Battery status detection device

Abstract

Battery condition detection device comprising: a main unit (10) configured to detect a state of a battery assembly (103) in a battery pack (100) in which a plurality of battery assemblies (101, 102, 103, 104, 105) are accommodated, which in turn contain a plurality of battery cells (110) arranged in series, a slave unit (20) configured to detect a state of a battery assembly (101, 102, 104, 105) in the battery pack (100) other than the battery assembly (103) that is a detection target of the master unit (10), and a first communication line (33) connecting the main unit (10) to the slave unit (20), wherein the main unit (10) is connected to a control device (50) configured to control the battery pack (100) via a second communication line (34) separate from the first communication line (33), wherein: the main unit (10) receives a detection result of the slave unit (20) from the slave unit (20) via the first communication line (33); characterized in that the main unit (10) calculates management information based on the detection result of the slave unit (20) and a detection result of the main unit (10) and sends the management information to the control device (50) via the second communication line (34); the management information includes results of a determination as to whether the battery cells (110) of the battery assemblies (101, 102, 103, 104, 105) are in an abnormal state or in a normal state.

Description

The present application claims priority to and incorporates in its entirety Japanese Patent Application No. 2016-187341 filed on Sep. 26, 2016 (published as JP 2018-54 334 A).The present invention relates to a battery state detection deviceTechnologies for detecting the state of batteries in a battery pack are known. Japanese Patent JP 5 621 765 B2 discloses a technique for a battery module including a battery block having a plurality of battery cells, a voltage detection circuit (state detection circuit) for detecting a voltage between terminals of each of the battery cells, and a flexible circuit board in which a voltage detection line for electrically connecting a positive electrode terminal or a negative electrode terminal of each of the battery cells and the voltage detection circuit (state detection circuit) is integrated with a substrate made of a flexible material.US 2011 / 0 101 920 A1 describes a battery system which consists of a plurality of modules with battery cells. A motherboard takes over external system control and data acquisition, while auxiliary boards only acquire state data.WO 2012 / 132 177 A1 describes a battery system having a plurality of modules, which detects an abnormality within the battery system and transmits a corresponding signal to a control unit.A battery state detection device that detects a state of batteries is communicatively connected to, for example, a controller such as a battery electronic control unit (battery ECU) that controls the battery pack. There is a need for a simpler configuration for communication wiring for the battery state detection device. A simpler configuration of the communication wiring can be achieved even if no modification of the communication wiring between the battery state detection device and the controller is required when the number of batteries or the number of stacks in the battery pack varies. In addition, it is desirable to reduce the communication load of the controller.It is an object of the present invention to provide a battery state detection device that can achieve a simpler configuration of communication wiring. It is another object of the present invention to provide a battery state detection apparatus that can reduce the communication load of a controller.This is achieved by the features of the independent claims. The dependent claims describe advantageous embodiments.These and other objects, features and advantages, as well as the technical and industrial significance of the invention, will be apparent from the following detailed description of presently preferred embodiments of the invention with reference to the accompanying drawings.BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 is a view showing an example of the circuit configuration of a battery state detection device according to an embodiment of the present invention FIG. 2 is a plan view schematically showing a configuration of the battery state detection device according to the embodiment. FIG. 3 is a plan view showing an example of a specific configuration of the battery state detection device of the embodiment. FIG. 4 is a flowchart showing an operation of the battery state detection device according to the embodiment. FIG. 5 is a perspective view schematically showing a configuration of a battery state detection device according to a first modification of the embodiment. FIG. 6 is a perspective view showing an example of a specific configuration of the battery state detection device according to the first modification of the embodiment.DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTHereinafter, a battery state detection device according to an embodiment of the present invention will be described with reference to the accompanying drawings. This embodiment does not limit the scope of the invention in any way. Components of the embodiment described below may be replaced by other substantially similar components by those skilled in the art.EmbodimentThe embodiment will be described below with reference