Battery cell monitoring device, battery management system and electric vehicle

Abstract

The utility model discloses a battery cell monitoring device, a battery management system and an electric automobile, the battery cell monitoring device comprises a plurality of battery cell monitoring modules, each of the plurality of battery cell monitoring modules is connected with a plurality of battery cells in a battery pack, and the plurality of battery cell monitoring modules are connected with a main control device through NFC. The plurality of battery cell monitoring modules are respectively arranged at positions corresponding to the plurality of battery cells; and the first battery cell monitoring module is used for receiving the voltage monitoring instruction from the main control device, monitoring the voltage values of the corresponding multiple battery cells according to the voltage monitoring instruction, and sending the voltage values of the corresponding multiple battery cells to the main control device through NFC, and the first battery cell monitoring module is any one of the multiple battery cell monitoring modules. In the embodiment of the invention, each battery cell monitoring module is arranged at the position of the plurality of monitored battery cells, so that the distance between the battery cell and the corresponding battery cell monitoring module is relatively short, the connecting line between the battery cell and the battery cell monitoring module is relatively short, and the cost can be reduced.

Description

Technical Field

[0001] The present application relates to the field of electronic circuit technology, and in particular to a battery cell monitoring device, a battery management system and an electric vehicle. Background Art

[0002] The battery management system (BMS) is mainly used to intelligently manage and maintain batteries, extend the battery life, monitor the battery status, and ensure the normal operation of electric vehicles. The battery pack of an electric vehicle includes many cells. In order to manage and maintain these cells, the battery management system may include a control motherboard and an integrated cell monitoring board. The positive and negative electrodes of the cell are connected to the integrated cell monitoring board through a flexible printed circuit board (FPC). However, the cost of using FPC connection is relatively high. Utility Model Content

[0003] The embodiments of the present application disclose a battery cell monitoring device, a battery management system and an electric vehicle for reducing costs.

[0004] In a first aspect, an embodiment of the present application discloses a battery cell monitoring device, comprising a plurality of battery cell monitoring modules, each of the plurality of battery cell monitoring modules is respectively connected to a plurality of battery cells in a battery pack, the plurality of battery cell monitoring modules are connected to a main control device via near field communication (NFC), and the plurality of battery cell monitoring modules are respectively arranged at positions corresponding to the plurality of battery cells;

[0005] The first battery cell monitoring module is used to receive a voltage monitoring instruction from the main control device, monitor the voltage values ​​of the corresponding multiple battery cells according to the voltage monitoring instruction, and send the voltage values ​​of the corresponding multiple battery cells to the main control device via NFC. The first battery cell monitoring module is any battery cell monitoring module among the multiple battery cell monitoring modules.

[0006] In a second aspect, an embodiment of the present application discloses a battery management system, including a main control device and a battery cell monitoring device disclosed in the first aspect;

[0007] The main control device is used to send a voltage monitoring instruction to the battery cell monitoring device via NFC;

[0008] The main control device is also used to receive the voltage values ​​of the cells in the battery pack from the cell monitoring device via NFC, and control the voltage balance of the cells in the battery pack according to the voltage values ​​of the cells in the battery pack.

[0009] In a third aspect, the present application discloses an electric vehicle, including a battery cell monitoring device as disclosed in the first aspect, or a battery management system as disclosed in the second aspect.

[0010] In the embodiment of the present application, the battery cell monitoring device includes multiple battery cell monitoring modules, each of the multiple battery cell monitoring modules is respectively connected to multiple battery cells in the battery pack, the multiple battery cell monitoring modules are connected to the main control device via NFC, and the multiple battery cell monitoring modules are respectively arranged at the positions corresponding to the multiple battery cells; the first battery cell monitoring module receives the voltage monitoring instruction from the main control device, monitors the voltage values ​​of the corresponding multiple battery cells according to the voltage monitoring instruction, and sends the voltage values ​​of the corresponding multiple battery cells to the main control device via NFC. It can be seen that the battery cell monitoring device includes multiple battery cell monitoring modules, each battery cell monitoring module monitors multiple battery cells, and each battery cell monitoring module is respectively arranged at the position of the monitored multiple battery cells. Since the battery cell monitoring module is arranged at the position of the monitored multiple battery cells, the distance between the battery cell and the corresponding battery cell monitoring module is closer, and the connection between the battery cell and the battery cell monitoring module is shorter, which can reduce the cost. In addition, since each battery cell monitoring module monitors multiple battery cells, the battery pack requires fewer battery cell monitoring modules, which can reduce the cost. Further, since the connection between the battery cell and the battery cell monitoring module is shorter, interference can be reduced. Furthermore, since the battery cell monitoring module communicates with the main control device via NFC, the anti-interference capability and the security of information transmission can be improved, and the cost can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0012] Figure 1 It is a structural schematic diagram of a battery cell monitoring device disclosed in an embodiment of the present application;

