Battery cell modeling for energy and power estimations in a battery pack applied to a HEV

In this paper we present the concept of cell battery modeling and its importance to the battery management system of a HEV. A review of possible equivalent circuits to model the battery electric behavior is made and we present the proposed equivalent circuit to this application. This model takes into consideration the temperature, current and state of charge conditions in which the battery is being used, without adding equations to state-space model. Then, we discuss the laboratory tests that need to be performed to provide information for the models. A test procedure is presented in 6 different scenarios. Finally, the results of the application of this methodology for a NMC battery cell are showed. The maximum RMSE found between real and estimated voltage by the model was 1.0041e-4. A state of charge estimation using this model showed a 1.995e-6 mean squared error.