to Figs. 1 to 4. The present embodiment relates to a battery state detection device and a battery control device. FIG. 1 is a view showing an example of the circuit configuration of the battery state detection device according to the embodiment. FIG. 2 is a plan view schematically showing a configuration of the battery state detection device according to the embodiment. FIG. 3 is a plan view showing an example of a specific configuration of the battery state detection device of the embodiment.As shown in FIG. 1, the battery state detection device 1 according to the embodiment is disposed in a battery pack 100. The battery state detection device 1 according to this embodiment includes a main unit 10, subunits 20, and a first communication line 33. A battery control device 200 according to this embodiment includes the battery state detection device 1 and a battery ECU 50.The battery pack 100 is installed in a vehicle such as an electric vehicle or a hybrid vehicle as a power source for driving. The battery state detection device 1 detects individual states of stacks 101, 102, 103, 104, and 105 in the battery pack 100. The battery state detection device 1 sends management information based on the results of detection to the battery ECU 50. The battery ECU 50 is a controller for controlling the battery pack 100. The battery ECU 50 controls the battery pack 100 according to the management information obtained from the battery state detection device 1. Examples of the control performed by the battery ECU 50 on the battery pack 100 include, for example, notifying a person in the vehicle of abnormalities in the battery pack 100, and controlling peripheral devices of the battery pack 100, and controlling the operation of the battery pack 100.The battery pack 100 includes a first stack 101, a second stack 102, a third stack 103, a fourth stack 104, a fifth stack 105, and a housing 106 in which the stacks 101, 102, 103, 104, and 105 are accommodated. The stacks 101, 102, 103, 104, and 105 are battery arrays each including a plurality of battery cells 110 arranged in rows. Each battery cell 110 is a secondary battery, such as a lithium ion battery. The battery pack 100 is arranged such that the positive electrode of one battery cell 110 and the negative electrode of a next battery cell 110 are adjacent to each other in rows to form a rectangular parallelepiped shape as a whole in the stacks 101, 102, 103, 104, and 105.The stacks 101, 102, 103, 104, and 105 are arranged in a plurality of rows in the case 106. In other words, the stacks 101, 102, 103, 104, and 105 are arranged in the case 106 in this order with a longitudinal side surface of one stack facing a longitudinal side surface of the next stack. Adjacent stacks are electrically connected to each other. A service plug 108 is disposed between the third stack 103 and the fourth stack 104. The first stack 101 is connected to a positive terminal electrode 109 a, and the fifth stack 105 is connected to a negative terminal electrode 109 b. As shown in FIGS. 1 and 2, bus bar modules 120 are disposed on the stacks 101, 102, 103, 104, and 105. Each busbar module 120 electrically connects the battery cells 110 to each other. Specifically, each bus bar module 120 includes a plurality of bus bars 121. Each bus bar 121 electrically connects electrodes of adjacent battery cells 110 to each other. The bus bars 121 according to this embodiment connect the battery cells 110 in series. In other words, the bus bars 121 connect the positive electrode of one battery cell 110 to the negative electrode of an adjacent battery cell 110. Each bus bar module 120 includes a circuit body connected to the bus bars 121. The circuit body is configured by, for example, a printed circuit body or a flexible printed circuit board (FPC). This configuration allows the battery pack 100 to have a shorter height and a lighter weight. The circuit body includes, for example, voltage detection lines 122 and a thermistor 30.The circuit body of the main unit 10 described later includes, for example, a high voltage circuit 11 and a low voltage circuit 12 as shown in FIG. 1, and the circuit body of the sub-units 20 includes a high voltage circuit 25 and a low voltage circuit 26. In the battery pack 100 according to this embodiment, the five stacks 101, 102, 103, 104, and 105 are connected to each other in series by the connectors 107.The main unit 10 detects the state of a stack within the stacks 101, 102, 103, 104, and 105 arranged in a plurality of rows. The main unit 10 according to this embodiment detects the state of the third stack 103 located at the center of the stacks. The main unit 10 is integrated with the bus bar module 120 of the third stack 103. Electronic parts configuring the main unit 10 are mounted on the bus bar module 120 of the third stack 103, the electronic parts constituting the electric circuit of the main unit 10.The main unit 10 includes the high voltage circuit 11 and the low voltage circuit 12. Specifically, a plurality of voltage detection lines 122 are connected to the high voltage circuit 11. As shown in FIG. 3, the voltage detection lines 122 are connected to the corresponding bus bars 121. The high voltage circuit 11 is electrically connected to the positive electrodes and the negative electrodes of the battery cells 110 via the voltage detection lines 122 and the bus bars 121. The high voltage circuit 11 includes a voltage detector that detects the voltages of the battery