[0013] Figure 2 It is a structural schematic diagram of a battery cell monitoring module disclosed in an embodiment of the present application;

[0014] Figure 3 It is a structural schematic diagram of another battery cell monitoring module disclosed in an embodiment of the present application;

[0015] Figure 4 It is a structural schematic diagram of a battery management system disclosed in an embodiment of the present application;

[0016] Figure 5 is a schematic diagram of the structure of another battery management system disclosed in an embodiment of the present application;

[0017] Figure 6 It is a cross-sectional schematic diagram of a battery monitoring system disclosed in an embodiment of the present application. DETAILED DESCRIPTION

[0018] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0019] The embodiments of the present application disclose a battery cell monitoring device, a battery management system and an electric vehicle, which are used to reduce costs.

[0020] In order to better understand the embodiments of the present application, the relevant technologies of the embodiments of the present application are described below.

[0021] The number of cells in the power battery pack of electric vehicles is large, generally greater than 100 strings. In order to manage these cells, the battery management system generally uses a control main board and an integrated cell monitoring board. The positive and negative poles of the cell are connected to the integrated cell monitoring board through FPC, and the control main board and the integrated cell monitoring board communicate through a daisy chain. The number of cells monitored by the integrated cell monitoring board is large, and each integrated cell monitoring board has only one cell monitoring module, so that the positive and negative poles of the cells far away from the cell monitoring module are connected to the integrated cell monitoring board through FPC. The required connection wires are long and the cost is high. In addition, the control main board and the integrated cell monitoring board communicate through a daisy chain, and the connection of the daisy chain communication is relatively complicated.

[0022] In order to solve the above problems, the industry has introduced a distributed cell monitoring board solution based on a single cell monitoring board. In the distributed cell monitoring board solution, a cell monitoring board is set on each cell, and a short-distance communication connection based on a 2.4Hz frequency is used between the cell monitoring board and the control main board, which can greatly reduce the FPC cost. However, since a cell monitoring board needs to be set on each cell, the number of cell monitoring boards required for the entire system is large, resulting in a high total cost. In addition, the use of 2.4Hz frequency communication to coordinate the communication of each cell monitoring board is more complicated and has lower reliability.

[0023] In order to solve the above problems, the present application designs a battery monitoring device, including multiple battery monitoring modules, each of which is connected to multiple batteries in the battery pack, multiple battery monitoring modules are connected to the main control device through NFC, and multiple battery monitoring modules are respectively arranged at the positions corresponding to the multiple batteries; the first battery monitoring module receives the voltage monitoring instruction from the main control device, monitors the voltage values ​​of the corresponding multiple batteries according to the voltage monitoring instruction, and sends the voltage values ​​of the corresponding multiple batteries to the main control device through NFC. It can be seen that the battery monitoring device includes multiple battery monitoring modules, each battery monitoring module monitors multiple batteries, and each battery monitoring module is respectively arranged at the position of the monitored multiple batteries. Since the battery monitoring module is arranged at the position of the monitored multiple batteries, the distance between the battery and the corresponding battery monitoring module is closer, and the connection between the battery and the battery monitoring module is shorter, which can reduce the cost. In addition, since each battery monitoring module monitors multiple batteries, the battery pack requires fewer battery monitoring modules, which can reduce the cost. Further, since the connection between the battery and the battery monitoring module is shorter, interference can be reduced. Furthermore, since the battery cell monitoring module communicates with the main control device via NFC, the anti-interference capability and the security of information transmission can be improved, and the cost can be reduced.

[0024] See also Figure 1 , Figure 1 Schematic diagram of the structure of a battery cell monitoring device disclosed in the embodiment of the present application. Figure 1 As shown, the battery cell monitoring device may include multiple battery cell monitoring modules, each of the multiple battery cell monitoring modules is respectively connected to multiple battery cells in the battery pack, the multiple battery cell monitoring modules are connected to the main control device via NFC, and the multiple battery cell monitoring modules are respectively arranged at positions corresponding to the multiple battery cells.

