A New SOH Prediction Model for Lithium-ion Battery for Electric Vehicles

State of health (SOH) prediction for lithium-ion battery is a key technology, which is a foundation of ensuring electrical vehicle system's safety and reliability. The paper proposes a novel SOH prediction model of lithium-ion battery based on sample entropy (SampEn). The cell voltage sequence under the HPPC (hybrid pulse power characteristic) profile is used as the input of the proposed model. The prediction model is established by calculating the sample entropy, using Arrhenius formula, optimizing and fitting polynomial. The tests of other five batteries are used to verify the model, with the prediction relative errs within two percent.