Battery pack high-voltage test method and system based on CAN message verification

Abstract

The invention discloses a battery pack high-voltage test method and system based on CAN message verification, and the method comprises the steps: a test terminal determines a verification algorithm and message sending information according to the editing information of a tester, and generates and stores a test scheme of a battery pack; the test terminal obtains the identity information of the battery pack, calls the bound test scheme and the dll file, and issues the test scheme and the dll file to the charging and discharging equipment; the charging and discharging equipment extracts a verification algorithm and message sending information according to the test scheme, periodically calls a dll file to calculate CAN data containing a verification value in the charging and discharging process, and sends a CAN packet to a CAN bus to the battery pack based on the obtained CAN data; the battery management system of the battery pack controls whether a contactor for controlling high-voltage electricity prevention in the battery pack is kept in a pull-in state or not according to the condition of receiving the CAN pack; therefore, the charging and discharging equipment periodically and automatically counts and verifies the CAN messages in the whole charging and discharging process, the operation is more convenient and quicker, and the control of the high-voltage output of the battery pack is more reliable and safer.

Description

Technical Field

[0001] The present invention relates to the field of battery testing, and in particular to a battery pack high voltage testing method and system based on CAN message verification. Background Art

[0002] Battery pack high voltage testing is a key link to ensure the safe, stable and reliable operation of high voltage battery packs in electric vehicles or related equipment. The main purpose of battery pack high voltage testing is to verify the performance, safety and reliability of the battery pack under high voltage environment. Through testing, key indicators such as the voltage tolerance, insulation performance, temperature characteristics and cycle life of the battery pack can be evaluated to ensure that the battery pack has excellent safety and stability in practical applications. The existing test scheme is that the charging and discharging equipment instructs the battery pack to start the high voltage test through CAN communication, tests for a period of time, and then instructs the battery pack to end the high voltage test through CAN communication. In addition, the tester needs to manually edit the CAN message every time. Because the high voltage test is relatively special, the current test scheme is insufficient in reliability, safety and convenience for high voltage testing.

[0003] The above information disclosed in this Background section is included only for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not form the prior art that is currently known to a person of ordinary skill in the art. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a battery pack high-voltage testing method and system based on CAN message verification in view of the above-mentioned defects of the prior art.

[0005] The technical solution adopted by the present invention to solve its technical problem is:

[0006] On the one hand, a battery pack high voltage test method based on CAN message verification is constructed, and the method includes:

[0007] The test terminal determines the verification algorithm and message sending information of the CAN message according to the selection and editing information of the tester, generates and saves the test plan of the battery pack, and the test information of the test plan includes the determined verification algorithm and message sending information;

[0008] The test terminal obtains the identity information of the battery pack, calls the test scheme pre-bound for the battery pack and the dll file pre-compiled by the developer based on the CAN communication matrix of the battery pack according to the obtained identity information, and sends it to the charging and discharging device;

[0009] The charging and discharging equipment extracts the verification algorithm and message sending information according to the test information contained in the test plan. During the charging and discharging process, the dll file is periodically called to calculate the CAN data containing the verification value, and the CAN packet is sent to the CAN bus to the battery pack based on the obtained CAN data, and the port voltage of the battery pack is detected to maintain a high voltage.

[0010] The battery management system of the battery pack controls whether the high-voltage protection contactor inside the battery pack remains in the energized state according to the situation of receiving the CAN packet.

[0011] Furthermore, in the method of the present invention, the charging and discharging device extracts the verification algorithm and the message sending information according to the test information contained in the test scheme, and during the charging and discharging process, periodically calls the dll file to calculate the CAN data containing the verification value, specifically including:

[0012] The charging and discharging device parses the test information according to the received test plan, and saves the parsed test information into the CAN message sending object;

[0013] The charging and discharging device reads the CAN message sending object in the memory, starts the thread for sending the CAN message and passes the CAN message sending object into the thread;

[0014] In the thread, according to the message sending information in the CAN message sending object, the CAN message sending object is passed into the dll file in the form of parameters;

[0015] The dll file selects the corresponding verification algorithm according to the incoming CAN message sending object, calculates the corresponding message count, passes the count byte and the known control byte into the selected verification algorithm to obtain the verification value, assigns the verification value to the predetermined byte in the byte array corresponding to the CAN message, and returns the byte array to the thread.

