Abstract: In one aspect the present disclosure relates to a system for measuring an internal resistance of a battery. The system may involve: a processor; a load module responsive to the processor for applying a load across the battery; a current sense subsystem for sensing the current flowing to the load module and generating a sensed current signal in accordance therewith; a multiplexer module in communication with the current sense subsystem for detecting voltages with the load coupled across the battery and uncoupled from the battery, and generating voltage signals in accordance therewith; and a filtering and amplification subsystem responsive to the multiplexer module, for filtering and amplifying a level of each of the voltage signals to produce modified voltage signals for use by the processor in determining the battery internal resistance.

Abstract: A method and apparatus is provided for determining when a battery, or one or more batteries within a battery pack, undergoes an undesired thermal event such as thermal runaway. The system uses a conductive member mounted in close proximity to, or in contact with, an external surface of the battery or batteries to be monitored. A resistance measuring system such as a continuity-tester or an ohmmeter is coupled to the conductive member, the resistance measuring system outputting a first signal when the temperature corresponding to the battery or batteries is within a prescribed temperature range and a second signal when the temperature exceeds a predetermined temperature that falls outside of the prescribed temperature range.

Abstract: In a status detector for a power supply, a power supply, and an initial characteristic extracting device for use with the power supply, a measuring unit obtains measured values of at least current, voltage and temperature of the electricity accumulating unit. A processing unit executes status detection of the electricity accumulating unit by using the measured values and the characteristic information of the electricity accumulating unit which is stored in a memory unit. A discrepancy detecting unit detects the presence of a discrepancy away from a theoretical value when a result of the status detection is changed over a predetermined threshold or reversed with respect to the measured values. A modifying unit modifies the characteristic information depending on the detected discrepancy.

Abstract: Battery system is widely used in emergent power plant or communication network power plant and its effective management is important. When any one of batteries connected to each other in series is failed during operation of the battery system, since reliability of the system cannot be secured, a problem is arisen to stable operation of the communication network. In a method of separating inferior battery, the battery is operated in floating charge state without separation to generate square current containing charge current and easily generated to flow through the battery cell, voltage signal generated from terminal voltage of the battery by the measuring signal is processed such that only internal impedance voltage signal is separated from harmonics ripple voltage and noise voltage by a synchronized detection calculating algorithm to calculate the internal impedance or effective value thereof (resistance component).

Abstract: An over-voltage detection and correction system for a transmitter of a mobile terminal that accounts for battery droop during a transmit burst is provided. In general, prior to ramp-up for a first transmit burst, a voltage of the battery of the mobile terminal at a no-load condition is measured. After ramp-up for the transmit burst, the voltage of the battery is measured at full-load, and a current provided to a power amplifier of the transmitter at full-load is detected. Based on the measured voltage of the battery at no-load, the measured voltage of the battery at full-load, and the detected current provided to the power amplifier at full-load, a resistance of the battery is determined. The battery resistance is thereafter updated as desired and used as an indicator of remaining battery-life or power of the battery of the mobile terminal.

Abstract: A detecting device and a detecting method for monitoring a battery module are provided. The battery module is electrically connected to a load and includes a first battery unit, a second battery unit and a connecting device. The connecting device connects the positive electrode of the first battery unit to the negative electrode of the second battery unit. The detecting device includes a shunt, a voltage detecting module and a control module. The shunt is serial connected between the battery module and the load to measures the load current. The voltage detecting module measures the voltage difference across the connecting device between the positive electrode and the negative electrode. The control module computes the equivalent resistance across the connecting device between the positive electrode and the negative electrode according to the load current and the voltage difference.

Abstract: A voltage detection apparatus includes: a battery including unit cells mutually connected in series; a first block including at least one of the unit cells; a second block including at least one of the unit cells, and provided adjacent to the first block; a first voltage detector connected to the first block, which detects a voltage between both ends of the unit cell in the first block, and which includes: a current source; a current detection element connected to the current source; and a voltage measuring unit which detects a voltage between both ends of the current detection element; and a second voltage detector connected to the second block, which has a similar construction with the first voltage detector. An abnormality detector of the voltage detection apparatus detects an abnormality of the voltage detectors in accordance with the voltages between both ends of the current detection elements.

