A Battery State of Charge Estimation Using Real-Time Characterization Data

Generally, the State of Charge (SoC) of a battery is used as an important parameter in the management energy system. Since the electrochemical process of such a device is complex and it is impossible to be accessed, its parameters such as SoC or energy storage capacity cannot directly be measured by any sensor. Besides, its dynamic energy storage does not depend only on its internal characteristics, but it also depends on its operating conditions. A method of the SoC determination may use certain electrical parameters such as the open circuit voltage or the internal impedance of the battery. For example, the Open Circuit Voltage OCV method is often described by a lookup table. This type of method is simple to implement and provides a good estimation of the SoC. However, an accurate estimate of SoC can only be obtained with an accurate measurement of OCV. This is due to an equilibrium voltage can only be measured after very long period of battery relaxation. In this work, we will study the different methods of SoC estimation for different batteries using real-time characterization data.