[0016] Furthermore, in the method of the present invention, the test terminal determines the verification algorithm of the CAN message and the message sending information according to the selection and editing information of the tester, specifically including:

[0017] The test terminal provides various options of verification algorithms for the tester to choose from through a drop-down box, and determines the verification algorithm selected by the tester according to the tester's drop-down box selection instruction;

[0018] The test terminal provides various options of the sending type through a drop-down box for the tester to choose from, and provides a text box corresponding to the sending type for the tester to edit specific sending parameters.

[0019] Furthermore, in the method described in the present invention, the sending type includes cyclic sending and multiple sending. The text box corresponding to the cyclic sending records the interval time between two adjacent sendings, and the text box corresponding to the multiple sending records the total number of sending times.

[0020] Furthermore, in the method described in the present invention, the option content corresponding to the drop-down box of the verification algorithm is provided in advance by the developer through the txt or excel document import method.

[0021] Furthermore, in the method of the present invention, the identity information is a barcode rule, and the method further comprises: after saving the test plan, obtaining the barcode rule input by the tester, and binding the input barcode rule to the test plan;

[0022] The test terminal obtains the identity information of the battery pack, specifically including: reading the QR code on the battery pack by scanning the code, and parsing the barcode rule therefrom.

[0023] Furthermore, in the method described in the present invention, the battery management system of the battery pack controls whether the contactor for controlling high-voltage electric shock protection inside the battery pack remains in an attracted state according to the situation of receiving the CAN packet, specifically including: if a CAN message is received, parsing the received CAN message, calculating the check value of the CAN message by the check algorithm recorded in the CAN message, comparing the locally calculated check value with the check value received on the CAN bus, and controlling whether the contactor for controlling high-voltage electric shock protection inside the battery pack remains in an attracted state according to the comparison result.

[0024] Furthermore, in the method described in the present invention, the control of whether the contactor for controlling high-voltage electrical protection inside the battery pack remains in an energized state based on the comparison result specifically includes: when the locally calculated check value is consistent with the check value received on the CAN bus, the battery management system of the battery pack controls the contactor to remain in an energized state; otherwise, the contactor is controlled to be disconnected.

[0025] Furthermore, in the method described in the present invention, the battery management system of the battery pack controls whether the contactor for controlling high-voltage electrical protection inside the battery pack remains in an energized state according to the situation of receiving the CAN packet, and also includes: if the corresponding CAN message is not received within a set time, the battery management system of the battery pack controls the contactor to disconnect.

[0026] On the second aspect, a battery pack high-voltage test system based on CAN message verification is constructed to implement the steps of the method described in any of the preceding items. The system includes a test terminal and a charging and discharging device. The test terminal communicates with the charging and discharging device via a network, and the charging and discharging device communicates with at least one battery pack via a CAN bus.

[0027] The battery pack high-voltage testing method and system based on CAN message verification of the present invention have the following beneficial effects: the present invention utilizes the terminal to edit the test plan, the tester can select the verification algorithm and send information, generate a test plan and send it to the charging and discharging equipment, the charging and discharging equipment will periodically call the dll file during the entire test process to calculate the CAN data containing the verification value and send it to the CAN bus to the battery pack, the battery management system of the battery pack controls whether the contactor for controlling the high-voltage protection inside the battery pack remains in the attracted state according to the situation of receiving the CAN package, so that the tester can formulate the test plan conveniently and quickly, the charging and discharging equipment periodically and automatically counts and verifies the CAN messages during the entire charging and discharging process, which is more convenient and quick, and the control of the high-voltage output of the battery pack is also more reliable and safe. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below. Obviously, the drawings in the following description are only embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the provided drawings without creative work:

[0029] Figure 1 It is a flow chart of a battery pack high voltage testing method based on CAN message verification of the present invention;

[0030] Figure 2 This is a schematic diagram of the editing interface of the test software. DETAILED DESCRIPTION

[0031] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Typical embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solutions of the present application, rather than limitations on the technical solutions of the present application. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0032] refer to Figure 1 The battery pack high voltage test method based on CAN message verification of the present invention comprises:

[0033] S100: The test terminal determines the verification algorithm and message sending information of the CAN message according to the selection and editing information of the tester, generates and saves the test plan of the battery pack, and the test information of the test plan includes the determined verification algorithm and message sending information;

[0034] S200: The test terminal obtains the identity information of the battery pack, calls the test scheme pre-bound for the battery pack and the dll file pre-compiled by the developer based on the CAN communication matrix of the battery pack according to the obtained identity information, and sends it to the charging and discharging device;

[0035] S300: the charging and discharging device extracts the verification algorithm and the message sending information according to the test information included in the test scheme, and during the charging and discharging process, periodically calls the dll file to calculate the CAN data including the verification value, sends the CAN packet to the CAN bus to the battery pack based on the obtained CAN data, and detects whether the port voltage of the battery pack maintains a high voltage;

[0036] S400: The battery management system of the battery pack controls whether the high-voltage protection contactor inside the battery pack remains in the energized state according to the situation of receiving the CAN packet.

[0037] It can be understood that S100 is the preparation work on the test terminal side before the actual test, S200 is the data transmission work on the test terminal side when the test starts, and S300 is the formal test process of the charging and discharging equipment and the battery pack.

[0038] The above method steps are described in detail below.

[0039] Specifically, before formulating a test plan, you need to first obtain the CAN communication matrix of the customer's battery pack. The CAN communication matrix refers to the CAN data structure for CAN communication between the battery pack and the charging and discharging equipment. The developer updates the configuration file based on the CAN communication matrix. The test terminal can be a PC, which is actually the test software running on the PC to implement the function. The tester can enter the test interface by running the test software on the PC. The test software will display the editing interface corresponding to the CAN communication matrix according to the configuration file, and display the content that the tester needs to edit in the CAN communication matrix in the form of a list, drop-down box, text box, etc. on the test interface of the terminal for the tester to edit. Figure 2 As shown, it mainly fills in the DBC value and requires the tester to select the verification algorithm and message sending information.

[0040] Therefore, in step S100, the test terminal determines the verification algorithm of the CAN message and the message sending information according to the tester's selection and editing information, specifically including: the test terminal provides various options of the verification algorithm for the tester to choose through a drop-down box, and determines the verification algorithm selected by the tester according to the tester's drop-down box selection instruction; the test terminal provides various options of the sending type for the tester to choose through a drop-down box, and provides a text box corresponding to the sending type for the tester to edit specific sending parameters.

[0041] Specifically, the sending type includes cyclic sending and multiple sending. Multiple sending means that the number of sending is fixed and sent at a set interval. Cyclic sending means sending continuously at an interval. Therefore, the text box corresponding to cyclic sending is the interval time between two adjacent sendings, and the text box will be activated when "cyclic sending" is selected in the drop-down box. The text box corresponding to multiple sending is the total number of sending times, and the text box will be activated when "multiple sending" is selected in the drop-down box.

[0042] Among them, the option content corresponding to the drop-down box of the verification algorithm is provided in advance by the developer through the txt or excel document import method.

[0043] In addition, developers can know the location of the verification algorithm and the location of the verification value, as well as other control bytes based on the CAN communication matrix. Therefore, a dll file can be prepared in advance for the CAN communication matrix and placed in the software running directory of the test terminal. The dll file is used to automatically calculate the CAN data that needs to be sent periodically during the charging and discharging process during the high-voltage test of the corresponding battery pack.

