Abstract: A storage battery is provided which has a first and second post for electrically coupling to an electrical system. A test plug is provided for use in coupling the storage battery to an electronic battery tester. In another aspect, a battery tester is provided having a plug configured to couple to a test plug of a storage battery for use in performing an electronic battery test on the storage battery.

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 test fixture for testing a plurality of longitudinal battery cells includes: a base plate; a plurality of holding structures for holding the battery cells, the holding structures being mounted on the base plate and configured to hold the battery cells with their longitudinal axes being perpendicular with respect to the base plate; and a plurality of contacts arranged on the base plate to electrically contact positive and negative terminals of each of the battery cells.

Abstract: A battery module voltage detector can reduce the difference in frequency response of an anti-aliasing filter for each battery module whose voltage is measured, and provide an accurate voltage measurement. The battery module voltage detector includes a plurality of switches connected to battery modules constituting a battery pack, resistors having an equal resistance value, and a filter composed of capacitors having equal capacitance and being disposed between the battery modules and the switches. The capacitors are divided into a first capacitor group and a second capacitor group which are symmetrical at the center of the battery pack. The first capacitor group is on the positive terminal side of the second battery. The second capacitor is on the negative terminal side of the battery pack. Capacitors may be connected between an output terminal of a (1+M/2)-th resistor and an N-th resistor, except a (1+m/2), the (1+M/2)-th resistor and the N-th resistor.

Abstract: A battery pack burn-in test system comprising first and second interconnection circuits for electrically interconnecting a first and a second battery pack respectively to the system; a data communication bus for coupling to respective battery management integrated circuits (ICs) of the first and second battery packs; and a system management unit coupled to the data communication bus. The system management unit may control a charging of the first battery pack during a burn-in test from a discharging of the second battery pack.

Abstract: A battery system utilizes a plurality of transformers interconnected with the battery cells. The transformers each have at least one transformer core operable for magnetization in at least a first magnetic state with a magnetic flux in a first direction and a second magnetic state with a magnetic flux in a second direction. The transformer cores retain the first magnetic state and the second magnetic state without current flow through said plurality of transformers. Circuitry is utilized for switching a selected transformer core between the first and second magnetic states to sense voltage and/or balance particular cells or particular banks of cells.

Abstract: Provided is a battery state monitoring circuit including a control circuit that applies, to a gate of a signal output transistor provided at a terminal for transmitting an overcharge detection signal, a potential at which the signal output transistor is turned off at a voltage lower than a minimum circuit operating voltage. Accordingly, in a battery device that uses the cascade-connected battery state monitoring circuits, charge is inhibited securely even at a power supply voltage lower than the minimum circuit operating voltage.

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 method for monitoring a lithium-ion battery cell includes monitoring a battery cell voltage and a corresponding state of charge of the battery cell during an electric power event which may include either an electric power charge event or an electric power discharge event. A measured potential-derivative is determined by differentiating the battery cell voltage in relation to the corresponding state of charge of the battery during the electric power event. The measured potential-derivative is compared with a preferred anode potential-derivative of an anode charge curve (for electric power discharge events) or an anode discharge curve (for electric power charge events), and with a preferred cathode potential-derivative of a cathode charge curve (for electric power charge events) or a cathode discharge charge curve (for electric power discharge events).

Abstract: Lower order control devices control plural battery cells configuring plural battery modules. An input terminal of the low order control device in the highest potential, an output terminal of the low order control device in the lowest potential, and a high order control device are connected by isolating units, photocouplers. Diodes which prevent a discharge current of the battery cells in the battery modules are disposed between the output terminal of the low order control device and the battery cells in the battery module on the low potential side. Terminals related to input/output of a signal are electrically connected without isolating among the plural low order control devices.

Abstract: In a voltage measuring device, according to a setting of input terminals for setting the number of unit cells to be measured SEL1, SEL2, SEL3, a logic circuit turns on switches in a switching circuit connected to the unit cells to measure a voltage across each unit cell.

