Design and Implementation of a Smart Lithium-Ion Battery Capacity Estimation System for E-Bike

This paper proposes a smart lithium-ion battery capacity estimation method for electric bicycles. Battery capacity information informs the electric vehicle driver of the residual battery working time, thus facilitating the estimation of mileage of electric bicycle and timing of battery charging to avoid overcharging or over-discharging. Factors such as different discharge rates, environmental temperature, battery charge and discharge efficiency and battery aging affect the released capacity of battery, which is an electrochemical reaction of battery. In addition to integrating the advantages of the coulometric measurement and open circuit voltage measurement methods, and the proposed smart lithium-ion battery capacity estimator also incorporates discharge current, temperature, battery aging, as well as charging efficiency factors into capacity correction to develop a highly accurate PIC single-chip lithium-ion battery capacity estimation system.