JP2016075557A - Battery monitoring circuit and battery module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow precise operation of voltages of battery cells and voltage decrease due to bus bars, for example, using a voltage measuring unit precisely measuring voltages in a range of voltages that the battery cells can take.SOLUTION: A CMU30 measures the voltages of battery cells 10A, 10C, 10E, and 10G not containing voltage decrease due to bus bar 20A to 20F and battery cells 10B, 10D, and 10F containing voltage decrease due to the bus bar 20A to 20F, via wirings connected to the positive and negative electrodes of the battery cell 10A, 10C, 10E, and 10G without the bus bars 20A to 20F. The CMU30 measures the voltages of battery cells 10B, 10D, and 10F not containing voltage decrease due to the bus bar 20A to 20F and battery cells 10A, 10C, 10E, and 10G containing voltage decrease due to the bus bar 20A to 20F, via wirings connected to the positive and negative electrodes of the battery cell 10B, 10D, and 10F without the bus bars 20A to 20F.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a battery monitoring circuit that monitors a plurality of batteries connected in series via a power line, and a battery module including the battery monitoring circuit.

  A battery module that generates high-voltage power by connecting a plurality of battery cells in series by a bus bar that is a power line is known. The battery module is provided with a CMU (Cell Monitoring Unit: battery monitoring circuit) that measures the output voltage of each battery cell. The CMU measures the voltage of each battery cell via both ends of the battery cells connected in series and the wiring connected between the battery cells (see, for example, Patent Document 1).

JP 2010-283918 A

  The bus bar that connects the battery cells is connected to the battery cells by bolting. There is a contact resistance between the battery cell and the bus bar, and when the CMU measures the voltage of each battery cell via the bus bar between the battery cells, the voltage may include a voltage drop due to the contact resistance. . Therefore, the CMU cannot measure the electromotive force accurately only by measuring the voltage of each battery cell via the bus bar between the battery cells.

  In addition to the voltage of the battery cell, the CMU is desired to be able to measure the influence of the contact resistance of the bus bar. On the other hand, the voltage measurement unit of the CMU may be designed so that the voltage can be accurately measured within a voltage range that the battery cell can take (for example, 3V to 4V). In this case, since the voltage drop due to the contact resistance of the bus bar is smaller than the voltage range that can be taken by the battery cell, it is difficult to accurately measure the voltage drop due to the contact resistance using the voltage measuring unit of the CMU. It is.

  An object of the present invention is to provide a battery monitoring circuit and a battery module that enable accurate grasping of a voltage of a battery cell, a voltage drop due to a power line, and the like.

  A first aspect is a battery monitoring circuit for monitoring a plurality of batteries connected in series via a power line, wherein each of the batteries does not include a voltage drop due to the power line, and the power line It is a battery monitoring circuit provided with the voltage measurement part which measures the voltage containing the voltage drop by.

  Moreover, the 2nd aspect is a voltage of the said battery which does not contain the voltage drop by the said power line and the voltage drop by the said power line measured in the said voltage measurement part in the 1st aspect. Is a battery monitoring circuit including a voltage drop specifying unit that specifies a physical quantity related to a voltage drop by a power line connected to the battery based on the voltage difference between

  Further, the third mode is the second mode, wherein the first voltage measuring unit is connected to at least one electrode terminal of a voltage not including a voltage drop due to the power line for each battery. It is a battery monitoring circuit that measures a voltage including a voltage drop caused by a power line.

  Moreover, a 4th aspect is the electrode terminal which is a physical quantity which concerns on the voltage drop by the said power line by dividing the said voltage difference by the electric current which flows into the said battery by the said voltage drop specific | specification part in a 3rd aspect. And a battery monitoring circuit for specifying a contact resistance with the power line.

  Further, a fifth aspect includes a current measurement unit that measures a current flowing through the battery using a resistance value given in advance as a contact resistance between the electrode terminal and the power line in the fourth aspect, The voltage drop specifying unit is a battery monitoring circuit that specifies a contact resistance between the electrode terminal and the power line using the current measured by the current measuring unit.

  Further, a sixth aspect includes a current measurement unit that measures a current flowing through the battery using the voltage characteristics of each battery in the fourth aspect, and the voltage measurement unit is measured by the current measurement unit. It is a battery monitoring circuit which specifies the contact resistance between the electrode terminal and the power line using the measured current.

  In addition, according to a seventh aspect, in any one of the third to sixth aspects, when the absolute value of the physical quantity related to the voltage drop specified by the voltage drop specifying unit exceeds a predetermined threshold, the battery and the It is a battery monitoring circuit including a contact abnormality determining unit that determines that there is an abnormality in contact with the power line.

  Further, an eighth aspect is the contact abnormality that performs a predetermined abnormality detection operation when the contact abnormality determination unit determines that the contact between the battery and the power line is abnormal in the seventh aspect. A battery monitoring circuit including a time processing unit.

  A ninth aspect is a battery monitoring circuit including an end voltage measurement unit that measures the voltage of the battery provided at the end in series in any one of the first to eighth aspects.

  Further, a tenth aspect is the ninth aspect, in which the end voltage measuring unit is configured to depend on a contact resistance of the external output terminal via an external output terminal connected to a battery provided at the series end. It is a battery monitoring circuit that measures the voltage of the battery including a voltage drop.

  Further, an eleventh aspect is the tenth aspect, in which the voltage of the battery provided at the series end measured by the voltage measuring unit and the contact resistance of the external output terminal measured by the end voltage measuring unit. The battery monitoring circuit includes a contact resistance specifying unit that specifies a physical quantity related to a voltage drop due to the contact resistance of the external output terminal based on a voltage difference with the voltage of the battery including a voltage drop due to.

  The twelfth aspect is the electrode terminal according to the third aspect, wherein the voltage drop specifying unit is a physical quantity related to a voltage drop caused by the power line by multiplying the voltage difference by a current flowing through the battery. And a battery monitoring circuit for calculating the amount of heat generated by calculating power consumption in the power line.

  Further, a thirteenth aspect is the twelfth aspect, further comprising a current measurement unit that measures a current flowing through the battery using a resistance value given in advance as a contact resistance between the electrode terminal and the power line, The voltage drop specifying unit is a battery monitoring circuit that calculates power consumption by calculating power consumption at the electrode terminal and the power line using the current measured by the current measuring unit.

  Further, a fourteenth aspect is the twelfth aspect, further comprising a current measurement unit that measures a current flowing through the battery using the voltage characteristics of each battery, wherein the voltage drop specifying unit is measured by the current measurement unit. A battery monitoring circuit that calculates power consumption by calculating power consumption at the electrode terminal and the power line using the measured current.

