Abstract: A system and method is provided for determining a target state of charge (SOC) to charge a storage battery in an electric vehicle using electric power from an external power source. Charging the storage battery to the target SOC occurs prior to starting a drive cycle of the vehicle. The target SOC is determined based on a profile of regenerative braking energy expected to be recovered and a profile of energy expected to be used from the battery during a portion of a future drive cycle.

Abstract: There is provided a measuring system capable of rendering a power source voltage of an internal circuit higher than a drivable voltage of the internal circuit by removing or reducing a chloride film with greater certainty, thereby enabling operation, and initial activation of the internal circuit to be normally executed, or preventing the internal circuit from running away. The measuring system comprises a thionyl chloride based primary cell, a cell voltage measurement unit, and an internal circuit provided with state-transition controller wherein in the case of transition of the internal circuit to a state thereof, having a discharge current larger than the discharge current in the present state thereof, the transition is made according to results of comparison of a voltage measured by the cell voltage measurement unit with a threshold on the basis of a discharge current in a state before, or after the transition of the internal circuit.

Abstract: A battery voltage monitoring apparatus monitoring an assembled battery voltage, the assembled battery including a plurality of battery cells, includes a voltage sensor detecting potential of the plurality of battery cells; an output logic circuit outputting a potential detect signal based on an output of the voltage sensor, the potential detect signal representing that abnormal potential is detected; and a delay circuit adding certain delay to the output of the voltage sensor and outputting the delayed voltage detect signal to the output logic circuit; wherein, the voltage sensor comprises at least one comparator having hysteresis characteristic, and detects the potential of the battery cell based on an output of the comparator.

Abstract: Each time that starting of a vehicle engine is completed, a vehicle control system derives an estimated amount by which the charge in the vehicle battery is less than a predetermined upper limit value of stored charge, and subtracts the estimated amount from the difference between the upper limit value and a lower limit value of stored charge, to obtain an initial allowable discharge amount. An automatic engine stop/restart function is thereafter enabled or inhibited in accordance with whether a net amount of discharge from the battery, since completion of the preceding engine start, exceeds the initial allowable discharge amount.

Abstract: An electrical apparatus including a battery module and a battery verification module is disclosed. The battery module has a verification circuit and an identification resistor. When the battery module is connected to the battery verification module, the battery verification module obtains a type information of the battery module according to the voltage level on a coupled point between a reference resistor and the identification resistor. The battery verification module transmits a verification request to the verification circuit to allow the verification circuit to transmit a verification signal to the battery verification module through a coupled path between the reference resistor and the identification resistor. The reference resistor is built in the battery verification module.

Abstract: System and method for estimating the time before recharging the rechargeable power source of an implantable medical device. In a method, the present charge level of the power source is determined by determining the percentage of total charge consumed over a period of time. The present charge level is then divided by the expected power use to determine time remaining before recharging. Another method utilizes a model to determine the faded capacity of the rechargeable power source based on the number of times the rechargeable power source has been charged and the duration of the rechargeable power source's life.

Abstract: A lithium-ion battery controlling apparatus includes a controller. The controller is configured to raise an upper-limit voltage in response to capacity degradation of a lithium-ion battery which is configured to supply power to a load and receive power from the load.

Abstract: A voltage measuring apparatus measures an output voltage of an assembled battery in which a plurality of unit cells are connected in series and are divided into a plurality of blocks. The apparatus includes: a block voltage detection section which detects a voltage of at least one of the plurality of blocks and provides an analog voltage signal; a reference power supply which generates a reference voltage; a sampling voltage generation section which generates a sampling voltage based on the reference voltage; a storage for storing voltage date corresponding to the sampling voltage; and an A/D conversion section of the block voltage detection section that digitizes the sampling voltage with the reference voltage for A/D conversion. A difference between the digitized sampling voltage and the voltage data is calculated and it is determined that abnormality occurs in the A/D conversion section when the difference is larger than a threshold.

