Battery management system

Abstract

A BMS (1) comprises a BMU (202) that manages a battery pack and a plurality of CMUs (101, 103, 302, 303) that monitor the battery pack. A first CMU (101) among the plurality of CMUs (101, 103, 302, 303) is provided with a first communication antenna (ANT1) and a first wireless communication circuit (111) for communication with the BMU (202). A second CMU (302) among the plurality of CMUs (101, 103, 302, 303) is provided with a second communication antenna (ANT5) and a second wireless communication circuit (315) for communication with the BMU (202). The modulation system of wireless communication by the first wireless communication circuit (111) and the modulation system of wireless communication by the second wireless communication circuit (315) are different.

Description

Battery Management System

[0001] The present disclosure relates to a battery management system for managing a battery pack.

[0002] Patent document 1 discloses a technology in which, when a functional unit within a battery management system fails to communicate wirelessly with a battery management unit, the functional unit changes the frequency of communication with the battery management unit and re-establishes a wireless communication connection with the battery management unit.

[0003] US Patent Application Publication No. 2020 / 0083722

[0004] However, with the technology disclosed in Patent Document 1, if the robustness of communication is low, there is a risk that the wireless communication connection cannot be re-established.

[0005] Therefore, the present disclosure provides a battery management system that can improve the robustness of communication within the battery management system.

[0006] The battery management system according to the present disclosure is a battery management system for managing an assembled battery, and includes a management circuit for managing the assembled battery and a plurality of monitoring circuits for monitoring the assembled battery, wherein a first monitoring circuit of the plurality of monitoring circuits includes a first wireless communication circuit and a first communication antenna for communicating with the management circuit, and a second monitoring circuit of the plurality of monitoring circuits includes a second wireless communication circuit and a second communication antenna for communicating with the management circuit, and wherein a modulation method for wireless communication by the first wireless communication circuit is different from a modulation method for wireless communication by the second wireless communication circuit.

[0007] The battery management system according to the present disclosure is a battery management system for managing an assembled battery, and includes a management circuit for managing the assembled battery and a plurality of monitoring circuits for monitoring the assembled battery, wherein a first monitoring circuit of the plurality of monitoring circuits includes a first wireless communication circuit and a first communication antenna for communicating with the management circuit, and a second monitoring circuit of the plurality of monitoring circuits includes a second wireless communication circuit and a second communication antenna for communicating with the management circuit, and wherein a wireless communication channel used for wireless communication by the first wireless communication circuit is different from a wireless communication channel used for wireless communication by the second wireless communication circuit.

[0008] These comprehensive or specific aspects may be realized as a system, a method, an integrated circuit, a computer program, or a computer-readable recording medium such as a CD-ROM, or may be realized as any combination of a system, a method, an integrated circuit, a computer program, and a recording medium.

[0009] According to a battery management system according to one aspect of the present disclosure, the robustness of communication within the battery management system can be increased.

[0010] 1 is an external view showing an example of a battery management system according to an embodiment; FIG. 2 is a configuration diagram showing an example of a battery management system according to an embodiment; FIG. 3 is a configuration diagram showing an example of a wireless communication circuit provided in a cell monitoring circuit; FIG. 4 is a configuration diagram showing an example of a voltage monitoring circuit provided in a cell monitoring circuit; FIG. 5 is a configuration diagram showing another example of a voltage monitoring circuit provided in a cell monitoring circuit; FIG. 6 is a configuration diagram showing an example of a current measuring circuit provided in a current monitoring circuit; FIG. 7 is a configuration diagram showing an example of a wireless communication circuit provided in a current monitoring circuit; FIG. 8 is a configuration diagram showing an example of a wireless communication circuit provided in a management circuit; FIG. 9 is a configuration diagram showing an example of an MCU provided in a management circuit; FIG. 10 is a diagram showing an example of a modulation method for wireless communication; FIG. 11 is a diagram showing an example of a wireless communication channel; FIG. 12 is a diagram showing an example of a transmitting wireless communication channel and a receiving wireless communication channel;

[0011] Hereinafter, the embodiments will be specifically described with reference to the drawings.

[0012] The embodiments described below are all comprehensive or specific examples, and the numerical values, shapes, materials, components, arrangement positions and connection forms of the components shown in the following embodiments are merely examples and are not intended to limit the present disclosure.

[0013] (Embodiment) A battery management system according to an embodiment will be described below.

[0014] FIG. 1 is an external view showing an example of a battery management system 1 (hereinafter also referred to as a BMS (Battery Management System) 1) according to an embodiment.

[0015] The BMS 1 is a system for managing an assembled battery. For example, the BMS 1 manages the SOC (State of Charge), SOH (State of Health), and SOP (State of Power) of the assembled battery. The BMS 1 also monitors abnormalities in the assembled battery. The BMS 1 includes a management circuit 200 that manages the assembled battery and multiple monitoring circuits 100 that monitor the assembled battery. For example, the assembled battery is configured by connecting multiple battery packs 10 in series or parallel. The battery pack 10 is also configured by one or more battery cells. When the battery pack 10 is configured by multiple battery cells, the multiple battery cells are connected in series.

[0016] For example, the monitoring circuit 100 is disposed on each of the plurality of battery packs 10. For example, the plurality of monitoring circuits 100 include a cell monitoring circuit (CMU (Cell Monitoring Unit)) that monitors one or more battery cells that constitute the assembled battery, or a current monitoring circuit (CMU (Current Monitoring Unit)) that measures the current flowing through the assembled battery. CMUs (Cell Monitoring Units) 101 and 103 and CMUs (Current Monitoring Units) 302 and 303, which are specific examples of the monitoring circuit 100, will be described later.

[0017] For example, the management circuit 200 is connected to the battery pack via a junction box 20. A BMU (Battery Management Unit) 202, which is a specific example of the management circuit 200, will be described later.

[0018] Next, a specific example of the BMS 1 according to the embodiment will be described with reference to FIGS. 2 to 6B.

[0019] FIG. 2 is a configuration diagram illustrating an example of the BMS 1 according to the embodiment.

[0020] 3A is a configuration diagram showing an example of the wireless communication circuit 111 included in the cell monitoring circuit (for example, the CMU 101). Note that Fig. 3A also shows the peripheral parts of the wireless communication circuit 111 in the configuration diagram of Fig. 2.

[0021] 3B is a configuration diagram showing an example of the voltage monitoring circuit 112 included in the cell monitoring circuit (for example, the CMU 101). Note that Fig. 3B also shows the peripheral parts of the voltage monitoring circuit 112 in the configuration diagram of Fig. 2.