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 microcontroller is disclosed. The microcontroller comprises a processor system and a high voltage interface coupled to the processor system and adapted to be coupled to a battery. The microcontroller further includes a battery management system for monitoring the battery and managing the battery based upon the monitoring of the battery. The microcontroller is a single chip. This one-chip solution saves design cost and PCB space in addition to broadening the functionality of the smart battery application. With the accuracy of the microcontroller, the charge status of the battery can be predicted more accurately and therefore effectively increases actual battery capacity.

Abstract: A state of charge optimizing device according to the present invention optimizes a state of charge of each of a plurality of cells which are connected in series to form an assembled battery, and conducts the optimization by discharging or charging a part or all of the plurality of cells so that the differences between the amount of charge after the optimization and the amount of charge in a predetermined state of charge become uniform.

Abstract: A battery module is provided for a battery system including at least two battery modules, where each battery module is provided with a module monitoring unit arranged to monitor at least one performance related parameter for each secondary cell in the battery module. Parameters relating to the performance for each battery module are stored in a memory on the respective module monitoring unit. An energy storage system with a battery pack including such a battery monitoring unit for monitoring the battery pack and a modular system of battery packs, each including at least two replaceable, interchangeable battery modules is also provided. The energy storage system can further include super- or ultracapacitor modules.

Abstract: A battery management system is provided for managing a battery that supplies power to a vehicle. The battery includes a plurality of cells. The battery management system includes a sensing unit for measuring a voltage of each of the plurality of cells. The battery management system detects at least one first cell among the plurality of cells that needs to be balanced according to the measured voltage of each of the plurality of cells. In addition, the battery management system performs a cell balancing operation on said at least one first cell by using different methods according to a driving state of the vehicle.

Abstract: The car power source apparatus is provided with a leakage detection circuit 3 having a battery 1 with a plurality of battery units 2 connected in series, a first series circuit 11 made up of first leakage detection resistors 12 and a first leakage detection switch 13 to connect the first connection node 10 of the series connected battery units 2 to ground 9, a second series circuit 21 made up of second leakage detection resistors 22 and a second leakage detection switch 23 to connect the second connection node 20 of the series connected battery units 2 to ground 9, and voltage detection circuits 4 to detect voltage of the first leakage detection resistors 12 and the second leakage detection resistors 22. Further, the car power source apparatus is provided with a failure detection circuit 5 to control the first leakage detection switch 13 and the second leakage detection switch 23 ON and OFF and determine failure of the leakage detection circuit 3 from voltages detected by the voltage detection circuits 4.

Abstract: A method and system for measuring voltage of individual cells connected in series includes a pair of busses connectable to the cells and a flying capacitor connectable to the busses. The capacitor stores the charge of one of the cells such that an analog-to-digital converter (ADC) connected to the capacitor may process an accurate representation of the voltage of the cell being measured.

Abstract: The application concerns a battery module, comprising cells, two external terminals, a message communication infrastructure, a module control unit comprising a message processing unit, connected to the infrastructure to send and receive messages. According to the application, at least two of the message systems chosen from among: a first message system for cell characterization, a second message system for cell forming, and a third message system for utilization of a battery pack comprising several modules connected via their user terminals, when the pack is associated with a consumer machine for the purpose of supplying it with electric energy, are provided in the message processing unit, which is able to be configured into any one of the message systems.

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: A voltage sensing device with which high-precision voltage sensing is possible without the need to obtain a unique correction constant for each device. A pair of voltage input nodes NCk and NCk-1 is selected from voltage input nodes NC0-NCn in switch part 10, and they are connected to sensing input nodes NA and NB in two types of patterns with different polarity (forward connection, reverse connection). Sensing input nodes NA and NB are held at reference potential Vm by voltage sensing part 20, and current Ina and Inb corresponding to the voltage at voltage input nodes NCk and NCk-1 flows to input resistors RIk and RIk-1. Currents Ina and Inb are synthesized at different ratios in voltage sensing part 20, and sensed voltage signal S20 is generated according to the synthesized current Ic. Sensed voltage data S40 with low error is generated according to the difference between the two sensed voltage signals S20 generated in the two connection patterns.