Abstract: A non-invasive method and device for determining the electrical impedance of an electrochemical system for electric power is disclosed. The voltage and current are measured at terminals as a function of time, and these measurements are converted to signals dependent on frequency. The signals dependent on frequency are subjected to at least one segmentation. For each segment, a power spectral density of the current signal ?I dependent on frequency and the cross power spectral density of the voltage and current signals ?IV dependent on frequency are determined for each segment. The electrical impedance of the electrochemical system is determined by calculating a ratio dependent on frequency of a mean of the power spectral densities ?I dependent on frequency to a mean of the cross power spectral densities ?IV dependent on frequency.

Abstract: Reactive replenishable device management comprises receiving device measurement data from at least one device, updating one or more device usage profiles associated with the at least one device, and if an analysis of the one or more device usage profiles indicates usage of the at least one device is sub-optimal, performing one or more of: controlling at least one of an attribute or an operation of the at least one device, issuing one or more device management recommendations to a user of the at least one device, and issuing one or more user alerts to the user. The at least one device comprises at least one of one or more replenishable devices, one or more replenishers associated with the one or more replenishable devices, and one or more other devices associated with the one or more replenishable devices.

Abstract: An over-voltage detection and correction system for a transmitter of a mobile terminal that accounts for battery droop during a transmit burst is provided. In general, prior to ramp-up for a first transmit burst, a voltage of the battery of the mobile terminal at a no-load condition is measured. After ramp-up for the transmit burst, the voltage of the battery is measured at full-load, and a current provided to a power amplifier of the transmitter at full-load is detected. Based on the measured voltage of the battery at no-load, the measured voltage of the battery at full-load, and the detected current provided to the power amplifier at full-load, a resistance of the battery is determined. The resistance of the battery is thereafter used to compensate for battery droop during over-voltage detection and correction for one or more subsequent transmit bursts.

Abstract: Included are embodiments of an ambulatory infusion device. Some embodiments include a battery receiving portion that receives a user-replaceable battery of variable individual characteristics. The user-replaceable battery may serve as a primary power source of the ambulatory infusion device and being successively depleted during application. Similarly, some embodiments include a dosing unit with an electrically powered actuator and an electronic controller that controls operation of the ambulatory infusion device. Still some embodiments include a testing unit that is operatively coupled to the electronic controller, the testing unit being designed to carry out a battery test, the battery test including determining an off-circuit voltage and an internal resistance of the user-replaceable battery. Still some embodiments include an alerting unit that is operatively coupled to the testing unit and/or the electronic controller to provide an alert to a device user in dependence of a battery test result.

Abstract: A conversion system includes a conversion circuit coupled to multiple cells for generating multiple sampling signals indicative of the cell voltages of the cells respectively. Each sampling signal is with respect to the same reference level. In addition, the conversion system includes a compensation circuit coupled to the conversion circuit for generating a compensation current that flows through at least one cell of the multiple cells via the conversion circuit for balancing the currents respectively flowing through the cells.

Abstract: A converter control unit responds to a command from a start determining unit to control a converter such that a ripple current is generated at a secondary battery. A storage unit stores a map defining a correlative relationship between the temperature and current of the secondary battery and internal resistance. An estimating unit estimates a value of internal resistance of the secondary battery based on each detection value of the temperature and current, and the map stored in the storage unit.

