Abstract: A vehicle controlling apparatus includes an engine processor, an electric motor, an electric power storage, an SOC detector, an internal resistance detector, and a resistance threshold setting unit. The engine processor is configured to stop an engine of a vehicle on the basis of a stop condition, and start the engine on the basis of a start condition. The engine processor is configured to prohibit a stop of the engine based on the stop condition based on determining that an internal resistance of the electric power storage detected by the internal resistance detector is equal to or greater than a resistance threshold set by the resistance threshold setting unit on the basis of a state of charge of the electric power storage, and permit the stop of the engine based on determining that the internal resistance is less than the resistance threshold.

Abstract: It is an object of one or more embodiments of the present disclosure to provide a battery charger with a constant current control loop, for use in linear and switching chargers. Advantages include digital controls and a comparator, for decreasing charging current towards termination. The technique of the disclosure eliminates a constant voltage loop and amplifier, without increasing charging time. The technique also simplifies porting the design to another process technology node, and reduces size.

Abstract: A battery monitoring system includes a data acquiring unit and a failure determining unit. The data acquiring unit acquires a plurality of types of monitoring data to monitor a state of a secondary battery. The failure determining unit determines whether the secondary battery has failed. The failure determining unit performs sparsity regularization using the monitoring data as variables and calculates a partial correlation coefficient matrix of the monitoring data. The failure determining unit calculates, as an abnormality level, an amount of change in a partial correlation coefficient, which is a component of the partial correlation coefficient matrix, between two partial correlation coefficient matrices calculated at different periods. The failure determining unit determines that the secondary battery has failed when the calculated abnormality level exceeds a predetermined threshold.

Abstract: The present application discloses a method, apparatus, device and medium for estimating performance parameters of a battery. The method for estimating performance parameters of a battery includes: generating a first curve segment to be calibrated during a process of adjusting a battery capacity in a first capacity interval with a first capacity value as an endpoint value; determining, in a preset reference curve, a first target curve segment that matches the first curve segment to be calibrated; determining a SOC interval corresponding to the first target curve segment as a SOC interval of the first curve segment to be calibrated; and estimating the performance parameters of the battery based on the SOC interval of the first curve segment to be calibrated, the performance parameters include a current SOC and/or a current battery capacity.

Abstract: A system for mitigating thermal runaway in a battery-powered electric vehicle (EV). The system includes a gas sensor configured to measure a level of at least one type of gas in a vicinity of a battery of the EV, a thermal event detector configured to determine, based on the measured level of the at least one type of gas, that the battery is experiencing out-gassing, and a communications interface configured to transmit an alert to a fleet management system regarding the out-gassing of the battery. The fleet management system alters an assignment of the EV in response to the out-gassing of the battery.

Abstract: Electrochemical impedance spectroscopy (EIS) may be used to measure the internal components of a battery or interfaces between connections inside a battery in order to determine a state of one or more subcomponents of the battery. In various embodiments, EIS testing of the battery may be conducted using various test waveforms, such as test waveforms with different voltages, currents, and/or frequencies, to identify and/or predict battery subcomponent and/or interface failures. In various embodiments, EIS testing of the battery may be used to determine when battery conditions are suitable for charging.

Abstract: The battery degradation detection device includes an impedance measurement unit and a degradation detection unit. The impedance measurement unit measures impedances of a battery at a plurality of frequencies. The impedance for at least one of the plurality of frequencies, measured by the impedance measurement unit, has a positive imaginary component. The degradation detection unit detects degradation of the battery on the basis of real components of the impedances at the plurality of frequencies detected by the impedance measurement unit.

Abstract: According to the present invention, a state management unit measures or estimates the AC resistance value of a secondary cell at a plurality of time points, estimates a predicted transition of the AC resistance value of the secondary cell on the basis of the AC resistance value at the plurality of time points, and estimates a remaining use period until the AC resistance value of the secondary cell reaches a resistance threshold value corresponding to a time point at which usage of the secondary cell ends. When the remaining use period of the secondary cell becomes shorter than a prescribed period, an operation management unit changes the usage manner of the secondary cell method to a usage manner that has a smaller load on the secondary cell, or stops the usage of the secondary cell.

