Fast Approach of Open Circuit Voltage Estimation for Li-ion Battery Based on OCV Error Compensation

As in a modern world, usages of rechargeable battery become sixth subsistence factor of human life from small appliances such as smart phone up to large industry scale like electric vehicle transportation. Hence, knowing the accurate remaining capacity or State of Charge (SOC) of the battery is a necessary parameter. Open Circuit Voltage (OCV) is an important indicator to show battery SOC. Unfortunately, we cannot measure OCV directly from the terminal of battery. To predict OCV after the battery has been charge or discharge, this process takes a very long resting time in order to let the reaction of chemistry inside the battery reach its steady state. To get rid of waste resting time, this paper proposes an easy and fast approach to estimate battery OCV by using OCV error compensation method. The Simulation and Experimental results show the proposed method is easy, fast and effective for OCV estimation.