Remaining-amount estimation device and method for secondary battery

摘要

An SOC-estimation-value-depending gain selection unit multiplies the deviation of an SOC estimation value (last calculated value) relative to an estimated SOC by a correction gain G1 to calculate a correction value. The SOC-estimation-value-depending gain selection unit selects a relatively small correction gain G1 when the SOC estimation value lies in the range in proximity to excessive charging and the SOC estimation value is corrected to a smaller value (toward the SOC control center), and when the SOC estimation value lies in the range in proximity to excessive discharging and the SOC estimation value is corrected to a larger value (toward the SOC control center). Thus, the correction is performed so as to indicate the safe side value for the secondary battery in charge/discharge control when the SOC estimation value is in proximity to excessive charging or excessive discharging.