Abstract: A vehicle battery diagnosis apparatus includes: a measurement unit configured to measure a battery cell voltage; and a controller configured to diagnose a cell voltage deviation based on the battery cell voltage. The controller calculates a self-discharge rate for each cell based on the battery cell voltage and a parking time and calculates the cell voltage deviation based on the battery cell voltage, and when the calculated cell voltage deviation is greater than a preset cell balancing reference voltage deviation, the controller compares cell balancing capacitance calculated based on a vehicle usage time with a maximum self-discharge rate among the calculated self-discharge rates for respective cells and determines whether cell balancing is enabled or diagnoses the cell voltage deviation.

Abstract: A computer-implemented method and a battery state estimating system for estimating a battery state of an electrochemical battery, including: calculating electrical impedance gradients from a provided series of electrical impedance measurements to generate a series of electrical impedance gradients; and determining a battery state of the electrochemical battery using computational means configured to receive as inputs at least the series of electrical impedance gradients, the computational means receiving and processing at least the provided series of calculated electrical impedance gradients to generate therefrom at least one output signal representing a battery state associated with the electrochemical battery.

Abstract: A method for determining a resistance parameter value of an electrical energy storage unit is disclosed, comprising the following steps: a) determining a current variable representing an electric current flowing into or out of the electrical energy storage unit; b) determining a first voltage variable, which represents an electrical voltage prevailing between two pole terminals of the electrical energy storage unit; c) determining a second voltage variable, which represents an electrical voltage and results from a mathematical model of the electrical energy storage unit, wherein the current variable determined in step a) is applied to the mathematical model and the latter comprises a resistance parameter which represents an internal resistance of the electrical energy storage unit and to which a first value is allocated; d) generating an adaptation value for the resistance parameter, wherein the adaptation value is dependent on a difference variable between the first voltage variable and the second voltage v

Abstract: A device for battery impedance measurement includes a switched capacitor network, a controller configured to operate the switched capacitor network to cause an alternating current to flow between a battery and an energy storage; and measurement circuitry configured to measure the alternating current flowing to or from the battery and a voltage across the battery.

Abstract: A method for calculating an accurate SOH of a battery pack by reducing an error occurring during SOH calculation of the battery pack.

Abstract: As one example, a filter apparatus includes an input to receive an electrical input signal. The filter apparatus includes a forward path connected between the input and an output of the filter apparatus. A feedback path is connected to provide feedback to the forward path based on an output signal at the output of the filter apparatus. A filter bypass is configured to provide the input signal directly to the output and to the feedback path for an activation phase of the filter apparatus. Diagnostics may also be performed.

Abstract: Provided is a method for calculating the SOH of a battery power pack. The method comprises the following steps: acquiring a charging curve of a cell of a battery power pack, and determining a current charging phase according to the charging curve, wherein the charging phase comprises a high voltage charging inflection point and a high voltage charging phase (S1); acquiring a battery pack power amount corresponding to the high voltage charging inflection point and a battery pack power amount corresponding to the high voltage charging phase (S2); calculating the remaining capacity of a cell according to the battery pack power amount corresponding to the high voltage charging inflection point and the battery pack power amount corresponding to the high voltage charging phase (S3); and calculating the SOH of the cell according to the remaining capacity (S4).

Abstract: An abnormality determination device for a secondary battery includes an internal-resistance calculation unit, a threshold memory unit, a capacity balance comparison unit, and an abnormality determination unit. The internal-resistance calculation unit detects an internal resistance in a negative-electrode reaction resistance dominant region in which a reaction resistance of a negative electrode is dominant in a charge and discharge reaction of the secondary battery. The threshold memory unit stores a capacity balance threshold used as a reference for determining abnormality in a balance between a capacity of a positive electrode and a capacity of the negative electrode in the secondary battery. The capacity balance comparison unit compares the internal resistance calculated by the internal-resistance calculation unit with the capacity balance threshold stored in the threshold memory unit.

Abstract: A measurement device includes: a host computer and a current source, wherein the host computer is configured to: control, when ambient temperature of a current detection device is at a preset temperature within an operation temperature range of a shunt of the current detection device, the current source to output a current with a preset current value to the current detection device; receive a calibrated current value sent by the current detection device; calculate a measurement error of the current detection device according to the preset current value and the calibrated current value; and instruct, when the measurement error is less than a preset current error, the current detection device to use the predetermined current calibration coefficient as a current calibration coefficient.