Abstract: In a voltage detecting apparatus, a voltage controlled oscillator, when an input voltage is applied thereto, outputs a signal with a logical value that is periodically inverted. A detector counts a number of logical inversion of the output signal from the voltage controlled oscillator over an interval between edges of pulses of a pulse signal to thereby generate, based on the counted number of logical inversion, digital data as a detected result of the input voltage. A determiner determines whether a reduction of a time required to detect the input voltage is higher in priority than an increase of a resolution of detection of the input voltage. A variably setting unit variably sets a frequency of the pulse signal based on a result of the determination of whether the reduction of the time required to detect the input voltage is higher in priority than the increase of the resolution of detection of the input voltage.

Abstract: Disclosed is a cell voltage monitoring apparatus for monitoring output voltages of a plurality of unit cells in a cell having the unit cells. The cell voltage monitoring apparatus includes: a reference voltage generator for generating a predetermined reference voltage from the unit cell generation voltage; a voltage comparator for comparing a generation voltage of a monitor unit cell and the reference voltage; a signal separator for outputting a signal that is electrically separated from an output signal of the voltage comparator; and an operation processor for determining normality of the cell voltage from a signal output by the signal separator.

Abstract: An apparatus is provided that includes a first circuit to determine when a battery current falls below a threshold, a second circuit to measure a battery voltage and current in response to the first circuit determining that the battery current falls below the threshold, and a third circuit to store the measured battery voltage and current.

Abstract: A method for monitoring the voltage of each of a plurality of cells of a battery pack is provided. The method may include monitoring a voltage potential for each of a plurality of cells in a battery pack utilizing a single channel of battery control unit within the battery pack. If, during discharge of the battery, e.g., the battery is being used to power a hand tool, the voltage potential of any cell is determined by the battery control unit to be below a predetermined minimum voltage, the battery control unit discontinues a current flow from battery pack to the tool. Additionally, during charging of the battery pack, if a voltage differential between any one of the cells and any other one of the cells is determined to be above a predetermined maximum differential, the battery control unit reduces the voltage potential stored in the cell having the higher voltage potential.

Abstract: A voltage monitor semiconductor device to monitor voltages of multiple rechargeable devices to output a detection result signal to indicate overcharge, over-discharge, or excess-current, the voltage monitor semiconductor device including multiple voltage input terminals, corresponding to the multiple rechargeable devices, to monitor the voltages of the corresponding rechargeable devices as monitor voltages; and a test signal generation circuit to generate a first test signal that inverts when at least one of the monitor voltages falls below a predetermined first threshold voltage that is not used normally as an abnormal state.

Abstract: A method for determining a voltage level across an electrical circuit of a powertrain includes measuring a plurality of voltage levels and utilizing a comparison test between at least two voltage levels of the plurality of voltage levels to determine the circuit voltage level.

Abstract: A method for use with a vehicle battery pack, where the method determines a voltage threshold that may prevent the vehicle battery pack from being overcharged. The voltage threshold may be a dynamic threshold that changes or adjusts over time in order to accommodate changing conditions in the vehicle battery pack, the vehicle and/or the surrounding environment. The method may consider one or more battery readings when determining the voltage threshold, including temperature, voltage and/or current readings. According to one embodiment, the method is designed to accommodate high-current, short-duration charging events, like regenerative breaking.

Abstract: Systems and methods are provided for monitoring the deterioration of a rechargeable battery. A battery monitoring system may be used to store charging information, discharge information and storage information for a rechargeable battery to a data store. The charging information may include a number of charge cycles incurred by the rechargeable battery. The discharge information may include a number discharge cycles incurred by the rechargeable battery. The storage information may include information relating to periods when the rechargeable battery is not being actively charged or discharged. The battery monitoring system may be further used to determine an amount of deterioration of a battery performance characteristic based on the stored charging information, discharge information and storage information.