cells 110. The high voltage circuit 11 detects cell voltages that are the voltages of the battery cells 110. The high voltage circuit 11 may calculate a sum of the detected cell voltages and perform equalization processing on the cell voltages.As shown in FIG. 1, the low voltage circuit 12 includes a computer 12 a, a first communication interface 12 b, and a second communication interface 12 c. The computer 12a performs various types of calculations. The thermistor 30 is connected to the low voltage circuit 12. The thermistor 30 outputs signals corresponding to the temperatures of the battery cells 110 of the third stack 103. The calculator 12 adetects the temperatures of the battery cells 110 of the third stack 103 based on the signals obtained from the thermistor 30. The low voltage circuit 12 is communicatively connected to the high voltage circuit 11. The calculator 12 adetermines whether an abnormality occurs in the third stack 103 based on the cell voltages or the sum of the cell voltages obtained from the high voltage circuit 11 through communication.The first communication line 33 is connected to the first communication interface 12 b. The computer 12 ais communicatively connected to the low-voltage circuits 26 of the subunits 20 via the first communication interface 12 band the first communication line 33. The second communication line 34 is connected to the second communication interface 12 c. The computer 12 acommunicates with the battery ECU 50 via the second communication interface 12 cand the second communication line 34. The communication protocol for communication over the first communication line 33 may be the same as or different from the communication protocol for communication over the second communication line 34.The subunits 20 are provided on the first stack 101, the second stack 102, the fourth stack 104, and the fifth stack 105, which are stacks other than the stack that is the acquisition target of the main unit 10. The subunits 20 of the stacks 101, 102, 104 and 105 have the same configuration. In this specification, the slave unit 20 that detects a state of the first stack 101 is referred to as a first slave unit 21. Accordingly, the subunits 20 that detect a state of the second stack 102, the fourth stack 104, and the fifth stack 105 are referred to as a second subunit 22, a third subunit 23, and a fourth subunit 24, respectively.The subunits 20 will be described with reference to the first subunit 21 in the first stack 101. The first sub unit 21 detects a state of the first stack 101. The first sub unit 21 is integrated with the bus bar module 120 of the first stack 101. Electronic parts configuring the first sub unit 21 are mounted on the bus bar module 120 of the first stack 101, the electronic parts constituting the electric circuit of the sub unit 20.The first sub unit 21 includes the high voltage circuit 25 and the low voltage circuit 26. the high voltage circuit 25 detects voltages of the battery cells 110 of the first stack 101 that is the detection target of the first sub unit 21. A plurality of voltage detection lines 122 are connected to the high voltage circuit 25. The high voltage circuit 25 is electrically connected to the positive electrodes and the negative electrodes of the battery cells 110 via the voltage detection lines 122. The high voltage circuit 25 includes a voltage detector that detects the voltages of the battery cells 110. The high voltage circuit 25 may calculate a sum of the detected cell voltages and perform equalization processing on the cell voltages.The low voltage circuit 26 includes a computer 26 aand a communication interface 26 b. The thermistor 30 disposed in the first stack 101 is connected to the low voltage circuit 26. The calculator 26 adetects the temperatures of the battery cells 110 of the first stack 101 based on the signals obtained from the thermistor 30. The low voltage circuit 26 is communicatively connected to the high voltage circuit 25.The first communication line 33 is connected to the communication interface 26 b. The computer 26 ais communicatively connected to the low voltage circuit 12 of the main unit 10 via the communication interface 26 band the first communication line 33. The computer 26 amay communicate with the subunits 20 of the other stacks 102, 104, and 105 via the first communication line 33.The calculator 26 aof the first slave unit 21 sends information such as cell voltages or the sum of the cell voltages of the first stack 101 obtained from the high voltage circuit 25 through communication and information such as battery temperatures thereof to the master unit 10.The calculator 12 aof the main unit 10 calculates management information based on the detection results of the subunits 21, 22, 23, and 24 and the detection result of the main unit 10. The management information includes, for example, results of determination as to whether the battery cells 110 of the stacks 101, 102, 103, 104, and 105 are in an abnormal state or in a normal state. The management information includes thermal states of the battery cells 110. The management information includes results of failure determination on the stacks 101, 102, 103, 104, and 105. The calculator 12 atransmits the management information to the battery ECU 50.The battery ECU 50 includes a communication interface 51 and a computer 52. The computer 52 communicates with the main unit 10 via the communication interface 51 and the second communication line 34. the computer 