The estimation of radial temperature distribution in cylindrical battery cells under unknown cooling conditions

The estimation of temperature inside a battery cell requires accurate information about the cooling condition even when the battery surface temperature is measured. This paper presents a model-based approach for estimating the temperature distribution inside a cylindrical battery under the unknown convective cooling condition. A reduced order thermal model using a polynomial approximation of the temperature profile inside the battery is used. A Dual Extended Kalman Filter (DEKF) is then applied for the identification of the convection coefficient and the estimation of the battery core temperature. Experimental results show that the proposed DEKF-based estimation method can provide an accurate prediction of the core temperature under the unknown cooling condition by measuring the battery current and voltage along with surface and ambient temperatures.