Integrated Circuit For Controlling Battery Cell and Vehicle Power Supply System

• US 20090087722A1
• Filed: 09/25/2008
• Published: 04/02/2009
• Est. Priority Date: 09/28/2007
• Status: Active Grant

• Current Assignee: Hitachi Automotive Systems Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi, Ltd., Hitachi Vehicle Energy, Ltd. (Hitachi, Ltd.)
• Inventors: Emori, Akihiko, Kikuchi, Mutsumi, Kudo, Akihiko, Kawahara, Youhei, Yamauchi, Tatsumi, Kubo, Kenji, Sakabe, Kei
• Granted Patent: US 9,130,379 B2
• Time in Patent Office: Days
• US Class Current: 429/61
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 50/64 Constructional details of batteries specially adapted for electric vehicles
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60L 58/14 Preventing excessive discharging
• CPC Class Codes: B60L 58/15 Preventing overcharging
• CPC Class Codes: B60L 58/21 having the same nominal voltage
• CPC Class Codes: B60L 58/22 Balancing the charge of battery modules
• CPC Class Codes: B60L 58/26 by cooling
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm
• CPC Class Codes: G01R 31/3835 involving only voltage measurements
• CPC Class Codes: G01R 31/396 Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery
• CPC Class Codes: G01R 31/52 Testing for short-circuits, leakage current or ground faults
• CPC Class Codes: G01R 31/54 Testing for continuity
• CPC Class Codes: G01R 35/00 Testing or calibrating of apparatus covered by the other groups of this subclass
• CPC Class Codes: H02J 7/0019 using switched or multiplexed charge circuits
• CPC Class Codes: H02J 7/0047 with monitoring or indicating devices or circuits
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 90/16 : Information or communication technologies improving the operation of electric vehicles

Abstract

A vehicle power supply system comprises a battery module that includes a plurality of battery cells, battery cell control devices and a signal transmission path through which signals are transmitted. The battery cell control device comprises a voltage measurement circuit that measures terminal voltages at the battery cells, an abnormality diagnosis circuit that diagnoses an abnormality in the battery cell control device, a timing control circuit that outputs a signal for instructing measurement phase and a signal for instructing diagnosis phase, and a communication circuit that outputs a signal indicating the terminal voltage and a signal based upon a diagnosis result by the abnormality diagnosis circuit.

Claims

1. A vehicle power supply system, comprising:

a battery module that is constituted with a plurality of serially connected battery cell groups each include a plurality of serially connected battery cells;

a plurality of battery cell control devices each disposed in correspondence to the plurality of battery cell groups; and

a signal transmission path through which signals that are input to or output from the plurality of battery cell control devices are transmitted, wherein;

each of the plurality of battery cell control devices comprises;

a voltage measurement circuit that measures terminal voltages at the individual battery cells in the corresponding battery cell group;

an abnormality diagnosis circuit that diagnoses an abnormality in the battery cell control device;

a timing control circuit that outputs a signal for instructing measurement phase during which the terminal voltage is measured, and, in synchronization with output of the measurement phase instruction signal, outputs a signal for instructing diagnosis phase during which diagnosis is executed by the abnormality diagnosis circuit; and

a communication circuit that outputs a signal indicating the terminal voltage measured by the voltage measurement circuit and a signal based upon a diagnosis result by the abnormality diagnosis circuit, to the signal transmission path, and wherein;

the abnormality diagnosis circuit diagnoses an abnormality in the battery cell control device in synchronization with the terminal voltage measurement based upon the diagnosis phase instruction signal.

2. A vehicle power supply system according to claim 1, wherein:

the voltage measurement circuit comprises;

a selection circuit that selects a terminal voltage of measurement target from the terminal voltages at the individual battery cells; and

a conversion circuit that converts an analog value of the terminal voltage having been selected by the selection circuit to a digital value, and wherein;

the abnormality diagnosis circuit diagnoses a selection operation by the selection circuit in synchronization with the terminal voltage measurement based upon the diagnosis phase instruction signal.