Abstract: An over-voltage detection and correction system for a transmitter of a mobile terminal that accounts for battery droop during a transmit burst is provided. In general, prior to ramp-up for a first transmit burst, a voltage of the battery of the mobile terminal at a no-load condition is measured. After ramp-up for the transmit burst, the voltage of the battery is measured at full-load, and a current provided to a power amplifier of the transmitter at full-load is detected. Based on the measured voltage of the battery at no-load, the measured voltage of the battery at full-load, and the detected current provided to the power amplifier at full-load, a resistance of the battery is determined. The battery resistance is thereafter updated as desired and used as an indicator of remaining battery-life or power of the battery of the mobile terminal.

Abstract: Battery insulation resistance measurement methods, insulation resistance measurement methods, insulation resistance determination apparatuses, and articles of manufacture are described. According to one aspect, a battery insulation resistance measurement method includes determining a voltage of a battery, determining a voltage of a first terminal of the battery with respect to a ground reference, determining a voltage of a second terminal of the battery with respect to the ground reference, and using the voltages of the battery, the first terminal and the second terminal, determining an insulation resistance of the battery with respect to the ground reference.

Abstract: An internal resistance testing device includes an excitation source and a battery pack, an adjustable resistance R, a sampling unit, and a control unit. The excitation source and the battery pack form a loop circuit. The adjustable resistance R may be located at the loop circuit formed by the excitation source and the battery pack. The sampling unit samples the voltage between two sides of the battery pack, the voltage between two sides of the adjustable resistance R, and the value of the adjustable resistance R. The control unit calculates internal resistance of the battery pack according to the signal value collected by the sampling unit. The internal resistances of different voltage-ranges the battery pack are determined by adjusting the value of the adjustable resistance R to cause the actual excitation voltage to be equal to the range voltage of the sampling unit.

Abstract: A buttery pack includes: one or two or more secondary batteries; a charge control switch that turns on/off a charging current to the secondary battery; a discharge control switch that turns on/off a discharging current from the secondary battery; a current-detecting element for detecting the charging current and the discharging current; a voltage measuring part that measures the voltage of the secondary battery; a control unit that controls the charge control switch and the discharge control unit; and a storage unit that stores an initial internal resistance of the secondary battery. The control unit measures a closed circuit voltage and a charging current during charging, and a first closed circuit voltage after a first waiting time and a second closed circuit voltage after a second waiting time. The second waiting time is longer than the first waiting time.

Abstract: A battery control device 1 has an electric circuit control unit 6 controlling a power supply; a voltage measuring unit 7 measuring a voltage; a current measuring unit 8 measuring an electric current; and a power source control unit 9, wherein the power source control unit 9 measures a first voltage defined as the voltage of the battery 4 and a first current defined as the current of the battery 4 in a state where the battery 4 supplies electric power to the load 3, measures a second voltage defined as the voltage of the battery 4 in a state where the supply of the electric power to the load 3 from the battery 4 is cut off, and calculates internal impedance of the battery 4 by dividing a value, obtained in a way that subtracts the first voltage from the second voltage, by the first current.

Abstract: A method and apparatus for measuring battery cell DC impedance by controlling charging of the battery cell. The method includes real-time characterization of a battery, (a) measuring periodically a DC impedance of the battery to determine a measured DC impedance; (b) ratioing the measured DC impedance to a reference DC impedance for the battery to establish an impedance degradation factor; (c) obtaining, during use of the battery and responsive to a set of attributes of the battery, an operational reference impedance for the battery; and (d) applying the impedance degradation factor to the operational reference impedance to obtain a real-time effective impedance for the battery.

Abstract: A method for evaluating the condition of a battery comprises coupling a first power transistor as or as part of a first external load in series with the battery, coupling a second power transistor as or as part of a second external load in series with the battery, and conducting each power transistor to draw a transient large current from the battery while sampling the voltage across the battery and voltage across the load, from which the internal resistance of the battery can be determined. The internal resistance of the battery can then be compared with a predetermined nominal value to issue a warning if the battery is weak. The invention enables, for example, a driver to correctly know the actual condition of an automobile battery in substantially real time while consuming a minimum amount of power.

