomena in battery cells or modules. However, there is still a research gap in the complete modeling of the whole battery pack, considering multiple components, for example, the presence of cable connections and their influence on the battery cells' temperature. This work aims to contribute to this topic, with a thermoelectric modeling framework for air‐cooled modular battery systems, considering the influence of different elements inside the battery pack. The models combine an analytical lumped parameter electric model for the battery module with an experimentally calibrated thermal‐fluid 3D finite element model (FEM). After the experimental electric and thermal characterization of a single battery module, a 3D FEM model in COMSOL Multiphysics is built for the whole battery pack at different loads. Results show a good accuracy of the proposed method, with a deviation of 2.1% between simulation and experimental results. It was verified that the presence of cable connections produced a higher temperature on the top of the battery modules. The tested air cooling methods were effective for reducing these local hotspots, reducing the cables and battery modules' temperatures from 125°C and 61.6°C to 45°C and 53.5°C, respectively, at full load, while also stabilizing the battery cells' average temperature. This shows the importance of modeling the whole battery pack and its auxiliary components for an adequate temperature prediction of the battery cells' temperature.