Abstract: A voltage detection unit detects voltage between both ends of a power storage unit. A current detection unit detects current flowing through the power storage unit. A control unit estimates a state of charge (SOC) of the power storage unit using an open circuit voltage (OCV) method based on the voltage detected by the voltage detection unit and estimates the SOC of the power storage unit using a current integration method based on the current detected by the current detection unit. The control unit compares the SOC estimated using the OCV method with the SOC estimated using the current integration method to determine whether micro short circuit occurs in the power storage unit.

Abstract: A voltage detection unit detects voltage between both ends of a power storage unit. A current detection unit detects current flowing through the power storage unit. A control unit estimates a state of charge (SOC) of the power storage unit using an open circuit voltage (OCV) method based on the voltage detected by the voltage detection unit and estimates the SOC of the power storage unit using a current integration method based on the current detected by the current detection unit. The control unit compares the SOC estimated using the OCV method with the SOC estimated using the current integration method to determine whether micro short circuit occurs in the power storage unit.

Abstract: A battery-state estimation device obtains, at a first timing, a first resistance value corresponding to a first open circuit voltage of a lithium-ion secondary battery and a second resistance value corresponding to a second open circuit voltage, which is higher than the first open circuit voltage, of the lithium-ion secondary battery. Further, the battery-state estimation device obtains, at a second timing which is different from the first timing, a third resistance value corresponding to the first open circuit voltage and a fourth resistance value corresponding to the second open circuit voltage. The battery-state estimation device determines presence or absence of lithium deposition in the lithium-ion secondary battery, based on a magnitude relation between a first variation amount of the third resistance value with respect to the first resistance value and a second variation amount of the fourth resistance value with respect to the second resistance value.

Abstract: A battery status estimation device includes an SOC determination unit for determining whether a charge rate of a battery should be estimated based on a full charge capacity or a dischargeable capacity of the battery, a full charge capacity estimation unit for estimating the full charge capacity, a discharge capacity estimation unit for estimating the dischargeable capacity, and a current integrated estimation unit for estimating the charge rate of the battery based on the full charge capacity or the dischargeable capacity.

Abstract: An electricity storage device includes a battery, a discharge device, and a controller for controlling charging and discharging of the battery. The discharge device includes a swelling member, a movable switch, and a discharge switch. When the swelling member swells, the movable switch is moved. When the movable switch is moved, the discharge switch is turned on. A signal indicating that the discharge switch is turned on is transmitted to the controller to cause the battery to start discharging of electricity.

Abstract: Internal resistance estimating part estimates internal resistance R of a secondary battery. SOH_R calculating part calculates SOH_R based on estimated internal resistance R. Storage stores an SOH_R-SOH_C table. SOH_C calculating part calculates SOH_C based on calculated SOH_R with reference to the SOH_R-SOH_C table. FCC estimating part estimates FCC based on calculated SOH_C.

Abstract: A battery-state estimation device obtains, at a first timing, a first resistance value corresponding to a first open circuit voltage of a lithium-ion secondary battery and a second resistance value corresponding to a second open circuit voltage, which is higher than the first open circuit voltage, of the lithium-ion secondary battery. Further, the battery-state estimation device obtains, at a second timing which is different from the first timing, a third resistance value corresponding to the first open circuit voltage and a fourth resistance value corresponding to the second open circuit voltage. The battery-state estimation device determines presence or absence of lithium deposition in the lithium-ion secondary battery, based on a magnitude relation between a first variation amount of the third resistance value with respect to the first resistance value and a second variation amount of the fourth resistance value with respect to the second resistance value.

Abstract: Current-integration estimation unit estimates the SOC of a battery by integrating the value of the current flowing through the battery. Open-circuit voltage estimation unit estimates the open-circuit voltage value of the battery from a value that includes at least the measured voltage value of the battery and indicates the state of the battery, and identifies the SOC corresponding to the open-circuit voltage value. In neither charged nor discharged state, SOC determination unit employs the SOC estimated by open-circuit voltage estimation unit. In charged or discharged state, SOC determination unit employs the SOC estimated by current-integration estimation unit without change or after correction using the SOC estimated by open-circuit voltage estimation unit. In parallel with the SOC estimation, SOH estimation unit estimates the SOH of the battery based on the variation value of the SOC employed by SOC determination unit and the integrated current value in the time period required for the variation.