Abstract: A method for determining the internal resistance of a battery, in particular a lead-acid vehicle battery, and an associated device for performing the method are described, in which differential values are calculated from the measured values for the voltage and the current, and these differential values are processed with the aid of a regulator, such as an integrator or a PID regulator. A signal results at the output of the regulator, which corresponds to the reciprocal value of the internal resistance of the battery. This signal is taken into consideration again in each following computing step. The functional capability may be inferred from its internal resistance.

Abstract: An on-board battery supervisor that monitors the state-of-charge (SOC) of a lead-acid vehicle battery and automatically disconnects loads from the battery to prevent over-discharging of the battery, is disclosed. As the battery is being discharged, the on-board battery supervisor disconnects loads at an SOC level that leaves enough energy in the battery to reliably start the vehicle engine, while providing as much energy as possible to accessory loads. The loads are automatically reconnected as the battery is charged. Some preferred embodiments of the invention are designed specifically for use in watercraft and a dual output version of the invention simplifies the electrical system. All embodiments have circuit breaker outputs, high peak current capability, a low quiescent current drain and a dual timer that allows accurate determination of the SOC of the battery.

Abstract: A battery management device is provided for accurately measuring in a simple manner the internal resistance (reciprocal of conductance) of a battery that serves as the determination reference of the deterioration level of a battery without the application of an AC voltage to the battery while the battery remains onboard, and determining and displaying the deterioration level of the onboard battery.

Abstract: A method of battery capacity measurement is actualized by battery internal resistance. This method establishes a controlled discharge path inside the battery module. The battery discharge current is a constant value despite of the variation of system loading current. The internal resistance measured by establishing this constant battery current can be used to obtain the battery capacity precisely.

Abstract: A capacity maintenance ratio determination device includes an impedance measurement unit and a capacity estimation unit. An alternating signal is applied from a signal generator to a battery. Frequency characteristics of AC impedance are calculated by the impedance measurement unit based on a response signal output from the battery in response to the alternating signal. A feature frequency is determined from the calculated frequency characteristics. The capacity estimation unit includes a memory and a determination unit. A correspondence relationship among a temperature of the battery, the feature frequency and a capacity maintenance ratio is stored in the memory. The determination unit determines the capacity maintenance ratio of the battery based on the temperature of the battery detected by a temperature detector, the determined feature frequency and the correspondence relationship stored in the memory.

Abstract: A battery monitor for monitoring the performance of at least one battery within an array of batteries, comprising: a data acquisition device for measuring at least one parameter of the at least one battery associated with the battery monitor, a first data interface operable to exchange data with a first device, and a second data interface operable to exchange data with a second device.

Abstract: A battery management system that estimates an internal impedance of a battery, a method of driving the same, a device that estimates an internal impedance of a battery, and a method of estimating the internal impedance of a battery. A method of driving a battery management system that estimates the internal impedance of a battery including a plurality of cells includes generating a battery equivalent model of the battery, receiving a terminal voltage signal and a charge and discharge current signal of the battery, and generating a first discrete signal corresponding to the terminal voltage signal of the battery and a second discrete signal corresponding to the charge and discharge current signal of the battery, and filtering the first discrete signal and the second discrete signal according to a frequency range corresponding to the battery equivalent model so as to estimate the internal impedance of the battery.

Abstract: A method and apparatus is provided for determining when a battery, or one or more batteries within a battery pack, undergoes an undesired thermal event such as thermal runaway. The system uses a conductive member mounted in close proximity to, or in contact with, an external surface of the battery or batteries to be monitored. A resistance measuring system such as a continuity-tester or an ohmmeter is coupled to the conductive member, the resistance measuring system outputting a first signal when the temperature corresponding to the battery or batteries is within a prescribed temperature range and a second signal when the temperature exceeds a predetermined temperature that falls outside of the prescribed temperature range.