Abstract: A method includes recording a branch current and a terminal voltage of each of two parallel connected cells of a battery pack during the battery pack being switched from a charging or discharging state through a rest state to a balance state, to obtain an internal resistance of each cell, and an open-circuit voltage (OCV) and a state of charge (SOC) of the battery pack in the balance state, to obtain an OCV and a SOC of each cell just before the battery pack is switched to the rest state; and obtaining an aging differential index according to the SOC of each cell just before the battery pack is switched to the rest state, the branch current of each cell just after the battery pack is switched to the rest state, and a rated capacity of the battery pack, to determine a relative aging level of the two cells.

Abstract: Various examples relate to techniques of monitoring a reliability of a cell-impedance measurement of a battery cell. In one example, a device includes a first interface configured to inject an AC excitation current into a battery cell and a shunt resistor coupled in parallel to the battery cell. The device also includes a second interface configured to inject an AC test current into the shunt resistor. The device also includes analog-to-digital converters configured to measure a cell voltage across the battery cell associated with the AC excitation current, a shunt voltage across the shunt resistor associated with the AC excitation current and the shunt voltage across the shunt resistor associated with the AC test current.

Abstract: A method for detecting failure of a battery cell due to an unknown discharge current, including connecting a detector in series between the battery cell and a power supply for supplying a charging power, determining whether the charging of the battery cell progresses by the charging power in excess of a predetermined battery cell specific charging reference time, measuring a current value of the battery cell in real time if the charging of the battery cell progresses in excess of the battery cell specific charging reference time, determining whether the current value of the battery cell measured in real time exceeds a predetermined battery cell specific failure determination reference current range value, and determining a state of the battery cell as a failure state if the current value of the battery cell exceeds the predetermined battery cell specific failure determination reference current range value.

Abstract: A device detects a deformation of an electrical energy store. The device has a measuring device which is designed to measure the electrical current/voltage behavior of the energy store, and an evaluation unit which is designed to detect a change in the current/voltage behavior and to determine the deformation on the basis of the change.

Abstract: Systems and methods of monitoring and testing a battery module, including generating Electrochemical Impedance Spectra (EIS) of one or more battery modules, fitting the EIS spectra to an equivalent circuit model to establish equivalent circuit fit parameters, measuring an open circuit voltage of the one or more battery modules, measuring a temperature of the one or more battery modules, combining the EIS equivalent circuit fit parameters with measured open circuit and temperature values to determine weighting parameters of the equivalent circuit fit parameters, applying the weighting parameters to the equivalent circuit fit parameters to generate weighted equivalent circuit fit parameters, and generating a state-of-health (SoH) measurement of the one or more battery modules based on the weighted equivalent circuit fit parameters.

Abstract: An apparatus is configured to determine the leakage resistance in respect of the positive and/or negative terminals of a vehicle battery. The apparatus includes a first pair of serially arranged resistors connected between the terminals with a first switch connected between the resistors and a second pair of serially arranged resistors connected between the vehicle chassis/nominal ground and the negative terminal or the positive terminal, with a second switch connected between the resistors. A further fifth resistor is connected between the vehicle chassis/nominal ground, and the negative terminal or the positive terminal via a third switch, and a controller is configured to selectively control the switches during processing steps.

Abstract: A battery performance evaluation device executes an alternating current impedance acquiring process (S1), an OCV acquiring process (S2), and an SOC estimating process (S3). The alternating current impedance acquiring process involves acquiring a measurement result of an alternating current impedance of a target secondary battery, the alternating current impedance measured by applying an application signal to the target secondary battery within a specific frequency range. The OCV acquiring process involves acquiring an OCV of the target secondary battery. The SOC estimating process involves estimating an SOC of the target secondary battery to be 0%, if an imaginary component of the measurement result of the acquired alternating current impedance at a predetermined frequency within the specific frequency range is greater than or equal to a first threshold value and the acquired OCV value is less than or equal to a second threshold value.

Abstract: A deterioration-state calculation method for a battery comprises: detecting current and voltage of the battery; calculating a charge state based on the detected value; calculating a first deterioration state of the battery for each predetermined period based on an elapsed time from the time use is started and an amount of charge-discharge; calculating a second deterioration state based on a change amount in the charge state of the battery and a change amount of current; calculating the second deterioration state for a plurality of times within the predetermined period; calculating reliability of calculation of the second deterioration state for each of a plurality of the second deterioration states based on the detected value; calculating a correction value of the deterioration state based on the second deterioration state with the reliability of the predetermined reliability or higher; and calculating the deterioration state by correcting the first deterioration state.

