A battery monitoring device according to an embodiment monitors a state of a secondary battery block including parallel cell blocks connected in series each of which includes battery cells connected in parallel. A calculator calculates direct-current internal resistance values of the parallel cell blocks based on a differential current between first and second current values detected by a current detector, voltages of the parallel cell blocks corresponding to the first and second current values detected by a voltage detector. A determiner performs anomaly determination for the parallel cell blocks from the direct-current internal resistance values of the parallel cell blocks and a maximum value of the direct-current internal resistance values of the parallel cell blocks.

An online impedance spectrum measuring device and method for a vehicle-mounted hydrogen fuel cell includes: a controllable alternating current source, configured to apply a sinusoidal alternating signal; a cell voltage signal preceding-stage measuring circuit, configured to select to communicate with one monocell via a voltage signal gating circuit; a current sensor and a cell current signal preceding-stage measuring circuit connected with the current sensor; and a signal conditioning and amplifying circuit, a multi-channel simultaneous sampling analog-digital conversion circuit, a digital signal processor and an upper computer, which are connected in sequence, wherein the signal conditioning and amplifying circuit is connected to the cell voltage signal preceding-stage measuring circuit and the cell current signal preceding-stage measuring circuit, separately; and the upper computer is connected with the controllable alternating source and the voltage signal gating circuit.

An online impedance spectrum measuring device and method for a vehicle-mounted hydrogen fuel cell includes: a controllable alternating current source, configured to apply a sinusoidal alternating signal; a cell voltage signal preceding-stage measuring circuit, configured to select to communicate with one monocell via a voltage signal gating circuit; a current sensor and a cell current signal preceding-stage measuring circuit connected with the current sensor; and a signal conditioning and amplifying circuit, a multi-channel simultaneous sampling analog-digital conversion circuit, a digital signal processor and an upper computer, which are connected in sequence, wherein the signal conditioning and amplifying circuit is connected to the cell voltage signal preceding-stage measuring circuit and the cell current signal preceding-stage measuring circuit, separately; and the upper computer is connected with the controllable alternating source and the voltage signal gating circuit.

Described methods and systems are used for in-situ impedance spectroscopy analysis of battery cells in multi-cell battery packs. Specifically, the cell impedances are determined while the pack continues to operate, such as being charged or discharged. For example, the pack voltage/power output remains unchanged while this analysis is initiated, performed, and ended. Cell impedance is determined based on the cell's response to the signal applied to the cell. For example, a current through the cell is charged while monitoring cells' voltage response. Although the power output of the changes during this testing, but the operation of the pack is not impacted due to the power compensation provided by one or more other cells in the pack thereby ensuring uninterrupted operation of the pack. This in situ testing is provided by the unique architecture of the pack, comprising multiple nodes and individual node controllers.

A method for measuring a complex impedance of a plurality of battery cells in a battery pack comprises controlling an excitation current through the plurality of battery cells in the battery pack; receiving, in a single common measurement circuit, a plurality of voltage signals corresponding to the plurality of battery cells; measuring the excitation current; and calculating a complex impedance of each of the battery cells in the plurality of battery cells based on the plurality of voltage signals and the measured excitation current in a single measurement cycle using either one analog-to-digital converter (ADC) per battery cell or two matched ADCs per battery cell.

A method for measuring a complex impedance of a plurality of battery cells in a battery pack comprises controlling an excitation current through the plurality of battery cells in the battery pack; receiving, in a single common measurement circuit, a plurality of voltage signals corresponding to the plurality of battery cells; measuring the excitation current; and calculating a complex impedance of each of the battery cells in the plurality of battery cells based on the plurality of voltage signals and the measured excitation current in a single measurement cycle using either one analog-to-digital converter (ADC) per battery cell or two matched ADCs per battery cell.

A storage battery device includes a plurality of cell modules including a plurality of battery cells, a data acquirer configured to acquire voltage data of the battery cells, a calculator configured to calculate a rise rate of an internal resistance value with respect to a default value according to the voltage data of the battery cells, and a storage configured to store therein the rise rate of the internal resistance value with respect to the default value.

A storage battery device includes a plurality of cell modules including a plurality of battery cells, a data acquirer configured to acquire voltage data of the battery cells, a calculator configured to calculate a rise rate of an internal resistance value with respect to a default value according to the voltage data of the battery cells, and a storage configured to store therein the rise rate of the internal resistance value with respect to the default value.

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.

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.