Development of thermal model for estimation of core temperature of batteries

Core temperature (Tc) estimation plays an important in role in establishing an effective thermal management system of a battery. In the present work, Tc of a lead acid (Pb) battery was estimated using a Kalman filter, based on a thermal model of the battery using convection resistances and capacitances. The governing equations based on measured surface temperature (Ts) and ambient temperature (Tamb) were derived. Since Tc cannot be measured directly, estimation technique was used to predict the same using measured Ts and Tamb. Five test cases for which the profiles of Tc versus time were available were analyzed. It was found that the errors in the predictions varied from 0.25 °C to 3.5 °C., depending on the nature of Tc profiles, with minimum errors when Tc has slow variations with time.