Calculation and Characteristics Analysis of Lithium Ion Batteries’ Internal Resistance Using HPPC Test

Internal resistance of battery can really reflect its own characteristics, which including health status of the battery, inconsistency, state of charge, thermal runaway. Method to calculate the internal resistance of the battery using HPPC (Hybrid Pulse Power Characterization) test which proposed by the FreedomCAR is introduced. Ohmic resistance, polarization resistance, discharge resistance and regen resistance are calculated based on MATLAB programming using HPPC test. The differences between the four kinds of internal resistance of lithium ion batteries are compared. Characteristics of the four kinds of internal resistance in charged-state and discharged-state are analyzed.