JP2023010707A - Battery monitoring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To assign IDs to each voltage monitor in a predetermined order when the communication between a battery ECU and each voltage monitor is wireless.

SOLUTION: A battery monitoring device 51 which includes a battery ECU 10 and a voltage monitor 20 monitors a plurality of unit batteries 63 included in an assembled battery 60 mounted on a vehicle. The battery ECU 10 wirelessly transmits a command. The voltage monitor 20 is installed in each battery block 62 in which a plurality of unit batteries 63 are grouped, detects voltage information of the unit batteries 63, and wirelessly transmits the voltage information to the battery ECU 10. The battery monitoring device 51 is provided with a monitor activation device 10, 20 that activates each voltage monitor 20 in a predetermined order recognized by the battery ECU 10 with a time lag. Each of the voltage monitors 20 wirelessly communicates with the battery ECU 10 in order of being activated so as to have an ID assigned.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2023,JPO&INPIT

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voltage monitoring device that monitors a plurality of unit cells of an assembled battery mounted on a vehicle.

Some voltage monitoring devices have a battery ECU and a plurality of voltage monitors connected to the battery ECU via communication lines. The battery ECU transmits commands to the voltage monitor through the communication line. The voltage monitor is installed for each battery block in which a plurality of unit batteries are grouped, detects voltage information of the unit batteries, and transmits the voltage information to the battery ECU via a communication line. As a document disclosing such a technique, for example, there is Patent Document 1 shown below.

Japanese Patent No. 5168176

In recent years, the electric power used in vehicles tends to increase. Therefore, the number of unit cells included in the assembled battery tends to increase, and accordingly the number of battery blocks and the number of voltage monitors corresponding to them tend to increase. Therefore, the number of communication lines connecting the battery ECU and each voltage monitor also increases. As a countermeasure, it has been proposed to perform wireless communication between the battery ECU and the voltage monitor.

In communicating between the battery ECU and each voltage monitor, the battery ECU needs to recognize which battery block the voltage detection value transmitted from each voltage monitor corresponds to. Therefore, it is necessary to allocate an ID to each voltage monitor in a predetermined order, for example, in order from those corresponding to low-potential battery blocks or from those corresponding to high-potential battery blocks.

In this regard, in a wired battery monitoring device equipped with a communication line, for example, a plurality of voltage monitors are connected in series by a communication line in a predetermined order, and the voltage monitors at both ends of the battery ECU are connected by a communication line in a cascade connection. can take the configuration of In that case, IDs can be assigned to the respective voltage monitors in a predetermined order by assigning the IDs in the order of communication.

However, when wireless communication is used, such a cascade connection configuration cannot be used, so it is necessary to assign an ID to each voltage monitor in a predetermined order by means different from this.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is mainly directed to assigning an ID to each voltage monitor in a predetermined order when the communication between the battery ECU and each voltage monitor is wireless. aim.

A battery monitoring device according to the present invention is a device for monitoring a plurality of unit batteries included in an assembled battery mounted on a vehicle. wherein the battery ECU wirelessly transmits a command to the voltage monitor, and the voltage monitor detects voltage information of the unit battery and wirelessly transmits it to the battery ECU , the battery ECU and each of the voltage monitors are connected to each other by wiring, and when each of the voltage monitors receives a signal from the battery ECU via each of the wirings, the voltage monitor wirelessly communicates with the battery ECU. ID is assigned by the battery ECU.

According to the present invention, the battery ECU can allocate an ID to each voltage monitor in a predetermined order.

1 is a circuit diagram showing a battery monitoring device according to a first embodiment; FIG. Flowchart showing ID allocation for each voltage monitor A circuit diagram showing a battery monitoring device of a second embodiment A graph showing the output voltage of each signal output port Flowchart showing ID allocation for each voltage monitor Circuit diagram showing the battery monitoring device of the third embodiment Flowchart showing ID allocation for each voltage monitor

Next, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the embodiments, and can be modified as appropriate without departing from the gist of the invention.

[First embodiment]
FIG. 1 is a circuit diagram showing a battery monitoring device 51 and its surroundings according to the first embodiment. The vehicle is equipped with an assembled battery 60, a battery monitoring device 51, an auxiliary battery 67, etc., in addition to a driving power unit.