Abstract: The first step includes performing FFT for a voltage and a current of a battery a plurality of times to thereby calculate the voltage and the current for each frequency. The second step includes determining whether or not the first condition and the second condition are satisfied for the current of the battery that is calculated for each frequency. The third step includes calculating an impedance component of the battery for each frequency range when at least one of the first condition and the second condition is not satisfied, and not calculating the impedance component of the battery for each frequency range when each of the first condition and the second condition is satisfied. The first condition shows that the current in a low frequency range is greater than a reference value. The second condition shows that the current in a frequency range is less than a reference value.

Abstract: A power supply device and a power supply control method with which charging and electric power supply can be continued efficiently, and a charge capacity can be added is disclosed. A power supply device including: plural battery units replaceably connected to a battery connection part, an output unit for outputting electric power from the battery unit to a load, and a control unit for controlling connection of the plural battery units with respect to the output unit, wherein the control unit selects a battery unit having a remaining charge amount that is smallest among the plural battery units and equal to or greater than a first predetermined amount, and connects the selected battery unit to the output unit.

Abstract: The present invention relates to a device and a method for diagnosing battery deterioration, the device comprising: a battery comprising at least one cell; a charging unit for charging the cell, and performing cut-off during a stabilization time in which the charged cell is stabilized; a sensing unit for measuring a current of the cell with respect to time; and a control unit for, by using the measured current, detecting an inflection point of the measured current, calculating a slope of the measured current in a first period after a time corresponding to the inflection point; and comparing the current slope of a reference cell, corresponding to the slope of the measured current, so as to diagnose whether the cell has deteriorated.

Abstract: A terminal device, a method for monitoring battery safety of a terminal device, and a system for monitoring battery safety of a terminal device are provided. The method for monitoring battery safety includes the following steps. A voltage of a battery of the terminal device is acquired in real time, and temperature of each area of a battery surface of the battery is acquired in real time, where the battery surface is divided into multiple areas. Whether a sudden change in voltage has occurred to the battery is determined according to the voltage of the battery acquired in real time, and whether the battery surface has an abnormal temperature area is determined according to the temperature of each area. Upon determining that the sudden change in voltage has occurred to the battery and the battery surface has the abnormal temperature area, the battery is determined to be currently abnormal.

Abstract: A vehicle battery system has a battery including a plurality of series connected cells, a bus bar electrically connected between an adjacent pair of the series connected cells, and circuitry. The circuitry injects a sinusoidal current waveform through the bus bar, obtains a magnitude of a sinusoidal voltage waveform contained by an overall voltage of the bus bar that is caused by the sinusoidal current waveform from a sampled and filtered version of the overall voltage and digital data defining the sinusoidal current waveform, obtains a resistance of the bus bar from the magnitude of the sinusoidal voltage waveform and a measured magnitude of the sinusoidal current waveform, and obtains a magnitude of current through the battery from a DC portion of a spectrum of the overall voltage and the resistance of the bus bar.

Abstract: Disclosed as a clock alignment module for a near field communication, NFC, controller operable in active load modulation, ALM, card mode, the module being operable during a transmit mode comprising transmit bursts and comprising: an input for receiving a field clock signal (CLK_FIELD); an output for outputting a local controller clock signal (CLK_FB); a transmit envelop unit configured to determine whether a time since an end of a latest transmit burst exceeds a threshold, Tdelay; and a phase locked loop, PLL, configured to selectively lock the phase of the local controller clock signal to the phase of the field clock signal, in response to the time exceeding the threshold and a next transmit burst not having started. Associated NFC controllers, integrated circuits and methods are also disclosed.

Abstract: An insulation detection method includes: a first and second equivalent resistances are calculated; the less one of the first and second equivalent resistances is taken as a first insulation resistance, which is an insulation resistance of the high voltage circuit on the side where the battery pack locates relative to the reference potential terminal; when the first insulation resistance is normal, the switch unit is closed, and a second insulation resistance is calculated according to the first and second equivalent resistances, voltages of a first and second sampling point when the switch unit is closed; the second insulation resistance is an insulation resistance of the high voltage circuit on the side where the load locates relative to the reference potential terminal; the insulation state of the high voltage circuit on the side where the load locates is determined according to the second insulation resistance.

Abstract: A vehicle battery diagnosis method and apparatus are provided. The vehicle battery diagnosis method includes receiving battery state history data including data stored based on state of charge (SOC) ranges of a battery and SOCs of the battery. Maximum distributions of the SOCs of the battery are then determined based on the battery state history data. A state of the battery is diagnosed based on a reduction rate among the maximum distributions of the SOCs of the battery based on the battery state history data.

