Battery system and charging rate estimation method

Abstract

To provide a battery system capable of estimating an SOC in a short time.SOLUTION: A battery system 1 for estimating an estimation charging rate of a secondary battery 2 comprises: a voltage detection unit for detecting a voltage of the secondary battery 2; a thickness measurement unit 12 for measuring a thickness of the secondary battery 2; and a charging rate estimation unit 13 for estimating the estimation charging rate of the secondary battery 2. The secondary battery 2 has a hysteresis characteristic in which a charging rate in charging differs from that in discharging for the same voltage and a hysteresis characteristic in which a charging rate in charging differs from that in discharging for the same thickness. The charging rate estimation unit 13 calculates a voltage charging rate on the basis of the voltage detected by the voltage detection unit, calculates a thickness charging rate on the basis of the thickness measured by the thickness measurement unit 12, and estimates the estimation charging rate on the basis of the voltage charging rate and the thickness charging rate.SELECTED DRAWING: Figure 1

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