Study of the Effect of Temperature and C-Rate on Inductor Based Active Cell Balancing for a Li-Ion Based Battery

Li-on based battery sources find immense significance in Electric Vehicle (EV). The battery management system (BMS) of a battery pack overlooks its respective components for safe and reliable operation of the pack. The BMS have various functionalities, one of them being the cell equalization module embedded in the BMS which helps to detect any unbalance in the series connected cells in the battery pack and equalize the charge stored among the individual cells of the battery pack to enhance the total amount of energy available from the battery cells. For State of Charge (SOC) based cell balancing, it is important to detect the cell parameters accurately and estimate the current status of battery current and terminal voltage. Inductor-based cell balancing offers higher efficiency compared to resistor-based balancing, as the inductor transfers energy between cells with minimal power losses. For the simulation of the system in hand, a precise and accurate modelling of Li-ion is required which could mimic the operation of the battery cell for the given application. This paper explores the 1-RC electrochemical model of a Li-ion battery and studies the effect of variation of temperature and different c-rate of charging current on the inductor-based cell equalization model. The analysis and results align and are in agreement with theoretical studies.