52 acquires the management information from the main unit 10 through communication.The battery ECU 50 is communicatively connected to an inverter 61 and an airbag ECU 62. The inverter 61 is disposed between, for example, the battery pack 100 and the motor of the vehicle. The inverter 61 may convert DC power output from the battery pack 100 to AC power and supply the AC power to the motor, and may convert AC power from the motor to DC power and supply the DC power to the battery pack 100. The battery ECU 50 communicates with the inverter 61 according to a command output from, for example, a vehicle control ECU installed in the vehicle. Specifically, the inverter 61 includes an inverter ECU that controls the inverter 61. The inverter ECU causes the inverter 61 to operate according to a command from the battery ECU 50. The computer 52 transmits a state of the battery pack 100, i.e., information on whether the battery pack 100 is normally operated, to the airbag ECU 62, for example.The battery ECU 50 is connected to a blower motor 63, an intake air temperature sensor 64, and a current sensor 65. The blower motor 63 is a motor that sends cooling air to the battery pack 100. The intake air temperature sensor 64 is a sensor that detects an intake air temperature of the blower motor 63. The current sensor 65 is a sensor that detects an input current and an output current to and from the battery pack 100. The computer 52 controls the blower motor 63 in accordance with the detection result of the intake air temperature sensor 64 and the thermal states of the battery cells 110 obtained from the main unit 10. The calculator 52 calculates the remaining charge of the battery pack 100 based on the detection result of the current sensor 65.The battery ECU 50 is connected to relays 53. The relays 53 connect the battery pack 100 to components in the vehicle and disconnect the battery pack 100 therefrom. The relays 53 are installed in, for example, an electrical connection box connected to the battery pack 100. The relays 53 are disposed between the battery pack 100 and the inverter 61, and between the battery pack 100 and a transformer, for example. The battery ECU 50 may disconnect the battery pack 100 by opening the relays 53.A power line 31 and a ground line 32 are connected to the main unit 10, the sub-units 20, and the battery ECU 50. The main unit 10, the slave units 20, and the battery ECU 50 are operated by power supplied from the common power line 31. The main unit 10, the slave units 20, and the battery ECU 50 are grounded via the common ground line 32. In this embodiment, the main unit 10 and the slave units 20 are connected to each other via a first cable 35. The first cable 35 includes the power line 31, the ground line 32, and the first communication line 33. The main unit 10 and the battery ECU 50 are connected via a second cable 36. The second cable 36 includes the power line 31, the ground line 32, and the second communication line 34.Next, the operation of the battery state detection device 1 according to this embodiment will be explained with reference to FIG. 4. The control procedure shown in FIG. 4 is repeatedly performed during an on-state of ignition, for example.In step S 1, the main unit 10 determines whether the first stack 101 is in a normal state. The calculator 12 aof the main unit 10 makes a determination in step S 1 based on the detection result of the cell voltages of the battery cells 110 in the first stack 101. For example, when all the values of the cell voltages of the battery cells 110 are in a normal range, the calculator 12 adetermines that the first stack 101 is in a normal state. When a battery cell 110 having a value of the cell voltage outside the normal range is present, the calculator 12 adetermines that the first stack 101 is not in a normal state. When the first stack 101 is determined to be normal in step S 1 (Yes in step S 1), the process proceeds to step S 2. If not (No in step S 1), the process proceeds to step S 3.In step S 2, the computer 12 aof the main unit 10 registers the determination that the first stack 101 is in a normal state. For example, the calculator 12 aactuates a flag indicating that the first stack 101 is in an abnormal state. After step S 2, the process proceeds to step S 4.In step S 3, the calculator 12 aof the main unit 10 registers the determination that the first stack 101 is in an abnormal state. For example, the calculator 12 asets the flag indicating that the first stack 101 is in an abnormal state. After step S 3, the process proceeds to step S 4.In step S 4, the main unit 10 determines whether the second stack 102 is in a normal state. The determination in step S 4 is performed in the same manner as in step S 1. When an affirmative determination is made in step S 4 (Yes in step S 4), the process proceeds to step S 5. If not (No in step S 4), the process proceeds to step S 6.In step S 5, the main unit 10 registers the determination that the second stack 102 is in a normal state. In step S 6, the main unit 10 registers the determination that the second stack 102 is in an abnormal state. For example, a flag indicating abnormality of the second stack 102 is switched between on and off at the registration in steps S6 and S5, respectively.The main unit 10 performs the determination and registration process from step S 1 to step S 6 respectively for the stacks 103 and 104 in the same manner. Here, assume that the total number of stacks is n, and the main unit 