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 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.

Provided is a battery pack comprising a plurality of batteries; and a plurality of memories that correspond respectively to the batteries and that each record deterioration information of the corresponding battery. Each set of a battery and a corresponding memory may be formed integrally as a battery cell. As a result, the deterioration information of each battery cell can be known even after the battery pack is disassembled.

A system and method for monitoring characteristics of an electric energy device includes generating an external short from the electric energy device. The external short occurs at a known distance from a sensor and has at least one known external resistance. The received signal representing change in electromagnetic field due to the applied external short may be analyzed to determine a signal parameter that is then analyzed in comparison to a lookup table, based on the known conditions including distance, temperature and the external resistance. The output of this analyses in comparison with expected values may be utilized to identify a characteristic of the energy device.

Various embodiments include a method for ascertaining a mean capacity loss of a battery storage device. The method may include: providing results of a measurement series on the battery storage device taken during a plurality of load cycles, each including a charging and a discharging phase; ascertaining a first and a second discharge capacity of the device using a first and a second calculation rule, wherein each calibration is different for correcting values of the current measurement; and carrying out an optimization process so a calibration of the current measurement is ascertained to achieve the greatest match of the ascertained first discharge capacity and the second discharge capacity.

A vehicle-mounted device for detecting battery state comprises a controller, a load unit, and a switch unit. The load unit is coupled to the battery, the switch unit is coupled between the battery and the load unit. The controller can control the switch unit to disconnect or connect the battery and the load unit at a predefined frequency. The controller can switch the load unit to generate ripple voltage on the battery, and measure the ripple voltage of each battery cell, an abnormal state of a battery can be determined according to the ripple voltage of each battery cell.

A method determines at least one power contact resistance or at least one resistance value corresponding to the at least one power contact resistance between at least one pack power contact of a battery pack and at least one apparatus power contact of an electrically driven work apparatus or of a charging apparatus. The pack power contact and the apparatus power contact touch one another and are loaded with a power current. The battery pack and the work apparatus or the charging apparatus are electrically connected by a data communication line for transmitting a data communication signal. The method determines the power contact resistance or the resistance value by comparing a signal voltage variable of the data communication line and a power voltage variable of the at least one pack power contact or of the apparatus power contact with one another, wherein the signal voltage variable or the power voltage variable is dependent on a voltage drop caused by the power current and the at least one power contact resistance.

In a DC impedance measurement routine for a battery the current load from a source is initially set to a low setting. The system waits for a set time in this state for the voltage readings to stabilize. Once the voltage is stable at the low current setting, the current setting is changed to a high value and the voltage is read quickly. Then the current load is set back to the low setting immediately after the reading is made. Several consecutive measurements are performed by repeating the steps above. A DC impedance measurement system that can be used to carry out the measurement routine. A multi-battery system can be monitored via a DC impedance measurement system and the routine being performed on each battery.

A measurement arrangement for determining a complex impedance of a first electrical component, wherein the measurement arrangement comprises the first component and a measuring unit, which is coupled to the first component and adapted to determine the complex impedance of the first component. The measurement arrangement comprises at least one second electrical component, which is arranged with the first component in a parallel circuit, which is hooked up in parallel with the measuring unit, wherein the parallel circuit comprises at least one switching device by which an electrical connection between the first and second component can be broken, and wherein the measurement arrangement is designed to temporarily break the electrical connection between the first component and the second component by the associated switching device in order to determine the first complex impedance of the first component.

Embodiments of the present disclosure provide a server cabinet power backup system and a testing method thereof. In a self-test process of the power backup unit, the battery management module may be configured to: control the battery pack to supply power to the self-test resistor to discharge the battery pack, control the battery pack to be charged after the battery pack is discharged, and collect a charge and discharge parameter of the battery pack, and the battery management module may be further configured to: determine attenuation performance of the power backup unit according to the charge and discharge parameter of the battery pack.