The assembled battery 60 has a plurality of unit batteries 63 connected in series. The plurality of unit batteries 63 are grouped into a plurality of battery blocks 62 . The battery monitoring device 51 has a battery ECU 10 and a plurality of voltage monitors 20, and is further provided with a power supply line 31, a plurality of power lines 33, and a plurality of detection lines 39. FIG.

The battery ECU 10 has a power supply unit 11, an MCU 13, and a parent device 16, and is further provided with a power supply port 10a, a plurality of power output ports 10b1 to 10bN, electrical wiring α, and communication wiring β. The base unit 16 has an antenna 16b. Each voltage monitor 20 has a monitoring IC 23 and a slave device 26, and is further provided with a power input port 20a, a plurality of detection ports 20d, electrical wiring α, communication wiring β, and detection wiring δ. The handset 26 has an antenna 26b. The parent device 16 and the child device 26 constitute a wireless device.

Next, each member etc. which were shown above are demonstrated. The power unit of the vehicle may be an engine, a motor, or a combination of both (hybrid). Each unit battery 63 may be a single cell battery, or may be a series connection body of cell batteries. The cell battery is a lithium battery in this embodiment, but may be another battery. A voltage monitor 20 is provided for each battery block 62 .

An auxiliary battery 67 is connected to the power port 10 a of the battery ECU 10 via a power line 31 . The power supply unit 11 is connected to the power supply port 10a, the MCU 13, and the parent device 16 by an electric wiring α. The power supply unit 11 includes a power supply switch. The power supply switch of the power supply unit 11 is turned on in conjunction with turning on the power switch of the vehicle (starting switch of the power unit), and is turned off in conjunction with that when the power switch of the vehicle is turned off. The power supply unit 11 does not supply power to the MCU 13 and the parent device 16 while the power supply switch is OFF. On the other hand, when the power supply switch is turned on, the power supply unit 11 supplies power supplied from the auxiliary battery 67 to the MCU 13 and the parent device 16 . Thereby, the battery ECU 10 is activated.

The MCU 13 issues commands and the like to the monitoring IC 23 . The command includes a command to acquire voltage information of the unit battery 63, a command to discharge the unit battery 63, and the like. The MCU 13 and the parent device 16 are communicably connected by a communication wiring β. The MCU 13 transmits a command or the like for the monitoring IC 23 to the parent device 16 through the communication wiring β. On the other hand, the parent device 16 transmits the voltage information and the like wirelessly received from the child device 26 to the MCU 13 through the communication wiring β.

In this embodiment, the MCU 13 constitutes a monitor activation device that sequentially activates the voltage monitors 20 with a time lag. The MCU 30 is connected to each of the power output ports 10b1 to 10bN by electrical wiring α.

The power output ports 10b1-10bN of the battery ECU 10 are connected to the power input ports 20a of the respective voltage monitors 20 via power lines 33. FIG. Specifically, the first power output port 10b1 is connected to the power input port 20a of the voltage monitor 20 corresponding to the battery block 62 with the lowest potential. The second power output port 10b2 is connected to the power input port 20a of the voltage monitor 20 corresponding to the battery block 62 with the second lowest potential. Similarly, the lower power output ports are sequentially connected to the power input ports 20a of the voltage monitor 20 corresponding to the battery block 62 on the low potential side. The MCU 30 then starts supplying power to the lower power output ports in order. Therefore, each voltage monitor 20 can be activated in order from the one corresponding to the low potential battery block 62 . Then, the master device 16 recognizes that each voltage monitor 20 is activated in order from the voltage monitor 20 corresponding to the battery block 62 with the low potential.

A power input port 20a of the voltage monitor 20 is connected to the monitoring IC 23 and the child device 26 by an electric wiring α. When power is supplied to the power input port 20a, the voltage monitor 20 is activated by supplying power to the monitoring IC 23 and slave device 26 .

The monitor IC 23 has a multiplexer. The multiplexer is connected to each detection port 20d by a detection wire δ. The plurality of detection ports 20 d are connected by detection lines 39 between both ends of the battery block 62 and respective terminals of the plurality of unit batteries 63 forming the battery block 62 . The multiplexer can sequentially detect voltage information between terminals of each unit battery 63 . The voltage information may be an actual voltage value, or may be information that can be converted into a voltage value, such as a current value flowing through a predetermined portion. The multiplexer can discharge each unit battery 63 as needed. Therefore, a balancing process can be performed to equalize the state of charge of each unit battery 63 .