[0022] 4 is a configuration diagram showing another example of the voltage monitoring circuit 114 provided in the cell monitoring circuit (e.g., the CMU 103). Note that Fig. 4 also shows the peripheral parts of the voltage monitoring circuit 114 in the configuration diagram of Fig. 2.

[0023] 5A is a block diagram showing an example of the current measurement circuit 314 included in the current monitoring circuit (e.g., the CMU 302). Note that Fig. 5A also shows the peripheral parts of the current measurement circuit 314 in the block diagram of Fig. 2.

[0024] 5B is a block diagram showing an example of the wireless communication circuit 315 included in the current monitoring circuit (e.g., the CMU 302). Note that Fig. 5B also shows the peripheral parts of the wireless communication circuit 315 in the block diagram of Fig. 2.

[0025] 6A is a block diagram showing an example of the wireless communication circuit 211 included in the management circuit (BMU 202). Note that Fig. 6A also shows the peripheral parts of the wireless communication circuit 211 in the block diagram of Fig. 2.

[0026] 6B is a block diagram showing an example of the MCU 213 included in the management circuit (BMU 202). Note that Fig. 6B also shows the peripheral parts of the MCU 213 in the block diagram of Fig. 2.

[0027] The specific example in Fig. 2 focuses on one battery pack 10 out of multiple battery packs 10, and Fig. 2 shows multiple battery cells 11 that make up one battery pack 10 in the battery pack as one or more battery cells that make up the battery pack. CMUs 101 and 103 and CMUs 302 and 303 are shown as the monitoring circuit 100, and BMU 202 is shown as the management circuit 200. A motor 400 is shown as a load to which power is supplied from the battery pack, along with a power line 405 (bus bar) that connects the battery pack and motor 400, a relay 401 inserted in the power line 405, and shunt resistors 403 and 404.

[0028] The relay 401 is a switch for interrupting the current flowing through the power line 405. For example, when the current monitored by the CMU 302 or 303 is determined to be abnormal, the relay 401 is turned off to interrupt the current flowing through the power line 405. Furthermore, for example, when the voltage monitored by the CMU 101 or 103 is determined to be abnormal, the relay 401 is turned off to interrupt the current flowing through the power line 405.

[0029] The shunt resistors 403 and 404 are resistors for measuring the current flowing through the power line 405 .

[0030] The CMUs 101 and 103 are an example of a cell monitoring circuit that monitors one or more battery cells that make up a battery pack. For example, the CMUs 101 and 103 monitor the voltages of multiple battery cells 11. Here, an example is shown in which the CMUs 101 and 103 each monitor the same battery cells 11 (specifically, battery cells 11 included in the same battery pack 10), but the CMUs 101 and 103 may each monitor different battery cells 11 (specifically, battery cells 11 included in different battery packs 10).

[0031] Although the CMUs 101 and 103 are connected to each other by wired communication, they do not necessarily have to be connected to each other by wired communication.

[0032] 2, the CMU 101 includes a wireless communication circuit 111 and a communication antenna ANT1 for communicating with the BMU 202. The CMU 101 also includes a voltage monitoring circuit 112. For example, the wireless communication circuit 111 and the voltage monitoring circuit 112 are implemented by different integrated circuits (ICs). Alternatively, the wireless communication circuit 111 and the voltage monitoring circuit 112 may be implemented by a single IC.

[0033] As shown in FIG. 3A , the wireless communication circuit 111 includes a voltage conversion circuit (Reg.) 121, a timer circuit (Timer) 122, a communication interface (Com. I / F) 123, a clock generation circuit (Clock gen) 124, a phase-locked loop (PLL) 125, a modulation circuit (Modulator) 126, a transmission circuit (Tx) 127, a demodulation circuit (Demodulator) 128, a reception circuit (Rx) 129, a nonvolatile memory (NVM) 130, a communication error determination circuit (RF Error) 131, and a startup circuit (Wake up) 132.

[0034] The voltage conversion circuit 121 is a circuit that converts the voltage input from the voltage monitoring circuit 112 into a voltage for operating the wireless communication circuit 111 and outputs the voltage.

[0035] The timer circuit 122 is a circuit that counts time. For example, the timer circuit 122 is used to cause the wireless communication circuit 111 to operate intermittently.

[0036] The communication interface 123 is an interface for communication between the wireless communication circuit 111 and the voltage monitoring circuit 112. Note that if the wireless communication circuit 111 and the voltage monitoring circuit 112 are realized by a single IC, the communication interface 123 does not need to be provided.

[0037] The clock generation circuit 124 is a circuit for generating a clock in the CMU 101 .

[0038] The phase synchronization circuit 125 is a circuit that adjusts the phase of the local signal so that it coincides with the phase of the received signal.

[0039] The modulation circuit 126 is a circuit that modulates the signal to be transmitted to the BMU 202 .

[0040] The transmission circuit 127 is a circuit for transmitting a signal to the BMU 202. The transmission circuit 127 transmits the signal to the BMU 202 via the communication antenna ANT1.

[0041] The demodulation circuit 128 is a circuit that demodulates the signal received from the BMU 202 .

[0042] The receiving circuit 129 is a circuit for receiving a signal from the BMU 202. The receiving circuit 129 receives a signal from the BMU 202 via the communication antenna ANT1.

[0043] The nonvolatile memory 130 stores identification information of the wireless communication circuit 111. For example, the nonvolatile memory 130 stores identification information "ID2A." Although the nonvolatile memory 130 is shown in FIG. 3A, the identification information may be stored in any memory included in the wireless communication circuit 111. For the wireless communication circuits described below, the memory in which the identification information is stored is not shown.

[0044] The communication error determination circuit 131 is a circuit that determines whether or not an abnormality has occurred in the communication between the CMU 101 and the BMU 202 .

[0045] The start-up circuit 132 is a circuit for starting up the wireless communication circuit 111 .

[0046] 2, for example, the CMU 101 may include an LED 133. The LED 133 emits light when the wireless communication circuit 111 satisfies a specific condition, for example.

[0047] As shown in FIG. 3B , the voltage monitoring circuit 112 includes a voltage conversion circuit (Reg.) 141, a timer circuit (Timer) 142, a multiplexer (MUX) 143, an AD converter (ADC) 144, a communication interface (Com. I / F) 145, a phase-locked loop (PLL) 146, an encryption circuit (Encryption) 147, and a switch 148.

[0048] The voltage conversion circuit 141 is a circuit that converts the voltage input from the battery pack into a voltage for operating the voltage monitoring circuit 112 and outputs the voltage.