  According to a fifteenth aspect, in any one of the first to fourteenth aspects, the voltage measurement unit includes a first voltage measurement unit and a second voltage measurement unit, and the first voltage measurement unit includes: For each battery connected to the odd number from the battery located at one end of the series connection, the voltage not including the voltage drop due to the power line and the even number counted from the battery located at the one end are connected. For each of the batteries, a voltage including a voltage drop due to the power line connected to at least one electrode terminal of the battery is measured, and the second voltage measuring unit is counted from the battery located at the one end. For each battery connected to the even number, the voltage not including the voltage drop due to the power line, and for each battery connected to the odd number from the battery located at the one end, At least one electrode A battery monitoring circuit for measuring the voltage including a voltage drop by the power line connected to the child.

  According to a sixteenth aspect, in any one of the first to fourteenth aspects, the voltage measurement unit includes a first voltage measurement unit and a second voltage measurement unit, and the first voltage measurement unit includes: And measuring the voltage of each battery, including a voltage drop caused by a power line connected to the negative electrode side of the battery, via the wiring connected to the positive terminal of each battery, and the second voltage. The measurement unit measures the voltage of each battery, including a voltage drop caused by a power line connected to the positive electrode side of the battery, via a wire connected to the negative electrode terminal of each battery. Circuit.

  According to a seventeenth aspect, in the fifteenth or sixteenth aspect, the battery voltage measured by the first voltage measurement unit when the current flowing through the battery is a predetermined threshold value or less, and the first A measurement abnormality that determines that the first voltage measurement unit or the second voltage measurement unit is abnormal when a voltage difference from the battery voltage measured by the second voltage measurement unit exceeds a predetermined threshold value A battery monitoring circuit including a determination unit.

  An eighteenth aspect is the seventeenth aspect, in which the predetermined abnormality detection is performed when the measurement abnormality determination unit determines that the first voltage measurement unit or the second voltage measurement unit is abnormal. It is a battery monitoring circuit provided with the measurement abnormal time process part which performs operation | movement.

  A nineteenth aspect is a battery module including a plurality of batteries connected in series via a power line and a battery monitoring circuit in any one of the first to eighteenth aspects.

  A twentieth aspect is a battery monitoring circuit for monitoring a plurality of batteries connected in series via a power line, wherein a voltage drop caused by a power line connected to at least one of a positive electrode and a negative electrode of the battery is detected. A first voltage measuring unit that measures the voltage of the battery including the second voltage measuring unit that measures a voltage of the battery that does not include a voltage drop included in the voltage measured by the first voltage measuring unit; A battery monitoring circuit including a voltage drop specifying unit that specifies a voltage drop caused by the power line based on a voltage difference between the voltage measured by the first voltage measuring unit and the voltage measured by the second voltage measuring unit. is there.

  According to at least one of the above aspects, at least one of the first voltage measurement unit and the second voltage measurement unit is not included in the voltage of the battery measured by the other voltage measurement unit. Measure the battery voltage including the voltage drop due to. Thereby, the battery monitoring circuit can provide accurate information for use in calculation of the voltage of the battery cell and the voltage drop due to the power line.

It is a figure which shows the external appearance of the battery module which concerns on at least 1 embodiment. It is a schematic block diagram which shows the structure of CMU which concerns on 1st Embodiment. It is a figure which shows the wiring of the battery cell and CMU in 1st Embodiment. It is a flowchart which shows operation | movement of CMU which concerns on 1st Embodiment. It is a figure which shows the wiring of the battery cell and CMU in 2nd Embodiment. It is a flowchart which shows operation | movement of CMU which concerns on 3rd Embodiment. It is a figure which shows the wiring of the battery cell and CMU in 4th Embodiment. It is a 1st flowchart which shows operation | movement of CMU which concerns on 4th Embodiment. It is a 2nd flowchart which shows operation | movement of CMU which concerns on 4th Embodiment. It is a figure which shows the wiring of a battery cell and CMU in case a battery module is provided with four battery cells.

<< First Embodiment >>
Hereinafter, the first embodiment will be described in detail with reference to the drawings.
FIG. 1 is a diagram illustrating an appearance of a battery module 1 according to at least one embodiment.
The battery module 1 includes a casing 2 that forms an outer shell, and a plurality of (seven in FIG. 1) battery cells 10A to 10G (hereinafter referred to as battery cells 10A to 10G) simply arranged as a battery. Cell 10), bus bars 20 </ b> A to 20 </ b> F that electrically connect the terminals of each battery cell 10 (hereinafter, the bus bars 20 </ b> A to 20 </ b> F are simply referred to as bus bar 20), and CMU 30 that monitors each battery cell 10 With. The CMU 30 is an example of a battery monitoring circuit.

The casing 2 is provided with external output terminals 3A and B for connecting the battery cells 10 connected in series and an external load or power source. The external output terminal 3A is connected to the positive electrode of the battery cell 10A via a bolt. The external output terminal 3B is connected to the negative electrode of the battery cell 10G via a bolt.
The battery cell 10 according to the present embodiment is a lithium ion secondary battery. In other embodiments, the battery cell 10 may be another secondary battery such as a lead secondary battery or a nickel hydride secondary battery. In other embodiments, the battery cell 10 may be a primary battery.
The bus bar 20 is connected to the battery cell 10 via a bolt. As the bolt is loosened, the contact resistance between the bus bar 20 and the battery cell 10 increases.

The CMU 30 monitors the voltage of each battery cell 10. Further, the CMU 30 calculates a contact resistance between the bus bar 20 and the battery cell 10 based on the voltage.
FIG. 2 is a schematic block diagram showing the configuration of the CMU 30 according to the first embodiment.
The CMU 30 includes a first voltage measurement unit 31, a second voltage measurement unit 32, a current measurement unit 33, a CPU 34, a main storage device 35, an auxiliary storage device 36, and an interface 37. The first voltage measurement unit 31 and the second voltage measurement unit 32 are multiplexers that measure the voltage of each battery cell 10 via a wiring connected to each battery cell 10.

  The current measuring unit 33 measures the current flowing through the battery cell 10. For example, the current measurement unit 33 measures current by receiving a signal from a current sensor connected in series to the battery cell 10. For example, the current measurement unit 33 divides the voltage measured by the first voltage measurement unit 31 or the second voltage measurement unit 32 by the contact resistance between the electrode terminal of each battery cell 10 and the bus bar 20. The current flowing through the battery cell 10 is measured. In this case, the contact resistance between the electrode terminal of each battery cell 10 and the bus bar 20 is measured in advance, and the current measurement unit 33 measures the current using the measurement result. In addition, for example, the current measurement unit 33 stores information on voltage characteristics that are the relationship between the voltage and current of each battery cell 10, and the first voltage measurement unit 31 or the second voltage measurement unit 32 depends on the voltage characteristics. Measure the current from the measured voltage.