The monitoring IC 23 and the slave device 26 are communicably connected by a communication wiring β. The child device 26 transmits commands and the like wirelessly received from the parent device 16 to the monitoring IC 23 through the communication wiring β. On the other hand, the monitoring IC 23 transmits voltage information and the like to the slave device 26 via the communication wiring β.

When a wireless communication connection is established between the parent device 16 and each child device 26, the parent device 16 wirelessly transmits a command or the like from the MCU 13 to each child device 26, and the child device 26 transmits voltage information or the like to the child device 26. 16 will be wirelessly transmitted.

FIG. 2 is a flow chart showing ID allocation for each voltage monitor 20. As shown in FIG. When the power switch of the vehicle is turned on, the battery ECU 10 is activated (S101). Next, the battery ECU 10 starts supplying power through the power line 33 to the battery block 62 with the lowest potential among the voltage monitors 20 that are not activated (S102). This activates the voltage monitor 20 (S103).

Next, the child device 26 of the voltage monitor 20 wirelessly communicates with the parent device 16 to establish a communication connection (S104). At this time, the parent device 16 assigns the lowest ID among the IDs that have not yet been assigned to the child device 26 that establishes the communication connection (S105). Next, the MCU 13 determines whether or not there is a voltage monitor 20 that has not yet started (S106). If it is determined that there is a voltage monitor 20 that has not yet started (S106: YES), the process returns to S102, and the voltage monitor 20 that has the lowest potential of the corresponding battery block 62 among the voltage monitors 20 that have not yet started is Then, power supply through the power line 33 is started (S102). Then, the control of S103 to S106 is similarly performed. On the other hand, when it is determined in S106 that all the voltage monitors 20 are activated (S106: NO), assignment of IDs to each voltage monitor 20 ends.

Specifically, starting power supply to the lowest voltage monitor 20 in S102 can be performed by starting power supply to the lowest power output port 10b1 that has not yet started power supply. . Further, the determination of whether or not there is a voltage monitor 20 that has not yet started in S106 is performed by, for example, one of the power output ports 10b1 to 10bN to which the power line 33 is connected that has not yet started supplying power. It can be done by determining whether or not there is. In S102 to S106, in this way, the child device 26 of the activated voltage monitor 20 and the parent device 16 wirelessly communicate to establish a communication connection (S102 to S104), and an ID is assigned to the child device 26 ( S105) After that, the next voltage monitor 20 is activated (S102).

According to this embodiment, the following effects are obtained. A plurality of voltage monitors 20 are activated in order from the battery block 62 corresponding to the battery block 62 having a low potential, and the child device 26 of the activated voltage monitor 20 communicates with the parent device 16 in order, and an ID is assigned. Therefore, an ID can be assigned to each child device 26 of each voltage monitor 20 in descending order of the corresponding battery block 62 having a low potential. Further, the battery ECU 10 itself sequentially supplies power to each of the plurality of voltage monitors 20, so that each voltage monitor 20 can be activated in sequence with a simple configuration.

[Second embodiment]
Next, a battery monitoring device 52 according to a second embodiment of the invention will be described. In the following embodiments, members that are the same as or correspond to those in the previous embodiments are denoted by the same reference numerals. However, the battery monitoring device itself is given a different code for each embodiment. This embodiment will be described based on the first embodiment, focusing on the differences therefrom.

FIG. 3 is a circuit diagram showing the battery monitoring device 52 of the second embodiment. The battery monitoring device 52 includes a plurality of signal lines 35 and a plurality of power lines 38 instead of the plurality of power lines 33 . The battery ECU 10 is provided with a plurality of signal output ports 10c1-10cN instead of the plurality of power output ports 10b1-10bN. Further, the battery ECU 10 is provided with a signal wiring γ instead of a part of the electric wiring α. The voltage monitor 20 is provided with a power port 20A and a signal input port 20b instead of the power input port 20a. Also, the voltage monitor 20 is provided with a power feeding section 21 .

