Excitation Pulse Influence on the Accuracy and Robustness of Equivalent Circuit Model Parameter Identification for Li-ion Batteries

An experimental dataset obtained from testing the LG INR18650 MJ1 lithium-ion battery with a capacity of 3500 mAh was used. To parameterize the battery's equivalent circuits, data on the voltage response to rectangular test current pulses of various durations (from 9 to 144 seconds) and amplitudes (in the range of 0.5C, 1C, 2C, 3C), recorded within the middle state-of-charge zone (55–45% SoC), were used. A total of 12 pulse duration and current combinations were generated, from which model parameters were extracted using the procedure for minimizing the root-mean-square error of the voltage. Nine validation current profiles, including eight meandering currents and one based on a real-world driving scenario (Urban Dynamometer Driving Schedule, UDDS), were used to check the quality of the model parameterization.