Fast State of Health Estiamtion for Lithium-ion Batteries Based on Partial Charging Time

The accurate estimation of state of health (SOH) for lithium-ion batteries is critical to the safety and reliability of energy storage system. However, SOH involves complex electrochemical mechanisms within the cell and cannot be measured directly. A method based on partial charging time is proposed to estimate battery SOH. In this study, Firstly, the incremental capacity characteristics with various aging degrees are analyzed, based on which, the specific terminal voltage interval is selected. The constant current charging time during specific voltage interval is selected as the health indicator. Then, the Gaussian process regression method is employed to establish the corresponding relationship between battery health indicator and SOH to achieve accurate and fast SOH estimation. Finally, the NASA dataset is adopted to verify the effectiveness of the proposed method, which indicates the superiority with the MAE and RMSE less than 1.8% and 1.6% respectively.