Next, each member etc. which were shown above are demonstrated. The signal wiring γ and the signal line 35 are conductors. The signal wiring γ and the signal line 35 transmit activation signals, but do not transmit commands and voltage values. The MCU 13 is connected to each of the signal output ports 10c1 to 10cN by signal wiring γ. The signal output ports 10c1-10cN of the battery ECU 10 are connected to the signal input ports 20b of the respective voltage monitors 20 via signal lines 35. FIG. Specifically, the first signal output port 10c1 is connected to the signal input port 20b of the voltage monitor 20 corresponding to the battery block 62 with the lowest potential. The second signal output port 10c2 is connected to the signal input port 20b of the voltage monitor 20 corresponding to the battery block 62 having the second lowest potential. Similarly, the lower signal output ports are sequentially connected to the signal input port 20b of the voltage monitor 20 corresponding to the battery block 62 on the low potential side. Then, the MCU 30 transmits activation signals in order from the lower signal output port.

The power supply portion 21 of the voltage monitor 20 is connected to the signal input port 20b through the signal wiring γ, and is connected to the power supply port 20A through the electric wiring α. The power port 20A is connected to the assembled battery 60 by the power line 38 .

The power supply unit 21 has a power supply switch, and the power supply switch is turned off while the start signal is not received, and turned on when the start signal is received. The power supply unit 21 does not supply power to the monitoring IC 23 and slave device 26 while the power supply switch is OFF. On the other hand, when the power supply switch is turned on, the power supply unit 21 supplies power supplied from the unit battery 63 to the monitoring IC 23 and the slave device 26 . This activates the voltage monitor 20 . Specifically, each power supply unit 21 acquires power from the unit battery 63 of the battery block 62 corresponding to the voltage monitor 20 to which it belongs.

FIG. 4 is a graph showing output voltages output from the signal output ports 10c1 to 10cN. The output voltages of the signal output ports 10c1 to 10cN are lowered in order from the lowest, ie, the first signal output port 10c1, the second signal output port 10c2, . The voltage Lo is switched to the high voltage Hi. This high voltage Hi serves as a start signal.

FIG. 5 is a flow chart showing ID allocation to each voltage monitor 20. As shown in FIG. When the power switch of the vehicle is turned on, the battery ECU 10 is activated (S201). Next, the battery ECU 10 transmits an activation signal via the signal line 35 to the voltage monitor 20 that has not been activated and whose corresponding battery block 62 has the lowest potential (S202). This activates the voltage monitor 20 (S203).

Next, the child device 26 of the voltage monitor 20 wirelessly communicates with the parent device 16 to establish a communication connection (S204). At this time, the parent device 16 assigns the lowest ID among the IDs that have not yet been assigned to the child device 26 that establishes the communication connection (S205). Next, it is determined whether or not there is a voltage monitor 20 that has not yet started (S206). If it is determined that there is a voltage monitor 20 that has not yet started (S206: YES), the process returns to S202, and the voltage monitor 20 that has the lowest potential of the corresponding battery block 62 among the voltage monitors 20 that have not yet started is Then, an activation signal is transmitted through the signal line 35 (S202). Then, the control of S203 to S206 is similarly performed. On the other hand, when it is determined in S206 that all the voltage monitors 20 are activated (S206: NO), assignment of IDs to each voltage monitor 20 ends.

Specifically, the transmission of the activation signal to the lowest voltage monitor 20 in S202 is performed by switching the output voltage of the lowest power output port, whose output voltage is the low voltage Lo, to the high voltage Hi. can be done. Further, the determination of whether or not there is a voltage monitor 20 that has not yet started in S206 is performed, for example, by the signal output ports 10c1 to 10cN to which the signal line 35 is connected whose output voltage is the low voltage Lo. This can be done by determining whether there is

According to this embodiment, the following effects are obtained. Since the battery ECU 10 only sends an activation signal through the signal line 35 and does not send power, it is permissible for the signal line 35 to have a larger electrical resistance than the power line 33 of the first embodiment. Therefore, it is possible to make the signal line 35 thinner than the power line 33 of the first embodiment. Further, since the signal line 35 does not transmit commands, voltage values, etc., but only transmits the high voltage Hi as an activation signal, the signal line 35 may be a simple conducting wire. Therefore, the wiring can be simplified as compared with the case where the battery ECU 10 and the voltage monitor 20 are connected by a general communication line.

Moreover, since the battery ECU 10 only sends a start signal and does not send electric power, the battery ECU 10 does not need to be provided with a circuit for supplying electric power to each voltage monitor 20 . Therefore, the circuit scale of the battery ECU 10 can be suppressed. In addition, since each voltage monitor 20 is supplied with power from the unit battery 63 that detects voltage, power can be ensured with a simple configuration.

