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.

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 comparatively simple method in which a voltage is applied to a battery and the current value thereof is measured. The method comprising steps of: a resistance increasing step of increasing resistance of an all solid state battery to 3.

Abstract: To determine in a simple and unequivocal manner whether measurement contacts at which a voltage is to be measured have been properly contacted in a measurement system, in the measurement system, after a discharge switch connecting a charging circuit to a voltage measurement device is closed, the charging circuit is discharged via an internal resistance of the voltage measurement device. When the discharge switch is closed, after a measurement switch connecting the voltage measurement device to the measurement contacts is closed, it is established whether the electrical system is contacted with the measurement system by analyzing the voltage curve at the voltage measurement device after closure of the measurement switch. Advantageously, after the discharge switch is closed, the charging circuit is discharged via a discharge resistor connected in series or in parallel with the voltage measurement device and via the internal resistance.

Abstract: A method for managing a battery according to a state of health of the battery, comprising, prior to using the battery, predetermining a maximum depth of discharge profile according to the state of health of the battery, the profile being dependent on a technology of the battery, on a nominal energy level to be made available each time the battery is discharged, the nominal energy level being substantially constant over a service life of the battery. While using the battery, a maximum depth of discharge of the battery is adjusted at regular intervals, each time the state of health of the battery decreases by a percentage corresponding to an update interval p % that is equal to p/100, that is, for all state of health values (SOHn) that are equal to SOH0-n×p %, where n is an integer comprised between 0 and 20/p.

Abstract: A resistance factor determining method of a secondary battery according to the present disclosure determines, when the secondary battery has a certain temperature and state of charge, a primary differential value regarding a charge initial I-V profile calculated from a current value at a point of intersection at which a charge final I-V profile according to changes in magnitude of the charging current meets a boundary line set to a charge upper limit as the resistance factor corresponding to the temperature and state of charge. Further, a charge power estimating apparatus and method according to the present disclosure estimates a charge power corresponding to the temperature and state of charge of the secondary battery while the secondary battery is being charged using the resistance factor pre-defined according to the state of charge and temperature of the secondary battery.

Abstract: Systems and methods of monitoring and controlling a back-up power supply are provided. The back-up power supply can include an uninterruptible power supply system configured with a plurality of primary battery banks maintained in long-term storage and a working battery maintained in an operable state. The back-up power supply system can monitor the condition of a first working battery to determine if the condition is below a performance threshold or a capacity threshold. The uninterruptible power supply system can transition a primary battery bank previously maintained in long-term storage to an operable state and designate the transitioned primary battery as a second working battery. The uninterruptible power supply system can switch the source of power provided by the back-up power supply from the first working battery to the second working battery.

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 battery health state evaluation method for evaluating a health state of a battery comprises a charging step, an idling step, a pulse discharging step, an evaluation index calculating step, and an evaluation result yielding step. The evaluation index calculating step retrieves a continuous voltage data and a continuous current data in a charging process, an idling process, and a pulse discharge process and calculates a plurality of evaluation indexed according to the continuous voltage data and continuous current data. The evaluation indexes are associated with the health state of the battery. The evaluation result yielding step evaluates the health state of the battery according to the indexes and yields an evaluation result. Therefore, the battery health state evaluation method is easy, convenient, and effective in performing a test quickly and accurately.

Abstract: A method for determining a state of a rechargeable battery includes obtaining a complex impedance measured by applying AC voltage or AC current to a rechargeable battery that is subject to determination and determining a state of the rechargeable battery based on the obtained complex impedance. The determining a state of the rechargeable battery includes determining whether or not a first capacity shift is occurring based on a comparison of a value of the complex impedance at a predetermined frequency with a first determination value used to determine a negative electrode capacity shift, and when determined that the first capacity shift is not occurring, determining whether or not a second capacity shift is occurring based on a comparison of a gradient of the complex impedance with respect to a real axis in a diffusion resistance region with a second determination value used to determine a positive electrode capacity shift.

Abstract: A vehicle system provides an excitation signal to an electrochemical system for use in Electrochemical Impedance Spectroscopy diagnostics. The electrochemical system is connectable to the vehicle system and the vehicle system includes a power stage, such as a charger, connectable to the electrochemical system for supplying electrical energy to the electrochemical system, and/or connectable to the electro-chemical system for withdrawing electrical energy from the electrochemical system, and an Excitation Generation Unit comprised by the power stage or operatively connected to the power stage. The Excitation Generation Unit is adapted for instructing the power stage to generate an excitation signal for use in the Electrochemical Impedance Spectroscopy diagnostics, and the power stage is adapted for generating the excitation signal and supplying the excitation signal to the electrochemical system when so instructed by the Excitation Generation Unit.

