SECONDARY BATTERY STATE DETECTING DEVICE AND SECONDARY BATTERY STATE DETECTING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a secondary battery state detecting device and a secondary battery state detecting method, capable of easily and accurately detecting that electrolytic solution of a secondary battery is refilled with water.SOLUTION: A secondary battery state detecting device 1 for detecting a state of a secondary battery 14 mounted on a vehicle comprises: deriving means (control unit 10) for deriving an element value of an equivalent circuit of the secondary battery; calculating means (control unit 10) for calculating open circuit voltage of the secondary battery; and determining means (control unit 10) for determining whether electrolytic solution of the secondary battery is refilled with water from the change of the element value of the equivalent circuit derived by the deriving means and the change of the open circuit voltage calculated by the calculating means.SELECTED DRAWING: Figure 1