METHOD AND APPARATUS FOR ESTIMATING STATE OF CHARGE OF LITHIUM ION BATTERY

摘要

A method and apparatus for estimating a state of charge of a lithium ion battery. The method comprises the steps of: A. fitting a relationship between an open circuit voltage and a state of charge of a lithium ion battery; B. estimating the state of charge of the lithium ion battery using an observer method; and C. with regard to the state of charge of the lithium ion battery estimated in step B, if it is greater than a predetermined threshold value, estimating the state of charge of the lithium ion battery using the observer method, and if it is less than the predetermined threshold value, estimating the state of charge of the lithium ion battery using an ampere-hour integral method. By means of the method and apparatus for estimating a state of charge of a lithium ion battery in the present invention, defects of an ampere-hour integral method and an observer method can be avoided, and the estimation accuracy in a whole life cycle and a whole state of charge area is improved.