Abstract: The present invention relates to a system and a method of protecting a battery, and particularly to a system and a method of protecting a battery, which compare current state information of a battery with reference state information and control an operation of a power supplying unit that supplies power supplied from the battery to a load based on a result of the comparison in order to block power supplied from the battery that is in a problem state, thereby protecting a load from the battery in the problem state.

Abstract: A method and a temperature detection circuit are disclosed. An example of the method includes driving an alternating current with a first frequency into a battery and detecting an imaginary part of a battery impedance at the first frequency; driving an alternating current with a second frequency different from the first frequency into the battery and detecting an imaginary part of the battery impedance at the second frequency; and calculating an intercept frequency at which the imaginary part equals a predefined value at least based on the imaginary part obtained at the first frequency and the imaginary part obtained at the second frequency.

Abstract: The present invention pertains to the detection of the state of charge of a battery, whereby the complex impedance in the diffusion region of the battery is used. An arithmetic device such as a computer determines the slope of the complex impedance at least two different frequencies in the diffusion region of a rechargeable battery when a straight-line approximation has been made. The state of charge of the rechargeable battery is detected by using the slope that has been determined, and the relationship between the state of charge and slopes that have been stored in advance in a storage means.

Abstract: A charging system for a high voltage battery includes a pair of contactors each electrically connected to one of positive and negative terminals of the battery and configured to enable charging of the battery when closed; and a controller programmed to generate a notification indicating that one of the contactors is welded closed based on port voltage values achieved while issuing a predetermined sequence of open and close commands to the contactors after charge completion.

Abstract: A sensor of a status determination device detects a magnitude of a terminal voltage of an auxiliary battery provided separately from a driving battery and a magnitude of a current flowing through the auxiliary battery. The driving battery is an electrical power source for a driving motor of a vehicle, and the auxiliary battery is an electrical power source for auxiliary equipment and has an output voltage lower than that of the driving battery. An internal resistance calculator calculates an internal resistance of the auxiliary battery based on the magnitude of the terminal voltage and the magnitude of the current detected by the sensor in a stable period that is before the auxiliary equipment is started and in which the magnitude of the terminal voltage and the magnitude of the current fall within predetermined fluctuation ranges, and those detected in a period after starting of the auxiliary equipment is detected.

Abstract: In a general aspect, a method can include providing an indication that the electronic device has changed from a battery charging state to a battery discharging state and measuring an initial measured state-of-charge (MSOC) value of a battery of the electronic device. In the event the initial MSOC value is above a threshold value, the method can further include determining a compensation value based on the initial MSOC value and the threshold value, determining an initial reported state of charge (RSOC) value by scaling the initial MSOC value using the compensation value and reporting the initial RSOC value using the electronic device.

Abstract: A method and system are disclosed for estimating cell voltage excursion in a battery pack in the presence of a sensing fault in which actual cell voltages of first and second battery cells in a block of battery cells become unknown or missing. The sensing fault is detected, and a cell voltage is determined for each cell in the block other than the first and second cells. The method also includes measuring a block voltage, calculating an average cell voltage in the block, and estimating that the first cell is equal to the calculated average cell voltage. All excursion or deviation of the measured block voltage from a sum of the cell voltages and the estimated cell voltage of the first cell is assigned to the second cell. A control action is executed using the estimated cell voltages, including selectively enabling or disabling functionality of the battery pack.

Abstract: Systems and methods for monitoring a state of health of a battery are disclosed. The state of health of the battery may be determined based on an internal resistance of the battery. The state of health of the battery may be determined based on a measured terminal voltage of the battery, a measured current of the battery, a temperature of the battery, and a state-of-charge of the battery.

Abstract: A battery pack includes a battery, a terminal unit, a first current path, a second current path, and a first voltage sensing path. The battery has first and second battery terminals. The terminal unit includes a first pack terminal, a second pack terminal, and a first sensing terminal. The first current path includes charging and discharging switches and is located between the first battery terminal and the first pack terminal. A charging current and discharging current of the battery flows on the first current path. The second current path is between the second battery terminal and the second pack terminal. The first voltage sensing path includes the first sensing terminal, and voltage between the first sensing terminal and another terminal corresponds to a voltage between the first battery terminal and the first sensing terminal.