Abstract: A sensing and control apparatus for a battery management system is provided. The sensing and control apparatus includes: a sensing unit and a main control unit. The sensing unit includes: a cell relay of a plurality of cell relays and a voltage detection unit. The cell relay is configured to be coupled to at least one of a plurality of cells. The voltage detection unit is coupled to a cell relay. The voltage detection unit is configured to: receive a reference voltage when each of the plurality of cell relays is turned off; and generate a second voltage by amplifying by a gain a first voltage that corresponds to the reference voltage. The main control unit is configured to calculate a valid gain corresponding to a ratio of the second voltage to the reference voltage when the temperature of the voltage detection unit is within a threshold temperature range.

Abstract: A power supply device includes battery units 10. Each unit 10 includes a battery block 2, a voltage detector 4, a power supply circuit 5, and a disconnection detector 8. The block 2 includes serially-connected battery cells 3. The voltage detector 4 detects the cell 3 voltages through voltage detection lines 6. The power supply circuit 5 supplies power from the block 2 to the voltage detector 4. The voltage detector 4 is powered by electric power from the block 2. The disconnection detector 8 detects disconnection of the lines 6 based on the detected cell 3 voltages. An unbalance resistor 12 is connected to one of the blocks 2 to increase power consumption of this block 2. Thus, a current flows in the line 6 that is connected to a node 16 between this block 2 and an adjacent block connected next to this block 2.

Abstract: Methods and systems for determining a state of charge of a battery are provided. A first component of the state of charge is calculated based on a first property of the battery. A second component of the state of charge is calculated based on a second property of the battery. The first component of the state of charge is weighted based on a rate of change of the first property relative to a change of the state of charge. The second component of the state of charge is weighted based on a rate of change of the second property relative to a change of the state of charge. The state of charge is determined based on the first and second weighted components.

Abstract: Lower order control devices control plural battery cells configuring plural battery modules. An input terminal of the low order control device in the highest potential, an output terminal of the low order control device in the lowest potential, and a high order control device are connected by isolating units, photocouplers. Diodes which prevent a discharge current of the battery cells in the battery modules are disposed between the output terminal of the low order control device and the battery cells in the battery module on the low potential side. Terminals related to input/output of a signal are electrically connected without isolating among the plural low order control devices.

Abstract: A system for estimating parameters of a fuel cell stack. The system includes a stack health monitor for monitoring minimum cell voltage, stack voltage and current density of the fuel cell stack. The stack health monitor also indicates when a predetermined minimum cell voltage threshold level has been achieved. The system further includes a controller configured to control the fuel cell stack, where the controller determines and records the average fuel cell voltage. The controller generates and stores artificial data points proximate to the one or more predetermined minimum cell voltage threshold levels each time the minimum cell voltage drops below the one or more predetermined minimum cell voltage threshold levels so as to provide an estimation of the fuel cell stack parameters including a minimum cell voltage trend and a minimum cell voltage polarization curve.

Abstract: According to a deterioration detecting method for rechargeable lithium batteries, battery voltages of a rechargeable lithium battery before and after the completion of charging or discharging are measured. An evaluation value is calculated based on the measured battery voltages. This evaluation value is compared with a reference value of the rechargeable lithium battery stored in advance. A deterioration level of the rechargeable lithium battery is estimated based on this comparison result. In addition, further deterioration can be suppressed by controlling charging and discharging of the rechargeable lithium battery based on the estimated deterioration level.

Abstract: An application for a battery management system that monitors current and voltage from one or more battery cells and determines if the current is above or below a predetermined value. If the current is below the predetermined value (e.g. a load from a few lights, etc), the battery management system disconnects the battery cells from the load when the voltage falls below a higher voltage threshold (e.g. 12V). If the current is above the predetermined value (e.g. a load from a starter motor cranking an engine), the battery management system disconnects the battery cells from the load when the voltage falls below a lover voltage threshold (e.g. 8V). Once disconnected a reset signal is required to reconnect the battery cell(s) to the load.