Abstract: An apparatus for detecting the state of a storage device prevents occurrence of a leakage current. A low-level detection unit is provided for each of blocks of a battery pack. Control units are connected to the blocks of the battery pack by way of first switches and are started upon receipt of power supply. The control units and measurement units are connected to the blocks by way of second switches. The control units activate the second switches after being started as a result of activation of the first switches, to thus receive power supply, and commence measurement of block voltages by means of the measurement units. The high-level detection unit supplies a read signal and a synchronous signal to the low-level detection units by way of the first switches.

Abstract: The battery voltage monitoring apparatus has a structure in which, for each adjacent two of battery cells, the positive electrode of the battery cell on the higher voltage side and the negative electrode of the battery cell on the lower voltage side are connected to a corresponding one of common terminals provided in an RC filter circuit. The common terminal is branched into first and second branches respectively connected with a first resistor and a second resistor. The first and second resistors are connected to a corresponding one of positive side detection terminals and a corresponding one of negative side detection terminals, respectively. A capacitor is connected across a corresponding one of pairs of the positive side and negative side detection terminals. Switches for making short circuits respectively between the positive side detection terminals and between the negative side detection terminals corresponding to each adjacent two battery cells are provided.

Abstract: The present invention relates to an apparatus and method for testing batteries, which can prevent errors from occurring due to the tolerance of voltage sensors when the charged states of batteries are measured, and can charge a battery having a charged state deteriorated due to the difference in the resistance of each battery. The apparatus includes a voltage circuit for measuring voltages of N batteries. A resistance circuit decreases voltages of batteries, which are greater than a reference voltage. A connection switch unit selects any one of the N batteries. A divert change unit separates polarities of each battery and changes positions of an cathode and a anode of the battery depending on separated polarities. A selection switch unit selectively connects the cathode and anode of the battery to an cathode and a anode of the voltage circuit or the resistance circuit.

Abstract: A system for determining battery characteristics based on differential current monitoring includes a first battery; a second battery, the second battery being connected in parallel with the first battery; and a differential current measurement module comprising at least one current measuring device, the differential current measurement module being configured to determine a differential current associated with the first battery and the second battery. A method for determining battery characteristics based on differential current monitoring includes determining a differential current associated with a first battery and a second battery, the first battery being connected in parallel with the second battery.

Abstract: Battery driven display device includes a battery, first and second comparators, non-volatile memory, controller driven by the voltage of the battery, and display device. Non-volatile memory stores the first and second reference voltages of the first and second comparators measured by using stabilized power supply. Controller detects when the first and second reference voltages of the first and second comparators become lower than the voltage of the battery when battery is connected, and determines the time at which end-point voltage of the battery will be reached based on the first and second detection times at the time of measurement and the measured reference voltages.

Abstract: Disclosed is method for producing a secondary battery, which enables the selection of a secondary battery having a defect caused by a micro short-circuit with high accuracy. Specifically disclosed is a step (S1) for producing a secondary battery, which includes an inspection step (S70) for selecting a secondary battery (1) having a defect caused by a micro short-circuit among multiple secondary batteries (1). The inspection step (S70) includes a self-discharge inspection in which the multiple secondary batteries (1) are allowed to stand at normal temperature for a predetermined period.

Abstract: Abnormal battery depletion can be detected in an implantable medical device. Battery capacity consumed can be measured using a coulometer and using a capacity-by-voltage device, and the measurements can be blended to determine battery status. A drop in battery voltage below a specified threshold can be detected to identify a high-current depletion fault, and an alarm can be provided to indicate the fault has been detected. The specified threshold can be determined as a function of battery capacity consumed. Other aspects and embodiments are provided herein.