Abstract: A battery capacity measuring device that measures the battery capacity of a rechargeable battery includes an impedance measurement unit that measures the complex impedance of a rechargeable battery, which is a subject to measurement, based on application of measurement AC power, a parameter calculation unit that calculates a parameter that is a ratio of a difference between measured angular speeds of two complex impedances having different measured angular speeds in a diffusion region among a plurality of measured complex impedances to a difference between components of the two complex impedances, and a capacity calculation unit that calculates the capacity of the rechargeable battery based on information that is set in advance and indicates the relationship between the capacity of the rechargeable battery and the parameter and a parameter calculated by the parameter calculation unit.

Abstract: A battery pack cooling system includes a plurality of cells disposed in an internal space of a battery pack case so as to form a cooling passage configured to cool the cell modules by cooling air flowing in the cooling passage. A first temperature sensor is a minimum temperature sensor disposed in the upstream position which becomes a lowest temperature. A second temperature sensor is a maximum temperature sensor disposed in the downstream position which becomes a highest temperature. A third temperature sensor is configured to measure the temperature of either the highest temperature or the lowest temperature disposed in a second cell module. A cooling passage includes a cooling air inlet passage, a cooling air exhaust passage, and a plurality of cooling branch passages disposed to connect the cooling air inlet passage and the cooling air exhaust passage in parallel.

Abstract: In a state monitoring of a storage battery, accuracy of estimation of the remaining service life of the storage battery can be improved by monitoring the state of the storage battery and distinguishing an initial failure and an accidental failure from degradation over time.

Abstract: A method of generating at least one recommended replacement time signal for a battery is provided. The method includes measuring a plurality of associated unloaded and loaded battery voltages. A delta voltage for each associated unloaded and loaded battery voltage is then determined. A select number of delta voltages are averaged. A minimum delta voltage is determined from a plurality of the averaged delta voltages. At least one recommended replacement time signal for the battery is generated with the use of the minimum delta voltage when at least one averaged delta voltage is detected that has at least reached a replacement threshold.

Abstract: A fuel cell internal state detection system includes estimation object state quantity setting unit for setting a suitable estimation object state quantity as an index of an internal state, an impedance value acquisition unit configured to obtain an impedance value of a fuel cell, an impedance usability judging unit configured to judge whether or not the obtained impedance value is usable for the calculation of the estimation object state quantity, estimation object state quantity calculation unit for calculating the estimation object state quantity set by the estimation object state quantity setting unit on the basis of the obtained impedance value when the impedance value is judged to be usable for the calculation of the estimation object state quantity by the impedance usability judging unit, and an unusable-scene process execution unit configured to perform an unusable-scene process when the impedance value is judged not to be usable for the calculation of the estimation object state quantity by the impeda

Abstract: An internal resistance estimation method for a secondary battery includes: acquiring an initial internal resistance value and temperature course information including a battery temperature and time information about time at which the battery temperature has been recorded; estimating an increased amount of the internal resistance value after a lapse of a predetermined time from the predetermined reference time on the basis of the temperature course information; estimating a reduced amount of the internal resistance value of the secondary battery resulting from a relative change between a range of use of a state of charge of the positive electrode and a range of use of a state of charge of the negative electrode on the basis of the temperature course information; and calculating an internal resistance variation in the lapse of the predetermined time on the basis of the increased amount and the reduced amount.

Abstract: Methods, systems, and apparatus of managing the lifespan of a battery are disclosed herein. A method comprises interpreting age data indicative of a current age of a battery, interpreting usage data indicative of a current usage of the battery, comparing the age data to the usage data, and allocating a propelling power from the battery in a hybrid electric vehicle (HEV) responsive to the comparison.

Abstract: Systems and methods for measuring voltage of a battery pack for an electrified vehicle, such as an electric or hybrid vehicle, include a battery having internal circuits that measure pack voltage and individual cell voltages, an electric machine powered by the battery to propel the vehicle via an external circuit that measures the pack voltage, and a processor programmed to publish the pack voltage to a vehicle network based on a first internal circuit voltage in response to a voltage differential among the internal circuits being less than a threshold and based on the individual cell voltages otherwise. The published pack voltage may be used by one or more battery or vehicle controllers to control various battery and vehicle functions including engine starting in a hybrid vehicle and battery charging and discharging, for example.