Abstract: A battery diagnosis device includes: one or more sensors which measure at least one of a current value, a voltage value, and a temperature value of a battery; a first determination unit which acquires, from the sensor, at least one of measured values of the current value, the voltage value, and the temperature value of the battery, and determines a state of the battery by using a first method, based on the acquired measured values; a second determination unit which acquires, from the sensor, at least one of measured values of the current value, the voltage value, and the temperature value of the battery, and determines the state of the battery by using a second method different from the first method, based on the acquired measured values; and a diagnosis unit which diagnoses the battery, based on determination results of the first determination unit and the second determination unit.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for the generation and use of a fast battery model. One of the methods includes obtaining temperature data for one or more locations within or on the surface of a battery, the temperature data comprising time-varying heat flow inputs applied to the battery and time-varying temperature signals generated by the battery. The method also includes processing the temperature data to generate a continuous-time thermal model having one or more time-delay elements and one or more parameters, wherein parameter values are fitted using the temperature data.

Abstract: An assembled battery is constituted of a plurality of battery blocks connected in series, each battery block including a plurality of cells. SBMs are provided corresponding to the battery blocks, respectively. Each of the SBMs is configured to monitor at least one of a voltage of each cell included in a corresponding battery block, and a voltage of the corresponding battery block. A total voltage monitoring circuit is configured to monitor the total voltage of the assembled battery, separately from the SBMs.

Abstract: A method for testing an all solid state battery with which the presence of short circuit or the presence of defect causing short circuit can be detected with high accuracy by a method in which a voltage is applied to a battery and the current value thereof is measured. The method includes the steps of: a resistance increasing step of increasing resistance of an all solid state battery to 3.2*105 ?·cm2 or more; a voltage applying step of applying voltage to an all solid state battery of which the resistance is increased; and a judging step of judging acceptability of the all solid state battery based on a current value measured in the voltage applying step.

Abstract: A method and system to determine if there is an open cell in a battery pack of cells arranged in a lattice. Voltage measurements from each parallel cell group along with information on the battery pack topology are used to estimate the resistance of each cell group. The resistance of each cell group is calculated based on the measured voltage less a nominal open circuit voltage divided by the current level of the battery pack. The average cell group resistance of the battery pack is also calculated. The cell group resistances are analyzed statistically using the resistance of each cell group and the average cell group resistance to reveal outliers which are indicative of open cell groups.

Abstract: The present disclosure relates to the field of battery state monitoring technologies, and in particular, to a battery state monitoring method and apparatus. The method is: monitoring a voltage value and a current value of an output end of a battery; determining a battery impedance value based on the voltage value; calculating an impedance voltage-drop value based on the current value and the battery impedance value; calculating an open circuit voltage of the battery based on the voltage value and the impedance voltage-drop value; when a difference of the open circuit voltage between two consecutive calculations is greater than or equal to a threshold, judging that the battery state is abnormal; and when the difference of the open circuit voltage between two consecutive calculations is determined to be lower than the threshold, updating the battery impedance value based on the voltage value and the current value.

Abstract: A method for monitoring battery safety is provided. When a terminal device remains coupled with an adaptor after charging of a battery of the terminal device is completed, in response to the terminal device being in a low-power state, recharge information of the terminal device is acquired. According to the recharge information of the terminal device, whether the battery is abnormal is determined. The disclosure further provides a system for monitoring battery safety and a non-transitory computer readable storage medium.

Abstract: Various embodiments of the present technology comprise a method and apparatus for battery management. In various embodiments, the apparatus comprises a lithium ion battery and a fuel gauge circuit to monitor the resistance and the capacity as the battery ages. The fuel gauge circuit utilizes the resistance and capacity values to compute resistance changes due to both cycle aging and calendar aging separately. The fuel gauge circuit utilizes the change in resistance values to determine aged capacity values. The fuel gauge circuit controls charging/discharging of the battery according to the aged capacity values.

Abstract: A system for differentiating short circuiting in a battery includes: a detector coupled to the battery; a monitor in communication with the detector, the monitor including a profile of a battery shorting behavior, and a comparator for matching data from the detector to the profile; and a controller for taking action based upon information from the detector. A method for detecting short circuiting in a battery includes the steps of: detecting a behavior of the battery; comparing the behavior of the battery to a predetermined battery behavior profile; determining the type of short based on the comparison; and taking mitigating action based on the determination. The system/method may monitor: temperature of the battery, heat generation from the battery, current flow through the battery, voltage drop across the battery, and/or combinations thereof. The system/method discriminates between the various battery shorting behaviors for aggressive response or passive response.