The CPU 34 reads a predetermined program from the auxiliary storage device 36 and develops it in the main storage device 35, and executes processing according to the program. Specifically, the CPU 34 calculates the contact resistance between the bus bar 20 and the battery cell 10 and determines the contact abnormality based on the voltage measured by the first voltage measurement unit 31 and the second voltage measurement unit 32. I do. The CPU 34 is an example of a voltage drop specifying unit, a battery voltage specifying unit, and a contact abnormality processing unit.
The interface 37 communicates with a BMU (Battery Management Unit) that is a management device of the battery module 1. The interface 37 outputs information indicating the voltage and contact resistance values calculated by the CPU 34 and the presence or absence of contact abnormality to the BMU.

Next, the wiring between the battery cell 10 and the first voltage measuring unit 31 and the second voltage measuring unit 32 in the battery module 1 according to the present embodiment will be described.
FIG. 3 is a diagram illustrating wiring between the battery cell 10 and the CMU 30 in the first embodiment.
As shown in FIG. 3, the battery cells 10 are connected in series in the order of battery cells 10A, 10B, 10C, 10D, 10E, 10F, and 10G from the positive electrode side. The battery cell 10A and the battery cell 10B are connected by a bus bar 20A. The battery cell 10B and the battery cell 10C are connected by a bus bar 20B. The battery cell 10C and the battery cell 10D are connected by a bus bar 20C. The battery cell 10D and the battery cell 10E are connected by a bus bar 20D. The battery cell 10E and the battery cell 10F are connected by a bus bar 20E. The battery cell 10F and the battery cell 10G are connected by a bus bar 20F. In addition, contact resistances Ra to Rf due to the bus bar 20 are generated between the battery cells 10.

  As shown in FIG. 3, the first voltage measuring unit 31 has eight input terminals, and each of the positive electrode of the battery cell 10A, the negative electrode of the battery cell 10A, the positive electrode of the battery cell 10C, the negative electrode of the battery cell 10C, The battery cell 10E is connected to the positive electrode of the battery cell 10E, the negative electrode of the battery cell 10E, the positive electrode of the battery cell 10G, and the negative electrode of the battery cell 10G by wiring without the bus bar 20. In other words, the first voltage measurement unit 31 is connected to the positive and negative electrodes of the battery cells 10 connected from the positive electrode side to the odd number without passing through the bus bar 20.

Then, the first voltage measurement unit 31 measures the voltage between two adjacent input terminals. Specifically, the first voltage measuring unit 31 measures the following voltages V1a to V1g.
The first voltage measurement unit 31 measures a voltage V1a between the positive electrode of the battery cell 10A and the negative electrode of the battery cell 10A. The voltage V1a is an input / output voltage of the battery cell 10A that does not include a voltage drop due to the bus bar 20. The first voltage measurement unit 31 measures a voltage V1b between the negative electrode of the battery cell 10A and the positive electrode of the battery cell 10C. The voltage V1b is input / output power of the battery cell 10B including a voltage drop caused by the bus bar 20A and the bus bar 20B. The first voltage measurement unit 31 measures a voltage V1c between the positive electrode of the battery cell 10C and the negative electrode of the battery cell 10C. The voltage V1c is an input / output voltage of the battery cell 10C that does not include a voltage drop due to the bus bar 20. The first voltage measurement unit 31 measures a voltage V1d between the negative electrode of the battery cell 10C and the positive electrode of the battery cell 10E. The voltage V1d is input / output power of the battery cell 10D including a voltage drop caused by the bus bar 20C and the bus bar 20D. The first voltage measurement unit 31 measures a voltage V1e between the positive electrode of the battery cell 10E and the negative electrode of the battery cell 10E. The voltage V1e is an input / output voltage of the battery cell 10E that does not include a voltage drop due to the bus bar 20. The first voltage measurement unit 31 measures a voltage V1f between the negative electrode of the battery cell 10E and the positive electrode of the battery cell 10G. The voltage V1f is input / output power of the battery cell 10F including a voltage drop caused by the bus bar 20E and the bus bar 20F. The first voltage measurement unit 31 measures a voltage V1g between the positive electrode of the battery cell 10G and the negative electrode of the battery cell 10G. The voltage V1g is an input / output voltage of the battery cell 10G that does not include a voltage drop due to the bus bar 20.

  The second voltage measuring unit 32 has eight input terminals, and each has a positive electrode of the battery cell 10A, a positive electrode of the battery cell 10B, a negative electrode of the battery cell 10B, a positive electrode of the battery cell 10D, a negative electrode of the battery cell 10D, and a battery. The bus bar 20 is not connected to the positive electrode of the cell 10F, the negative electrode of the battery cell 10F, and the negative electrode of the battery cell 10G. In other words, the second voltage measurement unit 32 is connected to the positive and negative electrodes of the battery cells 10 connected from the positive electrode side to the even-numbered cells without passing through the bus bar 20. Further, the second voltage measurement unit 32 is connected to the positive electrode of the battery cell 10A provided at the positive electrode end and the negative electrode of the battery cell 10G provided at the negative electrode end. The second voltage measurement unit 32 is an example of an end voltage measurement unit.

Then, the second voltage measurement unit 32 measures the voltage between two adjacent input terminals. Specifically, the second voltage measuring unit 32 measures the following voltages V2a to V2g.
The second voltage measurement unit 32 measures a voltage V2a between the positive electrode of the battery cell 10A and the positive electrode of the battery cell 10B. The voltage V2a is an input / output voltage of the battery cell 10A including a voltage drop caused by the bus bar 20A. The second voltage measurement unit 32 measures a voltage V2b between the positive electrode of the battery cell 10B and the negative electrode of the battery cell 10B. The voltage V2b is an input / output voltage of the battery cell 10B that does not include a voltage drop caused by the bus bar 20. In addition, the second voltage measuring unit 32 measures a voltage V2c between the negative electrode of the battery cell 10B and the positive electrode of the battery cell 10D. The voltage V2c is input / output power of the battery cell 10C including a voltage drop caused by the bus bar 20B and the bus bar 20C. The second voltage measurement unit 32 measures a voltage V2d between the positive electrode of the battery cell 10D and the negative electrode of the battery cell 10D. The voltage V2d is an input / output voltage of the battery cell 10D that does not include a voltage drop due to the bus bar 20. The second voltage measurement unit 32 measures a voltage V2e between the negative electrode of the battery cell 10D and the positive electrode of the battery cell 10F. The voltage V2e is input / output power of the battery cell 10F including a voltage drop caused by the bus bar 20D and the bus bar 20F. The second voltage measurement unit 32 measures a voltage V2f between the positive electrode of the battery cell 10F and the negative electrode of the battery cell 10G. The voltage V2f is an input / output voltage of the battery cell 10F that does not include a voltage drop due to the bus bar 20. The second voltage measuring unit 32 measures a voltage V2g between the negative electrode of the battery cell 10F and the negative electrode of the battery cell 10G. The voltage V2g is input / output power of the battery cell 10G including a voltage drop caused by the bus bar 20F.