Abstract: The invention relates to a battery system (100) with a battery (20), which is designed to supply a high voltage network (70) with electric energy, and a measuring device (130) for measuring at least one insulation resistance provided between the battery (20) and a housing of the battery (20). The measuring device (130) is equipped with two measuring paths (140, 150), each of which is paired with one of two high-voltage connections (21, 22) of the battery (20), each of which comprises a series circuit that comprises a first resistor (142, 152) and a relay (145, 155), and each of which is connected between the paired high-voltage connection (21, 22) and a point (25) that has a housing potential. Furthermore, each series circuit has a semiconductor switch (147, 157). The measuring device (130) also has two functional modes in which the relays (145, 155) of the measuring paths (140, 150) are closed.

Abstract: Systems and methods are provided for optimizing battery life in an electronic device. The device is configured to make periodic assessments of battery capacity by measuring the DC resistance value of the battery cell. The temperature of the battery cell and/or other characteristics of the device are used to determine a threshold DC resistance level. If the measured DC resistance value reaches a determined threshold level, the device can initiate a power-saving mode in which an operating parameter of the device is adjusted to decrease power consumption.

Abstract: It is possible to accurately estimate a starting current and calculate a precise starting minimum voltage without being influenced by a change in a storage battery state or a starting state by updating a current/voltage correlation characteristic corresponding to a deterioration state of a storage battery each time a current/voltage data set obtained when a starter is driven is newly stored in association with the deterioration state of the storage battery and by calculating the starting current corresponding to a present voltage immediately before start in accordance with the current/voltage correlation characteristic corresponding to the present deterioration state of the storage battery when determination is made as to whether or not to drive the starter.

Abstract: Systems and methods are provided for optimizing battery life in an electronic device. The device is configured to make periodic assessments of battery capacity by measuring the DC resistance value of the battery cell during the execution of a power-consuming operation. If the measured DC resistance value reaches a threshold level, the device can initiate a power-saving mode in which an operating parameter of the device is adjusted to decrease power consumption.

Abstract: A control system for a vehicle for optimizing the energy efficiency of a rechargeable electric battery system and/or for optimizing the lifetime of a rechargeable electric battery. The rechargeable electric battery system comprising: the rechargeable electric battery, a temperature management system for the rechargeable electric battery and one or more sensors for measuring one or more characteristics relating to the rechargeable electric battery. The control system comprising a control unit configured and arranged to receive data from the one or more sensors and being coupled to the temperature management system. The control unit being configured and arranged to determine in dependence upon data received from the one or more sensors, a time-weighted-average state-of-health of the rechargeable electric battery.

Abstract: A method of treating hypertension in a patient includes 1) generating, by an electroacupuncture device implanted beneath a skin surface of the patient at an acupoint corresponding to a target tissue location within the patient, stimulation sessions at a duty cycle that is less than 0.05, wherein the duty cycle is a ratio of T3 to T4, each stimulation session included in the stimulation sessions has a duration of T3 minutes and occurs at a rate of once every T4 minutes, and the electroacupuncture device comprises a central electrode of a first polarity and an annular electrode of a second polarity and that is spaced apart from the central electrode; and 2) applying, by the electroacupuncture device, the stimulation sessions to the target tissue location by way of the central electrode and the annular electrode in accordance with the duty cycle.

Abstract: Systems, devices, methods, computer-readable media, techniques, and methodologies are disclosed for increasing efficiency in power management for user devices. In some embodiments, a system voltage and battery voltage of a user device may be monitored and stored. The system voltage and battery voltage may be analyzed, and a system minimum voltage threshold for a user device may be modified based on the analysis of the measurements.

Abstract: Disclosed is an apparatus and method for estimating a parameter of a secondary battery. The apparatus according to the present disclosure includes a sensor means configured to measure a plurality of current-voltage data while a charging current decreases when a secondary battery is charged in such a pattern that the charging current increases to a peak value and then decreases, and a control means configured to receive an input of the plurality of current-voltage data from the sensor means, calculate a linear approximation equation representing a correlation between a current and a voltage from the plurality of current-voltage data, estimate an open-circuit voltage (OCV) of the secondary battery by reflecting a polarization voltage of the secondary battery quantified through a resistor-capacitor (RC) circuit on a Y intercept of the linear approximation equation, and estimate a state of charge (SOC) of the secondary battery from the estimated OCV.

Abstract: An apparatus and method for managing energy are disclosed herein. The apparatus for managing energy includes a State-of-Health (SOH) determination unit and an energy distribution unit. The SOH determination unit collects information about energy storage systems and energy facilities, and determines the SOH of each of the energy storage systems based on the information. The energy distribution unit distributes energy stored in the energy storage system to loads inside a building based on the information and the SOH.