10 performs the state determination and registration process for the third stack 103 to (n-1)thstack. After the determination and registration process on the (n-1)th stack, the process proceeds to step S 7.In step S 7, the main unit 10 determines the state of the n-th stack. In this embodiment, the total number n of the stacks is five, and the state of the fifth stack 105 is determined in step S 7. When the fifth stack 105 is determined to be normal in step S 7 (Yes in step S 7), the process proceeds to step S 8. If not (No in step S 7), the process proceeds to step S 9.In step S 8, the main unit 10 registers the determination that the fifth stack 105 is in a normal state. After step S 8, the process proceeds to step S 10.In step S 9, the main unit 10 registers the determination that the fifth stack 105 is in an abnormal state. After step S 9, the process proceeds to step S 10.In step S 10, the main unit 10 determines whether the stacks 101, 102, 103, 104, and 105 are in a normal state. If the registrations indicate that all the stacks 101, 102, 103, 104, and 105 are in a normal state, the computer 12 aof the master unit 10 makes an affirmative determination in step S 10. If a stack is registered as abnormal, the calculator 12 a makes a negative determination in step S 10. When an affirmative determination is made in step S 10 (Yes in step S 10), the process proceeds to step S 11. When a negative determination is made (No in step S 10), the process proceeds to step S 12.In step S11, the computer 12a of the main unit 10 notifies the battery ECU 50 of the normal state of the stacks. The calculator 12 atransmits a signal indicating that the stacks 101, 102, 103, 104, and 105 are in a normal state to the battery ECU 50 via the second communication line 34.In step S 12, the main unit 10 notifies the battery ECU 50 of the abnormal state of the stacks. The main unit 10 transmits a signal indicating that at least one of the stacks 101, 102, 103, 104, and 105 is in an abnormal state to the battery ECU 50 via the second communication line 34. the main unit 10 may transmit a signal specifically indicating which stack is in an abnormal state. After step S12, the control procedure is ended.When the battery ECU 50 is notified of an abnormal state of the stacks by the main unit 10, the battery ECU 50 performs an abnormal situation process. The abnormal situation process includes, for example, an operation of notifying the vehicle ECU of the abnormal state of the stacks. The abnormal situation process includes an operation of notifying the driver of the vehicle of the abnormal state of the stacks. The driver is notified of the abnormal state by lighting a warning lamp or a warning sound. The battery ECU 50 can disconnect the battery pack 100 by opening the relays 53. For example, when a plurality of battery packs 100 are installed in a vehicle, the battery ECU 50 may disconnect a battery pack 100 including a stack in an abnormal state and simultaneously maintain the power supply from the other battery packs 100.As described above, the battery state detection device 1 according to this embodiment includes the main unit 10, the subunits 20, and the first communication line 33. the main unit 10 detects a state of the stack 103 in the battery pack 100 including the stacks 101, 102, 103, 104, and 105, each including a plurality of battery cells 110 arranged in rows. The subunits 20 detect states of the stacks 101, 102, 104, and 105 in the battery pack 100, which are stacks other than the stack that is the detection target of the main unit 10. The first communication line 33 connects the main unit 10 to the slave units 20.The main unit 10 is connected to the battery ECU 50 that controls the battery pack 100 via the second communication line 34 separate from the first communication line 33. In the battery state detection device 1 according to this embodiment, the first communication line 33 connecting the main unit 10 to the slave units 20 is separate from the second communication line 34 connecting the main unit 10 to the battery ECU 50. In other words, the communication path between the main unit 10 and the slave units 20 is independent of the communication path between the main unit 10 and the battery ECU 50. This separate configuration achieves a simpler configuration of the communication wiring. For example, this configuration may reduce the total length of the communication lines or reduce the number of communication lines as compared with a case where the battery ECU 50 is connected to all the units 10, 21, 22, 23, and 24 via respective dedicated communication lines. In addition, with this configuration, no modification of the second communication line 34 needs to be made even when the number of the battery cells 110 or the number of the stacks in the battery pack 100 is changed, thereby achieving a simpler configuration of the communication wiring.The configuration of the battery state detection device 1 according to this embodiment can reduce the communication load of the battery ECU 50. For example, this configuration can significantly reduce the amount of data received by the battery ECU 50 compared to a case where the battery ECU 50 is communicatively connected to all the units 10, 21, 22, 23, and 24. This results in a reduction in the calculation load of the battery ECU 50.The configuration of the battery state detection device 1 according to this embodiment allows greater flexibility in modifying the configuration of