[0049] The timer circuit 142 is a circuit that counts time. For example, the timer circuit 142 is a circuit for intermittently operating the wireless communication circuit 111. Note that although the CMU 101 includes the timer circuits 122 and 142 in the wireless communication circuit 111 and the voltage monitoring circuit 112, it is not necessary to include both the timer circuits 122 and 142. In other words, the wireless communication circuit 111 does not have to include the timer circuit 122, and the voltage monitoring circuit 112 does not have to include the timer circuit 142.

[0050] The multiplexer 143 selects one battery cell 11 from the plurality of battery cells 11 and outputs the voltage across the selected battery cell 11. In other words, the multiplexer 143 can output the voltages of the plurality of battery cells 11.

[0051] The AD converter 144 converts the voltage value (analog value) of the battery cell 11 selected by the multiplexer 143 into a digital value.

[0052] The communication interface 145 is an interface for communication between the wireless communication circuit 111 and the voltage monitoring circuit 112. Note that if the wireless communication circuit 111 and the voltage monitoring circuit 112 are implemented by a single IC, the communication interface 145 does not need to be provided.

[0053] The phase synchronization circuit 146 is a circuit that adjusts the phase of the local signal so that it coincides with the phase of the received signal.

[0054] The encryption circuit 147 is a circuit that encrypts and decrypts signals. For example, the encryption circuit 147 encrypts signals to be transmitted to the wireless communication circuit 111 and eventually to the BMU 202 using an encryption key.

[0055] The switch 148 is a switch, such as a transistor, that switches on and off the supply of power to the wireless communication circuit 111. The switch 148 is controlled by a control signal from the startup circuit 132. The startup circuit 132 controls the switch 148 to control the supply of power to the wireless communication circuit 111, thereby controlling the startup of the wireless communication circuit 111.

[0056] The CMU 101 detects the voltage values ​​of each of the plurality of battery cells 11 using the voltage monitoring circuit 112 , and transmits the detected voltage values ​​to the BMU 202 using the wireless communication circuit 111 .

[0057] 2, the CMU 103 includes a wireless communication circuit 113 and a communication antenna ANT3 for communicating with the BMU 202. The CMU 103 also includes a voltage monitoring circuit 114. For example, the wireless communication circuit 113 and the voltage monitoring circuit 114 are implemented by different ICs. Alternatively, the wireless communication circuit 113 and the voltage monitoring circuit 114 may be implemented by a single IC.

[0058] The function of the wireless communication circuit 113 is explained by replacing the voltage monitoring circuit 112 with a voltage monitoring circuit 114, the communication antenna ANT1 with a communication antenna ANT3, and the CMU101 with a CMU103 in the explanation of the wireless communication circuit 111.

[0059] As shown in FIG. 4, the voltage monitoring circuit 114 includes a voltage conversion circuit (Reg.) 141, a timer circuit (Timer) 142, a communication interface (Com. I / F) 145, an encryption circuit (Encryption) 147, a switch 148, and comparators 149 to 152.

[0060] The description of the functions of the voltage conversion circuit 141, timer circuit 142, communication interface 145, encryption circuit 147 and switch 148 provided in the voltage monitoring circuit 114 is the same as the description of those provided in the voltage monitoring circuit 112 described above, except that the wireless communication circuit 111 is replaced with the wireless communication circuit 113, the voltage monitoring circuit 112 with the voltage monitoring circuit 114, and the CMU 101 with the CMU 103.

[0061] Each of the comparators 149 to 152 is provided in a one-to-one correspondence with each of the plurality of battery cells 11. Here, four comparators 149 to 152 are shown as an example, but the number of comparators corresponds to the number of battery cells 11. For example, if four battery cells 11 are connected in series as the plurality of battery cells 11, the comparator 149 compares the voltage of the first battery cell 11 with a predetermined voltage, the comparator 150 compares the voltage of the second battery cell 11 with the predetermined voltage, the comparator 151 compares the voltage of the third battery cell 11 with the predetermined voltage, and the comparator 152 compares the voltage of the fourth battery cell 11 with the predetermined voltage. In this way, by providing a comparator for each of the plurality of battery cells 11, the voltage monitoring circuit 114 can determine whether each of the plurality of battery cells 11 is at or above a predetermined voltage (e.g., an overvoltage) or whether each of the plurality of battery cells 11 is at or below a predetermined voltage (e.g., a too low voltage). In other words, the voltage monitoring circuit 114 can determine whether the voltage of each of the plurality of battery cells 11 is abnormal.

[0062] The CMU 103 uses the voltage monitoring circuit 114 to determine whether the voltage of each of the plurality of battery cells 11 is abnormal, and transmits the determination result to the BMU 202 via the wireless communication circuit 113 .

[0063] The CMU 103 may include a voltage monitoring circuit 112 instead of the voltage monitoring circuit 114. That is, the CMU 103 may detect the voltage values ​​of each of the multiple battery cells 11 and transmit the detected voltage values ​​to the BMU 202. The CMU 101 may include a voltage monitoring circuit 114 instead of the voltage monitoring circuit 112. That is, the CMU 101 may determine whether or not the voltage of each of the multiple battery cells 11 is abnormal and transmit the determination result to the BMU 202.

[0064] 2, the CMU 302 includes a current measurement circuit 314 that measures the current flowing through the battery pack. The CMU 302 also includes a wireless communication circuit 315 and a communication antenna ANT5 for communicating with the BMU 202. For example, the wireless communication circuit 315 and the current measurement circuit 314 are implemented by different ICs. However, the wireless communication circuit 315 and the current measurement circuit 314 may also be implemented by a single IC.

[0065] As shown in FIG. 5A, the current measuring circuit 314 includes an amplifier circuit 321, an AD converter (ADC) 322, a communication interface (Com. I / F) 323, a phase locked loop (PLL) 324, and an encryption circuit (Encryption) 325.

[0066] The amplifier circuit 321 amplifies the voltage generated across the shunt resistor 403. The resistance value of the shunt resistor 403 is very small, and the voltage generated across the shunt resistor 403 is also small, so the amplifier circuit 321 is provided.

[0067] The AD converter 322 converts the value (analog value) of the voltage generated across the shunt resistor 403 into a digital value.

[0068] The communication interface 323 is an interface for communication between the wireless communication circuit 315 and the current measurement circuit 314. Note that if the wireless communication circuit 315 and the current measurement circuit 314 are realized by a single IC, the communication interface 323 does not need to be provided.

[0069] The phase synchronization circuit 324 is a circuit that adjusts the phase of the local signal so that it coincides with the phase of the received signal.

[0070] The encryption circuit 325 is a circuit that encrypts and decrypts signals. For example, the encryption circuit 325 encrypts signals to be transmitted to the wireless communication circuit 315 and eventually to the BMU 202 using an encryption key.