[0025] The battery cell monitoring device may include multiple battery cell monitoring modules. Exemplarily, the battery cell monitoring device may include more than four battery cell monitoring modules. Multiple battery cell monitoring modules can avoid the situation where each battery cell monitoring module monitors a large number of battery cells, so that the connection between the battery cell monitoring module and the battery cells to be monitored is long, thereby reducing costs.

[0026] Each of the multiple cell monitoring modules monitors multiple cells in the battery pack. For example, assuming that the battery pack includes 120 cells, the cell monitoring device includes 12 cell monitoring modules, and each cell monitoring module monitors 20 cells in the battery pack. Each cell monitoring module monitors multiple cells, which can avoid the situation where the number of cells monitored by each cell monitoring module is small, resulting in a large number of cell monitoring modules required, thereby avoiding the situation where the cost is higher due to the large number of cell monitoring modules, and reducing the cost.

[0027] Different battery cell monitoring modules monitor different battery cells, which can avoid overlapping between battery cells monitored by different battery cell monitoring modules, and can reduce the demand for battery cell monitoring modules, thereby saving resources. The number of battery cells monitored by each battery cell monitoring module can be the same or different.

[0028] Multiple battery cell monitoring modules are connected to the main control device via NFC. Since NFC is a short-range wireless communication method, there is no connection line between the battery cell monitoring module and the main control device. Instead, they are connected wirelessly, which reduces the connection lines between the battery cell monitoring module and the main control device. The cost of the transceiver chip for NFC communication is low, which can reduce costs and improve production efficiency. In addition, since the battery cell monitoring module communicates with the main control device via NFC, interference can be reduced and the security and reliability of information transmission can be improved.

[0029] It should be understood that the battery cell monitoring module and the main control device can also be connected and communicated through other short-distance communication technologies.

[0030] Multiple battery cell monitoring modules are respectively arranged at positions corresponding to multiple battery cells, that is, each battery cell monitoring module is arranged at the positions of multiple battery cells to be monitored. Since the battery cell monitoring modules are arranged at positions corresponding to the battery cells, the distance between the positive and negative electrodes of the battery cells and the battery cell monitoring modules is shorter, and the required connection wires are shorter, which can improve the accuracy of monitoring, and can reduce costs and interference. In addition, since the battery cell monitoring modules are arranged at positions corresponding to the battery cells, the height is relatively low, and no additional space in the battery pack is required, which can save battery pack space, thereby reducing the area of ​​the battery pack.

[0031] When multiple battery cell monitoring modules perform monitoring separately and then communicate with the main control device, various problems may easily occur. Therefore, the main control device can manage and control the monitoring of multiple battery cell monitoring modules. In order to manage and control multiple battery cell monitoring modules, the main control device can generate voltage monitoring instructions as needed, and then send voltage monitoring instructions to multiple battery cell monitoring modules. The voltage monitoring instructions sent by the main control device to different battery cell monitoring modules can be the same or different. That is, different battery cell monitoring modules can be controlled by the same voltage monitoring instruction or by different voltage monitoring instructions.

[0032] In the case where the voltage monitoring instructions sent by the main control device to different battery cell monitoring modules are the same, the main control device may generate one voltage monitoring instruction, and then may send the voltage monitoring instruction to the multiple battery cell monitoring modules respectively.

[0033] When the voltage monitoring instructions sent by the main control device to different battery cell monitoring modules are different, the main control device can generate multiple voltage monitoring instructions, and then send corresponding voltage monitoring instructions to multiple battery cell monitoring modules respectively. Multiple voltage monitoring instructions may be generated at the same time or not. Multiple voltage monitoring instructions include the identification of the corresponding battery cell monitoring module so that the corresponding battery cell monitoring module can receive the voltage monitoring instruction sent to itself.

[0034] After receiving the voltage monitoring instruction from the main control device, the first battery cell monitoring module can monitor the voltage values ​​of the corresponding multiple battery cells according to the voltage monitoring instruction, and then send the voltage values ​​of the corresponding multiple battery cells to the main control device via NFC. The first battery cell monitoring module is any battery cell monitoring module among the multiple battery cell monitoring modules.

