Patent ID: 8378687

Claim:
A measuring method of a battery, comprising: measuring frequency characteristics of an internal impedance of the battery by an AC impedance method using a measuring apparatus; determining, by a computer, frequency characteristics of an impedance using an impedance model of the battery; determining, by the computer, parameters of elements constituting the impedance model so that calculation results of frequency characteristics of the impedance match measured results of frequency characteristics of the internal impedance; and determining from the parameters, by the computer, a parameter of an element representing an ease of mobility of charges on a surface of a positive electrode of the battery and that of an element representing the ease of mobility of charges on the surface of a negative electrode, wherein the battery is a lithium ion battery, characteristics of the lithium ion battery are measured by the computer by comparing a size relation between the parameter of the element representing the ease of mobility of charges on the surface of the positive electrode of the lithium ion battery and that of the element representing the ease of mobility of charges on the surface of the negative electrode of the lithium ion battery, and an initial value to be given to a parameter of an element related to lithium ion diffusion in the negative electrode is set to be larger than that to be given to a parameter of an element related to lithium ion diffusion in the positive electrode when determining optimal values of the parameters.