Abstract: A battery includes multiple conductive plates and a permeable electrolytic material and an ion membrane located between the conductive plates. The battery also includes at least one wire located within one or more of the permeable electrolytic material and the ion membrane. The at least one wire can be configured to regulate a flow of ions through the ion membrane based on an electrical signal flowing through the at least one wire. The at least one wire could also be configured to generate a magnetic field within the permeable electrolytic material based on another electrical signal flowing through the at least one wire. The battery could further include a temperature sensor wire within the permeable electrolytic material.

Abstract: A fuel battery system is comprised of a power source circuit, a rotating electrical machine that is a load, a memory device and a control unit. Here, a battery learning system corresponds to an arrangement including a fuel battery that is a structural component of the power source circuit, a high frequency signal source, an electric current detection means, a voltage detection means, the memory device and a battery learning part that is a structural element of the control unit. An impedance value can be obtained from alternating current components of respective detecting values of the electric current detection means and the voltage detection means. The battery learning unit has an I-V characteristic curve learning module that learns an I-V characteristic curve and a learning prohibition judgment module that judges whether or not an acquiring interval of the impedance value is over a predetermined threshold interval set in advance, and prohibits learning if the former is over the latter.

Abstract: A battery monitor circuit. The circuit includes a control module, a resistive load having a resistive value between a first and a second terminals and a part of that resistive value between the first and an intermediate terminals, a switch configured to couple the full load between circuit input and a common potential in response a pulse signal, a first comparator having inputs separately coupled to a voltage reference and the intermediate terminal, a second comparator having inputs separately coupled to the voltage reference and an input potential, a latch, a detection module having input coupled to second comparator output, and an alarm module. The latch is configured to latch a value at output of first comparator to another input of the detection module in response to the pulse signal; if input potential is less than a preselected magnitude, detection module output is configured to activate the alarm module.

Abstract: There is provided an impedance measuring system which can accurately measure the impedance of a fuel cell. A motor rotation number detection unit successively detects the rotation number of a motor controlled by an inverter and outputs the detection result to a superposition signal generation unit The superposition signal generation unit sets the frequency of an impedance measuring signal to a non-resonant frequency so that the control signal of the motor not resonate with the impedance measuring signal. Thus, by setting the frequency of the impedance measuring signal to the non-resonant frequency, the resonance with the motor is suppressed, which can improve impedance measurement accuracy.

Abstract: A processor executes a program to calculate values of the internal resistance R of a battery and updates a database of parameters defining the dependence of internal resistance on the battery state of charge (SOC) and temperature. The database is utilized to obtain the information needed to make accurate remaining run-time calculations. The processor may also execute a program to effectuate entry of a database into memory representative of characteristics of the battery including values of measured open circuit voltages (OCV) of the battery and determinations of “starting SOC” values that correspond to the most recently measured values of OCV after the battery has stabilized. The processor may also execute programs to determine the present SOC of the battery, the present battery capacity, and the remaining run-time of the device powered by the battery.

Abstract: A current Ibe and a voltage Vbe before a large current discharge in a secondary battery are stored in a memory. Plural voltage-current pairs are detected and stored in the memory during the large current discharge. Next, a regression curve (or a regression line) is obtained based on the plural voltage-current pairs stored in the memory using a well-known method. A discharge current Ip which exceeds a current-sensor detectable range is input in the regression curve to obtain a voltage Vp. A maximum discharge coordinate is set using the discharge current Ip and the voltage Vp. An internal resistance Rin of the secondary battery is calculated based on an inclination of a line that connects the coordinates (Ibe, Vbe) and (Ip, Vp).

Abstract: In an apparatus for detecting a state of a battery serving as a power source for cranking an internal combustion engine, a detecting unit and an internal resistance calculating unit are installed. The detecting unit detects a current and a voltage of the battery during a cranking period of the internal combustion engine, and outputs a parameter associated with at least one of the detected current and voltage of the battery. When a degree of change in the parameter within a specified period included in the cranking period is equal to or greater than a predetermined threshold, the internal resistance calculating unit calculates an internal resistance of the battery based on values of the current and voltage of the battery, the values of the current and the voltage being detected within the specified period.