Next, the cell battery monitoring operation by the CMU 30 according to the present embodiment will be described.
FIG. 4 is a flowchart showing the operation of the CMU 30 according to the first embodiment.
When the CMU 30 starts the cell battery monitoring operation, the first voltage measurement unit 31 measures the voltage V1a between the positive electrode of the battery cell 10A and the negative electrode of the battery cell 10A. In addition, the second voltage measurement unit 32 measures the voltage V2a between the positive electrode of the battery cell 10A and the positive electrode of the battery cell 10B (step S1). At this time, the current measuring unit 33 measures the current flowing through the battery cell 10 (step S2). The first voltage measuring unit 31, the second voltage measuring unit 32, and the current measuring unit 33 output the measured voltage values V1a and V2a and the current value I to the CPU.

  The CPU 34 specifies the voltage V1a measured by the first voltage measuring unit 31 as the input / output voltage of the battery cell 10A (step S3). Next, the CPU 34 specifies a voltage drop caused by the bus bar 20A by subtracting the voltage V1a from the voltage V2a measured by the second voltage measuring unit 32 (step S4). Next, the CPU 34 specifies the contact resistance Ra between the bus bar 20A and the battery cell 10A by dividing the voltage drop caused by the bus bar 20A by the value of the current measured by the current measuring unit 33 (step S5).

  Next, the CPU 34 outputs, to the first voltage measuring unit 31 and the second voltage measuring unit 32, a signal for changing the battery cell 10 that is a voltage measurement target to the next battery cell 10 (step). S6). The next battery cell 10 means the battery cell 10 connected to the negative electrode side of the battery cell 10 whose voltage was measured last time. For example, when the battery cell 10 whose voltage was measured last time is the battery cell 10A, the next battery cell 10 is the battery cell 10B. When the first voltage measurement unit 31 and the second voltage measurement unit 32 receive an input of a signal from the CPU 34, the first voltage measurement unit 31 and the second voltage measurement unit 32 switch input terminals used for calculation. Thereby, the 1st voltage measurement part 31 and the 2nd voltage measurement part 32 switch the voltage measurement object to the following battery cell 10, and measure the voltage of the said battery cell 10 (step S7). Specifically, the first voltage measuring unit 31 measures the voltage V1b when measuring the voltage V1a last time. Similarly, the second voltage measuring unit 32 measures the voltage V2b when measuring the voltage V2a last time. At this time, the current measuring unit 33 measures the current flowing through the battery cell 10 (step S8). The first voltage measuring unit 31, the second voltage measuring unit 32, and the current measuring unit 33 output the measured voltage value and current value I to the CPU.

  The CPU 34 inputs and outputs the voltage measured by the first voltage measuring unit 31 or the voltage measured by the second voltage measuring unit 32 that does not include a voltage drop due to the bus bar 20 to / from the battery cell 10 to be measured. The voltage is specified (step S9). For example, when the first voltage measurement unit 31 measures the voltage V1b and the second voltage measurement unit 32 measures the voltage V2b, the CPU 34 uses the voltage V2b that does not include the voltage drop due to the bus bar 20 as the battery cell 10B. Specified as input / output voltage.

  Next, the CPU 34 subtracts the voltage drop of the bus bar 20 specified last time from the difference between the voltage measured by the first voltage measuring unit 31 and the voltage measured by the second voltage measuring unit 32 to thereby determine the measurement target. The voltage drop by the bus bar 20 connected to the negative electrode side of the battery cell 10 is specified (step S10). For example, when the first voltage measurement unit 31 measures the voltage V1b and the second voltage measurement unit 32 measures the voltage V2b, the CPU 34 determines the voltage of the bus bar 20A specified in step S5 from the difference between V1b and V2b. By subtracting the drop, the voltage drop of the bus bar 20B is specified. Next, the CPU 34 divides the identified voltage drop by the value of the current measured by the current measuring unit 33 in step S <b> 8, so that the bus bar connected to the measurement target battery cell 10 and the negative electrode side of the battery cell 10. The contact resistance with 20 is specified (step S11).

  Next, the CPU 34 determines whether or not the voltages of all the battery cells 10 and the bus bars 20 have been specified (step S12). If the CPU 34 determines that there is a battery cell 10 and a bus bar 20 for which the voltage is not specified (step S12: NO), the CPU 34 returns to step S6 and sets the battery cell 10 to be measured for voltage to the next battery cell 10. Change it.

  On the other hand, when it is determined that the voltages of all the battery cells 10 and the bus bar 20 have been specified (step S12: YES), the CPU 34 outputs the voltage of the battery cell 10 and the contact resistance of the bus bar 20 to the BMU via the interface 37. (Step S13). Next, the CPU 34 determines whether or not any of the contact resistances specified in step S5 and step S11 exceeds a predetermined threshold (step S14). When it is determined that the contact resistance exceeds the threshold (step S14: YES), the CPU 34 determines that an abnormality has occurred in the connection between the battery cell 10 and the bus bar 20, and notifies the BMU of the occurrence of the abnormality ( Step S15). The notification of the occurrence of an abnormality is an example of an abnormality detection operation. In another embodiment, the CPU 34 may execute an abnormality detection operation such as, for example, stopping the output of all the battery cells 10.

  When the CPU 34 determines that there is no contact resistance exceeding the threshold value (step S14: NO), or when the abnormality detection operation is executed in step S15, the monitoring process at the timing ends. The CMU 30 may autonomously execute the monitoring process again after a predetermined time has elapsed, or may execute the monitoring process again in accordance with an instruction from the BMU.

Thus, the CMU 30 according to the present embodiment includes, for each battery cell 10, a voltage that does not include a voltage drop due to the bus bar 20 and a voltage drop due to the bus bar 20 connected to at least one electrode terminal of the battery cell 10. Measure the voltage. Thereby, the CMU 30 can accurately calculate the voltage of the battery cell 10 and the voltage drop caused by the bus bar 20. In addition, the CMU 30 according to the embodiment uses the voltage measuring units 31 and 32 that accurately measure the voltage within the range of the voltage that the battery cell 10 can take, and accurately detects the voltage of the battery cell 10 and the voltage drop due to the bus bar 20. Can be calculated. Further, the CMU 30 according to the present embodiment can determine whether or not there is a contact abnormality between the battery cell 10 and the bus bar 20 based on the specified voltage drop.
In particular, the first voltage measurement unit 31 and the second voltage measurement unit 32 measure the voltage at the same time in synchronization with each other, so that the voltage drop caused by the bus bar 20 can be accurately performed regardless of whether or not the current I varies. Can be identified well.

  In addition, although this embodiment demonstrated the case where CPU34 detected the abnormality of the connection of the battery cell 10 and the bus-bar 20 based on whether contact resistance exceeds a predetermined threshold value, it is not restricted to this. For example, in another embodiment, an abnormality may be detected based on whether the voltage drop value exceeds a predetermined threshold. In this case, the CMU 30 may not include the current measurement unit 33.

