IC Curve-Based Lithium-Ion Battery SOC Estimation at High Rate Charging Current

Abstract

The safety of battery operation requires a reliable battery management system (BMS) with an accurate and rapid estimation of battery state of charge (SOC), especially at fast charging scenarios. This article proposes an incremental capacity (IC) curve-based battery SOC estimation method at a high rate charging current, where SOC-IC functions are derived to estimate battery SOC using the measured IC value. Moreover, various charging currents and battery packs with different battery numbers are used to validate the effectiveness of the proposed method. Results demonstrate that the proposed method can provide accurate battery SOC estimation results at high rate charging current and can be easily adopted for varying charging current and battery pack. With its accuracy and computational efficiency, the proposed method can be incorporated into battery BMS for providing reliable SOC estimation at fast charging conditions.