Abstract: An engine start device includes a generator, a battery charged by the generator, a starter, an electric double layer capacitor and a DC/DC converter. The electric double layer capacitor is connected between the starter and the battery. The DC/DC converter has an input terminal connected to the battery and the electric double layer capacitor. The DC/DC converter has an output terminal connected to the starter and the electric double layer capacitor. According to voltage of the battery, internal DC resistance of the battery or internal DC resistance of the electric double layer capacitor, the DC/DC converter effects control of charge voltage of the electric double layer capacitor so as to stabilize voltage applied to a starter motor and stabilize the engine start.

Abstract: An apparatus for sensing a leakage current of a battery comprises a floating capacitor charged with a voltage detected from a cathode or anode terminal of a battery; a terminal selection switching unit for selecting a voltage detection path for the cathode or anode terminal; a charge switching unit for charging the floating capacitor with a detection voltage of the cathode or anode terminal, detected through the selected voltage detection path; a polarity reverse switching unit for reversing a polarity of the detection voltage of the anode terminal charged to the floating capacitor; and a leakage current determining unit for sensing the detection voltage of the cathode terminal charged to the floating capacitor and the polarity-reversed detection voltage of the anode terminal charged to the floating capacitor to calculate a leakage resistance, and comparing the calculated leakage resistance with a criterion insulation resistance to determine whether a leakage current occurs.

Abstract: An assembled battery system is disclosed that includes a plurality of serially-connected battery cells; voltage detecting lines connectable at one ends to electrodes of the battery cells of the assembled battery; electric resistors serially-connected at one ends to the other ends of the voltage detecting lines; capacitors connected to the other ends of the electric resistors, each of the capacitors being configured to electrically interconnect one of the voltage detecting lines and the other voltage detecting line; voltage measuring circuits connected respectively to each of the voltage detecting lines; electrically openable short-circuiting switches arranged between the capacitors and the voltage measuring circuits and parallel-connected to the capacitors; and a monitoring circuit that detects a difference between a first measurement result and a second measurement result with respect to each of the short-circuiting switches and a failure of the voltage detecting lines, the short-circuiting switches or the v

Abstract: A method and a charger for auxiliarily charging a secondary battery to a desired SOC with high accuracy. A charger for a secondary battery includes a charge termination condition storing unit which stores a relationship between open circuit voltages OCV of a plurality of secondary batteries and an amount of change of terminal voltage ?V until a desired state of charge SOC is reached, which is previously created. A target terminal voltage Vmap at the time of the auxiliary charge is calculated by adding the amount of change of terminal voltage ?V corresponding to the open circuit voltage OCV of a secondary battery to be auxiliarily charged to the open circuit voltage OCV which is measured. A terminal voltage Vb of the secondary battery at the time of auxiliary charge and the target terminal voltage Vmap are compared to each other by a comparison unit, and when the target terminal voltage Vmap is reached, auxiliary charge is terminated.

Abstract: Example embodiments of the systems and methods of cell imbalance detection disclosed herein may prevent any cell of a multi-cell battery pack from exceeding over voltage conditions of the battery. In an example embodiment, automatic cell imbalance detection may be performed using two cells in series. The example embodiment determines the relative cell voltages. If a difference between the two cells of more than a certain threshold is detected, a cell balancing circuit may be activated to discharge the cell with the higher voltage. Example embodiments use no microprocessor, nor an ADC. An advantage of this approach over previous solutions is the relative knowledge of the cell voltages.

Abstract: A battery pack is provided. The battery pack includes first battery cells, a second battery cell coupled to one of the first battery cells, a voltage sensing and balancing circuit for measuring voltages of the first battery cells and for maintaining voltage balance between the first battery cells, a controller that includes an analog-to-digital (A/D) converter, and an analog switch for measuring a voltage value of the second battery cell and for transferring the measured voltage value to the A/D converter. The controller is for controlling charging and discharging of the first and second battery cells. The analog switch includes a flying capacitor, a first switch unit for transferring a voltage between the second battery cell and the flying capacitor, a second switch unit for transferring a voltage of the flying capacitor to the A/D converter, and a first diode for protecting a voltage source from a surge current.