the battery pack 100. For example, a larger number of stacks may be required in the battery pack 100 to increase the capacity of the battery pack 100. In this case, the battery state detection device 1 according to this embodiment can be adjusted for a larger number of stacks by modifying only the first communication line 33 and not the second communication line 34.In the battery state detection device 1 according to this embodiment, the main unit 10 does not receive the results of the subunits 20 from the subunits 20 via the first communication line 33. the main unit 10 sends the management information based on the detection results of the subunits 20 and the detection result of the main unit 10 to the battery ECU 50 via the second communication line 34. the main unit 10 centrally controls the stacks 101, 102, 103, 104, and 105, thereby achieving efficient management of the operation of the battery pack 100. With this configuration, the individual battery cells 110 do not need to be monitored by the battery ECU 50, thereby reducing the monitoring load for the battery ECU 50.The first communication line 33 is used for communication for monitoring the states of the stacks 101, 102, 103, 104, and 105, and the second communication line 34 is used for communicating management information based on the monitoring results. This configuration can reduce the communication traffic in the second communication line 34, thereby reducing the communication load of the battery ECU 50.The battery ECU 50 does not need to monitor the individual battery cells 110 or the individual stacks 101, 102, 103, 104, 105. This configuration allows variation in the number of battery cells 110 or stacks 101, 102, 103, 104, and 105 without changing the software in the battery ECU 50. In other words, by integrating monitoring functions of the battery pack 100 in the main unit 10, the versatility and extendibility of the battery ECU 50 can be improved. As a result, even if the number of battery cells 110 or the number of stacks is larger, the processing load of the battery ECU 50 is not substantially increased.The main unit 10 according to this embodiment is integrated with the bus bar module 120 that electrically connects the battery cells 110 of the third stack 103 to each other. The subunits 20 according to this embodiment are integrated with the bus bar modules 120 that electrically connect the battery cells 110 of the stacks 101, 102, 104, and 105 to each other, and the states of the stacks are detected by the corresponding subunits 20. For example, the first sub unit 21 is integrated with the first stack bus bar module 120. By integrating the units 10 and 20 with the bus bars 120, for example, a shorter height and lighter weight of the battery pack 100 can be achieved, and a reduction in the number of parts can be achieved.The number of stacks in the battery pack 100 is not limited to five. The stacks 101, 102, 103, 104, and 105 may each include any number of battery cells 110. The stacks 101, 102, 103, 104, and 105 may be connected in parallel in the battery pack 100. The battery cells 110 in the stacks 101, 102, 103, 104, and 105 may be connected in parallel. The first cable 35 and the second cable 36 may be configured by, for example, a covered wire instead of a flat cable.First Modification of EmbodimentNext, a first modification of the embodiment will be described. FIG. 5 is a perspective view schematically showing a configuration of a battery state detection device according to the first modification of the embodiment. FIG. 6 is a perspective view showing an example of a specific configuration of the battery state detection device according to the first modification of the embodiment. The battery state detection device 1 according to the first modification is different from the battery state detection device 1 according to the above-described embodiment, for example, in that the main unit 10 is configured by a first substrate 70 and a second substrate 71. The first substrate 70 is also used for the substrates configuring the subunits 20. Functions such as a management function of the main unit 10 are installed in the second substrate 71. The substrates 70 and 71 according to the first modification are, for example, plate-like rigid substrates such as a printed circuit board (PCB).As shown in FIG. 5, the main unit 10 is disposed in the third stack and detects the state of the third stack 103 in the same manner as in the above-described embodiment. The subunits 21, 22, 23, and 24 respectively detect the states of the stacks 101, 102, 104, and 105. The main unit 10 and the sub units 20 according to the first modification are fixed on upper surfaces of covers 123. The covers 123 are insulation members formed of, for example, a synthetic resin. Each cover 12 is formed on the upper surface of the corresponding stack 101, 102, 103, 104, or 105 such that the cover 123 covers the bus bars 121.As shown in FIG. 6, the subunits 21, 22, 23, and 24 are configured by first substrates 70. Each first substrate 70 is connected to the bus bars 121 via the voltage detection lines 122. The first substrates 70 each include a computer 70 aand a first communication interface 70 b(see FIG. 5 ). The computer 70 adetects voltages of the battery cells 110. The computer 70 amay be configured to obtain temperatures of the battery cells 110 from the thermistor 30 in the same manner as described above.The main unit 10 includes the first substrate 70 and the second