Abstract: A test apparatus and corresponding method for simulating an internal cell short and initiating thermal runaway in a battery cell is disclosed whereby the cell is internally heated through rapid charge and discharge cycles at high currents. The magnitude of the selected current may be modulated to simulate a cell short with the desired power profile without unrealistically heating neighboring cells or interfering with the thermal environment of the cell within the module.

Abstract: Lower order control devices control plural battery cells configuring plural battery modules. An input terminal of the low order control device in the highest potential, an output terminal of the low order control device in the lowest potential, and a high order control device are connected by isolating units, photocouplers. Diodes which prevent a discharge current of the battery cells in the battery modules are disposed between the output terminal of the low order control device and the battery cells in the battery module on the low potential side. Terminals related to input/output of a signal are electrically connected without isolating among the plural low order control devices.

Abstract: A circuit used for determining a cell number of several battery cells. The circuit includes a detection block and a controller, and operates in a first detection mode and a second detection mode. The detection block is coupled to each of the battery cells. In the first detection mode, the detection block provides a terminal voltage signal indicative of a terminal voltage of a battery cell. In the second detection mode, the detection block provides a cell voltage signal indicative of a cell voltage of the battery cell. The controller compares the terminal voltage signal with a first threshold in the first detection mode and compares the cell voltage signal with a second threshold in the second detection mode, and provides a cell count signal indicative of the cell number based on the terminal voltage signal and the cell voltage signal.

Abstract: A power supply device includes negative-side and positive-side battery blocks serially connected to each other through a resistor element 19. The ends of the element 19 correspond to reference and auxiliary ground points 8A and 8B. A voltage detector 3 detects the voltages of battery modules 2 of a load-driving battery 1. The detector 3 includes an asymmetric resistor circuit that is asymmetrically constructed with respect to the reference point 8A. The detector 3 detects the voltage of the auxiliary point 8B with respect to the reference point 8A in a load driven state. A disconnection detecting circuit 20 compares the detected voltage with a reference voltage of the auxiliary point 8B with respect to the reference point 8A not in the load driven state, and determines that the line 9 is disconnected in the load driven state if the deviation of the detected voltage from the reference voltage falls out of a predetermined range.

Abstract: A power cell system such as a fuel cell system, with apparatus for detecting a discontinuity. A power cell system, e.g. a fuel cell system, includes a plurality of power cells, e.g. fuel cells and plurality of first resistances, the plurality of power cells and first resistances being connected in the form of a ladder circuit, and electronic filters each having a first connection to a first node between two of the first resistances, each electronic filter having a second resistance and a charge storage device connected to the second resistance.

Abstract: An apparatus for balancing charge capacity of battery cell includes a voltage sensing/discharging circuit having a battery with cell group, a switching unit for selectively connecting both terminals of each battery cell to conductive lines, capacitor connected to the conductive lines, a voltage amplifying unit connected to both terminals of capacitor via a first switch, and a discharge resistance connected to both terminals of capacitor via a second switch; and a voltage balancing unit for controlling the switching unit in ON state of first switch to connect both terminals of each battery cell to the conductive lines and then sense voltage of each battery cell through the voltage amplifying unit, and controlling the switching unit in OFF state of first switch to charge voltage of balancing-requiring cell to the capacitor and then turning on the second switch to discharge charged voltage of capacitor through the discharge resistance.

Abstract: The invention relates to a device for measuring the electrical cell voltages in several electrical storage cells of an electrical storage medium. Each storage cell has an associated measuring device and the measurement values of the measurement devices are read out based on a read command of a control unit. According to the invention, a synchronization line leading from the control unit to the measurement devices or from one of the measurement devices to all other measurement devices is provided for simultaneously reading out the measurement values. The invention further relates to a corresponding method.

Abstract: A fault tolerant battery management system includes redundancy, with applications including electric vehicles. Portions of its circuitry are constituted in distinct fault domains with control, monitoring, and balancing of cells circuitry fault-effect-isolated from the circuitry associated with built-in real-time testing. Built-in tests are orchestrated in fault domains isolated from the functional circuitry being verified. These built-in tests provide test stimulus unique for each cell measurement. Cell balancing is performed in a fault tolerant manner. It takes at least two independent faults, in two mutually distinct fault domains, to negatively affect balancing capability or to interfere with a redundant circuit's ability to operate. The built-in tests allow operation without the requirement for data cross-compare between redundant measuring electronic elements. Testing and balancing functions are interlocked through encoded enabling methodologies and transmit enables on serial buses.