[0035] The first battery cell monitoring module monitors the voltage values ​​of the corresponding multiple battery cells. It can be understood that the first battery cell monitoring module monitors the corresponding multiple battery cells in sequence to obtain the voltage values ​​of the multiple battery cells. That is, the voltage values ​​of the multiple battery cells corresponding to the first battery cell monitoring module are not monitored simultaneously, but are obtained through multiple monitoring.

[0036] A voltage monitoring instruction can control a battery cell monitoring module to monitor the voltage values ​​of multiple battery cells at a time. Specifically, after receiving a voltage monitoring instruction, the battery cell monitoring module can monitor the voltage values ​​of multiple battery cells according to the voltage monitoring instruction, and then send the voltage values ​​of multiple battery cells to the main control device. After receiving the next voltage monitoring instruction, the battery cell monitoring module can monitor the voltage values ​​of multiple battery cells according to the next voltage monitoring instruction, and then send the monitored voltage values ​​of multiple battery cells to the main control device.

[0037] A voltage monitoring instruction can control a battery cell monitoring module to monitor the voltage values ​​of multiple battery cells multiple times. Exemplarily, after receiving a voltage monitoring instruction, the battery cell monitoring module can periodically monitor the voltage values ​​of multiple battery cells according to the voltage monitoring instruction and send them to the main control device. Exemplarily, after receiving a voltage monitoring instruction, the battery cell monitoring module can periodically or regularly monitor the voltage values ​​of multiple battery cells according to the voltage monitoring instruction within a preset time period and send them to the main control device.

[0038] It can be seen that the battery cell monitoring module has a voltage monitoring function, and the main control device can control the battery cell monitoring module to monitor the voltage value of the corresponding battery cell.

[0039] exist Figure 1In the described battery cell monitoring device, the battery cell monitoring device includes multiple battery cell monitoring modules, each battery cell monitoring module monitors multiple battery cells, and each battery cell monitoring module is respectively arranged at the positions of the multiple monitored battery cells. Since the battery cell monitoring modules are arranged at the positions of the multiple monitored battery cells, the distance between the battery cells and the corresponding battery cell monitoring modules is closer, and the connection between the battery cells and the battery cell monitoring modules is shorter, which can reduce costs. In addition, since each battery cell monitoring module monitors multiple battery cells, fewer battery cell monitoring modules are required for the battery pack, which can reduce costs. Further, since the connection between the battery cells and the battery cell monitoring modules is shorter, interference can be reduced. Furthermore, since the battery cell monitoring modules communicate with the main control device through NFC, the anti-interference ability and the security of information transmission can be improved, and the cost can be reduced.

[0040] In some embodiments, the second battery cell monitoring module can monitor the temperature value of the area corresponding to the multiple battery cells, and can send the temperature value of the corresponding area to the main control device via NFC. The second battery cell monitoring module is a battery cell monitoring module among the multiple battery cell monitoring modules.

[0041] It can be seen that the battery cell monitoring module also has a temperature monitoring function, which can monitor the temperature value of the area where the corresponding battery cell is located.

[0042] The battery cell monitoring module can monitor the temperature value of the corresponding area based on the control of the main control device. The main control device can send a temperature monitoring instruction to the battery cell monitoring module. After the battery cell monitoring module receives the temperature monitoring instruction from the main control device, it can monitor the temperature value of the area where the corresponding multiple battery cells are located according to the temperature monitoring instruction, and then send the temperature value of the corresponding area to the main control device via NFC.

[0043] The battery cell monitoring module can also actively monitor the temperature value of the corresponding area. During the use of the battery, the battery cell monitoring module can monitor the temperature value of the corresponding area in real time, periodically or regularly.

[0044] The voltage monitoring instruction and the temperature monitoring instruction may be the same monitoring instruction. In this case, the monitoring instruction has the function of triggering voltage monitoring and the function of triggering temperature monitoring.

[0045] The voltage monitoring instruction and the temperature monitoring instruction can be different monitoring instructions. In this case, the voltage monitoring instruction has the function of triggering voltage monitoring. The temperature monitoring instruction has the function of triggering temperature monitoring.

[0046] In one case, each of the multiple cell monitoring modules has a temperature monitoring function, and the multiple cell monitoring modules can be used to accurately monitor the temperature values ​​of different areas in the battery pack. The second cell monitoring module is any cell monitoring module among the multiple cell monitoring modules.

