METHOD AND APPARATUS OF ESTIMATING SALT CONCENTRATION IN ELECTROLYTE SOLUTION OF SECONDARY BATTERY

A method of estimating a salt concentration in an electrolyte solution of a secondary battery includes: a capacity acquiring step S of acquiring a capacity of a secondary battery that is to be an estimation object; a discharging time acquiring step S of acquiring a discharging time when the secondary battery is discharged under a predetermined condition; and a salt concentration estimating step S of estimating the salt concentration in the electrolyte solution of the secondary battery based on the acquired capacity of the secondary battery, the acquired discharging time, and a table recording a relationship between the capacity, the discharging time, and the salt concentration in the electrolyte solution of the secondary battery, related to the secondary battery that is to be the estimation object.