Storage battery residual quantity estimation device and residual quantity estimation method

摘要

PROBLEM TO BE SOLVED: To solve the problem that trying to calculate remaining capacity of a storage battery more accurately increases the number of arithmetic processes.SOLUTION: A remaining capacity estimating device for storage batteries includes: a current detector which detects a level of current flowing through a storage battery; a voltage detector which detects a level of voltage across output terminals of the storage battery; and a storage battery remaining capacity estimation unit which estimates a level of stored power from a relationship between stored power and an open-circuit voltage of the storage battery, the detected level of current, and the detected level of voltage, computes a stored power level variation which is the amount of change in the stored power level, and increases or decreases the stored power level in accordance with the computed stored power level variation.