| 摘要 |
A State of Charge (SOC) estimation device for a secondary battery in which a correlation curve indicating a relationship between an SOC and Open Circuit Voltage (OCV) differs between a charging process and discharging process. The SOC estimation device estimates the SOC based on a relational formula in which as actually measured OCV increases, weights are assigned to the correlation curve indicating the relationship between the SOC and OCV in the discharging process, and as actually measured OCV decreases, weights are assigned to the correlation curve indicating the relationship between the SOC and OCV in the charging process. With the SOC estimation device, when the correlation curve indicating the relationship between the SOC and OCV differs between the charging and discharging processes, not only when the secondary battery is being used but also when use is started after use of the secondary battery is stopped, SOC can be accurately estimated. |
