Effect of Sample Interval on the Parameter Identification Results of RC Equivalent Circuit Models of Li-ion Battery: An Investigation Based on HPPC Test Data

The validity of the equivalent circuit model (ECM), which is crucial for development lithium-ion batteries (LIBs) and state evaluation, primarily dependent on precision findings parameter identification. In this study, commonly used first-order RC (1-RC) second-order (2-RC) models were selected A time series voltage with different sample intervals function fitting based least square method, extracted from hybrid pulse power characteristic (HPPC) test data a commercial punch LIB, set to be 0.1 s, 0.2 0.5 1.0 s evaluate effect interval identification results. When more than results reveal that 2-RC model’s goodness fit marginally declines, some scenarios, bias between fitted terminal curve increases obviously. With all under consideration, 1-RC imitative satisfactory. This work demonstrates samples, in addition method itself, affects accuracy robustness identification, showing larger advantages low frequency compared model.