[0047] In another case, some of the multiple battery cell monitoring modules have a temperature monitoring function, and the remaining battery cell monitoring modules do not have a temperature monitoring function. Exemplarily, one of the two adjacent battery cell monitoring modules has a temperature monitoring function. It can be seen that temperature monitoring can be achieved using fewer temperature monitoring devices, which can reduce costs. The second battery cell monitoring module is any battery cell monitoring module in this part of the battery cell monitoring modules.

[0048] In some embodiments, the third battery cell monitoring module can receive a discharge instruction including a battery cell identification of a second battery cell from the main control device, and control the discharge of the second battery cell corresponding to the battery cell identification according to the discharge instruction. The third battery cell monitoring module is a battery cell monitoring module among multiple battery cell monitoring modules, and the second battery cell is a battery cell among the multiple battery cells corresponding to the third battery cell monitoring module.

[0049] When the main control device determines that the voltage of the second battery cell is higher, a discharge instruction can be sent to the third battery cell monitoring module. The discharge instruction may include the battery cell identification of the second battery cell. After receiving the discharge instruction from the main control device, the third battery cell monitoring module can control the second battery cell corresponding to the battery cell identification to discharge, and the voltage balance of the battery cells in the battery pack can be achieved by controlling the discharge of the battery cell with higher voltage.

[0050] See also Figure 2 , Figure 2 Schematic diagram of the structure of a battery cell monitoring module disclosed in the embodiment of the present application. Figure 2 As shown, the battery cell monitoring module may include a monitoring unit, a first multiplexer, a second multiplexer and an NFC communication unit.

[0051] The monitoring unit is connected to the first multiplexer, the second multiplexer and the NFC communication unit respectively, and the first multiplexer and the second multiplexer are connected to corresponding multiple battery cells respectively.

[0052] It can be seen that each battery cell monitoring module includes a monitoring unit, an NFC communication unit and two multiplexers. The NFC communication unit is responsible for communicating with the main control device, that is, receiving information from the main control device and forwarding it to the monitoring unit, and receiving information from the monitoring unit and forwarding it to the main control device. The monitoring unit is responsible for monitoring control. The two multiplexers select the battery cells to be monitored based on the control of the monitoring unit.

[0053] This monitoring unit can use time division multiplexing logic to control the two multiplexers to select the same battery cell at the same time, so that the monitoring unit monitors the voltage value of the battery cell. For example, assuming that a battery cell monitoring module monitors 6 battery cells, the monitoring unit can first control the two multiplexers to select the first battery cell and monitor the voltage value of the first battery cell, then control the two multiplexers to select the second battery cell and monitor the voltage value of the second battery cell, then control the two multiplexers to select the third battery cell and monitor the voltage value of the third battery cell, then control the two multiplexers to select the fourth battery cell and monitor the voltage value of the fourth battery cell, then control the two multiplexers to select the fifth battery cell and monitor the voltage value of the fifth battery cell, then control the two multiplexers to select the sixth battery cell and monitor the voltage value of the sixth battery cell.

[0054] The NFC communication unit can receive a voltage monitoring instruction from the main control device via NFC, and then send the voltage monitoring instruction to the monitoring unit. After the monitoring unit receives the voltage monitoring instruction from the NFC communication unit, it can control the first multiplexer and the second multiplexer to select the first battery cell according to the voltage monitoring instruction, detect the voltage value of the first battery cell, obtain the voltage values ​​of the corresponding multiple battery cells, and then send the voltage values ​​of the corresponding multiple battery cells to the NFC communication unit. After the NFC communication unit receives the voltage values ​​of the corresponding multiple battery cells from the monitoring unit, it can send the voltage values ​​of the corresponding multiple battery cells to the main control device via NFC. The first battery cell is any one of the corresponding multiple battery cells.

[0055] The monitoring unit is connected to the control end and the output end of the two multiplexers respectively. An input end of the first multiplexer is connected to the positive pole (or negative pole) of a battery cell, and an input end of the second multiplexer is connected to the negative pole (or positive pole) of the battery cell. When the monitoring unit controls the two multiplexers to select the battery cell through the control ends of the two multiplexers, the monitoring unit can connect the positive pole and the negative pole of the battery cell through the two multiplexers, so as to detect the voltage value of the battery cell.