[0044] For example, Table 1 shows a specific CAN communication matrix:

[0045] Table 1

[0046]

[0047] The byte0 is where the checksum is stored. The CAN message count is in the lower 4 bits of byte1 in the CAN message, so the maximum value of the lower 4 bits in byte1 is determined to be 15 (2^4-1), which means that when the CAN message count is greater than 15, it is reset to 0. When the dll file is executed, the CAN message count will be performed. When the CAN message count is greater than 15, it is reset to 0. The checksum value to be written into byte0 is calculated based on the count value and the checksum algorithm selected by the tester through the drop-down box.

[0048] For example, when testing the battery pack using the E2E verification type, the tester edits the sending type in the editing interface and selects cyclic sending and fills in 100ms for the interval time. This means that during the test, the CAN verification message is sent cyclically at an interval of 100ms. The corresponding control message constitutes other byte data in the CAN packet, such as Figure 2 As shown, the values ​​corresponding to other control messages are filled in according to the DBC signal point name corresponding to the frame ID corresponding to the imported CAN matrix.

[0049] After saving the test plan in step S100, the test plan needs to be bound to the battery pack. The tester enters the binding interface of the test interface and enters the barcode rules of the battery pack (scan code input or manual input). Correspondingly, step S100 also includes: after the test plan is saved on one side of the test terminal, the barcode rules entered by the tester are obtained, and the entered barcode rules are bound to the test plan. At this point, the preparations before the test are completed.

[0050] When testing is required, step S200 is executed. In step S200, the QR code on the battery pack is read by scanning, and the barcode rule is parsed from it. By matching the barcode rule, the barcode rule that is consistent with the currently scanned barcode rule is found from the saved barcode rules, and the test plan pre-bound to the battery pack and the dll file pre-compiled by the developer based on the CAN communication matrix of the battery pack are called through the barcode rule, and sent to the charging and discharging device for storage through the network protocol.

[0051] After receiving the test plan and dll file, the charging and discharging device executes step S300 to parse the test information contained in the test plan, and extract the verification algorithm, message sending information, and control message data in the DBC signal point name. After obtaining these data, formal high-voltage charging and discharging must be implemented. The charging and discharging equipment mainly performs two tasks during the charging and discharging process: the first task is to periodically send CAN packets, and the second task is to detect in real time whether the port voltage of the battery pack maintains high voltage. These two tasks are performed simultaneously. The second task is already available and will not be elaborated on. The execution process of the first task is described in detail below, mainly as follows:

[0052] S301: The charging and discharging device saves the parsed test information into the CAN message sending object;

[0053] The CAN of a channel on the charging and discharging device and the CAN of the battery pack form a CAN bus system. A charging and discharging device can be configured with multiple channels, that is, it can simultaneously implement the charging and discharging test of multiple battery packs. Therefore, each battery pack corresponds to a CAN message sending object.

[0054] S302: The charging and discharging device reads the CAN message sending object in the memory, starts a thread for sending the CAN message and transfers the CAN message sending object to the thread;

[0055] S303: in the thread, according to the message sending information in the CAN message sending object, the CAN message sending object is passed into the dll file in the form of a parameter;

[0056] S304: The dll file selects a corresponding verification algorithm according to the incoming CAN message sending object, and calculates the corresponding message count (for example, the example corresponding to Table 1, that is, after the CAN message count exceeds 15, it is automatically reset to 0 and restarts counting), passes the count byte and the known control byte into the selected verification algorithm to obtain the verification value, assigns the verification value to the predetermined byte in the byte array corresponding to the CAN message (for example, the example corresponding to Table 1, that is, the byte0 byte to be assigned to the byte array), and returns the byte array to the thread.

[0057] S305: After obtaining the sent array, the thread is returned to the thread. The thread converts the byte array returned by the dll into a CAN packet according to the CAN message sending object and sends it to the CAN bus of the battery pack and the charging and discharging device.