Moreover, although this embodiment demonstrated the case where the voltage of the battery cell 10 and the contact resistance of the bus bar 20 were specified in order from the positive electrode side, it is not restricted to this. For example, in another embodiment, the voltage of the battery cell 10 and the contact resistance of the bus bar 20 may be specified in order from the negative electrode side. In this case, the second voltage measurement unit 32 may not measure the voltage V2a.
Furthermore, in another embodiment, the CPU 34 may calculate the power consumption of the electrode terminal and the power line, which is a physical quantity related to the voltage drop by the power line, and specify the amount of heat generated by the contact resistance. The power consumption can be calculated by multiplying the voltage difference between the voltage of the battery not including the voltage drop due to the power line and the voltage of the battery including the voltage drop due to the power line by the current flowing through the battery.

<< Second Embodiment >>
Next, the second embodiment will be described in detail.
The battery module 1 includes an external output terminal 3 as a configuration for connecting the battery cell 10 and an external load or power source. An external load or power supply is connected to the external output terminal 3 via a predetermined power line. At this time, the power line and the external output terminal 3 are connected by bolting or the like. Therefore, when the bolt is loosened, a contact resistance is generated between the external output terminal 3 and the power line.

  In addition to the first embodiment, the CMU 30 of the battery module 1 according to the second embodiment specifies the contact resistance at the output terminal of the battery module 1 and determines whether there is a contact failure. The battery module 1 according to the second embodiment is different from the first embodiment in the wiring between the battery cell 10 and the CMU 30 and the operation of the CPU 34. The CPU 34 according to the second embodiment is an example of a contact resistance specifying unit and a contact abnormality determining unit.

FIG. 5 is a diagram illustrating wiring between the battery cell 10 and the CMU 30 in the second embodiment.
As shown in FIG. 5, the second voltage measuring unit 32 measures a voltage V2a ′ between the power line connected to the external output terminal 3A and the positive electrode of the battery cell 10B instead of the voltage V2a. The voltage V2g is input / output power of the battery cell 10A including a voltage drop due to contact resistance between the power line and the external output terminal 3A and a voltage drop due to the bus bar 20A. The second voltage measuring unit 32 measures the voltage V2g ′ between the power line connected to the external output terminal 3B and the negative electrode of the battery cell 10F instead of the voltage V2g. The voltage V2g is input / output power of the battery cell 10G including a voltage drop due to contact resistance between the power line and the external output terminal 3B and a voltage drop due to the bus bar 20F.

  Thereby, the CPU 34 according to the second embodiment provides the contact resistance between the power line and the external output terminal 3 in addition to the input / output voltage of the battery cell 10 and the contact resistance between the battery cell 10 and the bus bar 20. Can be calculated. In addition, when the CPU 34 determines in step S14 described above that there is a contact resistance (amount related to voltage drop) between the power line and the external output terminal 3 that exceeds a predetermined threshold, Execute the detection operation.

<< Third Embodiment >>
Next, a third embodiment will be described.
In the CMU 30 of the battery module 1 according to the third embodiment, in addition to the operation of the first embodiment, the first voltage measuring unit 31 and the second voltage measuring unit 32 can normally measure the voltage. It is determined whether or not. The configuration of the battery module 1 according to the third embodiment is the same as that of the first embodiment. On the other hand, the CMU 30 according to the third embodiment executes the following process in addition to the process according to the first embodiment. The CMU 30 according to the second embodiment is an example of a measurement abnormality determination unit and a measurement abnormality time processing unit.

FIG. 6 is a flowchart showing the operation of the CMU 30 according to the third embodiment.
First, when the CMU 30 starts a voltage measurement normality confirmation operation, the current measurement unit 33 measures the current flowing through the battery cell 10 (step S101). Next, the CPU 34 determines whether or not the current measured by the current measuring unit 33 is equal to or less than a predetermined threshold (step S102). The threshold value is such a value that it can be considered that almost no current flows through the battery cell 10.

  When the CPU 34 determines that the current measured by the current measuring unit 33 is greater than the predetermined threshold (step S102: NO), the CPU 34 returns to step S101 and repeats the process until the current becomes equal to or less than the threshold. On the other hand, when the CPU 34 determines that the current measured by the current measurement unit 33 is equal to or less than the predetermined threshold (step S102: YES), the first voltage measurement unit 31 and the second voltage measurement unit 32 measure each. The voltage of the target battery cell 10 is measured (step S103). Note that the battery cell 10 to be measured at the time of the first execution is a battery cell 10A. That is, the first voltage measuring unit 31 measures the voltage V1a, and the second voltage measuring unit 32 measures the voltage V2a.

  Next, the CPU 34 calculates a difference between the voltage measured by the first voltage measuring unit 31 and the voltage measured by the second voltage measuring unit 32, and determines whether or not the difference is equal to or less than a predetermined threshold value. (Step S104). The threshold value is a value corresponding to an allowable error of the voltage measured by the first voltage measuring unit 31 and the second voltage measuring unit 32. When the CPU 34 determines that the difference between the two voltages is greater than the predetermined threshold (step S104: NO), the CPU 34 determines that an abnormality has occurred in the first voltage measurement unit 31 or the second transmission measurement unit. The BMU is notified of the occurrence of an abnormality (step S105). The notification of the occurrence of an abnormality is an example of an abnormality detection operation.

When the CPU 34 determines that the difference between the two voltages is equal to or less than a predetermined threshold (step S104: YES), or when an abnormality detection operation is performed in step S105, whether or not the voltages of all the battery cells 10 have been compared Is determined (step S106). When it is determined that there is a battery cell 10 whose voltage is not compared (step S106: NO), the CPU 34 changes the battery cell 10 to be measured for voltage to the next battery cell 10 (step S107). And CPU34 returns a process to step S103, and compares the voltage about the following battery cell 10. FIG.
On the other hand, if it is determined that the voltages of all the battery cells 10 have been compared (step S106: YES), the CPU 34 ends the voltage measurement normality confirmation operation.

  Thus, the CMU 30 according to the present embodiment determines whether the first voltage measurement unit 31 and the second voltage measurement unit 32 are abnormal in addition to the calculation of the voltage of the battery cell 10 and the voltage drop by the bus bar 20. can do.

<< Fourth Embodiment >>
Next, a fourth embodiment will be described.
The battery module 1 according to the fourth embodiment is different from the first embodiment in the wiring between the battery cell 10 and the CMU 30 and the operation of the CPU 34.

FIG. 7 is a diagram illustrating wiring between the battery cell 10 and the CMU 30 according to the fourth embodiment.
As shown in FIG. 7, the first voltage measuring unit 31 has eight input terminals, and each of the positive electrode of the battery cell 10A, the positive electrode of the battery cell 10B, the positive electrode of the battery cell 10C, the positive electrode of the battery cell 10D, The battery cell 10E is connected to the positive electrode of the battery cell 10F, the positive electrode of the battery cell 10F, the positive electrode of the battery cell 10G, and the negative electrode of the battery cell 10G by wiring without passing through the bus bar 20. That is, the first voltage measurement unit 31 is connected to the positive electrode of each battery cell 10 without the bus bar 20 interposed therebetween. The first voltage measurement unit 31 is connected to the negative electrode of the battery cell 10G provided at the end on the negative electrode side. The first voltage measurement unit 31 is an example of an end voltage measurement unit.

