An apparatus for diagnosing an insulation condition between a battery pack and the ground includes a first resistor element electrically connected between a positive terminal of the battery pack and the ground, and a control circuit. The control circuit records a current flowing through the first test port as a first test current, while a high-level voltage is being applied between the positive terminal and the ground. The controller diagnoses the insulation condition between the battery pack and the ground, based on the first test current.

A management device 50 for power storage elements is provided with a cause analysis unit 51 that, when the voltages of power storage elements B1-B4 are reduced to a prescribed level or physical quantities correlated with the voltages are reduced to prescribed values after the supply of power to the power storage elements B1-B4 has been stopped, analyzes the cause of the voltage reduction in power storage elements B1-B4 or the cause of the reduction in the physical quantities correlated with voltages to the prescribed values, on the basis of measurement data of the power storage elements B1-B4 measured after the supply of power has been stopped.

The present technology relates to a battery cell jig including film-type pressure sensors, and a method of measuring a swelling of a battery cell using the same. According to the present invention, by using film-type pressure sensors, the volume of the measuring apparatus can be reduced, and abnormal degeneration of the battery cell by the pressure difference for each location of the battery cell can be prevented.

A method for managing a plurality of batteries that are electrically coupled together includes (1) monitoring respective voltages of the plurality of batteries and (2) in response to a respective voltage of a first battery of the plurality of batteries reaching a first threshold value at a first time, reducing a charge or discharge rate of the first battery, relative to at least a second battery of the plurality of batteries. Charge and discharge rates may be adaptively managed such that each battery reaches the first threshold value at substantially the same time.

A method for managing a plurality of batteries that are electrically coupled together includes (1) monitoring respective voltages of the plurality of batteries and (2) in response to a respective voltage of a first battery of the plurality of batteries reaching a first threshold value at a first time, reducing a charge or discharge rate of the first battery, relative to at least a second battery of the plurality of batteries. Charge and discharge rates may be adaptively managed such that each battery reaches the first threshold value at substantially the same time.

A secondary battery status estimation device includes a sensor unit configured to detect a terminal voltage of a secondary battery, and an internal resistance calculator configured to calculate a direct current internal resistance of the secondary battery based on the terminal voltage and the charge-discharge current detected by the sensor unit. The internal resistance calculator calculates a direct current internal resistance based on the terminal voltage and the charge-discharge current detected by the sensor unit, in a stable period that is before starting a driving source for driving a vehicle and in which the terminal voltage and the charge-discharge current of the secondary battery fall within a predetermined fluctuation range, and in a high-current output period in which electric power for starting the driving source is output from the secondary battery and the terminal voltage of the secondary battery is brought to substantially minimum.

A light fixture for a public transportation train system powers an antenna used for train signaling. The antenna can provide to the train a location marker associated with the location of the antenna. The antenna can provide to the train other data communicated to the light fixture through the light fixture communication system.

A light fixture for a public transportation train system powers an antenna used for train signaling. The antenna can provide to the train a location marker associated with the location of the antenna. The antenna can provide to the train other data communicated to the light fixture through the light fixture communication system.

A method of evaluating a power storage device includes at least [a] to [f] below. [a] A power storage device is prepared. [b] A charge level of the power storage device is adjusted to produce a first potential difference between a positive electrode and a negative electrode. [c] The positive electrode or the negative electrode is selected as a reference electrode. [d] After the charge level is adjusted, an operation to insert a conductive rod-shaped member into a stack portion along a direction of stack of the positive electrode and the negative electrode is performed while a second potential difference between the reference electrode and the rod-shaped member is measured. [e] The rod-shaped member is stopped. [f] The power storage device is evaluated based on a state of the power storage device after the rod-shaped member is stopped.

A method for detecting internal short circuit of a battery, includes: discharging a battery with a first current I.sub.1 at a moment t.sub.1; calculating a first discharge voltage drop ΔV.sub.1 of the battery at a moment t.sub.1+dt; discharging the battery with a second current I.sub.2 at a moment t.sub.2, where I.sub.1≠I.sub.2; calculating a second discharge voltage drop ΔV.sub.2 of the battery at a moment t.sub.2+dt; and determining, based on the first current I.sub.1, the first discharge voltage drop ΔV.sub.1, the second current I.sub.2, and the second discharge voltage drop ΔV.sub.2, whether the battery has an internal short circuit. In this application, whether the battery has an internal short circuit can be accurately determined, thereby ensuring safety of an electronic apparatus and a user.