[0058] The channels on the charging and discharging equipment are independent of each other or do not interfere with each other. The CAN bus is also a channel directly connected to the battery pack. The CAN signal uploaded by the battery pack is transmitted to the charging and discharging equipment through the bus. The CAN message of the charging and discharging equipment is sent to the battery management system (BMS) of the battery pack through the CAN bus. The BMS receives the corresponding CAN packet through the CAN bus. After the battery management system of the battery pack receives the CAN packet, it executes step S400. According to the situation of receiving the CAN packet, it controls whether the contactor that controls the high-voltage protection inside the battery pack remains in the energized state. Specifically, there are two situations:

[0059] S401: If the battery pack receives a CAN message, the received CAN message is parsed, the check value of the CAN message is calculated using the check algorithm recorded in the CAN message, the locally calculated check value is compared with the check value received on the CAN bus, and the contactor controlling the high-voltage protection inside the battery pack is controlled to remain in the energized state based on the comparison result.

[0060] Among them, the control of whether the contactor for controlling high-voltage electrical protection inside the battery pack remains in the energized state according to the comparison result specifically includes: when the locally calculated check value is consistent with the check value received on the CAN bus, the battery management system of the battery pack controls the contactor to remain in the energized state; otherwise, the contactor is controlled to be disconnected, so that the high-voltage port voltage outside the battery pack will drop.

[0061] Since the battery pack needs to maintain a high voltage state during the charging and discharging process, if the charging and discharging equipment detects that the voltage at the high-voltage port of the battery pack drops during the charging and discharging process, charging and discharging will not be able to proceed normally.

[0062] S402: If the battery pack does not receive the corresponding CAN message within a set time, the battery management system of the battery pack controls the contactor to disconnect.

[0063] After the test is completed, the thread sending the CAN message will end, the BMS will not receive the CAN verification message, the internal contactor of the battery pack will be controlled to disconnect, the battery pack will end its high voltage output, the charge and discharge test will end, and the test will be completed.

[0064] In the above, during the entire charging and discharging process, the charging and discharging equipment will count the CAN messages and calculate the verification value according to the set interval time, and send the combined known CAN messages; after the BMS receives the CAN package, it will calculate the verification value locally and compare it with the verification value in the CAN package, and compare the verification results. When one of the results is not equal to the received verification value, the BMS will promptly send a control disconnection instruction to the internal contactor of the battery pack, and the charging and discharging process will be abnormal. During the charging and discharging process, when the charging and discharging equipment does not send the CAN message that needs to be verified, the BMS will also disconnect the internal contactor of the battery pack, or when the BMS does not receive the corresponding CAN verification message within the set time, the BMS will also control the internal contactor of the battery pack to disconnect. In this way, the embodiment maintains high-voltage output by automatically sending CAN packets periodically during the high-voltage charging and discharging process, which is safer and more reliable. Moreover, it can adapt to the CAN message sending of any battery pack. The test software can customize the sending type and verification algorithm of the CAN message by editing and selecting the corresponding function, reducing the time of converting the editing test process into a CAN message and reducing the time cost.

[0065] Based on the same inventive concept, the present invention also claims protection for a battery pack high voltage test system based on CAN message verification, which implements the steps of the above method. The system includes a test terminal and a charging and discharging device, wherein the test terminal communicates with the charging and discharging device via a network, and the charging and discharging device communicates with at least one battery pack via a CAN bus.

[0066] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0067] The words "equal", "same", "simultaneous" or other similar terms are not limited to absolute equality or sameness in mathematical terms. When implementing the rights described in this patent, they can be close in an engineering sense or within an acceptable error range.

[0068] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing related hardware through a computer program, and the program can be stored in a computer-readable storage medium, and when the program is executed, it can include the processes of the embodiments of the above-mentioned methods. The storage medium can be a disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM), etc.

[0069] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A battery pack high voltage test method based on CAN message verification, characterized in that: The method comprises: The test terminal determines the verification algorithm and message sending information of the CAN message according to the selection and editing information of the tester, generates and saves the test plan of the battery pack, and the test information of the test plan includes the determined verification algorithm and message sending information; The test terminal obtains the identity information of the battery pack, calls the test scheme pre-bound for the battery pack and the dll file pre-compiled by the developer based on the CAN communication matrix of the battery pack according to the obtained identity information, and sends it to the charging and discharging device; The charging and discharging equipment extracts the verification algorithm and message sending information according to the test information contained in the test plan. During the charging and discharging process, the dll file is periodically called to calculate the CAN data containing the verification value, and the CAN packet is sent to the CAN bus to the battery pack based on the obtained CAN data, and the port voltage of the battery pack is detected to maintain a high voltage. The battery management system of the battery pack controls whether the high-voltage protection contactor inside the battery pack remains in the energized state according to the situation of receiving the CAN packet.