Then, the first voltage measurement unit 31 measures the voltage between two adjacent input terminals. Specifically, the first voltage measurement unit 31 measures the following voltages V3a to V3g.
The first voltage measurement unit 31 measures a voltage V3a between the positive electrode of the battery cell 10A and the positive electrode of the battery cell 10B. The voltage V3a is an input / output voltage of the battery cell 10A including a voltage drop caused by the bus bar 20A. The first voltage measurement unit 31 measures a voltage V3b between the positive electrode of the battery cell 10B and the positive electrode of the battery cell 10C. The voltage V3b is input / output power of the battery cell 10B including a voltage drop caused by the bus bar 20B. The first voltage measurement unit 31 measures a voltage V3c between the positive electrode of the battery cell 10C and the positive electrode of the battery cell 10D. The voltage V3c is an input / output voltage of the battery cell 10C including a voltage drop caused by the bus bar 20C. The first voltage measurement unit 31 measures a voltage V3d between the positive electrode of the battery cell 10D and the positive electrode of the battery cell 10E. The voltage V3d is input / output power of the battery cell 10D including a voltage drop caused by the bus bar 20D. The first voltage measurement unit 31 measures a voltage V3e between the positive electrode of the battery cell 10E and the positive electrode of the battery cell 10F. The voltage V3e is an input / output voltage of the battery cell 10E including a voltage drop caused by the bus bar 20E. The first voltage measurement unit 31 measures a voltage V3f between the positive electrode of the battery cell 10F and the positive electrode of the battery cell 10G. The voltage V3f is input / output power of the battery cell 10F including a voltage drop caused by the bus bar 20F. The first voltage measurement unit 31 measures a voltage V3g between the positive electrode of the battery cell 10G and the negative electrode of the battery cell 10G. The voltage V3g is an input / output voltage of the battery cell 10G that does not include a voltage drop due to the bus bar 20.

  The second voltage measuring unit 32 has eight input terminals, each of which has a positive electrode of the battery cell 10A, a negative electrode of the battery cell 10A, a negative electrode of the battery cell 10B, a negative electrode of the battery cell 10C, a negative electrode of the battery cell 10D, and a battery. The bus bar 20 is not connected to the negative electrode of the cell 10E, the negative electrode of the battery cell 10F, and the negative electrode of the battery cell 10G. That is, the second voltage measuring unit 32 is connected to the negative electrode of each battery cell 10 without the bus bar 20 interposed therebetween. The second voltage measurement unit 32 is connected to the positive electrode of the battery cell 10A provided at the end on the positive electrode side. The first voltage measurement unit 31 is an example of an end voltage measurement unit.

Then, the second voltage measurement unit 32 measures the voltage between two adjacent input terminals. Specifically, the second voltage measurement unit 32 measures the following voltages V4a to V4g.
The second voltage measurement unit 32 measures a voltage V4a between the positive electrode of the battery cell 10A and the negative electrode of the battery cell 10A. The voltage V4a is an input / output voltage of the battery cell 10A that does not include a voltage drop caused by the bus bar 20.
The second voltage measurement unit 32 measures a voltage V4b between the negative electrode of the battery cell 10A and the negative electrode of the battery cell 10B. The voltage V4b is an input / output voltage of the battery cell 10B including a voltage drop caused by the bus bar 20A. The second voltage measurement unit 32 measures a voltage V4c between the negative electrode of the battery cell 10B and the negative electrode of the battery cell 10C. The voltage V4c is input / output power of the battery cell 10C including a voltage drop caused by the bus bar 20B. The second voltage measurement unit 32 measures a voltage V4d between the negative electrode of the battery cell 10C and the negative electrode of the battery cell 10D. The voltage V4d is an input / output voltage of the battery cell 10D including a voltage drop caused by the bus bar 20C. In addition, the second voltage measurement unit 32 measures a voltage V4e between the negative electrode of the battery cell 10D and the negative electrode of the battery cell 10E. The voltage V4e is input / output power of the battery cell 10E including a voltage drop caused by the bus bar 20D. The second voltage measurement unit 32 measures a voltage V4f between the negative electrode of the battery cell 10E and the negative electrode of the battery cell 10F. The voltage V4f is an input / output voltage of the battery cell 10F including a voltage drop caused by the bus bar 20E. The second voltage measuring unit 32 measures a voltage V4g between the negative electrode of the battery cell 10F and the negative electrode of the battery cell 10G. The voltage V4g is input / output power of the battery cell 10G including a voltage drop caused by the bus bar 20F.

Next, the cell battery monitoring operation by the CMU 30 according to the present embodiment will be described.
FIG. 8 is a first flowchart showing the operation of the CMU 30 according to the fourth embodiment. FIG. 9 is a second flowchart showing the operation of the CMU 30 according to the fourth embodiment.
When the CMU 30 starts the cell battery monitoring operation, the first voltage measurement unit 31 measures the voltage V3a between the positive electrode of the battery cell 10A and the positive electrode of the battery cell 10B. Further, the second voltage measuring unit 32 measures the voltage V4a between the positive electrode of the battery cell 10A and the negative electrode of the battery cell 10A (step S201). At this time, the current measuring unit 33 measures the current flowing through the battery cell 10 (step S202). The first voltage measuring unit 31, the second voltage measuring unit 32, and the current measuring unit 33 output the measured voltage values V3a and V4a and the current value I to the CPU 34.

  The CPU 34 specifies the voltage V4a measured by the second voltage measuring unit 32 as the input / output voltage of the battery cell 10A (step S203). Next, the CPU 34 subtracts the voltage V4a from the voltage V3a measured by the first voltage measuring unit 31, thereby specifying a voltage drop due to the bus bar 20A (step S204). Next, the CPU 34 specifies the contact resistance Ra between the bus bar 20A and the battery cell 10A by dividing the voltage drop caused by the bus bar 20A by the value of the current measured by the current measuring unit 33 (step S205).

  Next, the CPU 34 outputs, to the first voltage measuring unit 31 and the second voltage measuring unit 32, a signal for changing the battery cell 10 that is a voltage measurement target to the next battery cell 10 (step). S206). Thereby, the 1st voltage measurement part 31 and the 2nd voltage measurement part 32 switch the voltage measurement object to the following battery cell 10, and measure the voltage of the said battery cell 10 (step S207). Specifically, the first voltage measuring unit 31 measures the voltage V3b when measuring the voltage V3a last time. Similarly, the second voltage measurement unit 32 measures the voltage V4b when measuring the voltage V4a last time. At this time, the current measuring unit 33 measures the current flowing through the battery cell 10 (step S208). The first voltage measuring unit 31, the second voltage measuring unit 32, and the current measuring unit 33 output the measured voltage value and current value I to the CPU.

