Abstract: A power feeding system of the present disclosure includes a control unit. In a case where a magnitude of supply destination power is smaller than an upper limit value of the power supply capability of the power source, the control unit controls the charge/discharge control circuit so as to meet the supply destination power based on power output from the power source, and to charge the storage battery with power which is a difference obtained by subtracting the supply destination power from the upper limit value of the power supply capability of the power source. In a case where the magnitude of the supply destination power is more than or equal to the upper limit value of the power supply capability of the power source, the control unit controls the charge/discharge control circuit so as to meet the supply destination power by both the power source and the storage battery.

Abstract: A battery system includes a nickel-metal hydride battery and an ECU that controls charging and discharging of the nickel-metal hydride battery. The ECU calculates a discharge electricity amount showing an integrated value of a current discharged from the nickel-metal hydride battery, and further calculates ?SOC of the nickel-metal hydride battery in a prescribed time period. The ECU calculates a charge reserve capacity of the nickel-metal hydride battery based on a temperature of the nickel-metal hydride battery, the discharge electricity amount, and the ?SOC.

Abstract: A method for determining a negative electrode capacity of a rechargeable battery is performed by a measurement device that includes a voltage detector that detects a voltage value of the rechargeable battery, a current detector that detects a current value of the rechargeable battery, and a state of charge detector that detects a state of charge of the rechargeable battery. The method includes calculating an absolute value of a voltage slope indicating a voltage change amount with respect to a discharge amount when the state of charge of the rechargeable battery is less than 40%, comparing the absolute value of the voltage slope with a preset lower limit, and determining that the negative electrode capacity of the rechargeable battery has decreased when the absolute value of the voltage slope is less than or equal to the lower limit.

Abstract: A power feeding system of the present disclosure includes a control unit. In a case where a magnitude of supply destination power is smaller than an upper limit value of the power supply capability of the power source, the control unit controls the charge/discharge control circuit so as to meet the supply destination power based on power output from the power source, and to charge the storage battery with power which is a difference obtained by subtracting the supply destination power from the upper limit value of the power supply capability of the power source. In a case where the magnitude of the supply destination power is more than or equal to the upper limit value of the power supply capability of the power source, the control unit controls the charge/discharge control circuit so as to meet the supply destination power by both the power source and the storage battery.

Abstract: A rechargeable battery state determination method determines whether a rechargeable battery is in a micro-short-circuit-prone state, which is a state that is highly likely to form a micro-short circuit.

Abstract: A battery system includes a nickel-metal hydride battery and an ECU that controls charging and discharging of the nickel-metal hydride battery. The ECU calculates a discharge electricity amount showing an integrated value of a current discharged from the nickel-metal hydride battery, and further calculates ?SOC of the nickel-metal hydride battery in a prescribed time period. The ECU calculates a charge reserve capacity of the nickel-metal hydride battery based on a temperature of the nickel-metal hydride battery, the discharge electricity amount, and the ?SOC.

Abstract: A battery state estimation device for estimating a charged electric charge quantity of a rechargeable battery includes an impedance measurement unit configured to measure a plurality of complex impedances of the rechargeable battery by supplying measurement power to the rechargeable battery, a parameter calculation unit configured to calculate a parameter that includes a ratio of a difference between measurement angular velocities of two complex impedances in a diffusion region among the measured complex impedances to a difference between components of the two complex impedances, and an electric charge quantity estimation unit configured to estimate a charged electric charge quantity of the rechargeable battery based on the calculated parameter and preset correlated information between the charged electric charge quantity of the rechargeable battery and the parameter.

Abstract: A method for determining a state of a rechargeable battery includes obtaining a complex impedance measured by applying AC voltage or AC current to a rechargeable battery that is subject to determination and determining a state of the rechargeable battery based on the obtained complex impedance. The determining a state of the rechargeable battery includes determining whether or not a first capacity shift is occurring based on a comparison of a value of the complex impedance at a predetermined frequency with a first determination value used to determine a negative electrode capacity shift, and when determined that the first capacity shift is not occurring, determining whether or not a second capacity shift is occurring based on a comparison of a gradient of the complex impedance with respect to a real axis in a diffusion resistance region with a second determination value used to determine a positive electrode capacity shift.

Abstract: The present invention pertains to the detection of the state of charge of a battery, whereby the complex impedance in the diffusion region of the battery is used. An arithmetic device such as a computer determines the slope of the complex impedance at least two different frequencies in the diffusion region of a rechargeable battery when a straight-line approximation has been made. The state of charge of the rechargeable battery is detected by using the slope that has been determined, and the relationship between the state of charge and slopes that have been stored in advance in a storage means.

Abstract: A method for reusing a vehicle rechargeable battery to rebuild an assembled battery from a plurality of battery units having a usage history is provided. The method includes measuring a remaining charge of each of a plurality of battery units obtained by dismantling an assembled battery having a usage history. The method further includes selecting from the battery units a battery unit in which the measured remaining charge is greater than or equal to a remaining charge lower limit value, which is set in a range that is greater than zero and less than a lower limit value of a remaining charge control range of a vehicle in which the assembled battery was installed, and assembling a new assembled battery using the selected battery unit.

Abstract: A battery state estimation device for estimating a charged electric charge quantity of a rechargeable battery includes an impedance measurement unit configured to measure a plurality of complex impedances of the rechargeable battery by supplying measurement power to the rechargeable battery, a parameter calculation unit configured to calculate a parameter that includes a ratio of a difference between measurement angular velocities of two complex impedances in a diffusion region among the measured complex impedances to a difference between components of the two complex impedances, and an electric charge quantity estimation unit configured to estimate a charged electric charge quantity of the rechargeable battery based on the calculated parameter and preset correlated information between the charged electric charge quantity of the rechargeable battery and the parameter.