Abstract: A system for making high voltage measurements to measure a voltage of a battery pack and detect of an isolation fault. The system includes a first resistive divider comprising at least a first resistive element and a second resistive element. The system also includes a second resistive divider comprising the second resistive element and a third resistive element. The system also includes a plurality of switches comprising a first switch and a second switch coupled between the second resistive element and the battery pack. The system further includes a controller configured to control the plurality of switches to operate in first mode to measure the voltage of the battery pack based on a voltage produced by the first resistive divider, and to control the plurality of switches to operate in at least a second mode to detect an isolation fault based on a voltage produced by the second resistive divider.

Abstract: A battery tester determines a remaining level of charge of a battery mounted within a separate electronic device having an audio jack. The battery tester includes a plug and a circuit having a high impedance input amplifier. At least one electrical contact of the plug is electrically coupled to an input of the high impedance input amplifier. The plug is removably insertable within the audio jack such that the battery of the separate electronic device is electrically connected to the input of the high impedance input amplifier. When electrically coupled to the battery, an output of the high impedance input amplifier provides a signal proportional to the remaining level of charge of the battery, whereby the remaining level of charge of the battery is obtainable by the battery tester without having to remove the battery from the electronic device.

Abstract: A battery system for vehicle comprises a battery unit that is constituted with a plurality of serially connected cell groups each include a plurality of serially connected battery cells, integrated circuits that are each disposed in correspondence to one of the cell groups of the battery unit and each measure terminal voltages at the battery cells in the corresponding cell group, and a signal transmission path through which one of the integrated circuits is connected to another one of the integrated circuits or to a circuit other than that of the integrated circuits.

Abstract: The present invention provides a battery voltage measurement system and battery voltage measurement method that may reduce the size of the battery voltage measurement system. A regulator generates a constant voltage based on a battery voltage, and inputs the constant voltage to an analog input terminal of an AID converter. The battery voltage is directly inputted to a reference voltage terminal of the AID converter via a terminal (a pad). The A/D converter uses the battery voltage as a reference voltage, determines the level of the input voltage which is the constant voltage, in respect to the reference voltage, and outputs a conversion result. The conversion results increase with a decrease in the battery voltage. Accordingly, the battery voltage is measured and monitored by a processing section on the basis of the conversion results.

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 voltage monitoring circuit includes a first power supply terminal to be connected to the positive terminal of a battery pack having rechargeable cells connected in series; a first supply voltage sensing terminal to be connected to the positive terminal of the battery pack; a first resistor connected between the first power supply terminal and the first supply voltage sensing terminal; a second supply voltage sensing terminal to be connected to the negative terminal of a first rechargeable cell of the rechargeable cells, the first rechargeable cell being on the positive terminal side of the battery pack and connected to the positive terminal of the battery pack; a second resistor connected between the second supply voltage sensing terminal and the first power supply terminal; and a first comparator configured to compare a voltage at the first power supply terminal and a voltage at the first supply voltage sensing terminal.

Abstract: A method of evaluating battery packs is described. The method includes measuring a cell open voltage for each battery cell group in a section of battery cells; measuring a voltage under charge, or a voltage under load, or both, at a predetermined time interval for each battery cell group in the section of battery cells; determining the magnitude of the difference between the open cell voltage and the voltage under charge, or the voltage under load, or both, for each battery cell group in the section of battery cells by subtracting the voltage under charge from the cell open voltage, or subtracting the voltage under load from the cell open voltage, or both; and determining if the magnitude of the difference between the open cell voltage and the voltage under charge, or the voltage under load, or both, for each battery cell group in the section of battery cells exceeds a predetermined level.