2. The method according to claim 1, characterized in that The charging and discharging device extracts the verification algorithm and the message sending information according to the test information contained in the test scheme, and periodically calls the dll file to calculate the CAN data containing the verification value during the charging and discharging process, specifically including: The charging and discharging device parses the test information according to the received test plan, and saves the parsed test information into the CAN message sending object; The charging and discharging device reads the CAN message sending object in the memory, starts the thread for sending the CAN message and passes the CAN message sending object into the thread; In the thread, according to the message sending information in the CAN message sending object, the CAN message sending object is passed into the dll file in the form of parameters; The dll file selects the corresponding verification algorithm according to the incoming CAN message sending object, calculates the corresponding message count, passes the count byte and the known control byte into the selected verification algorithm to obtain the verification value, assigns the verification value to the predetermined byte in the byte array corresponding to the CAN message, and returns the byte array to the thread.

3. The method according to claim 1, characterized in that The test terminal determines the verification algorithm of the CAN message and the message sending information according to the selection and editing information of the tester, specifically including: The test terminal provides various options of verification algorithms for the tester to choose from through a drop-down box, and determines the verification algorithm selected by the tester according to the tester's drop-down box selection instruction; The test terminal provides various options of the sending type through a drop-down box for the tester to choose from, and provides a text box corresponding to the sending type for the tester to edit specific sending parameters.

4. The method according to claim 3, characterized in that: The sending type includes cyclic sending and multiple sending. The text box corresponding to the cyclic sending records the interval time between two adjacent sendings, and the text box corresponding to the multiple sending records the total number of sending times.

5. The method according to claim 3, characterized in that: The options corresponding to the drop-down box of the verification algorithm are provided in advance by the developer through the import method of txt or excel document.

6. The method according to claim 1, characterized in that The identity information is a barcode rule, and the method further includes: after saving the test plan, obtaining the barcode rule input by the tester, and binding the input barcode rule to the test plan; The test terminal obtains the identity information of the battery pack, specifically including: reading the QR code on the battery pack by scanning the code, and parsing the barcode rule therefrom.

7. The method according to claim 1, characterized in that The battery management system of the battery pack controls whether the contactor for controlling high-voltage electric shock protection inside the battery pack remains in an attracted state according to the situation of receiving the CAN packet, specifically including: if a CAN message is received, parsing the received CAN message, calculating the check value of the CAN message by using the check algorithm recorded in the CAN message, comparing the locally calculated check value with the check value received on the CAN bus, and controlling whether the contactor for controlling high-voltage electric shock protection inside the battery pack remains in an attracted state according to the comparison result.

8. The method according to claim 7, characterized in that The controlling of whether the high-voltage protection contactor inside the battery pack remains in the energized state according to the comparison result specifically includes: when the locally calculated check value is consistent with the check value received on the CAN bus, the battery management system of the battery pack controls the contactor to remain in the energized state; otherwise, the contactor is controlled to be disconnected.

9. The method according to claim 7, characterized in that: The battery management system of the battery pack controls whether the contactor for controlling high-voltage electrical protection inside the battery pack remains in an energized state according to the situation of receiving the CAN packet, and also includes: if the corresponding CAN message is not received within a set time, the battery management system of the battery pack controls the contactor to disconnect.

10. A battery pack high voltage test system based on CAN message verification, characterized in that: Implement the steps of the method described in any one of claims 1 to 9, wherein the system includes a test terminal and a charging and discharging device, the test terminal communicates with the charging and discharging device via a network, and the charging and discharging device communicates with at least one battery pack via a CAN bus.

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