Investigating the effects of variable pulse charging on temperature during charging of battery electric vehicles

• Main Authors: Oruganti K.S.P., Vaithilingam C.A., Ramasamy A.
• Other Authors: 57209333413
• Format: Article
• Published: Elsevier Ltd 2025
• Subjects: State of charge; % reductions; Battery chargers; Battery pack; Electrochemical impedance spectroscopy; Electrochemical-impedance spectroscopies; EV charger; Pulse charger; Pulse charging; Reduction in charging temperature; Variable pulse charging

This study investigates the efficacy of variable pulse charging (VPC) on charging 18,650 secondary battery packs (12 V, 20 Ah) with NMC chemistry. VPC, a modern technique applied to secondary battery charging, aims to mitigate effects like a thermal runaway and thermal propagation caused by increased charging temperature. VPC involves varied duty factors (10 % to 90 %), charging rates (0.5C, 1C, 1.5C), and an optimal switching frequency determined through frequency response analysis. Its digital model is based on in situ electrochemical impedance spectroscopy measurements and MATLAB/Simulink simulations. At charging rates of 0.5C (10 A), 1C (20 A), and 1.5C (30 A), the temperature of the battery pack reaches 42.46 �C, 57.87 �C, and 70.37 �C, respectively. However, implementing VPC at a 50 % duty factor yields temperature reductions of 3.66 �C, 5.06 �C, and 5.42 �C, respectively. Similarly, employing VPC at a 10 % duty cycle results in temperature reductions of 11.2 �C, 17.7 �C, and 19.1 �C, respectively. The results indicate a significant reduction in charging temperature compared to constant current charging. Furthermore, the 1C condition is validated using a custom-made dual active bridge DC-DC variable pulse charger. In conclusion, applying optimal frequency-based VPC with specific duty factors demonstrates the potential to reduce temperature elevation during battery pack charging significantly. ? 2024 Elsevier Ltd