Abstract: One aspect of the invention involves: monitoring a voltage of a battery over time; evaluating whether a rate of voltage decrease of the battery is in excess of a threshold; and indicating that the battery is subject to a low voltage condition when the rate of voltage decrease exceeds the threshold. Another aspect of the invention involves: causing a circuit powered by a battery to respond to battery replacement by thereafter applying a selected load to the battery during a selected time interval. A further aspect involves: periodically sampling a voltage of a battery; and applying a load to the battery during a selected time interval before each sampling of the battery voltage.

Abstract: A system and method for measuring voltage of individual cells connected in series includes a single flying capacitor. The capacitor stores the charge of one of the cells such that a primary analog-to-digital converter (ADC) connected to the capacitor may process a representation of the voltage of the cell being measured. A secondary ADC is connected directly to the cell being measured. The measurements of the primary and secondary ADCs are then compared to verify the accuracy of the flying capacitor.

Abstract: A circuit for detecting battery cell abnormalities in a multi-cell series battery for effectively and quickly detecting abnormalities with a simple, small circuit that provides improved reliability, safety and service life of the multi-cell series battery. In the voltage monitoring device 12, immediately after the start of the monitoring cycle of any battery cell BTi, cell voltage abnormality detector 14 checks whether cell voltage Vi is outside of the normal operating range. The cell voltage abnormality detector 14 has: a group of selection switches 18 for selecting any battery cell BT of multi-cell series battery 10 and retrieving its voltage to first and second monitoring terminals A, B; cell voltage/monitoring current converter 20; monitoring current/monitoring voltage converter 22; comparison/evaluation circuit 24; evaluation signal output circuit 26 and abnormality detection controller 28.

Abstract: The charge state of a battery powering a starter of a motor vehicle is evaluated to determine whether the battery voltage is sufficiently high to re-start an internal combustion engine during a stop/start operating mode. The engine is operated to drive a generator so that the generator output voltage is at a level below a setpoint value for a time period. At the end of the time period, the battery voltage is measured and if it exceeds a threshold voltage the battery charge state is determined to be sufficient to re-start the engine. The threshold voltage is approximately equal to the rated battery voltage. If the measured battery voltage is below the threshold voltage value, indicating that the battery will not have sufficient charge to re-start the motor, automatic shut-off of the engine when the vehicle stops is suppressed.

Abstract: A battery monitoring system for a battery including multiple battery cells is disclosed. The battery monitoring system includes multiple first switch sets coupled across the battery cells respectively, an energy storage element, and a comparator coupled to the energy storage element via a second switch set. The energy storage element samples cell voltages of the battery cells via the first switch sets respectively. The comparator compares a respective cell voltage with a first reference signal to determine whether a fault condition occurs on a respective battery cell. The second switch set and one of the first switch sets are turned on alternately.

Abstract: An abnormality of a current sensor or a voltage sensor is detected. An abnormality detecting section reads out a charging/discharging current I of a secondary battery detected by the current sensor and a battery voltage V of the secondary battery, calculates an estimated battery voltage Vs on the basis of an electromotive force E and an internal resistance r of the secondary battery, and judges the current sensor to be abnormal if the difference between the battery voltage V and the estimated battery voltage Vs is greater than a predetermined threshold and the charging/discharging current I exceeds a predetermined allowable range, and judges the voltage sensor to be abnormal if the difference is greater than the predetermined threshold and the charging/discharging current I is within the predetermined allowable range.

Abstract: A control unit (16) of a replacement determination device charges one or more battery modules (10) as determination targets, and measures the voltage change value of the battery module (10) in a predetermined period of time from the time of stoppage of charge by using a voltage measuring device (14). If the voltage change value becomes equal to or more than a reference voltage change value consecutively a predetermined number of times which is equal to or more than one, the control unit determines that the battery module (10) needs to be replaced.

Abstract: The invention provides a method of adjusting a battery pack capable of reducing a difference in charge level between a plurality of secondary batteries constituting the battery pack and capable of restraining an increase in battery voltage difference between the secondary batteries of the battery pack in association with the adjustment of the charge level. A method of adjusting a battery pack includes a first adjusting process for discharging all secondary batteries of a first battery group so that charge levels of the secondary batteries of the first battery group fall within a charge level range determined based on a charge level of a secondary battery of a second battery group and further a second adjusting process for discharging all the secondary batteries of the first and second battery groups by the same electric quantity respectively.