3. A vehicle power supply system according to claim 2, wherein:

the timing control circuit outputs the signal for instructing the measurement phase for each of the battery cells, and, in synchronization with output of the measurement phase instruction signal, outputs a signal for instructing diagnosis phase for diagnosis of selection operation by the selection circuit.

4. A vehicle power supply system according to claim 2, wherein:

the signal transmission path comprises at least a first signal transmission path and a second signal transmission path independently;

the signal indicating the terminal voltage is transmitted through the first signal transmission path; and

the signal based upon the diagnosis result of the selection circuit is transmitted through the second signal transmission path.

5. A vehicle power supply system according to claim 4, wherein:

the signal based upon the diagnosis result transmitted through the second signal transmission path is a one-bit signal.

6. A vehicle power supply system, comprising:

a battery module that is constituted with a plurality of serially connected battery cell groups each include a plurality of serially connected battery cells;

a plurality of battery cell control devices each disposed in correspondence to the plurality of battery cell groups; and

a signal transmission path through which signals that are input to or output from the plurality of battery cell control devices are transmitted, wherein;

each of the plurality of battery cell control devices comprises;

a voltage measurement circuit that measures terminal voltages at the individual battery cells in the corresponding battery cell group;

a comparator circuit that compares a terminal voltage value output from the voltage measurement circuit with a voltage threshold value used for diagnosis of over-charge/over-discharge of the battery cells;

a diagnosis result output circuit that outputs a signal indicating diagnosis result corresponding to the over-charge/over-discharge if a diagnosis result based upon a comparison result by the comparator circuit indicates the over-charge/over-discharge;

a comparison value generating circuit that generates a comparison value which is used for an abnormality diagnosis in the battery cell control device and which is in a known magnitude relationship to a predetermined input value that is input to the comparator circuit; and

a communication circuit that outputs a signal indicating the terminal voltage measured by the voltage measurement circuit and an abnormality signal based upon the diagnosis result signal to the signal transmission path, and wherein;

each of the plurality of battery cell control devices compares an input value that is input to the comparator circuit with the comparison value via the comparator circuit, and, if the comparison result is different from the known magnitude relationship, judges that an abnormality has occurred in the battery cell control device and outputs the diagnosis result signal corresponding to the abnormality in the battery cell control device from the diagnosis result output circuit.

7. A vehicle power supply system according to claim 6, comprising a voltage generating circuit that generates a voltage, wherein:

the vehicle power supply system measures a voltage generated by the voltage generating circuit via the voltage measurement circuit, inputs a measurement value of the generated voltage to the comparator circuit as the input value, and, if the comparison result with the comparison value generated corresponding to the generated voltage is different from the known magnitude relationship, judges that an abnormality has occurred at the voltage measurement circuit and outputs the diagnosis result signal corresponding to the abnormality at the voltage measurement circuit from the diagnosis result output circuit.

8. A vehicle power supply system according to claim 7, wherein:

the signal transmission path comprises at least a first signal transmission path and a second signal transmission path independently;

the signal indicating the terminal voltage is transmitted through the first signal transmission path; and

the signal based upon the diagnosis result of the voltage measurement circuit is transmitted through the second signal transmission path.

9. A vehicle power supply system according to claim 8, wherein:

the signal based upon the diagnosis result transmitted through the second signal transmission path is a one-bit signal.

10. A vehicle power supply system according to claim 6, wherein:

the vehicle power supply system uses one of voltage thresholds for diagnosis of the over-charge/over-discharge as the input value, uses a value that is obtained by increasing or decreasing the one of voltage thresholds as the comparison value, inputs both values to the comparator circuit for comparison, and, if the comparison result is different from the known magnitude relationship, judges that an abnormality has occurred at the comparator circuit and outputs the diagnosis result signal corresponding to the abnormality at the comparator circuit from the diagnosis result output circuit.

11. A vehicle power supply system according to claim 10, wherein:

the signal transmission path comprises at least a first signal transmission path and a second signal transmission path independently;

the signal indicating the terminal voltage is transmitted through the first signal transmission path; and

the signal based upon the diagnosis result of the comparator circuit is transmitted through the second signal transmission path.