[0071] 5B, the wireless communication circuit 315 includes a voltage conversion circuit (Reg.) 331, a timer circuit (Timer) 332, a communication interface (Com. I / F) 333, a clock generation circuit (Clock gen) 334, a phase-locked loop (PLL) 335, an encryption circuit (Encryption) 336, a modulation circuit (Modulator) 337, a transmission circuit (Tx) 338, a demodulation circuit (Demodulator) 339, a reception circuit (Rx) 340, a communication error determination circuit (RF Error) 341, and a wake-up circuit (Wake up) 342. Also, in FIG. 5B, "ID1A" is shown as identification information of the wireless communication circuit 315.

[0072] The voltage conversion circuit 331 is a circuit that converts a voltage input from an arbitrary power source into a voltage for operating the wireless communication circuit 315 and outputs the voltage.

[0073] The timer circuit 332 is a circuit that counts time.

[0074] The communication interface 333 is an interface for communication between the wireless communication circuit 315 and the current measurement circuit 314. Note that if the wireless communication circuit 315 and the current measurement circuit 314 are realized by a single IC, the communication interface 333 does not need to be provided.

[0075] The clock generation circuit 334 is a circuit for generating a clock in the CMU 302 .

[0076] The phase synchronization circuit 335 is a circuit that adjusts the phase of the local signal so that it coincides with the phase of the received signal.

[0077] The encryption circuit 336 is a circuit that encrypts and decrypts signals. For example, the encryption circuit 336 encrypts signals to be transmitted to the BMU 202 using an encryption key. Note that although the CMU 302 includes the encryption circuits 325 and 336 in the current measurement circuit 314 and the wireless communication circuit 315, it is not necessary for both the encryption circuits 325 and 336 to be included. In other words, the wireless communication circuit 315 does not have to include the encryption circuit 336, or the current measurement circuit 314 does not have to include the encryption circuit 325.

[0078] The modulation circuit 337 is a circuit that modulates the signal to be transmitted to the BMU 202 .

[0079] The transmission circuit 338 is a circuit for transmitting a signal to the BMU 202. The transmission circuit 338 transmits the signal to the BMU 202 via the communication antenna ANT5.

[0080] The demodulation circuit 339 is a circuit that demodulates the signal received from the BMU 202 .

[0081] The receiving circuit 340 is a circuit for receiving a signal from the BMU 202. The receiving circuit 340 receives a signal from the BMU 202 via the communication antenna ANT5.

[0082] The communication error determination circuit 341 is a circuit that determines whether or not an abnormality has occurred in communication between the CMU 302 and the BMU 202 .

[0083] The start-up circuit 342 is a circuit for starting up the current measuring circuit 314 .

[0084] 2, for example, the CMU 302 may include an LED 343. The LED 343 emits light when, for example, the wireless communication circuit 315 satisfies a specific condition.

[0085] 2, the CMU 303 includes a current measurement circuit 316 that measures the current flowing through the battery pack. The CMU 303 also includes a wireless communication circuit 317 and a communication antenna ANT6 for communicating with the BMU 202. For example, the wireless communication circuit 317 and the current measurement circuit 316 are implemented by different ICs. However, the wireless communication circuit 317 and the current measurement circuit 316 may also be implemented by a single IC.

[0086] The function of the current measuring circuit 316 is explained by replacing the shunt resistor 403 with a shunt resistor 404, the current measuring circuit 314 with a current measuring circuit 316, and the wireless communication circuit 315 with a wireless communication circuit 317 in the explanation of the current measuring circuit 314.

[0087] The function of the wireless communication circuit 317 is explained by replacing the current measurement circuit 314 with a current measurement circuit 316, the wireless communication circuit 315 with a wireless communication circuit 317, the CMU 302 with a CMU 303, and the communication antenna ANT5 with a communication antenna ANT6 in the explanation of the wireless communication circuit 315. The identification information of the wireless communication circuit 317 is assumed to be "ID1B".

[0088] 2, BMU 202 includes a wireless communication circuit 211 and a communication antenna ANT2, and a wireless communication circuit 212 and a communication antenna ANT4 for communicating with CMUs 101 and 103 and CMUs 302 and 303. BMU 202 also includes an MCU 213 for managing the battery pack. Note that wireless communication circuits 211 and 212 and MCU 213 may be implemented by a single IC (e.g., a single MCU).

[0089] 6A, the wireless communication circuit 211 includes a voltage conversion circuit (Reg.) 221, a timer circuit (Timer) 222, a communication interface (Com. I / F) 223, a clock generation circuit (Clock gen) 224, a phase-locked loop (PLL) 225, a modulation circuit (Modulator) 226, a transmission circuit (Tx) 227, a demodulation circuit (Demodulator) 228, a reception circuit (Rx) 229, a communication error determination circuit (RF Error) 231, and a wake-up circuit (Wake up) 232. Also, in FIG. 6A, "ID0A" is shown as identification information of the wireless communication circuit 211.

[0090] The voltage conversion circuit 221 is a circuit that converts a voltage input from an arbitrary power source into a voltage for operating the wireless communication circuit 211 and outputs the voltage.

[0091] The timer circuit 222 is a circuit that counts time.

[0092] The communication interface 223 is an interface for communication between the wireless communication circuit 211 and the MCU 213. If the wireless communication circuit 211 and the MCU 213 are realized by a single IC, the communication interface 223 does not need to be provided.

[0093] The clock generation circuit 224 is a circuit for generating a clock in the BMU 202 .

[0094] The phase synchronization circuit 225 is a circuit that adjusts the phase of the local signal so that it matches the phase of the received signal.

[0095] The modulation circuit 226 is a circuit that modulates the signal to be transmitted to the CMU 101 or 103 or the CMU 302 or 303 .

[0096] The transmission circuit 227 is a circuit for transmitting a signal to the CMU 101 or 103 or the CMU 302 or 303. The transmission circuit 227 transmits a signal to the CMU 101 or 103 or the CMU 302 or 303 via the communication antenna ANT2.

[0097] The demodulation circuit 228 is a circuit that demodulates the signal received from the CMU 101 or 103 or the CMU 302 or 303 .

[0098] The receiving circuit 229 is a circuit for receiving a signal from the CMU 101 or 103 or the CMU 302 or 303. The receiving circuit 229 receives a signal from the CMU 101 or 103 or the CMU 302 or 303 via the communication antenna ANT2.

[0099] The communication error determination circuit 231 is a circuit that determines whether or not an abnormality has occurred in the communication between the CMU 101 or 103 or the CMU 302 or 303 and the BMU 202 .

