Abstract: A battery management device to be mounted on an electric vehicle including a driving wheel, a traveling motor configured to generate a driving force for the driving wheel, and a battery configured to store electric power to be consumed by the traveling motor. The battery management device includes a detector configured to detect a state of the battery, and a controller configured to calculate a characteristic value indicating performance of the battery based on an output of the detector, and manage charging and discharging of the battery based on the characteristic value. The controller is configured to, when the characteristic value has deterioration, determine whether the deterioration of the characteristic value is reversible deterioration based on the output of the detector. The controller is configured to, upon determining that the deterioration of the characteristic value is the reversible deterioration, return the characteristic value to a value before the deterioration.

Abstract: A power source control system for a vehicle is provided, which includes a traction motor, the system including a first battery that is a bipolar battery and is to be used as a power source for the traction motor; a second battery that is a bipolar battery different from the first battery; a mirror current generator circuit configured to generate a mirror current based on a current flowing through the first battery; a mirror current supply source circuit configured to cause the mirror current to flow through the second battery; and a diagnostic circuit configured to perform degradation diagnosis on the second battery on a basis of at least one of a voltage or a temperature of the second battery.

Abstract: A power source control system for a vehicle is provided, which includes a traction motor, the system including a first battery that is a bipolar battery and is to be used as a power source for the traction motor; a second battery that is a bipolar battery different from the first battery; a mirror current generator circuit configured to generate a mirror current based on a current flowing through the first battery; a mirror current supply source circuit configured to cause the mirror current to flow through the second battery; and a diagnostic circuit configured to perform degradation diagnosis on the second battery on a basis of at least one of a voltage or a temperature of the second battery.

Abstract: A rotary-wing aircraft includes a fuselage, and an external device. The fuselage is provided with a rotary wing. The external device is mounted on the outside of the fuselage. The external device includes a mounting device, a mass variation device, and a damper. The mounting device is fixed to the fuselage and disposed so as to project in a lateral direction of the fuselage. The mass variation device is mounted on the mounting device and has mass that varies as the mass variation device is used. The damper couples the fuselage to the mounting device and supports the mounting device. The damper includes a stiffness variable mechanism configured to change stiffness of the damper in response to variation in the mass of the mass variation device.