12. A vehicle power supply system according to claim 11, wherein:

the signal based upon the diagnosis result transmitted through the second signal transmission path is a one-bit signal.

13. A vehicle power supply system according to claim 6, comprising a voltage generating circuit that generates a voltage, wherein:

the vehicle power supply system measures a voltage generated by the voltage generating circuit via the voltage measurement circuit, inputs a measurement value of the generated voltage to the comparator circuit as the input value, and, if the comparison result with the comparison value generated corresponding to the generated voltage is different from the known magnitude relationship, judges that an abnormality has occurred at the voltage measurement circuit and outputs the diagnosis result signal corresponding to the abnormality at the voltage measurement circuit from the diagnosis result output circuit; and

the vehicle power supply system inputs one of voltage thresholds for diagnosis of the over-charge/over-discharge as the input value and a value that is obtained by increasing or decreasing the one of voltage thresholds as the comparison value in the known magnitude relationship to the input value into the comparator circuit, compares the one of voltage thresholds with the value obtained by increasing or decreasing the one of voltage thresholds, and, if the comparison result is different from the known magnitude relationship, judges that an abnormality has occurred at the comparator circuit and outputs the diagnosis result signal corresponding to the abnormality at the comparator circuit from the diagnosis result output circuit.

14. A vehicle power supply system comprising:

a battery module that is constituted with a plurality of serially connected battery cell groups each include a plurality of serially connected battery cells;

a plurality of battery cell control devices each disposed in correspondence to the plurality of battery cell groups; and

a signal transmission path through which signals that are input to or output from the plurality of battery cell control devices are transmitted, wherein;

each of the plurality of battery cell control devices comprises;

a voltage measurement circuit that measures terminal voltages at the individual battery cells in the corresponding battery cell group;

a comparator circuit that compares a terminal voltage value output from the voltage measurement circuit with a voltage threshold value used for diagnosis of over-charge/over-discharge of the battery cells;

a diagnosis result output circuit that outputs a diagnosis result signal corresponding to the over-charge/over-discharge if a diagnosis result based upon a comparison result by the comparator circuit indicates the over-charge/over-discharge;

a comparison value generating circuit that generates a comparison value which is used for an abnormality diagnosis in the battery cell control device and which is in a known magnitude relationship to a predetermined input value that is input to the comparator circuit;

a communication circuit that outputs a signal indicating the terminal voltage measured by the voltage measurement circuit and an abnormality signal based upon the diagnosis result signal to the signal transmission path; and

a timing control circuit that outputs a signal for instructing measurement phase during which the terminal voltage is measured, and, in synchronization with output of the measurement phase instruction signal, outputs a signal for instructing diagnosis phase during which an abnormality diagnosis is executed in the battery cell control device, and wherein;

each of the plurality of battery cell control devices executes a first diagnosis for diagnosing an abnormality in the battery cell control device in synchronization with the terminal voltage measurement based upon the diagnosis phase instruction signal and a second diagnosis for diagnosing an abnormality in the battery cell control device based upon whether or not a comparison result of an input value that is input to the comparator circuit with the comparison value via the comparator circuit is different from the known magnitude relationship, and, if there is an abnormality in the battery cell control device, outputs the diagnosis result signal corresponding to the abnormality in the battery cell control device from the diagnosis result output circuit and outputs the abnormality signal based upon the output diagnosis result signal from the communication circuit to the signal transmission path.

15. A vehicle power supply system according to claim 14, wherein:

the voltage measurement circuit comprises;

a selection circuit that selects a terminal voltage of measurement target from the terminal voltages at the individual battery cells, and

a conversion circuit that converts an analog value of the terminal voltage having been selected by the selection circuit to a digital value, and wherein;

the first diagnosis, which is a diagnosis for a selection operation by the selection circuit, is executed in synchronization with the terminal voltage measurement based upon the diagnosis phase instruction signal.