Abstract: An electric storage module includes: a plurality of electric storage units; a casing that houses the plurality of electric storage units, and includes a pair of resin side plates that hold and support at least the plurality of electric storage units from opposite sides; a plurality of conductive members for electrically connecting the plurality of electric storage units; a metal cover member that covers the casing on an outside of each of the side plates; and a peripheral wall protruding from each of the side plates so as to surround each of the plurality of conductive members, wherein: a height of the peripheral wall from each of the side plates is higher than a height of the conductive members from each of the side plates, and smaller than a distance from each of the side plates to the cover member.

Abstract: A system for measuring individual cell voltages of a fuel cell stack includes a plurality of voltage scanning units (VSU). Each VSU is arranged for being connected to a group of cells, belonging to the fuel cell stack, the group of cells being provided with terminals that allow measuring a cell voltage. Each VSU comprises a filter/regulator that provides a voltage reference signal Vref, that is applied to a first terminal of a first cell of the group of cells. The VSU further includes a multiplexer arranged for consecutively connecting the other terminals of the group of cells to a first input of an A/D converter, whereby the A/D converter is further provided with a second input for receiving the voltage reference signal Vref. The ADC is further arranged for being fed with a supply voltage Vsup+ and for A/D converting a signal derived from the signals at the first and second input.

Abstract: Modeling and testing are used to characterize consequences of a first lithium-ion cell having an internal short. The vulnerability of a second lithium-ion cell being induced into thermal runaway by the energy released by the first cell undergoing an internal short is quantified. Characteristics of the packaging of Li-ion cells within a battery pack are analyzed. Combined, these analyses determine the robustness required of a cell in order to withstand a nearby cell's internal short given that the battery is maintained within the specified operational envelope by a BMS and this envelope is modified in real-time as required to meet the safety requirement. Robustness factors are: age, history of charging/discharging, as well as immediate state of charge and environment. In operation, the cell's operational history is incorporated into a model. When the model indicates cell robustness at a predetermined lower limit, operation of the cell is ceased or limited.

Abstract: A cell voltage measuring apparatus of a battery pack comprises a plurality of multiplexers connected corresponding to each cell group of the battery pack and operated to output a voltage signal of each cell in each cell group based on a reference potential applied from a corresponding cell group; a plurality of floating capacitors connected corresponding to each cell in each cell group and on which the voltage of each cell is charged and held; a switching means for enabling the voltage of each cell to be charged and held on each corresponding floating capacitor; and a controller for controlling the switching means per each cell group to enable the voltage of each cell to be charged and held on each corresponding floating capacitor and controlling each multiplexer to measure the cell voltage held on each floating capacitor of each cell group connected to each corresponding multiplexer.

Abstract: Provided is an apparatus for measuring current and voltage of a secondary battery pack in synchronization manner, comprising a voltage measurement circuit for periodically measuring and outputting the level of a charging voltage of each of a plurality of battery cells contained in a battery pack; a current measurement circuit for periodically measuring and outputting the level of current flowing into or out of the battery pack; and a control unit for synchronizing a time difference between a current measurement time point of the battery pack and a voltage measurement time point of each battery cell with a reference delay time.

Abstract: A number and a combination of N-pole connectors and (N+1)-pole connectors are determined such that a number of fuel cells included in the fuel cell stack and a number of all of poles included in the plurality of terminal-side connectors are equal to each other. Further, when the number of fuel cells of the fuel cell stack changes, the change can be addressed by changing the number and the combination of the N-pole connectors and the (N+1)-pole connectors without newly providing a terminal-side connector other than the N-pole connector and the (N+1)-pole connector.

