A Comprehensive Review of State of Charge Estimation

Modern energy storage relies predominantly on lithium-ion batteries, thus requiring a dependable Battery Management System (BMS). One of the most demanding BMS tasks is estimating the battery’s State of Charge (SOC), which is estimated indirectly using voltage, current and temperature readings. This article reviews techniques that are currently utilized for estimating SOC such as Direct methods, model-based techniques and data-driven techniques. The article will evaluate and discuss the traditional and hybrid methods, strengths and weaknesses of each technique. This paper Summarizes the key gaps which are identified to full fill the SOC estimation.