16. A vehicle power supply system according to claim 15, wherein:

the timing control circuit outputs the signal for instructing the measurement phase for each of the battery cells, and, in synchronization with output of the measurement phase instruction signal, outputs a signal for instructing diagnosis phase for diagnosis of selection operation by the selection circuit.

17. A vehicle power supply system according to claim 14, wherein:

the signal transmission path comprises at least a first signal transmission path and a second signal transmission path independently;

the signal indicating the terminal voltage is transmitted through the first signal transmission path; and

the signal based upon results of the first diagnosis and the second diagnosis is transmitted through the second signal transmission path.

18. A vehicle power supply system according to claim 17, wherein:

the signal based upon the diagnosis result transmitted through the second signal transmission path is a one-bit signal.

19. A vehicle power supply system, comprising:

a lithium battery module that is constituted with a plurality of serially connected lithium battery groups each include a plurality of serially connected lithium battery cells;

a plurality of integrated circuits each disposed in correspondence to the plurality of lithium battery groups; and

a signal transmission path through which signals that are input to or output from the plurality of integrated circuits are transmitted, wherein;

each of the plurality of integrated circuits comprises;

a selection circuit that selects a terminal voltage of measurement target from terminal voltages at individual lithium battery cells in a corresponding lithium battery group;

an analog/digital converter that converts the terminal voltage having been output from the selection circuit from an analog value to a digital value;

a digital comparator circuit that compares the digital value indicating the terminal voltage that has been output from the analog/digital converter with a voltage threshold value used for diagnosis of over-charge/over-discharge;

a communication circuit that transmits a signal indicating an abnormality through the signal transmission path based upon a comparison result by the digital comparator circuit;

a voltage generating circuit that generates a predetermined voltage; and

a digital generating circuit that generates a digital value which is in a known magnitude relationship to the predetermined voltage, and wherein;

each of the plurality of integrated circuits selects the predetermined voltage generated by the voltage generating circuit via the selection circuit, converts the predetermined voltage from an analog value to a digital value via the analog/digital converter, compares the digital value that has been output from the analog/digital converter with the digital value that has been output from the digital generating circuit via the digital comparator circuit, and, if the comparison result is different from the known magnitude relationship, transmits the abnormality signal from the communication circuit to the signal transmission path.

20. A vehicle power supply system, comprising:

a lithium battery module that is constituted with a plurality of serially connected lithium battery groups each include a plurality of serially connected lithium battery cells;

a plurality of integrated circuits each of which is disposed in correspondence to the plurality of lithium battery groups and in each of which a plurality of circuits are integrated including a selection circuit, an analog/digital converter, a communication circuit, a diagnosis circuit, and a voltage generating circuit; and

a signal transmission path through which signals that are input to or output from the plurality of integrated circuits are transmitted, and wherein;

each of the plurality of integrated circuits selects via the selection circuit a terminal voltage from terminal voltages input from individual lithium battery cells in a corresponding lithium battery group, converts an analog value of the selected terminal voltage to a digital value via the analog/digital converter, and transmits the converted digital value of the terminal voltage from the communication circuit to the signal transmission path; and

each of the plurality of integrated circuits selects via the selection circuit a predetermined voltage output from the voltage generating circuit, converts an analog value of the selected predetermined voltage to a digital value via the analog/digital converter, diagnoses whether or not an abnormality has occurred in the integrated circuits via the diagnosis circuit based upon the converted digital value of the predetermined voltage, and, if the diagnosis result indicates an abnormal state, transmits a signal indicating an abnormality from the communication circuit to the signal transmission path.

21. A vehicle power supply system according to claim 20, wherein:

the integrated circuits each comprise a stage circuit that controls a timing of circuit operations;

the selection circuit operates based upon an output from the stage circuit; and

the diagnosis circuit operates at a predetermined cycle based upon an output from the stage circuit.

