An online capacity estimation method for lithium ion battery cells using the significant points

摘要

This paper presents an online capacity estimation method for lithium ion battery cells. The method takes advantage of the significant points defined by state of charge (SOC) and transferred charge. And the unscented Kalman filter based (UKF-based) SOC estimation method is applied for the selection of the significant points. Based on multi significant points, the accurate and robust online capacity estimation can be achieved. The method is validated on a commercial C/NCM battery cell with dynamic load profiles, and proves to provide accurate and robust capacity estimation.