Thermal Electrochemical Dynamic Modeling of Sealed Lead Acid Batteries

Abstract

Limitations to battery technology ranks second as the most vital problem facing the electronic and mechanical engineering industry in the future. The life span and performance of batteries specifically SLI (Starting – Lighting – Ignition) lead acid batteries have been well documented by researchers [2-9]. One of the utmost problems facing the lead acid battery performance is the thermal effect on the batteries active materials and capacity. Despite the fact that there has been some focus on the thermodynamic principles in the battery performance, a comprehensive model of the effects is lacking. The Auburn University research will address the absence of an in-depth model of battery performance and different temperatures during the life span. The modeling focuses on the Gibbs free energy, entropy, and enthalpy changes for varying temperatures for different charging and discharging parameters. Also, the model incorporates control volumes for each of the major constituents of the battery cells (casing, electrolyte, and electrodes). Once the thermal effects are addressed through simulation, the MATLAB model will be tested against experimental results using a thermal chamber provided by Auburn University. The thermal chamber will be used to vary the atmospheric temperature to the extremes between 0 and 80 degrees Celsius. Laboratory results will be used to validate the computerized modeling of battery performance. Additionally, vibration testing will be set to reproduce the battery environment in automotive applications in close proximity to the vehicle engine and suspension. Thermal effects will be modeled using finite element software for further representation of the battery performance under extreme environments.