22. A vehicle power supply system, comprising:

a lithium battery module that is constituted with a plurality of serially connected lithium battery groups each include a plurality of serially connected lithium battery cells;

a plurality of integrated circuits each of which is disposed in correspondence to the plurality of lithium battery groups and in each of which a plurality of circuits are integrated including a selection circuit, an analog/digital converter, a serial communication circuit, a one-bit communication circuit, a diagnosis circuit, and a voltage generating circuit; and

a plurality of signal transmission paths through which signals that are input to or output from the plurality of integrated circuits are transmitted, and wherein;

each of the plurality of integrated circuits selects via the selection circuit a terminal voltage from terminal voltages input from individual lithium battery cells in a corresponding lithium battery group, converts an analog value of the selected terminal voltage to a digital value via the analog/digital converter, and transmits the converted digital value of the terminal voltage from the serial communication circuit to one of the signal transmission paths; and

each of the plurality of integrated circuits selects via the selection circuit a predetermined voltage output from the voltage generating circuit, converts an analog value of the selected predetermined voltage to a digital value via the analog/digital converter, diagnoses whether or not an abnormality has occurred in the integrated circuits via the diagnosis circuit based upon the converted digital value of the predetermined voltage, and, if the diagnosis result indicates an abnormal state, transmits a one-bit signal indicating an abnormality from the one-bit communication circuit to another one of the signal transmission paths.

23. A vehicle power supply system according to claim 22, wherein:

the integrated circuits each comprise a stage circuit that controls a timing of circuit operations;

the selection circuit operates based upon an output from the stage circuit; and

the diagnosis circuit operates at a predetermined cycle based upon an output from the stage circuit.

24. A vehicle power supply system, comprising:

a lithium battery module that is constituted with a plurality of serially connected lithium battery groups each include a plurality of serially connected lithium battery cells;

a plurality of integrated circuits each disposed in correspondence to the plurality of lithium battery groups; and

a plurality of signal transmission paths through which signals that are input to or output from the plurality of integrated circuits are transmitted, wherein;

each of the plurality of integrated circuits comprises;

a selection circuit that selects a terminal voltage of measurement target from terminal voltages at individual lithium battery cells in a corresponding lithium battery group;

an analog/digital converter that converts the terminal voltage having been output from the selection circuit from an analog value to a digital value;

a digital comparator circuit that compares the digital value indicating the terminal voltage that has been output from the analog/digital converter with a voltage threshold value used for diagnosis of over-charge/over-discharge;

a communication circuit that transmits the digital value of the terminal voltage and a signal indicating an abnormality;

a voltage generating circuit that generates a predetermined voltage; and

a digital generating circuit that generates a digital value which is in a known magnitude relationship to the predetermined voltage, and wherein;

the communication circuit includes a serial transmission terminal and a one-bit signal transmission terminal;

the serial transmission terminals are serially connected by electrically connecting a transmission side of a serial transmission terminal at one of the serially connected integrated circuits to a reception side of a serial transmission terminal at another one of the serially connected integrated circuits through one of the signal transmission paths;

the one-bit signal transmission terminals are serially connected by electrically connecting a transmission side of a one-bit signal transmission terminal at one of the serially connected integrated circuits to a reception side of a one-bit signal transmission terminal at another one of the serially connected integrated circuits through another one of the signal transmission paths;

each of the plurality of integrated circuits selects a predetermined voltage generated by the voltage generating circuit via the selection circuit, converts an analog value of the predetermined voltage to a digital value via the analog/digital converter, compares the digital value that has been output from the analog/digital converter with the digital value that has been output from the digital generating circuit via the digital comparator circuit, and, if the comparison result is different from the known magnitude relationship, transmits the abnormality signal from the communication circuit to another one of the signal transmission paths via the one-bit signal transmission terminal; and

the abnormality signal transmitted from one of the plurality of integrated circuits is transmitted to another integrated circuit via the signal transmission path and input to the integrated circuit via a reception side of a one-bit signal transmission terminal of the integrated circuit.