[Third embodiment]
FIG. 6 is a circuit diagram showing the battery monitoring device 53 of the third embodiment. This embodiment will be described based on the second embodiment, focusing on the differences therefrom. The battery monitoring device 53 includes one signal line 35 and multiple connection lines 36 instead of the multiple signal lines 35 . The battery ECU 10 is provided with one signal output port 10c instead of the plurality of signal output ports 10c1 to 10cN. Each voltage monitor 20 is also provided with a signal output port 20c.

Next, each member etc. which were shown above are demonstrated. The signal output port 10c of the battery ECU 10 is connected by a signal line 35 to the signal input port 20b of the voltage monitor 20 (predetermined voltage monitor) corresponding to the battery block 62 with the lowest potential. The child device 26 is connected to the signal output port 20c by a signal wiring γ. The signal output port 20c of each voltage monitor 20 is connected by a connection line 36 to the signal input port 20b of the voltage monitor 20 corresponding to the battery block 62 one level higher than the battery block 62 corresponding to the voltage monitor 20 in question. ing. Thereby, a plurality of voltage monitors 20 are connected in series. The connection line 36 is a conducting wire. The connection line 36 may be the same conductor as the signal line 35, or may be a different conductor. In this embodiment, the MCU 13 and slave device 26 constitute a monitor activation device that sequentially activates each voltage monitor 20 with a time lag.

FIG. 7 is a flow chart showing assignment of IDs to each voltage monitor 20. As shown in FIG. When the power switch is turned ON, the battery ECU 10 is activated (S301). Next, the battery ECU 10 transmits an activation signal to the voltage monitor 20 connected by the signal line 35 (S302). As a result, the voltage monitor 20 corresponding to the battery block 62 with the lowest potential is activated (S303).

Next, the child device 26 of the voltage monitor 20 wirelessly communicates with the parent device 16 to establish a communication connection (S304). At this time, the parent device 16 assigns the lowest ID among the IDs that have not yet been assigned to the child device 26 with which the communication connection is to be established (S305).

Next, if there is a voltage monitor 20 one level higher than the voltage monitor 20, the child device 26 to which the ID is assigned transmits a start signal to the voltage monitor 20 one level higher through the connection line 36 (S306). ). As a result, if there is a voltage monitor 20 one level higher, that voltage monitor 20 is activated (S307). Next, if there is a voltage monitor 20 activated by this, the child device 26 of the voltage monitor 20 transmits a wireless signal to the parent device 16 while keeping the ID-assigned state. Then, it is determined whether or not the master device 16 has received a radio signal from the slave device 26 with no ID (S308).

If the master device 16 receives a wireless signal from the slave device 26 without an ID (S308: YES), the process returns to S304 to establish a communication connection by wirelessly communicating with the slave device 26 without an ID (S304). ). Then, the control from S305 to S308 is repeated. On the other hand, in S308, if the wireless signal is not received from the child device 26 without an ID (S308: NO), the assignment of the ID to each child device 26 ends (S309).

Specifically, in S306, if there is a voltage monitor 20 one level higher than the activated voltage monitor 20, the control of transmitting the activation signal to the higher voltage monitor 20 is, for example, This can be done by the slave unit 26 transmitting an activation signal to the signal output port 20c. In this case, if the connection line 36 is connected to the signal output port 20c, that is, if there is a higher voltage monitor 20, the activation signal will be sent to the higher voltage monitor 20. FIG. On the other hand, if the connection line 36 is not connected to the signal output port 20c, that is, if there is no upper voltage monitor 20, the activation signal will not be sent to the upper voltage monitor 20. FIG.

According to this embodiment, the following effects are obtained. Since the adjacent voltage monitors 20 are connected by the connection line 36, the battery ECU 10 needs to be connected only to one voltage monitor 20. FIG. Therefore, compared to the second embodiment in which the battery ECU 10 and each voltage monitor 20 are connected by the signal line 35, the wiring can be simplified.

Further, even if the number of voltage monitors 20 increases, the number of voltage monitors 20 connected in series only increases. Therefore, it is possible to prevent the occurrence of a situation in which the number of signal output ports 10c becomes insufficient due to an increase in the number of voltage monitors 20 and the situation cannot be handled.