Abstract: A battery controller for controlling an assembled battery configured by connecting battery groups each including battery cells, includes: voltage measuring units that are provided respectively for the battery groups each to measure a voltage of each of the battery cells included in a corresponding battery group; a minimum value detecting unit that detects a minimum value of the battery cells for each of the battery groups based upon the measured voltage of each of the battery cells; a reference value setting unit that sets a reference value used to determine an abnormal voltage drop for each of the battery groups based upon the measured voltage of each of the battery cells; and an abnormality determining unit that makes a determination that an abnormal voltage drop is present, if a difference between the reference value and the minimum value exceeds a predetermined value, for each of the battery groups.

Abstract: A method of testing a battery is provided the method may include: (a) applying a heavy load to the battery, (b) measuring the voltage V1 between the positive and negative terminals of the battery after a first time period under which the battery is subjected to the heavy load; (c) removing the heavy load, (d) waiting for a second length of time, (e) reading the voltage across the positive and negative terminals after the second length of time V2, (f) performing a cold cranking amps CCA test if the CCA test indicates a CCA value above a first threshold, then consider V2, if V2 is below the second threshold than skip to step g but if V2 is above a second threshold than determine if the V2 is above a third threshold, if V2 is above a third threshold than determine that the battery is good and skip steps g-h; but if V2 is below the third threshold then if a battery charge flag has been set, determine that the battery is bad and skip steps g and h, if the battery charge flag has not been set, determine that the ba

Abstract: Systems and methods are provided for monitoring a voltage. A level shifter is configured to generate a current proportional to the voltage of the battery cell. A delta-sigma modulator is configured to convert the current into a first density modulated bitstream representing the voltage of the battery cell. A first reference source is configured to provide a second density modulated bitstream representing a first threshold voltage. A first comparator is configured to compare the first density modulated bitstream and the second density modulated bitstream.

Abstract: A battery monitoring system is provided to monitor a battery stack having multiple cells connected in series. The monitoring system includes monitor modules to monitor respective subsets of the cells of the battery stack, each monitor module, in response to one or more control signals, measuring cell voltages of the respective subset of cells and providing at least one readout signal that represents the sampled cell voltages, the monitor modules being electrically connected in a stack such that each monitor module is referenced to the voltage of the respective subset of cells, and the control signals and the readout signal are connected through the monitor modules of the stack, and a system control unit to provide the control signals to the monitor modules and to receive the readout signals from the monitor modules.

Abstract: An apparatus for measuring a battery cell voltage includes a battery having a cell group; a first switching unit for selectively connecting both terminals of each battery cell of the cell group to conductive lines; a first voltage charging unit connected between the conductive lines to primarily charge a cell voltage; a second voltage charging unit for relaying the charged voltage in the first voltage charging unit for secondary charging; a cell voltage sensing unit for sensing the voltage charged in the second voltage charging unit; and a second switching unit for interconnecting the voltage charging units in the charged voltage relaying mode and isolating the voltage charging units in the charged voltage sensing mode. This apparatus realizes isolation between a high voltage battery and a voltage sensing unit, thereby allowing voltage sensing of each battery cell included in a high voltage battery using a part with low withstanding voltage.

Abstract: An AC impedance meter measures an AC impedance of fuel cells against at least a specific frequency. A sensor group detects at least one operating condition of the fuel cells. A detection unit compares a degradation reference value corresponding to the detected operating condition with a resistance value led from the measured AC impedance and detects performance degradation in the fuel cells based on a result of the comparison. This arrangement enables easy detection of performance degradation in the fuel cells, irrespective of a variation in operating condition of the fuel cells.