25. An integrated circuit for controlling battery cell that is an integrated circuit electrically connected to a plurality of battery cells serially connected and disposed to measure terminal voltages at the individual battery cells, comprising:

a plurality of voltage receiving terminals through which terminal voltages at the individual battery cells are taken in;

a voltage measurement circuit that measures terminal voltages at the individual battery cells taken in through the plurality of voltage-receiving terminals;

a timing control circuit that outputs a signal for instructing measurement phase during which the terminal voltage is measured and, in synchronization with output of the measurement phase instruction signal, outputs a signal for instructing diagnosis phase during which an abnormality diagnosis is executed;

an abnormality diagnosis circuit that diagnoses an abnormality in the integrated circuit in synchronization with the terminal voltage measurement based upon the diagnosis phase instruction signal;

a communication circuit that transmits a signal indicating the terminal voltage measured by the voltage measurement circuit and a signal based upon a diagnosis result by the abnormality diagnosis circuit; and

a signal terminal that is electrically connected to the communication circuit so as to transmit/receive a signal.

26. An integrated circuit for controlling battery cell that is an integrated circuit electrically connected to a plurality of battery cells serially connected and disposed to measure terminal voltages at the individual battery cells, comprising:

a plurality of voltage receiving terminals through which terminal voltages at the individual battery cells are taken in;

a voltage measurement circuit that measures terminal voltages at the individual battery cells taken in through the plurality of voltage receiving terminals;

a comparator circuit that compares a terminal voltage value output from the voltage measurement circuit with a voltage threshold value used for diagnosis of over-charge/over-discharge of the battery cells;

a diagnosis result output circuit that outputs a signal indicating diagnosis result corresponding to the over-charge/over-discharge if a diagnosis result based upon a comparison result by the comparator circuit indicates the over-charge/over-discharge;

a comparison value generating circuit that generates a comparison value which is used for abnormality diagnosis in integrated circuits and which is in a known magnitude relationship to a predetermined input value that is input to the comparator circuit;

a communication circuit that outputs a signal indicating the terminal voltage measured by the voltage measurement circuit and an abnormality signal based upon the diagnosis result signal; and

a signal terminal that is electrically connected to the communication circuit so as to transmit/receive a signal, and wherein;

the integrated circuit for controlling battery cell compares an input value that is input to the comparator circuit with the comparison value via the comparator circuit, and, if the comparison result is different from the known magnitude relationship, judges that an abnormality has occurred in the integrated circuit and outputs the diagnosis result signal corresponding to the abnormality in the integrated circuit from the diagnosis result output circuit.

27. An integrated circuit for controlling battery cell that is an integrated circuit electrically connected to a plurality of battery cells serially connected and disposed to measure terminal voltages at the individual battery cells, comprising:

a plurality of voltage receiving terminals through which terminal voltages at the individual battery cells are taken in;

a voltage measurement circuit that measures terminal voltages at the individual battery cells taken in through the plurality of voltage receiving terminals;

a comparator circuit that compares a terminal voltage value output from the voltage measurement circuit with a voltage threshold value used for diagnosis of over-charge/over-discharge of the battery cells;

a diagnosis result output circuit that outputs a signal indicating diagnosis result corresponding to the over-charge/over-discharge if a diagnosis result based upon a comparison result by the comparator circuit indicates the over-charge/over-discharge;

a comparison value generating circuit that generates a comparison value which is used for an abnormality diagnosis in the integrated circuits and which is in a known magnitude relationship to a predetermined input value that is input to the comparator circuit;

a communication circuit that outputs a signal indicating the terminal voltage measured by the voltage measurement circuit and an abnormality signal based upon the diagnosis result signal to the signal transmission path;

a timing control circuit that outputs a signal for instructing measurement phase during which the terminal voltage is measured, and, in synchronization with output of the measurement phase instruction signal, outputs a signal for instructing diagnosis phase during which an abnormality diagnosis is executed in integrated circuits; and

a signal terminal that is electrically connected to the communication circuit so as to transmit/receive a signal, wherein;

the integrated circuit for controlling battery cell executes a first diagnosis for diagnosing an abnormality in the integrated circuit in synchronization with measurement of the terminal voltage based upon the diagnosis phase instruction signal and a second diagnosis for diagnosing an abnormality in the integrated circuit based upon whether or not a comparison result of an input value that is input to the comparator circuit with the comparison value via the comparator circuit is different from the known magnitude relationship, and, if there is an abnormality in the integrated circuit, outputs the diagnosis result signal corresponding to the abnormality in the integrated circuit from the diagnosis result output circuit and outputs the abnormality signal based upon the output diagnosis result signal from the communication circuit through the transmission terminal.

