Partial Charging Method for Lithium-Ion Battery State-of-Health Estimation

In this paper a lithium-ion battery State-of-Health (SoH) estimation method denoted Partial Charging Method (PCM) is proposed. The method is applied to Nickel-Manganese-Cobalt (NMC) battery cells exposed to cycling and calendar aging at 11 different test conditions. The influence of partial charging voltage intervals and charging rate on the SoH estimation error has been investigated. The results indicate that the PCM is independent on the charging rate and the aging conditions, and a SoH estimation Root-Mean-Square-Error of 2.4% is achieved.