[Other embodiments]
The above embodiment can also be implemented with the following modifications. For example, the parent device 16 is made to recognize that each child device 26 will be activated in order from the voltage monitor 20 corresponding to the high potential battery block 62, and each child device 26 is activated in that order and assigned an ID. good too. Further, for example, a plurality of battery blocks 62 are provided in parallel, and the parent device 16 is made to recognize that each child device 26 is activated in order from the voltage monitor 20 corresponding to the battery block 62 at one end of the row. The machines 26 may be activated in that order and assigned IDs.

Further, for example, in the first embodiment, power may be directly supplied from the power supply unit 11 of the battery ECU 10 to the power output ports 10b1 to 10bN. Then, the MCU 13 may control ON/OFF of the power supply.

Further, for example, a portion that functions as a monitor activation device that activates each voltage monitor 20 may be separated from the MCU 13 and provided outside the battery ECU 10 . Further, for example, in the second or third embodiment, power may be supplied to the power supply section 21 of each voltage monitor 20 from another battery such as the auxiliary battery 67 instead of from the unit battery 63 .

DESCRIPTION OF SYMBOLS 10... Battery ECU, 20... Voltage monitor, 51-53... Battery monitor, 60... Assembled battery, 62... Battery block, 63... Unit battery.

The battery monitoring device of the present invention comprises:
A device for monitoring a plurality of unit batteries of an assembled battery mounted on a vehicle,
a battery ECU; a voltage monitor installed for each battery block obtained by dividing the plurality of unit batteries into groups; A battery monitoring device that wirelessly transmits to a monitor, and the voltage monitor detects voltage information of the unit battery and wirelessly transmits it to the battery ECU,
Each of the voltage monitors is assigned an ID by the battery ECU via wireless communication with the battery ECU in order from the one to which power is supplied,
When the power switch of the vehicle is turned on, the power supply unit is turned on in conjunction with it, and sequentially supplies power to each of the voltage monitors.
The battery monitoring device of the present invention comprises:
A device for monitoring a plurality of unit batteries of an assembled battery mounted on a vehicle,
a battery ECU; and a voltage monitor installed for each battery block into which the unit batteries are grouped, the battery ECU wirelessly transmitting a command to the voltage monitor, and the voltage monitor In a battery monitoring device that detects battery voltage information and wirelessly transmits it to the battery ECU,
Each of the voltage monitors is sequentially activated with a time lag in conjunction with the activation of the battery ECU,
Each of the voltage monitors is assigned an ID by the battery ECU via wireless communication with the battery ECU in order from the activated one.
The battery monitoring device of the present invention comprises:
A device for monitoring a plurality of unit batteries of an assembled battery mounted on a vehicle,
a battery ECU; and a voltage monitor installed for each battery block into which the unit batteries are grouped, the battery ECU wirelessly transmitting a command to the voltage monitor, and the voltage monitor In a battery monitoring device that detects battery voltage information and wirelessly transmits it to the battery ECU,
A monitor activation device is provided for activating each of the voltage monitors with a time lag in a predetermined order recognized by the battery ECU. is assigned.

Claims (6)

A device for monitoring a plurality of unit batteries (63) of an assembled battery (60) mounted on a vehicle,
It has a battery ECU (10) and a voltage monitor (20) installed for each battery block (62) in which the plurality of unit batteries are grouped, and the battery ECU wirelessly transmits a command to the voltage monitor. and the voltage monitor detects the voltage information of the unit battery and wirelessly transmits it to the battery ECU, in the battery monitoring device (51 to 53),
The battery ECU and each voltage monitor are connected to each other by wiring (33, 35), respectively,
A battery monitoring apparatus according to claim 1, wherein each voltage monitor is assigned an ID by the battery ECU through wireless communication with the battery ECU when a signal is received from the battery ECU via each wiring. 2. The battery monitoring apparatus according to claim 1, wherein the battery ECU assigns an ID to each voltage monitor in a predetermined order by transmitting a signal to each of the voltage monitors for each of the wires in a predetermined order. 3. The battery monitoring device according to claim 1, wherein the battery ECU identifies each voltage monitor based on the state of the signal transmitted through each wiring. The battery monitoring device according to any one of claims 1 to 3, wherein the battery ECU is connected to an auxiliary battery (87) via a power supply line (31). 5. The battery monitoring device according to claim 4, wherein the power supply switch for the auxiliary battery is interlocked with a power switch of the vehicle. The battery monitoring device according to any one of claims 1 to 5, wherein said voltage monitor comprises a multiplexer capable of detecting voltage information between terminals of each said unit battery.

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