Battery management device, power supply device, and SOC estimation method

摘要

The current integration estimating unit (51) estimates the SOC of the battery by integrating the value of the current flowing through the battery. The open-circuit voltage estimation unit (52) estimates the open-circuit voltage value of the battery from a value indicating the state of the battery including at least the value of the measured voltage of the battery, and specifies the SOC corresponding to the open-circuit voltage value. The SOC determination unit (53) adopts the SOC estimated by the open circuit voltage estimation unit (52) during non-charge / discharge of the battery, and is estimated by the current integration estimation unit (51) during charge / discharge of the battery. The SOC is estimated with high accuracy by adopting the SOC as it is or after being corrected with the SOC estimated by the open-circuit voltage estimation unit (52). In parallel with the estimation of the SOC, the SOH estimation unit (54) calculates the SOH of the battery based on the change value of the SOC adopted by the SOC determination unit (53) and the current integrated value in the period required for the change. presume.