  The CPU 34 specifies the input / output voltage of the battery cell 10 to be measured by subtracting the voltage drop of the bus bar 20 specified last time from the voltage measured by the second voltage measuring unit 32 (step S209). Next, the CPU 34 subtracts the input / output voltage specified in step S209 from the voltage measured by the first voltage measurement unit 31, thereby the voltage by the bus bar 20 connected to the negative electrode side of the battery cell 10 to be measured. A descent is specified (step S210). Next, the CPU 34 divides the identified voltage drop by the value of the current measured by the current measuring unit 33 in step S <b> 8, so that the bus bar connected to the measurement target battery cell 10 and the negative electrode side of the battery cell 10. The contact resistance with 20 is specified (step S211).

  Next, the CPU 34 determines whether or not the voltage to the battery cell 10F and the bus bar 20E has been specified (step S212). CPU34 returns to step S206, when it determines with the thing which has not specified the voltage among the battery cells 10 and the bus-bar 20 to the battery cell 10F and the bus-bar 20E (step S212: NO), and is set as the voltage measurement object. The battery cell 10 to be changed is changed to the next battery cell 10.

  On the other hand, when it determines with CPU34 having specified the voltage to the battery cell 10F and the bus-bar 20F (step S212: YES), the 1st voltage measurement part 31 is between the positive electrode of the battery cell 10G, and the negative electrode of the battery cell 10G. The voltage V3g of is measured. Further, the second voltage measuring unit 32 measures the voltage V4g between the negative electrode of the battery cell 10F and the negative electrode of the battery cell 10G (step S213). At this time, the current measuring unit 33 measures the current flowing through the battery cell 10 (step S214). The first voltage measuring unit 31, the second voltage measuring unit 32, and the current measuring unit 33 output the measured voltage values V3g and V4g and the current value I to the CPU 34.

  The CPU 34 specifies the voltage V3g measured by the second voltage measuring unit 32 as the input / output voltage of the battery cell 10G (step S215). Next, the CPU 34 specifies again the voltage drop caused by the bus bar 20F by subtracting the voltage V3g from the voltage V4g measured by the first voltage measuring unit 31 (step S216). Next, the CPU 34 again specifies the contact resistance Rf between the bus bar 20F and the battery cell 10G by dividing the voltage drop by the bus bar 20F by the value of the current measured by the current measuring unit 33 (step S217).

  Next, the CPU 34 outputs the voltage of the battery cell 10 and the contact resistance of the bus bar 20 to the BMU via the interface 37. Next, the CPU 34 determines whether any of the contact resistances specified in step S205 and step S211 exceed a predetermined threshold (step S218). If it is determined that there is a contact resistance exceeding the threshold (step S218: YES), the CPU 34 determines that an abnormality has occurred in the connection between the battery cell 10 and the bus bar 20, and notifies the BMU of the occurrence of the abnormality ( Step S219). The notification of the occurrence of an abnormality is an example of an abnormality detection operation. In another embodiment, the CPU 34 may execute an abnormality detection operation such as, for example, stopping the output of all the battery cells 10.

  When the CPU 34 determines that there is no contact resistance exceeding the threshold (step S218: NO), or when the abnormality detection operation is executed in step S215, the monitoring process at the timing ends. The CMU 30 may autonomously execute the monitoring process again after a predetermined time has elapsed, or may execute the monitoring process again in accordance with an instruction from the BMU.

As described above, the CMU 30 according to this embodiment uses the voltage measurement unit that accurately measures the voltage within the range of voltages that the battery cell 10 can take, as in the first embodiment. In addition, the voltage drop caused by the bus bar 20 can be accurately calculated. Further, the CMU 30 according to the present embodiment can determine whether or not there is a contact abnormality between the battery cell 10 and the bus bar 20 based on the specified voltage drop.
In particular, the first voltage measurement unit 31 and the second voltage measurement unit 32 measure the voltage at the same time in synchronization with each other, so that the voltage drop caused by the bus bar 20 can be accurately performed regardless of whether or not the current I varies. Can be identified well.

As described above, the embodiment has been described in detail with reference to the drawings. However, the specific configuration is not limited to that described above, and various design changes and the like can be made.
For example, in the above-described embodiment, the case where the voltage is measured using the two multiplexers of the first voltage measuring unit 31 and the second voltage measuring unit 32 is described, but the present invention is not limited to this. For example, the voltage may be measured by providing a voltmeter corresponding to each voltage. For example, the voltage may be measured using a single multiplexer having the functions of both the first voltage measuring unit 31 and the second voltage measuring unit 32. On the other hand, as in the above-described embodiment, by using two multiplexers, the CMU 30 can easily switch input terminals and can use a conventional multiplexer having the number of battery cells 10 plus one input terminal. The effect that can be obtained.

Moreover, although embodiment mentioned above demonstrated the case where the battery module 1 was equipped with seven battery cells 10, it is not restricted to this. In other embodiments, the number of battery cells 10 may be 8 or more, or 6 or less.
FIG. 10 is a diagram illustrating wiring between the battery cell 10 and the CMU 30 when the battery module 1 includes four battery cells 10. For example, as shown in FIG. 9, the number of battery cells 10 may be an even number such as four. When the number of battery cells 10 is an even number, the first voltage measurement unit 31 is connected to the negative electrode of the battery cell 10 provided at the end on the negative electrode side.

  Moreover, although embodiment mentioned above demonstrated the case where CPU34 of CMU30 calculated the voltage drop and resistance value of the bus-bar 20, it is not restricted to this. For example, a BMU that has acquired information on each voltage from the CMU 30 or its upper control apparatus may perform the calculation.

In other words, according to the above-described embodiment, the first voltage measurement unit 31 and the second voltage measurement unit 32 include a battery cell including a voltage drop due to the bus bar 20 connected to at least one of the positive electrode and the negative electrode of the battery cell 10. The voltage of 10 and the voltage of the battery cell 10 not including the voltage drop are measured.
Thereby, CMU30 can measure a voltage correctly using the voltage measurement part which measures a voltage correctly within the range of the voltage which the battery cell 10 can take. Furthermore, since the voltage drop due to the bus bar 20 can be specified based on the voltage difference between the voltage measured by the first voltage measuring unit 31 and the voltage measured by the second voltage measuring unit 32, the CMU 30 It is possible to provide accurate information to be used for the calculation of the voltage drop by the 10 voltages and the power line.

  In at least one embodiment, the auxiliary storage device 36 is an example of a tangible medium that is not temporary. As another example of the tangible medium that is not temporary, a semiconductor memory connected via the interface 37 can be cited. When this program is distributed from the BMU or the like to the CMU 30 via a communication line, the CMU 30 that has received the distribution may develop the program in the main storage device 35 and execute the above processing.