[0100] The startup circuit 232 is a circuit for starting up the MCU 213 .

[0101] The function of the wireless communication circuit 212 will be described by replacing the communication antenna ANT2 with the communication antenna ANT4 in the description of the wireless communication circuit 211. The identification information of the wireless communication circuit 212 is "ID0B".

[0102] 6B , the MCU 213 includes an encryption circuit 241, an identification circuit (ID identification circuit) 242, an encryption circuit 243, and an identification circuit (ID identification circuit) 244. The MCU 213 is connected to a CAN (Controller Area Network), and a firewall is provided between the MCU 213 and the CAN. The MCU 213 also stores a table (Table of cell position and RF com. ID) 245 that indicates the correspondence between the positions of the multiple battery cells 11 in the battery pack 10 and the identification information of the wireless communication circuit provided in the CMU of each battery pack 10.

[0103] The encryption circuits 241 and 243 are circuits that encrypt and decrypt signals. For example, the encryption circuits 241 and 243 decrypt signals transmitted from the CMUs 101 and 103 or the CMUs 302 and 303 using encryption keys.

[0104] The identification circuits 242 and 244 use the table 245 to identify the position of the battery cell 11 in the battery pack 10 in which the voltage value of the battery cell 11 included in the signal transmitted from the CMU 101 corresponds to. The identification circuits 242 and 244 also use the table 245 to identify the position of the battery cell 11 in the battery pack 10 in which the determination result of the voltage of the battery cell 11 included in the signal transmitted from the CMU 103 corresponds to.

[0105] With the above circuit configuration, the BMS 1 operates as follows.

[0106] When BMU202 obtains the status (e.g., voltage values) of multiple battery cells 11 monitored by a CMU assigned with identification information "ID2A," it broadcasts a request signal to cause the CMU assigned with identification information "ID2A" to send the monitoring results to BMU202.

[0107] The CMU 101 receives the request signal and, because the request signal contains identification information that matches its own identification information "ID2A," determines that the request signal is addressed to the CMU 101 and performs processing to transmit the monitoring results of the multiple battery cells 11 that it monitors to the BMU 202. Specifically, the CMU 101 acquires the voltage values ​​of each of the multiple battery cells 11 using the multiplexer 143 and transmits each voltage value, information indicating the position of the battery cell 11 at which each voltage value corresponds, and identification information of the CMU 101 to the BMU 202. For example, depending on which battery cell 11 the multiplexer 143 selected when acquiring a voltage value, it can identify the position of the battery cell 11 at which the voltage value corresponds.

[0108] In response to the request signal, the BMU 202 receives from the CMU 101 information indicating the voltage values ​​of the plurality of battery cells 11 monitored by the CMU 101 and identification information of the CMU 101. By comparing this information with the table 245, the BMU 202 can identify which battery pack 10 and which position the battery cell 11 is associated with for each of the plurality of battery cells 11.

[0109] In addition, when BMU202 obtains the status (e.g., the result of determining whether there is an abnormal voltage) of multiple battery cells 11 monitored by a CMU assigned with identification information "ID2B", it broadcasts a request signal to cause the CMU assigned with identification information "ID2B" to send the monitoring results to BMU202.

[0110] The CMU 103 receives the request signal and, because the request signal contains identification information that matches its own identification information "ID2B," determines that the request signal is addressed to itself and performs processing to transmit the monitoring results of the multiple battery cells 11 that it monitors to the BMU 202. Specifically, the CMU 103 determines whether the voltage of each of the multiple battery cells 11 is abnormal using comparators 149 to 152, and transmits to the BMU 202 the determination results that the voltage of each of the multiple battery cells 11 is abnormal, information indicating the position of the battery cell 11 that this determination result relates to, and identification information of the CMU 103. For example, depending on which comparator acquired the voltage as the determination result, it is possible to identify the position of the battery cell 11 that this determination result relates to.

[0111] In response to the request signal, the BMU 202 receives from the CMU 103 information indicating the determination results of voltage abnormalities of the plurality of battery cells 11 monitored by the CMU 103 and identification information of the CMU 103. By comparing this information with the table 245, the BMU 202 can identify which battery pack 10 and which position of the battery cell 11 each of the determination results of voltage abnormalities of the plurality of battery cells 11 corresponds to.

[0112] In addition, when BMU 202 obtains the status of the battery pack monitored by the CMU assigned with the identification information "ID1A" (for example, the current flowing through the battery pack), it broadcasts a request signal to the CMU assigned with the identification information "ID1A" to send the monitoring results to BMU 202.

[0113] CMU 302 receives the request signal, and because the request signal contains identification information that matches its own identification information "ID1A," CMU 302 performs processing to transmit the monitoring results of the battery pack that it monitors to BMU 202. Specifically, CMU 302 measures the current flowing through the battery pack and transmits the results to BMU 202. This allows BMU 202 to obtain the current flowing through the battery pack.

[0114] In addition, when BMU 202 obtains the status of the battery pack monitored by the CMU assigned with the identification information "ID1B" (e.g., the current flowing through the battery pack), it broadcasts a request signal to the CMU assigned with the identification information "ID1B" to send the monitoring results to BMU 202.

[0115] The CMU 303 receives the request signal and, because the request signal contains identification information that matches its own identification information "ID1B," performs processing to transmit the monitoring results of the battery pack that it monitors to the BMU 202. Specifically, the CMU 303 measures the current flowing through the battery pack and transmits the results to the BMU 202. This allows the BMU 202 to obtain the current flowing through the battery pack.

[0116] Any one of CMUs 101 and 103 and CMUs 302 and 303 is a first monitoring circuit having a first wireless communication circuit and a first communication antenna for communicating with BMU 202, and any other one of CMUs 101 and 103 and CMUs 302 and 303 is a second monitoring circuit having a second wireless communication circuit and a second communication antenna for communicating with BMU 202. In other words, the first monitoring circuit may be any one of CMUs 101 and 103 and CMUs 302 and 303 as long as it is a CMU different from the second monitoring circuit, and the second monitoring circuit may be any one of CMUs 101 and 103 and CMUs 302 and 303 as long as it is a CMU different from the first monitoring circuit.

[0117] For example, the BMS 1 is often mounted on the underside of a vehicle and must perform wireless communication in a very narrow space. In this case, communication quality may be degraded due to interference or reflection. In response to this, for example, by differentiating the modulation method for wireless communication by the first wireless communication circuit from the modulation method for wireless communication by the second wireless communication circuit, the degradation of communication quality can be suppressed. Furthermore, for example, by differentiating the wireless communication channel used for wireless communication by the first wireless communication circuit from the wireless communication channel used for wireless communication by the second wireless communication circuit, the degradation of communication quality can be suppressed.