substrate 71. the first substrate 70 is communicatively connected to the second substrate 71. The first substrates 70 of the slave units 20 and the first substrate 70 of the master unit 10 are connected to each other via the first cable 35. Preferably, the first cable 35 is a flat cable such as an FPC, an FFC, or a printed circuit body. The first communication interfaces 70 bare communicatively connected via the first communication line 33 in the first cable 35.The second substrate 71 includes a computer 71 aand a second communication interface 71 b. The second substrate 71 and the battery ECU 50 are connected via the second cable 36. The second cable 36 may be a flat cable such as an FPC, an FFC, or a printed circuit body. The second communication interface 71 bis communicatively connected to the battery ECU 50 via the second communication line 34 in the second cable 36. In the same manner as in the battery state detection device 1 according to the above-described embodiment, the first communication line 33 connecting the main unit 10 to the slave units 20 is separate from the second communication line 34 connecting the main unit 10 to the battery ECU 50. The calculator 71 aacquires cell voltages and battery temperatures detected by the calculators 70 aof the slave units 20 and the calculator 70 aof the master unit 10 through communication. The calculator 71 atransmits management information based on the obtained detection results to the battery ECU 50.Second Modification of EmbodimentThe voltage sensing lines 122 may be configured by an FFC or covered wires. The stacks 101, 102, 103, 104, and 105 may be arranged in layers in the vertical direction and also in rows in the horizontal direction.The above-described embodiment and the modifications thereof can be implemented by an appropriate combination of the contents mentioned for the embodiment and the modifications.The battery state detection device according to the embodiment includes: a main unit configured to detect a state of a single battery array in a battery pack in which a plurality of battery arrays are accommodated, which in turn include a plurality of battery cells arranged in rows; a sub unit configured to detect a state of a battery array in the battery pack, which is a battery array other than the detection target of the main unit; and a first communication line connecting the main unit to the sub unit. The main unit is connected to a controller that controls the battery pack via a second communication line that is separate from the first communication line. The battery state detection device according to the embodiment can achieve a simpler configuration of communication wiring by providing the first communication line connecting the main unit to the sub unit separately from the second communication line connecting the main unit to the controller. The separate configuration of the first communication line from the second communication line can reduce the communication load of the controller.While the invention has been described above with reference to specific embodiments, the following claims are not limited to the embodiments described herein, which may be modified and altered in various ways without departing from the scope of the invention.

Claims

A battery state detection apparatus comprising: a main unit (10) configured to detect a state of a battery assembly (103) in a battery pack (100) in which a plurality of battery assemblies (101, 102, 103, 104, 105) including a plurality of battery cells (110) arranged in series are accommodated; a sub unit (20) configured to detect a state of a battery assembly (101, 102, 104, 105) in the battery pack (100) other than the battery assembly (103) which is a detection target of the main unit (10); and a first communication line (33) connecting the main unit (10) to the sub unit (20), wherein the main unit (10) is connected to a controller (50) configured to control the battery pack (100) via a second communication line (34) separate from the first communication line (33), A device for manufacturing a battery cell according to an exemplary embodiment of the present invention is connected to a device for manufacturing a battery cell according to an exemplary embodiment of the present invention, wherein: the main unit (10) receives a detection result of the sub-unit (20) from the sub-unit (20) via the first communication line (33); characterized in that the main unit (10) calculates management information based on the detection result of the sub-unit (20) and a detection result of the main unit (10), and transmits the management information to the controller (50) via the second communication line (34); the management information includes results of a determination as to whether the battery cells (110) of the battery arrays (101, 102, 103, 104, 105) are in an abnormal state or in a normal state.The battery state detection device according to claim 1, wherein: the main unit (10) is integrated with a bus bar module (120) that electrically connects the battery cells (110) in the battery assembly (103) to each other, a state of the battery assembly (103) is detected by the main unit (10), and the sub-unit (20) is integrated with a bus bar module (120) that electrically connects the battery cells (110) in the battery assembly (101, 102, 104, 105) to each other, a state of the battery assembly (101, 102, 104, 105) being detected by the sub-unit (20).

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