Abstract: A method and the device are provided for determining state of health of the battery, in addition to the power supply system using the device, to reduce operational and processing load by expanding the data sampled at the time when the battery is caused to discharge square wave pulses into the square wave is provided. The method includes determining state of health of a battery by causing the battery to discharge square wave pulses with a prescribed cycle at a prescribed current value. Response voltages are sampled at a time of a pulse-discharge. The sampled response voltages are sampled into orthogonal square wave components. An amplitude of the square wave component is divided by the current value of the pulse-discharge to obtain a pseudo-impedance. A state of health of the battery based on the pseudo-impedance is determined.

Abstract: A battery includes multiple conductive battery plates and a complex electrolytic material located between the conductive battery plates. The battery also includes a conductive sensor wire located within the complex electrolytic material. The conductive sensor wire may be configured to generate a magnetic field within the complex electrolytic material based on an electrical signal flowing through the conductive sensor wire. The battery may further include a temperature sensor wire within the complex electrolytic material.

Abstract: An apparatus that estimates the ohmic resistances of N batteries includes voltage and current measurement modules that respectively measure the voltage and current of each of the N batteries. An ohmic resistance estimating module over N+1 time periods receives the voltage and current measurements of each of the N batteries and receives consecutive voltage and current measurements for one of the N batteries. N is a positive integer and the ohmic resistance estimating module estimates the ohmic resistance of the battery that is associated with the consecutive voltage and current measurements.

Abstract: The invention relates to a motor vehicle battery sensor element comprising a resistor element 2 and at least two spatially separated electric contacts 16 positioned on the resistor element 2. To increase the measuring accuracy and to reduce the temperature variance, it is proposed that the resistor element 2 along with the electric contacts 16 is coated with a metal coating 8.

Abstract: The invention relates to a new VRLA battery float model. The model covers the steady state and transient float charge behavior of both positive and negative electrodes. Backup analysis verifies the internal polarization distribution for a conventional 2V-cell polarization behaviors can be identified without the need for a physical reference electrode. The estimated individual electrode polarization allows early detection of common failure modes like negative plate discharge as well as a reference for float voltage optimisation. Furthermore, the positive polarization relating to minimum grid corrosion may be correlated with the occurrence of the peak of a “Tafel” like resistance used by the model. The model encourages utilisation of low signal perturbation for testing a cell's state of health and state of charge conditions while at float.

Abstract: An electronic battery tester and method includes generating battery test data from an electronic battery test. The battery test data is transmitted over a wireless communication medium. In another aspect, a method and apparatus is provided for receiving battery test data from a wireless communication medium. Also, a diagnostic battery charger, which is capable of transmitting battery condition information to an external receiver, is provided.

Abstract: A DC power supply system in which the resistance of a battery is measured. The voltage of the DC power supply is reduced such that the battery supplies some current to the load, and the voltage and current are measured. The voltage of the DC power supply is further reduced such that the battery supplies increased power to the load, and the voltage and current are measured. A resistance value is computed, and may be compared with various pre-established criteria. The battery resistance may also be measured by comparing the charging time of a known resistive-capacitive circuit with the charging time established at a prior measurement epoch.

Abstract: A battery state of health estimator and similar method, system and computer product is disclosed providing for a estimate of a state of health (SOH) of one or more batteries, comprising, estimating a sampling of internal resistances of the one or more batteries, generating a time history of the internal resistance over a predetermined amount of time, generating a cumulative internal resistance histogram from the time history, calculated a final estimate of internal resistance of said one or more batteries which represents the calculated SOH of said one or more batteries and comparing the calculated SOH to a predetermined critical resistance threshold. If the calculated SOH is less than the predetermined critical resistance threshold, the battery is in no worse than a “Blue Monday” condition, and if the calculated SOH is greater than the critical resistance threshold, then the one or more batteries has failed.

