Estimation of lithium-ion battery model parameters using experimental data

Abstract

Lithium battery cells are commonly modeled using an equivalent circuit with large lookup tables for each circuit element, allowing flexibility for the model to match measured data as close as possible. Pulse discharge curves and charge curves are collected experimentally to characterize the battery performance at various operating points. It can be extremely difficult to fit the simulation model to the experimental data using optimization algorithms, due to the number of values in the lookup tables. This paper describes a detailed procedure of how estimate the battery model parameters using experimental data. the experiment is realized with a computer that realize the control of charge and discharge process sending SCPI commands via serial communication to the Four Quadrant Power Supply from Kepco Inc. with 100V and 10A as limits. The estimation of each battery model parameter is made to lithium-ion battery with a capacity of 20 Ah, and the presented methodology can be easily adapted to any type of battery. The mean objective of the results is estimate the battery parameters to posteriorly use the battery model to estimate the SoC by adaptive method. As results, after the estimation of each parameter, it is possible to observe the resistances exponential behavior, where they decrease as SoC decrease. As conclusions, this paper can contribute to the field of measurement of magnetic and non electric quantities, where it helps to determine the Battery Equivalent Circuit Model and its parameters.