Abstract: A battery capacity measuring device that measures the battery capacity of a rechargeable battery includes an impedance measurement unit that measures the complex impedance of a rechargeable battery, which is a subject to measurement, based on application of measurement AC power, a parameter calculation unit that calculates a parameter that is a ratio of a difference between measured angular speeds of two complex impedances having different measured angular speeds in a diffusion region among a plurality of measured complex impedances to a difference between components of the two complex impedances, and a capacity calculation unit that calculates the capacity of the rechargeable battery based on information that is set in advance and indicates the relationship between the capacity of the rechargeable battery and the parameter and a parameter calculated by the parameter calculation unit.

Abstract: A method for determining a state of a rechargeable battery includes obtaining a complex impedance measured by applying AC voltage or AC current to a rechargeable battery that is subject to determination and determining a state of the rechargeable battery based on the obtained complex impedance. The determining a state of the rechargeable battery includes determining whether or not a first capacity shift is occurring based on a comparison of a value of the complex impedance at a predetermined frequency with a first determination value used to determine a negative electrode capacity shift, and when determined that the first capacity shift is not occurring, determining whether or not a second capacity shift is occurring based on a comparison of a gradient of the complex impedance with respect to a real axis in a diffusion resistance region with a second determination value used to determine a positive electrode capacity shift.

Abstract: A method for regenerating a nickel metal hydride battery is provided. The nickel metal hydride battery includes a hydrogen absorbing alloy that serves as a negative electrode material and a safety valve that opens when an internal pressure of a battery case is greater than or equal to a predetermined pressure. The method includes connecting a plurality of nickel metal hydride batteries in parallel. Each nickel metal hydride battery is formed by integrating one or more battery cells. The method further includes overcharging the nickel metal hydride batteries by supplying current from a charge unit that is connected in parallel to the nickel metal hydride batteries. The method further includes, when each nickel metal hydride battery is overcharged, restoring a discharge reserve of a negative electrode by releasing at least some of an oxygen gas generated at a positive electrode out of the battery case through the safety valve.

Abstract: A battery state determination device, which determines a micro-short-circuiting tendency state, includes an impedance meter that applies an AC voltage or an AC current of a measurement frequency to a rechargeable battery, which is subject to determination, and measures complex impedance. The device further includes a detector that detects an absolute value of an imaginary axis component of the complex impedance. The device further includes a determiner that compares the absolute value of the imaginary axis component detected by the detector with a lower limit threshold value. The lower limit threshold value is set based on a measurement result of the absolute value of the imaginary axis component of the rechargeable battery in the micro-short-circuiting tendency state. When the absolute value of the imaginary axis component is smaller than the lower limit threshold value, the determiner determines that the rechargeable battery is in the micro-short-circuiting tendency state.

Abstract: A battery capacity measuring device that measures the battery capacity of a rechargeable battery includes an impedance measurement unit that measures the complex impedance of a rechargeable battery, which is a subject to measurement, based on application of measurement AC power, a parameter calculation unit that calculates a parameter that is a ratio of a difference between measured angular speeds of two complex impedances having different measured angular speeds in a diffusion region among a plurality of measured complex impedances to a difference between components of the two complex impedances, and a capacity calculation unit that calculates the capacity of the rechargeable battery based on information that is set in advance and indicates the relationship between the capacity of the rechargeable battery and the parameter and a parameter calculated by the parameter calculation unit.

Abstract: This battery state determination device (10) is provided with: a voltage detection unit (13) that detects the voltage (V) of a rechargeable battery (M) to be evaluated; a current detection unit (12) that detects the current of the rechargeable battery (M); a charge state detection unit (11) that detects the state of charge (SOC) of the rechargeable battery (M); and a determination unit (11) configured so as to calculate the absolute value of the voltage gradient (G), which indicates the change in voltage with respect to the discharge amount (Ah), when the state of charge (SOC) of the rechargeable battery (M) is less than 40%, compare the absolute value of the voltage gradient (G) to a pre-set upper limit value (Gmax), and, when the absolute value of the voltage gradient (G) is greater than the upper limit value (Gmax), determine that a small short circuit has occurred in the rechargeable battery (M).

Abstract: A method for regenerating a nickel metal hydride battery is provided. The nickel metal hydride battery includes a hydrogen absorbing alloy that serves as a negative electrode material and a safety valve that opens when an internal pressure of a battery case is greater than or equal to a predetermined pressure. The method includes connecting a plurality of nickel metal hydride batteries in parallel. Each nickel metal hydride battery is formed by integrating one or more battery cells. The method further includes overcharging the nickel metal hydride batteries by supplying current from a charge unit that is connected in parallel to the nickel metal hydride batteries. The method further includes, when each nickel metal hydride battery is overcharged, restoring a discharge reserve of a negative electrode by releasing at least some of an oxygen gas generated at a positive electrode out of the battery case through the safety valve.

Abstract: This method for restoring battery capacity is provided with an oxygen-generating/exhausting step for charging a nickel-metal-hydride storage battery, causing the generation of oxygen gas in a positive electrode, opening a safety valve device, and discharging at least a portion of the oxygen gas through the safety valve device to the outside of the battery. The battery temperature when starting the step is in the range of ?30 to 10° C. and the SOC is in the range of (30-Ta) to 100%, or the battery temperature (Ta) is in the range of 10 to 50° C. and the SOC is in the range of 20-100%.

Abstract: A method for adjusting a battery module including a plurality of connected cells is provided. Each of the connected cells is a nickel-metal hydride battery including a positive electrode containing an active material of which a main component is nickel hydroxide, a negative electrode containing a hydrogen adsorption alloy, and an electrolytic solution that is an alkali solution. The method includes over-discharging the battery module so that a state of charge reaches 0% in every one of the connected cells.