Abstract: The rechargeable battery abnormality detection apparatus is provided with an internal short circuit detection section (20b) that monitors rechargeable battery (1) voltage change when no charging or discharging takes place, and detects internal short circuit abnormality when battery voltage drop during a predetermined time period exceeds a preset threshold voltage; a degradation appraisal section (20d) that judges the degree of rechargeable battery degradation; and a threshold control section (20c) that incrementally increases the threshold voltage according to the degree of degradation determined by the degradation appraisal section (20d).

Abstract: A battery monitor apparatus and method for an automotive battery system including a battery for supplying power to in-vehicle electrical equipment and sensors for detecting battery voltage, the charge/discharge current and the battery temperature are disclosed. The capacitance and the internal actual resistance of the battery are calculated at the time of starting the engine. Further, the theoretical internal resistance of the battery corresponding to the ambient temperature and the battery open-circuit voltage during the stationary engine state are detected in advance. Based on the change in the battery open-circuit voltage, the battery change is provisionally determined. After that, battery change or degeneration can be determined based on battery capacitance, the actual and theoretical internal resistance values of the battery, the battery open-circuit voltage and the provisional battery change determination value.

Abstract: An automated method is provided for testing an electrical circuit using a system tester. Load leads and sense leads of the tester are connectable to any two points of an electrical circuit, such as in a vehicle system, for displaying in real time the impedance between the tested circuit points. A controller is responsive to various sensed signals to calculate impedance, admittance or conductance, and related parameters, such as available cranking current, and provide results for read out or display. A load may be connected across the circuit points under test, the sensed signals derived from a current sense amplifier, a DC voltage amplifier, a ripple amplifier, and an AC amplifier.

Abstract: A method of determining an internal resistance of a energy source that can be modeled as a voltage generator with a series resistance, such as but not limited to a battery or ultracapacitor. The internal resistance may be determined by averaging one or more weighting internal resistance values calculated from a number of sampled current and/or voltage measurement taken from the energy source.

Abstract: A vehicle power supply device has a capacitor unit including capacitors storing auxiliary power; a temperature sensor; a charge circuit; a capacitor-unit current detector; a capacitor-unit voltage detector; a controller; a storage; and a determination unit. The determination unit determines the degradation level of the capacitor unit based on at least one of an internal resistance standard value and a corrected calculated value of capacitance. This structure determines degradation of the vehicle power supply device more accurately than ever, so that the device can be used until the end of the actual life.

Abstract: A method utilizing the resistance of the electrolytic membrane of a fuel cell is known conventionally as a method for detecting abnormality occurring in the fuel cell. As shown on FIG. 4, resistance of the electrolytic membrane increases as the temperature thereof decreases or the moisture content thereof decreases (i.e. dry state), and decreases as the temperature increases or the moisture content increases (i.e. wet state), and thereby it was difficult to judge whether a deterioration in performance or a simple drop in performance has occurred by simply detecting an increase in resistance. A criterion for judging a deterioration in performance of a fuel cell based on the resistance of an electrolytic membrane is thereby set higher as the electrolytic membrane approaches a dry state and temperature thereof decreases and set lower as the electrolytic membrane approaches a wet state and the temperature thereof increases.

Abstract: An apparatus is provided to calculate a quantity indicating a charged state of an on-vehicle battery. The battery powers a starter starting up an on-vehicle engine. In the apparatus, a plurality of pairs of data consisting of current and voltage of the battery are acquired at predetermined sampling intervals during a cranking period of the engine in response to starting up the starter. At intervals, a value of an internal resistance of the battery is calculated based on the plurality of pairs of data of current and voltage. The internal resistance is one kind of the charged-state indicating quantity. An open voltage difference is calculated, which is a difference between a pseudo circuit-open voltage of the battery given before starting up the starter and a pseudo circuit-open voltage of the battery given after the cranking period. The value of the internal resistance is corrected using the open voltage difference.