STATE ESTIMATING DEVICE OF SECONDARY BATTERY

摘要

A battery state estimating unit estimates an internal state of a secondary battery according to a battery model equation in every arithmetic cycle, and calculates an SOC based on a result of the estimation. A parameter characteristic map stores a characteristic map based on a result of actual measurement performed in an initial state (in a new state) on a parameter diffusion coefficient and a DC resistance in the battery model equation. The parameter change rate estimating unit estimates a DC resistance change rate represented by a ratio of a present DC resistance with respect to a new-state parameter value by parameter identification based on the battery model equation, using battery data measured by sensors as well as the new-state parameter value of the DC resistance corresponding to the present battery state and read from the parameter characteristic map.