Analytic Analysis of the Data-Dependent Estimation Accuracy of Battery Equivalent Circuit Dynamics

This letter investigates the fundamental relationship between the estimation accuracy of the equivalent circuit dynamics and the measurement data, i.e., input current and output voltage. Specifically, the Cramer-Rao bounds of the model parameter estimation are derived analytically as explicit functions of generic input/output data. The derivation is performed in both discrete-time and Laplace representation, and for both single- and multi-variable estimation scenarios. The sinusoidal current input is then used as an example for illustration. The analytic results could benefit the estimation practice in multiple ways, including the estimation reliability/robustness evaluation, offline experiment design for system identification, and data selection for online estimation.