Abstract: The present disclosure includes systems and methods for state of charge estimation. In one embodiment, the present disclosure includes a method comprising receiving a voltage corresponding to a state of charge of a battery, converting the voltage to an estimated state of charge using different algorithms across different ranges. In another embodiment, an offset state of charge is applied to a first state of charge to produce an estimated state of charge.

Abstract: A secondary battery is charged at a predetermined charging current density to a first SOC, and discharged at a discharging current density same as the charging current density to a second SOC smaller than the first SOC, the voltage thereof is stabilized by leaving the secondary battery for a predetermined time while maintaining the secondary battery in the range of ±3° C. from the battery temperature of the secondary battery that has been discharged, the secondary battery the voltage of which has been stabilized is self-discharged under room temperature, and the presence or absence of a short-circuit is detected on the basis of a voltage drop amount after a given time.

Abstract: A method of manufacturing for a secondary battery. The secondary battery is configured to include an electrode group in a battery package. The electrode group includes a positive electrode, a negative electrode, and a separator. The manufacturing method includes: (a) measuring a first voltage drop amount of the secondary battery with the passage of time in a state in which a compression force in a direction parallel to a lamination direction of the electrode group is applied to the electrode group via the battery package; (b) measuring a second voltage drop amount of the secondary battery with the passage of time in a state in which the compression force is released; and (c) detecting a small short circuit of the secondary battery by comparing the first voltage drop amount and the second voltage drop amount.

Abstract: A battery remaining amount detection unit includes: a voltage measurement section configured to measure a voltage of a battery; an open-circuit voltage calculation section configured to calculate an estimated open-circuit voltage; and a remaining amount detection section configured to detect a remaining amount of the battery from the estimated open-circuit voltage, in which the open-circuit voltage calculation section is configured to calculate a first voltage change amount as a voltage change amount from a no-load voltage when no load is applied to the battery and a closed-circuit voltage when a load is applied to the battery, and the open-circuit calculation section is configured to calculate the estimated open-circuit voltage based on the closed-circuit voltage of the battery and the first voltage change amount.

Abstract: A method and an electronic device are disclosed for measuring a current. The device measures a temperature between a first sampling point and a second sampling point on a metal structure carrying a current to be measured. The device outputs a first signal according to the measured temperature and a second signal after sampling and filtering the first signal. The device detects the first voltage signal at the first sampling point and the second voltage signal at the second sampling point. The device samples and filters a difference between the first voltage signal and the second voltage signal and outputs a third voltage signal. The device restores the second signal to a temperature value representing a temperature between the first sampling point and the second sampling point and calculates a resistance value between the first sampling point and the second sampling point according to the temperature value.

Abstract: A method and a system for estimating the State of Health (SOH) of a battery set are disclosed. The method utilizes a discrete quantization algorithm to estimate the SOH of the battery set, wherein the voltage standard deviations are calculated according to the loop voltages of the battery cells, and comparing the rated discharge capacity with the voltage standard deviations for estimating the SOH of the battery set.

Abstract: A battery sensing section measures a voltage across a secondary battery. A current sensing section measures a current flowing through the secondary battery. A control section holds the value of an external impedance present in a discharge path outside the secondary battery, discharges the secondary battery from a first time to a second time at which an integrated discharge capacity based on a measured discharge current becomes equal to a predetermined discharge capacity reference value, calculates the internal impedance present in the secondary battery at the second time based on the measured voltage, calculates the second open voltage at the second time by multiplying the sum of the external impedance and the internal impedance by the measured discharge current, and calculates the recovered capacity of the secondary battery based on the first open voltage at the first time, the second open voltage and the discharge capacity reference value.

Abstract: An implantable medical device (IMD) is disclosed having measurement circuitry for measuring one or more currents in the IMD, such as the currents drawn from various power supply voltages. Such currents are measured without disrupting normal IMD operation, and can be telemetered from the IMD for review. Switching circuitry in line with the current being measured is temporarily opened for a time period to disconnect the power supply voltage from the circuitry being powered. A voltage across a capacitance in parallel with the circuitry is measured when the switching circuitry is opened and again closed at the end of the time period, with the circuitry drawing power from the charged capacitance during this time period. The average current drawn by the power supply voltage is determined using the difference in the measured voltages, the known capacitance, and the time period between the measurements.