28. An integrated circuit for controlling battery cell that is an integrated circuit electrically connected to a plurality of lithium battery cells serially connected and disposed to measure terminal voltages at the individual lithium battery cells, comprising:

a plurality of voltage receiving terminals;

a signal transmission/reception terminal;

a selection circuit;

an analog/digital converter;

a communication circuit;

a diagnosis circuit; and

a voltage generating circuit, wherein;

the integrated circuit for controlling battery cell is configured to select via the selection circuit a terminal voltage from terminal voltages input from the individual lithium battery cells via the plurality of voltage receiving terminals, to convert an analog value of the selected terminal voltage to a digital value via the analog/digital converter, and to transmit the converted digital value of the terminal voltage from the communication circuit via the signal transmission terminal; and

the integrated circuit for controlling battery cell selects via the selection circuit a predetermined voltage output from the voltage generating circuit, converts an analog value of the selected predetermined voltage to a digital value via the analog/digital converter, diagnoses whether or not an abnormality has occurred in the integrated circuit via the diagnosis circuit based upon the converted digital value of the predetermined voltage, and, if the diagnosis result indicates an abnormal state, transmits a signal indicating an abnormality from the communication circuit via the signal transmission terminal.

29. An integrated circuit for controlling battery cell that is an integrated circuit electrically connected to a plurality of lithium battery cells serially connected and disposed to measure terminal voltages at the individual lithium battery cells, comprising:

a plurality of voltage receiving terminals;

a plurality of signal transmission/reception terminals;

a selection circuit;

an analog/digital converter;

a serial communication circuit;

a one-bit communication circuit;

a diagnosis circuit; and

a voltage generating circuit, wherein;

the integrated circuit for controlling battery cell is configured to select via the selection circuit a terminal voltage from terminal voltages input from the individual lithium battery cells via the plurality of voltage receiving terminals, to convert an analog value of the selected terminal voltage to a digital value via the analog/digital converter, and to transmit the converted digital value of the terminal voltage from the serial communication circuit via one of the plurality of signal transmission terminals; and

the integrated circuit for controlling battery cell selects via the selection circuit a predetermined voltage output from the voltage generating circuit, converts an analog value of the selected predetermined voltage to a digital value via the analog/digital converter, diagnoses whether or not an abnormality has occurred in the integrated circuit via the diagnosis circuit based upon the converted digital value of the predetermined voltage, and, if the diagnosis result indicates an abnormal state, transmit a signal indicating an abnormality from the one-bit communication circuit via another one of the plurality of the signal transmission terminals.

30. An integrated circuit for controlling battery cell that is an integrated circuit electrically connected to a plurality of lithium battery cells serially connected and disposed to measure terminal voltages at the individual lithium battery cells, comprising:

a plurality of voltage receiving terminals;

a signal transmission/reception terminal;

a selection circuit;

an analog/digital converter;

a communication circuit;

a diagnosis circuit;

a digital comparator circuit; and

a digital value output circuit, wherein;

the integrated circuit for controlling battery cell is configured to select via the selection circuit a terminal voltage from terminal voltages input from the individual lithium battery cells via the plurality of voltage receiving terminals, to convert an analog value of the selected terminal voltage to a digital value via the analog/digital converter, and to transmit the converted digital value of the terminal voltage from the communication circuit via the signal transmission terminal; and

the integrated circuit for controlling battery cell outputs from the digital value output circuit a first digital value and a second digital value which is in a predetermined magnitude relationship to the first digital value, compares the first and second digital values via the digital comparator circuit, diagnoses whether or not an abnormality has occurred in the integrated circuit via the diagnosis circuit based upon whether or not the comparison result is in the predetermined magnitude relationship, and, if the diagnosis result indicates an abnormal state, transmits a signal indicating an abnormality from the communication circuit via the signal transmission terminal.