Abstract: A control device for controlling charging of a rechargeable battery, the control device being configured to: determine the voltage of the battery during charging of the battery, stop charging, when the determined voltage exceeds a predetermined upper voltage limit, determine the voltage of the battery after stopping charging, determine the voltage difference between the predetermined upper voltage limit and the determined voltage of the battery after stopping charging, and continue charging, when the determined voltage difference exceeds a predetermined threshold. A corresponding method controls charging of a rechargeable battery.

Abstract: A battery control system including a secondary battery within which gas is generated with use, and a controller configured to control charging/discharging of the secondary battery. In the controller, a measurer is configured to measure a resistance of the secondary battery, and a stop director is configured to stop charging/discharging of the secondary battery when the resistance of the secondary battery has exceeded a predetermined resistance threshold.

Abstract: The invention describes a calorimetric measurement set-up having a sensor unit (1) for controlling the quality of the operation of a battery having a cathode and an anode, wherein the measurement set-up or the sensor unit (1) is connected to data processing electronics (11) via a communication link (12) and sensor measured values are therefore recorded and processed. This measurement set-up is intended to achieve reproducible and sufficiently accurate quality control of a battery.

Abstract: The present invention relates to an apparatus and a method for estimating a state of a battery, and more particularly, an apparatus for estimating a state of a battery includes: a first SOC estimating unit estimating a first state of charging (SOC) of the battery based on open circuit voltage and a temperature of the battery; a first SOH estimating unit estimating a first state of health of the battery based on the first SOC and the current of the battery; and a second SOC estimating unit estimating a second SOC of the battery based on the first SOH, charging/discharging voltage, the temperature, and the current of the battery or estimating the second SOC of the battery based on the charging/discharging voltage, the temperature, and the current of the battery.

Abstract: A battery pack includes a plurality of unit cells, each including an electrode body having a structure in which a positive electrode and a negative electrode are stacked, and a busbar that electrically connects a positive electrode terminal to a negative electrode terminal between the unit cells. The unit cells are stacked adjacent to one another in the same direction as a direction in which the positive electrode and the negative electrode of the electrode body are stacked. The busbar electrically connects the unit cells disposed apart from each other among the unit cells excluding the unit cells disposed adjacent to each other.

Abstract: A device that estimates the residual capacity of a lithium ion battery (3) that starts an engine starter (1), includes a control section (30) that calculates resistance values of a cathode and anode of the lithium ion battery based on detected values of a voltage sensor (SN1) and a current sensor (SN2) at the time when a first time has elapsed, and at the time when a second time longer than the first time has elapsed, from startup of the engine starter, and estimates the residual capacity from increases over time in the resistance values. The control section (30) starts the engine starter with the lithium ion battery under conditions under which the startup time of the engine starter will be longer when the last startup time of the engine starter is shorter than the second time or when a predetermined time period has elapsed from the last estimation.

Abstract: Methods, apparatuses, and systems for measuring impedance spectrum, power or energy density, and/or spectral density using frequency component analysis of power converter voltage and current ripple are described herein. An example method for measuring impedance spectrum, power spectrum, or spectral density can include measuring an alternating current (AC) ripple associated with a power converter, where the AC ripple includes an AC current ripple and an AC voltage ripple. The method can also include performing a frequency analysis to obtain respective frequency components of the AC current ripple and the AC voltage ripple, and calculating an impedance spectrum, a power spectrum, or a spectral density of an electrical component based on the respective frequency components of the AC current ripple and the AC voltage ripple.

Abstract: A method and a test fixture for evaluating a battery cell are described, wherein the battery cell is composed of a cell body having a plurality of electrode foils that are joined to both a positive terminal and a negative terminal at weld junctions. The method includes retaining the cell body of the battery cell in a first clamping device and gripping one of the positive and negative terminals in a terminal gripper. A dynamic stress end effector coupled to the terminal gripper is employed to apply a vibrational excitation load to the one of the positive and negative terminals. Impedance between the positive terminal and the negative terminal is monitored via a controller, and integrity of the weld junction of the one of the positive and negative terminals is evaluated based upon the impedance.