Abstract: A power supply with and input and output includes an amplifier configured to set an output voltage of the power supply output equal to a fixed input voltage for the power supply. The power supply has a first output stage coupled to the amplifier and configured to source and sink current at the output of the power supply between a first voltage rail and a third voltage rail. The power supply has a second output stage coupled to the amplifier and configured to source and sink current to the output of the power supply between a second voltage rail and the third voltage rail. A selection device is configured to enable the first and second output stages based on a selection input signal. The selection device is situated outside of the first and the second output stages.

Abstract: To provide a voltage measurement device for measuring a battery voltage of a secondary battery formed by serially connecting a plurality of battery blocks, which is able to calculate the battery voltage in block units even though a potential detection line is disconnected. Specifically, when the voltage detection unit fails to measure the battery voltage of the measurement target battery block by selecting potential detection lines connected to both terminals of the measurement target battery block, the switch control unit selects the potential detection lines connected to both terminals of the battery block group including a serially connected plurality of battery blocks including the measurement target battery block, then measures the integrated voltage of the battery block group, and measures the battery voltage of the measurement target battery block based on the measured integrated voltage.

Abstract: Voltage translator circuitry may include a path including a first resistor, a current controlling device, and a second resistor coupled in series. The voltage translator circuitry may further include an operational amplifier having a positive supply terminal to accept a positive supply voltage and a negative supply terminal to accept a negative supply voltage, neither the positive or negative supply voltage at ground voltage. The first resistor may further be coupled to a positive terminal of the battery cell to be monitored. The operational amplifier may have an input coupled to a negative terminal of the battery cell to be monitored. The voltage translator circuitry may further include an output terminal coupled to a node of the path between the current controlling device and the second resistor. The output terminal may be configured to provide the ground referenced cell voltage for the battery cell.

Abstract: A secondary battery includes a plurality of battery cells and measures voltages of the battery cells. The secondary battery includes a capacitive device, a relay and an A/D converter. The capacitive device is connected to the battery cells to sequentially store the voltages of the battery cells. The relay is between the battery cells and the capacitive device, and sequentially connects the battery cells to the capacitive device. The A/D converter is connected to the capacitive device to receive and convert the voltages of the battery cells.

Abstract: A battery cell tab monitoring apparatus includes a conductive element electrically connected between two battery cells. The conductive element is connected to a sensing circuit including a pull-down current source connected to pull current from the conductive element and/or a pull-up current source connected to drive current into the conductive element. A voltage measuring circuit is connected to sense voltages during operation of the pull-down current source and the pull-up current source to be used to determine the status of the conductive element. For instance, voltages beyond certain fixed or variable thresholds indicate that the conductive element is flexing or cracking, which can be a precursor to its breaking. Voltages beyond other fixed or variable thresholds indicate that the conductive element is fully disconnected. The current sources used to push and pull the sensing currents may be used to bring the battery cells into balance when an imbalance is detected.

Abstract: The battery fault determination apparatus includes battery monitor sections connected in a daisy chain, each of which is provided for a corresponding one of unit batteries each including battery cells connected in series to monitor the battery cells and output an output signal indicative of a monitoring result, and a control section configured to output a control signal to the battery monitor sections. The control signal and the output signal are cascaded through the battery monitor sections causing each battery monitor section to perform a state change between a state to monitor overcharge of the battery cells and a state to monitor wire breakage. Each battery monitor section is configured to receive the control signal from the immediately upstream-side battery monitor section, make a detection whether the state change has been performed correctly, and output the output signal including a detection result to the immediately downstream-side battery monitor section.

Abstract: A battery system includes a battery pack, a detecting portion, a storage portion, and a determining portion. The battery pack 10 includes serially-connected parallel battery units 1 each of which includes battery cells 2 connected in parallel. The detecting portion 5 detects voltage and current of the units 1, and calculates the accumulated current value of each of the units 1. The storage portion 6 stores reference voltage values to be associated the accumulated current value of each of the units 1. The determining portion 7 reads, from the storage portion 6, one of the reference voltages corresponding to the accumulated value of each of the units 1, and compares the read reference voltage with the detection voltage of the each of the units 1. Thus, a battery cell internal short circuit is detected if the difference between the detection voltage and the read reference voltage exceeds a threshold.

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.