[0118] When the modulation method for wireless communication by the first wireless communication circuit and the modulation method for wireless communication by the second wireless communication circuit are different, for example, the modulation method for wireless communication by the first wireless communication circuit is one of a spread spectrum method, an Orthogonal Frequency Division Multiplexing (OFDM) method, and an Ultra Wide Band (UWB) method, and the modulation method for wireless communication by the second wireless communication circuit is a method among the spread spectrum method, the OFDM method, and the UWB method that is different from the modulation method for wireless communication by the first wireless communication circuit.

[0119] FIG. 7 is a diagram showing an example of a modulation method for wireless communication.

[0120] The spread spectrum (e.g., FHSS (Frequency Hopping Spread Spectrum)) system, OFDM system, and UWB system shown in Fig. 7 are modulation systems that can easily ensure communication quality even under adverse conditions. By selecting and using two of these modulation systems, it is possible to increase communication redundancy and achieve greater robustness.

[0121] The spread spectrum method can realize interference-resistant communications using simple circuits.

[0122] Although the communication performance of wireless communication can vary depending on the transmission path determined by the frequency (wavelength) and the location of the communication station, the OFDM method can select the optimal frequency (i.e., the optimal transmission path) to carry out communication.

[0123] The UWB system uses wideband radio, so wide-area communication is possible even with a narrow transmission path within the BMS 1 .

[0124] In the communication within the BMS 1, transmission is performed in a very narrow free space, and therefore the above three modulation methods are suitable as modulation methods that are selectively used to ensure redundancy.

[0125] For example, if CMU 101 is the first monitoring circuit and CMU 302 is the second monitoring circuit, then wireless communication circuit 111 becomes the first wireless communication circuit, communication antenna ANT1 becomes the first communication antenna, wireless communication circuit 315 becomes the second wireless communication circuit, and communication antenna ANT5 becomes the second communication antenna.

[0126] In this case, the monitoring results of the CMU 101 and the CMU 302 are transmitted to the BMU 202 using different modulation methods. For example, the voltage values ​​of the multiple battery cells 11 and the current values ​​flowing through the battery pack (the current values ​​flowing through each of the multiple battery cells 11) are transmitted to the BMU 202. In this way, the BMU 202 measures the internal impedance of each of the multiple battery cells 11.

[0127] For example, if CMU 101 is the first monitoring circuit and CMU 103 is the second monitoring circuit, then wireless communication circuit 111 becomes the first wireless communication circuit, communication antenna ANT1 becomes the first communication antenna, wireless communication circuit 113 becomes the second wireless communication circuit, and communication antenna ANT3 becomes the second communication antenna.

[0128] In this case, the monitoring results of the CMU 101 and the CMU 103 are transmitted to the BMU 202 using different modulation methods. For example, the voltage values ​​of the plurality of battery cells 11 and the determination results of voltage anomalies of the plurality of battery cells 11 are transmitted to the BMU 202 using different modulation methods.

[0129] Since the modulation method for the wireless communication by the first wireless communication circuit and the modulation method for the wireless communication by the second wireless communication circuit are different, it is possible to suppress deterioration of communication quality due to interactions between the wireless communication by the first wireless communication circuit and the wireless communication by the second wireless communication circuit (e.g., the influence of spurious signals), etc., and thus it is possible to increase the robustness of communication within the BMS 1.

[0130] When the wireless communication channel used for wireless communication by the first wireless communication circuit is different from the wireless communication channel used for wireless communication by the second wireless communication circuit, for example, the wireless communication channel used for wireless communication by the first wireless communication circuit is assigned according to identification information assigned to the first monitoring circuit, and the wireless communication channel used for wireless communication by the second wireless communication circuit is assigned according to identification information assigned to the second monitoring circuit.

[0131] FIG. 8 is a diagram showing an example of a wireless communication channel.

[0132] 8, the wireless communication channel "Ch1" is assigned to the monitoring circuit with the identification information "ID1." Similarly, the wireless communication channels "Ch2" to "Ch8" are assigned to the monitoring circuits with the identification information "ID2" to "ID8," respectively.

[0133] For example, if CMU101 is the first monitoring circuit and CMU302 is the second monitoring circuit, the wireless communication circuit 111 becomes the first wireless communication circuit, the communication antenna ANT1 becomes the first communication antenna, the wireless communication circuit 315 becomes the second wireless communication circuit, and the communication antenna ANT5 becomes the second communication antenna. A wireless communication channel corresponding to the identification information "ID2A" is assigned to CMU101, and a wireless communication channel corresponding to the identification information "ID1A" is assigned to CMU302, and the wireless communication channel of CMU101 and the wireless communication channel of CMU302 are different from each other.

[0134] In this case, the monitoring results of the CMU 101 and the CMU 302 are transmitted to the BMU 202 via different wireless communication channels. For example, the voltage values ​​of the multiple battery cells 11 and the current values ​​flowing through the battery pack (the current values ​​flowing through each of the multiple battery cells 11) are transmitted to the BMU 202 via different wireless communication channels. In this way, the BMU 202 measures the internal impedance of each of the multiple battery cells 11.

[0135] For example, if CMU 101 is a first monitoring circuit and CMU 103 is a second monitoring circuit, the wireless communication circuit 111 becomes the first wireless communication circuit, the communication antenna ANT1 becomes the first communication antenna, the wireless communication circuit 113 becomes the second wireless communication circuit, and the communication antenna ANT3 becomes the second communication antenna. A wireless communication channel corresponding to the identification information "ID2A" is assigned to CMU 101, and a wireless communication channel corresponding to the identification information "ID2B" is assigned to CMU 103, and the wireless communication channel of CMU 101 and the wireless communication channel of CMU 103 are different from each other.

[0136] In this case, the monitoring results of the CMU 101 and the CMU 103 are transmitted to the BMU 202 via different wireless communication channels. For example, the voltage values ​​of the plurality of battery cells 11 and the determination results of voltage anomalies of the plurality of battery cells 11 are transmitted to the BMU 202 via different wireless communication channels.

[0137] Since the wireless communication channel used for wireless communication by the first wireless communication circuit and the wireless communication channel used for wireless communication by the second wireless communication circuit are different, it is possible to suppress deterioration of communication quality due to interactions (e.g., the influence of spurious signals) between the wireless communication by the first wireless communication circuit and the wireless communication by the second wireless communication circuit, thereby improving the robustness of communication within the BMS 1.