  The program may be for realizing a part of the functions described above. Further, the program may be a so-called difference file (difference program) that realizes the above-described function in combination with another program already stored in the auxiliary storage device 36.

  DESCRIPTION OF SYMBOLS 1 ... Battery module 2 ... Housing 3 ... External output terminal 10 ... Battery cell 20 ... Bus bar 30 ... CMU 31 ... 1st voltage measurement part 32 ... 2nd voltage measurement part 33 ... Current measurement part 34 ... CPU 35 ... Main Storage device 36 ... Auxiliary storage device 37 ... Interface

Claims (20)

A battery monitoring circuit for monitoring a plurality of batteries connected in series via a power line,
A battery monitoring circuit comprising a voltage measuring unit that measures a voltage not including a voltage drop due to the power line and a voltage including a voltage drop due to the power line for each battery. Based on the voltage difference between the voltage of the battery not including the voltage drop due to the power line and the voltage of the battery including the voltage drop due to the power line measured by the voltage measurement unit, the battery was connected to the battery The battery monitoring circuit according to claim 1, further comprising a voltage drop specifying unit that specifies a physical quantity related to a voltage drop by the power line. The previous voltage measurement unit measures, for each battery, a voltage that does not include a voltage drop due to the power line and a voltage that includes a voltage drop due to the power line connected to at least one electrode terminal of the battery. The battery monitoring circuit according to 2. The voltage drop specifying unit specifies a contact resistance between the electrode terminal and the power line, which is a physical quantity related to a voltage drop by the power line, by dividing the voltage difference by a current flowing through the battery. The battery monitoring circuit described in 1. A current measuring unit for measuring a current flowing through the battery using a resistance value given in advance as a contact resistance between the electrode terminal and the power line;
The battery monitoring circuit according to claim 4, wherein the voltage drop specifying unit specifies a contact resistance between the electrode terminal and the power line using the current measured by the current measuring unit. A current measuring unit that measures the current flowing through the battery using the voltage characteristics of each battery;
The battery monitoring circuit according to claim 4, wherein the voltage drop specifying unit specifies a contact resistance between the electrode terminal and the power line using the current measured by the current measuring unit. A contact abnormality determining unit that determines that there is an abnormality in contact between the battery and the power line when an absolute value of a physical quantity related to a voltage drop specified by the voltage drop specifying unit exceeds a predetermined threshold. The battery monitoring circuit according to any one of claims 3 to 6. The battery monitoring circuit according to claim 7, further comprising: a contact abnormality processing unit that performs a predetermined abnormality detection operation when the contact abnormality determination unit determines that there is an abnormality in contact between the battery and the power line. . The battery monitoring circuit according to any one of claims 1 to 8, further comprising: an end voltage measuring unit that measures a voltage of the battery provided at the series end. The said end voltage measurement part measures the voltage of the said battery including the voltage drop by the contact resistance of the said external output terminal via the external output terminal connected to the battery provided in the said series end. The battery monitoring circuit described in 1. The voltage difference between the voltage of the battery provided at the series end measured by the voltage measurement unit and the voltage of the battery including the voltage drop due to the contact resistance of the external output terminal measured by the end voltage measurement unit. The battery monitoring circuit according to claim 10, further comprising: a contact resistance specifying unit that specifies a physical quantity related to a voltage drop due to the contact resistance of the external output terminal. The voltage drop specifying unit multiplies the voltage difference by a current flowing through the battery to calculate power consumption in the electrode terminal and the power line, which is a physical quantity related to a voltage drop by the power line, and to calculate a heat generation amount. The battery monitoring circuit according to claim 3 to be specified. A current measuring unit for measuring a current flowing through the battery using a resistance value given in advance as a contact resistance between the electrode terminal and the power line;
The battery monitoring circuit according to claim 12, wherein the voltage drop specifying unit specifies a heat generation amount by calculating power consumption in the electrode terminal and the power line using the current measured by the current measuring unit. A current measuring unit that measures the current flowing through the battery using the voltage characteristics of each battery;
The battery monitoring circuit according to claim 12, wherein the voltage drop specifying unit specifies a heat generation amount by calculating power consumption in the electrode terminal and the power line using the current measured by the current measuring unit. The voltage measurement unit includes a first voltage measurement unit and a second voltage measurement unit,
The first voltage measuring unit includes a voltage not including a voltage drop due to the power line and a battery positioned at the one end for each battery connected to an odd number of batteries counted from the battery positioned at one end of the series connection. For each of the batteries connected to the even number, the voltage including a voltage drop due to the power line connected to at least one electrode terminal of the battery is measured.
The second voltage measuring unit includes a voltage not including a voltage drop due to the power line and a battery positioned at the one end for each battery connected to an even number of cells counted from the battery positioned at the one end. The voltage including a voltage drop by the power line connected to at least one electrode terminal of the battery is measured for each battery connected to the odd number. The battery monitoring circuit according to item. The voltage measurement unit includes a first voltage measurement unit and a second voltage measurement unit,
The first voltage measurement unit is configured to measure a voltage of each battery including a voltage drop caused by a power line connected to a negative electrode side of the battery via a wiring connected to a positive electrode terminal of the battery. Measure and
The second voltage measurement unit is configured to measure a voltage of each battery including a voltage drop caused by a power line connected to a positive electrode side of the battery via a wiring connected to a negative electrode terminal of the battery. taking measurement,
The battery monitoring circuit according to any one of claims 1 to 14. A voltage difference between the battery voltage measured by the first voltage measurement unit and the battery voltage measured by the second voltage measurement unit when a current flowing through the battery is equal to or less than a predetermined threshold value. The battery monitoring circuit according to claim 15 or 16, further comprising a measurement abnormality determining unit that determines that there is an abnormality in the first voltage measuring unit or the second voltage measuring unit when a predetermined threshold is exceeded. . 18. A measurement abnormality processing unit that executes a predetermined abnormality detection operation when the measurement abnormality determination unit determines that there is an abnormality in the first voltage measurement unit or the second voltage measurement unit. The battery monitoring circuit described in 1. A plurality of batteries connected in series via a power line;
A battery module comprising: the battery monitoring circuit according to any one of claims 1 to 18. A battery monitoring circuit for monitoring a plurality of batteries connected in series via a power line,
A first voltage measuring unit for measuring a voltage of the battery including a voltage drop caused by a power line connected to at least one of the positive electrode and the negative electrode of the battery;
A second voltage measuring unit for measuring the voltage of the battery not including a voltage drop included in the voltage measured by the first voltage measuring unit;
A battery monitoring circuit comprising: a voltage drop specifying unit that specifies a voltage drop caused by the power line based on a voltage difference between the voltage measured by the first voltage measuring unit and the voltage measured by the second voltage measuring unit.

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