Internal state estimating device for secondary battery and method for estimating internal state of secondary battery

An internal state estimating device for a secondary battery, comprising:

• a sensor detecting an output of the secondary battery;
• an internal state estimating portion estimating an internal state of said secondary battery by providing a parameter value including a material property value of said secondary battery to a battery model capable of estimating an internal reaction of said secondary battery based on said parameter value, and in addition, calculating a predicted value of said output of said secondary battery based on an estimation result;
• and
• a parameter generating portion providing said parameter value to said internal state estimating portion, and generating an updated parameter value that is said parameter value provided to said internal state estimating portion when said internal state is estimated next time by updating said parameter value based on a value detected by said sensor and said predicted value,
• said parameter generating portion including
• a parameter estimating portion estimating said parameter value such that said detected value is equal to said predicted value, and
• a parameter updating portion storing said parameter value, and providing said parameter value stored to said internal state estimating portion while updating said parameter value stored to said updated parameter value based on an estimation result of said parameter estimating portion, and
• the internal state estimating device for a secondary battery further comprising:
• a deterioration characteristic storage portion storing a deterioration characteristic indicating a standard change in said parameter value with respect to a degree of use of said secondary battery in advance;
• and
• a deterioration estimating portion estimating a deterioration state of said secondary battery based on said deterioration characteristic and said updated parameter value.