[0138] Furthermore, in the BMS 1, it is important to measure the voltages of the multiple battery cells 11 that make up the assembled battery simultaneously. This is because the voltages of the multiple battery cells 11 measured at the same time are required to detect an abnormality in the assembled battery. By using different wireless communication channels for communication of the measurement results of each voltage, communication for these measurement results can be performed simultaneously, thereby improving the ability to detect an abnormality in the assembled battery.

[0139] Furthermore, it is important to measure the voltage and current of each of the multiple battery cells 11 constituting the battery pack simultaneously. This is because the internal impedance (voltage / current) of the battery cells 11 measured at the same time is required to estimate the SOC, SOH, SOP, etc. of the battery pack. By using different wireless communication channels for communication of the voltage measurement results and communication of the current measurement results, it is possible to simultaneously communicate these measurement results. This improves the accuracy of measuring the internal impedance of the battery cells 11, thereby improving the accuracy of estimating the SOC, SOH, SOP, etc. of the battery pack.

[0140] Furthermore, by using the identification information assigned to each CMU, it is possible to easily assign a different wireless communication channel to each CMU.

[0141] Furthermore, for example, the transmitting wireless communication channel used for wireless communication by the first wireless communication circuit and the receiving wireless communication channel used for wireless communication by the first wireless communication circuit may be different.

[0142] FIG. 9 is a diagram showing an example of a transmitting wireless communication channel and a receiving wireless communication channel.

[0143] 9, a monitoring circuit having identification information "ID1" is assigned a transmission wireless communication channel of "Transmission Ch1" and a reception wireless communication channel of "Reception Ch1." Similarly, monitoring circuits having identification information "ID2" to "ID8" are assigned transmission wireless communication channels of "Transmission Ch2" to "Transmission Ch8" and reception wireless communication channels of "Reception Ch2" to "Reception Ch8," respectively.

[0144] For example, when the CMU 101 is the first monitoring circuit, a transmitting wireless communication channel and a receiving wireless communication channel according to the identification information "ID2A" are assigned to the CMU 101. In this case, signal transmission from the BMU 202 to the CMU 101 and signal transmission from the CMU 101 to the BMU 202 can be performed simultaneously.

[0145] In this way, by using different wireless communication channels for transmission and reception and performing full-duplex communication, the time required to measure the internal impedance of the battery cell 11 and the like can be reduced.

[0146] (Other Embodiments) As described above, the embodiments have been described as examples of the technology according to the present disclosure. However, the technology according to the present disclosure is not limited to these, and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made as appropriate. For example, the following modifications are also included in one embodiment of the present disclosure.

[0147] In the above embodiment, an example in which two current monitoring circuits are provided has been described, but only one current monitoring circuit may be provided, or no current monitoring circuit may be provided.

[0148] In the above embodiment, each component included in the BMS 1 may be configured with dedicated hardware, or may be realized by executing a software program suitable for each component. Each component may be realized by a program execution unit such as a CPU or processor reading and executing a software program recorded on a recording medium such as a hard disk or semiconductor memory.

[0149] Some or all of the functions of the BMS 1 according to the above-described embodiment are typically realized as an LSI, which is an integrated circuit. These may be individually implemented as single chips, or may be integrated into a single chip that includes some or all of the functions. Furthermore, the integrated circuit is not limited to an LSI, and may be realized using a dedicated circuit or a general-purpose processor. It is also possible to use an FPGA (Field Programmable Gate Array) that can be programmed after LSI manufacturing, or a reconfigurable processor that can reconfigure the connections and settings of circuit cells within the LSI.

[0150] Furthermore, if an integrated circuit technology that can replace LSI emerges due to advances in semiconductor technology or other derived technologies, it is natural that each component included in BMS 1 may be integrated using that technology.

[0151] In addition, this disclosure also includes forms obtained by making various modifications to the embodiments that a person skilled in the art would think of, and forms realized by arbitrarily combining the components and functions in each embodiment within the scope of the present disclosure.

[0152] (Additional Notes) The above description of the embodiments discloses the following techniques.

[0153] (Technology 1) A battery management system for managing an assembled battery, comprising: a management circuit for managing the assembled battery; and a plurality of monitoring circuits for monitoring the assembled battery, wherein a first monitoring circuit of the plurality of monitoring circuits comprises a first wireless communication circuit and a first communication antenna for communicating with the management circuit; and a second monitoring circuit of the plurality of monitoring circuits comprises a second wireless communication circuit and a second communication antenna for communicating with the management circuit, and wherein a modulation method for wireless communication by the first wireless communication circuit is different from a modulation method for wireless communication by the second wireless communication circuit.

[0154] With this, since the modulation method for wireless communication by the first wireless communication circuit and the modulation method for wireless communication by the second wireless communication circuit are different, it is possible to suppress deterioration of communication quality due to interaction (e.g., the influence of spurious signals) between the wireless communication by the first wireless communication circuit and the wireless communication by the second wireless communication circuit, thereby improving the robustness of communication within the battery management system.

[0155] (Technology 2) A battery management system according to Technology 1, wherein a modulation method for wireless communication by the first wireless communication circuit is one of a spread spectrum method, an OFDM method, and an UWB method, and a modulation method for wireless communication by the second wireless communication circuit is a method different from the modulation method for wireless communication by the first wireless communication circuit, which is one of a spread spectrum method, an OFDM method, and an UWB method.

[0156] According to this, two modulation methods are selected from these modulation methods and used, thereby increasing communication redundancy and achieving stronger robustness.

[0157] (Technology 3) A battery management system for managing an assembled battery, comprising: a management circuit for managing the assembled battery; and a plurality of monitoring circuits for monitoring the assembled battery, wherein a first monitoring circuit of the plurality of monitoring circuits comprises a first wireless communication circuit and a first communication antenna for communicating with the management circuit; and a second monitoring circuit of the plurality of monitoring circuits comprises a second wireless communication circuit and a second communication antenna for communicating with the management circuit, and wherein a wireless communication channel used for wireless communication by the first wireless communication circuit is different from a wireless communication channel used for wireless communication by the second wireless communication circuit.

[0158] With this, since the wireless communication channel used for wireless communication by the first wireless communication circuit and the wireless communication channel used for wireless communication by the second wireless communication circuit are different, it is possible to suppress deterioration of communication quality due to interaction (e.g., the influence of spurious signals) between the wireless communication by the first wireless communication circuit and the wireless communication by the second wireless communication circuit, thereby improving the robustness of communication within the battery management system.

[0159] Furthermore, in a battery management system, it is important to measure the voltages of the multiple battery cells that make up the assembled battery simultaneously. This is because the voltages of the multiple battery cells must be measured at the same time when detecting an abnormality in the assembled battery. By using different wireless communication channels to communicate the measurement results of each voltage, communication for these measurement results can be carried out simultaneously, improving the ability to detect abnormalities in the assembled battery.

[0160] Furthermore, simultaneous measurement of the voltage and current of each of the multiple battery cells constituting the battery pack is important. This is because the internal impedance (voltage / current) of the battery cells measured at the same time is required to estimate the SOC, SOH, SOP, etc. of the battery pack. By using different wireless communication channels for communication of the voltage measurement results and communication of the current measurement results, communication for these measurement results can be performed simultaneously. This improves the accuracy of measuring the internal impedance of the battery cells, and ultimately improves the accuracy of estimating the SOC, SOH, SOP, etc. of the battery pack.

[0161] (Technology 4) A battery management system according to Technology 3, wherein a wireless communication channel used for wireless communication by the first wireless communication circuit is assigned according to identification information assigned to the first monitoring circuit, and a wireless communication channel used for wireless communication by the second wireless communication circuit is assigned according to identification information assigned to the second monitoring circuit.

[0162] According to this, by using the identification information assigned to the monitoring circuit, it is possible to easily assign a different wireless communication channel to each monitoring circuit.

[0163] (Technology 5) A battery management system according to any one of technologies 1 to 4, in which a transmitting wireless communication channel used for wireless communication by the first wireless communication circuit is different from a receiving wireless communication channel used for wireless communication by the first wireless communication circuit.

[0164] By using different wireless communication channels for transmission and reception and performing full-duplex communication, it is possible to reduce the time required to measure the internal impedance of a battery cell, etc.

[0165] (Technology 6) A battery management system according to any one of technologies 1 to 5, wherein the plurality of monitoring circuits include a cell monitoring circuit that monitors one or more battery cells that constitute the assembled battery, or a current monitoring circuit that measures the current flowing through the assembled battery.

[0166] Thus, the monitoring circuit may be a cell monitoring circuit or a current monitoring circuit.

[0167] The present disclosure can be applied to a battery management system in which wireless communication is performed within the system.

[0168] 1 BMS 10 Battery pack 11 Battery cell 20 Junction box 100 Monitoring circuit 101, 103 CMU (Cell Monitoring Unit) 111, 113, 211, 212, 315, 317 Wireless communication circuit 112, 114 Voltage monitoring circuit 121, 141, 221, 331 Voltage conversion circuit 122, 142, 222, 332 Timer circuit 123, 145, 223, 323, 333 Communication interface 124, 224, 334 Clock generation circuit 125, 146, 225, 324, 335 Phase synchronization circuit 126, 226, 337 Modulation circuit 127, 227, 338 Transmission circuit 128, 228, 339 Demodulation circuit 129, 229, 340 Receiving circuit 130 Non-volatile memory 131, 231, 341 Communication error determination circuit 132, 232, 342 Start circuit 133, 343 LED 143 Multiplexer 144, 322 AD converter 147, 241, 243, 325, 336 Encryption circuit 148 Switch 149, 150, 151, 152 Comparator 200 Management circuit 202 BMU 213 MCU 242, 244 Identification circuit 245 Table 302, 303 CMU (Current Monitoring Unit) 314, 316 Current measurement circuit 321 Amplification circuit 400 Motor 401 Relay 403, 404 Shunt resistor 405 Power line ANT1, ANT2, ANT3, ANT4, ANT5, ANT6 Communication antenna

Claims

1. A battery management system for managing a battery pack, A management circuit for managing the battery pack; a plurality of monitoring circuits for monitoring the battery pack; a first monitoring circuit of the plurality of monitoring circuits includes a first wireless communication circuit and a first communication antenna for communicating with the management circuit; a second monitoring circuit of the plurality of monitoring circuits includes a second wireless communication circuit and a second communication antenna for communicating with the management circuit; a modulation method for wireless communication by the first wireless communication circuit and a modulation method for wireless communication by the second wireless communication circuit are different from each other; Battery management system.

2. A battery management system for managing a battery pack, A management circuit for managing the battery pack; a plurality of monitoring circuits for monitoring the battery pack; a first monitoring circuit of the plurality of monitoring circuits includes a first wireless communication circuit and a first communication antenna for communicating with the management circuit; a second monitoring circuit of the plurality of monitoring circuits includes a second wireless communication circuit and a second communication antenna for communicating with the management circuit; a wireless communication channel used for wireless communication by the first wireless communication circuit is different from a wireless communication channel used for wireless communication by the second wireless communication circuit; Battery management system.

3. a transmitting wireless communication channel used for wireless communication by the first wireless communication circuit is different from a receiving wireless communication channel used for wireless communication by the first wireless communication circuit; The battery management system according to claim 1 or 2.

4. the plurality of monitoring circuits include a cell monitoring circuit that monitors one or more battery cells that constitute the battery pack, or a current monitoring circuit that measures a current flowing through the battery pack; The battery management system according to claim 1 or 2.

5. A battery management system for managing a battery pack, comprising: A management circuit for managing the battery pack; a plurality of monitoring circuits for monitoring the battery pack; a first monitoring circuit of the plurality of monitoring circuits includes a first wireless communication circuit and a first communication antenna for communicating with the management circuit; a second monitoring circuit of the plurality of monitoring circuits includes a second wireless communication circuit and a second communication antenna for communicating with the management circuit; a modulation method for wireless communication by the first wireless communication circuit and a modulation method for wireless communication by the second wireless communication circuit are different, a modulation method for wireless communication by the first wireless communication circuit is any one of a spread spectrum method, an OFDM (Orthogonal Frequency Division Multiplexing) method, and a UWB (Ultra Wide Band) method; a modulation method for wireless communication by the second wireless communication circuit is a spread spectrum method, an OFDM method, or an UWB method, which is different from a modulation method for wireless communication by the first wireless communication circuit; Battery management system.

6. A battery management system for managing a battery pack, comprising: A management circuit for managing the battery pack; a plurality of monitoring circuits for monitoring the battery pack; a first monitoring circuit of the plurality of monitoring circuits includes a first wireless communication circuit and a first communication antenna for communicating with the management circuit; a second monitoring circuit of the plurality of monitoring circuits includes a second wireless communication circuit and a second communication antenna for communicating with the management circuit; a wireless communication channel used for wireless communication by the first wireless communication circuit is different from a wireless communication channel used for wireless communication by the second wireless communication circuit, a wireless communication channel used for wireless communication by the first wireless communication circuit is assigned in accordance with identification information given to the first monitoring circuit; a wireless communication channel used for wireless communication by the second wireless communication circuit is assigned in accordance with identification information assigned to the second monitoring circuit; Battery management system.