[0056] Since the battery cell monitoring device adopts a multiplexer, voltage monitoring of multiple battery cells can be achieved through time division multiplexing, which can improve monitoring efficiency.

[0057] See also Figure 3 , Figure 3 is a schematic diagram of the structure of another battery cell monitoring module disclosed in the embodiment of the present application. Figure 3 The cell monitoring module shown is composed of Figure 2 The cell monitoring module shown is optimized. Figure 3 As shown, the battery cell monitoring module may further include a temperature detection unit, and the temperature detection unit is connected to the monitoring unit.

[0058] The battery cell monitoring module may include a temperature detection unit, which may be a temperature sensor, or other devices or chips capable of detecting temperature.

[0059] The temperature detection unit can monitor the temperature value of the area corresponding to the multiple battery cells, that is, it can detect the temperature value of the area corresponding to the multiple chips, and then send the temperature value of the corresponding area to the monitoring unit. After the monitoring unit receives the temperature value of the corresponding area from the temperature detection unit, it can send the temperature value of the corresponding area to the NFC communication unit. After the NFC communication unit receives the temperature value of the corresponding area from the monitoring unit, it can send the temperature value of the corresponding area to the main control device via NFC.

[0060] The temperature detection unit may monitor the temperature value of the area corresponding to the plurality of battery cells based on the control of the detection unit, or may monitor the temperature value of the area corresponding to the plurality of battery cells in real time.

[0061] See also Figure 4 , Figure 4 Schematic diagram of a battery management system disclosed in an embodiment of the present application. Figure 4 As shown, the battery management system may include a main control device and a cell monitoring device. The cell monitoring device includes a plurality of cell monitoring modules, each of the plurality of cell monitoring modules is respectively connected to a plurality of cells in a battery pack, the plurality of cell monitoring modules are connected to the main control device via NFC, and the plurality of cell monitoring modules are respectively arranged at positions corresponding to the plurality of cells.

[0062] In the case where the main control device requires the battery cell monitoring module to monitor the voltage value of the battery cell, the main control device can send a voltage monitoring instruction to the battery cell monitoring device via NFC, that is, it can send a voltage monitoring instruction to the first battery cell monitoring module in the battery cell monitoring device. The first battery cell monitoring module can receive the voltage monitoring instruction from the main control device, can monitor the voltage values ​​of the corresponding multiple battery cells according to the voltage monitoring instruction, and can send the voltage values ​​of the corresponding multiple battery cells to the main control device via NFC. After the main control device receives the voltage value from the battery cell monitoring device, that is, the voltage value of the first battery cell monitoring module via NFC, it can control the voltage balance of the battery cells in the battery pack according to the voltage value of the battery cells in the battery pack. The first battery cell monitoring module is any battery cell monitoring module among the multiple battery cell monitoring modules.

[0063] The main control device can compare the voltage values ​​of the battery cells in the monitored battery pack. When the absolute value of the difference between the voltage values ​​of any two battery cells in the battery pack is less than the voltage threshold, it indicates that the voltage value difference between the battery cells in the battery pack is small, and the voltage balance of the battery cells in the battery pack can be determined.

[0064] When the absolute value of the difference between the voltage values ​​of at least two battery cells in the battery pack is greater than or equal to the voltage threshold, it indicates that there are battery cells with a large difference in voltage values ​​in the battery pack, and it can be determined that the voltages of the battery cells in the battery pack are unbalanced. When the voltage value of the second battery cell is greater than the voltage values ​​of more than half of the battery cells in the battery pack, it indicates that the voltage of the second battery cell is higher. In order to balance the voltages of the battery cells included in the battery, a discharge instruction can be sent to the third battery cell monitoring module corresponding to the second battery cell, and the discharge instruction includes the battery cell identification of the second battery cell. So that the third battery cell monitoring module discharges the second battery cell according to the discharge instruction to achieve voltage balance of the battery cells in the battery pack.

[0065] For example, assume that the battery pack includes 5 battery cells, and the monitored voltage values ​​of these 5 battery cells are 5V, 5.5V, 4.5V, 6.5V and 5.2V respectively, and the voltage threshold is 1V. Since 6.5V is significantly different from 5V, 5.5V, 4.5V and 5.2V, indicating that the voltage of 6.5V is higher, the main control device can send a discharge instruction to the battery cell monitoring device, so that the battery cell monitoring device controls the battery cell to discharge according to the discharge instruction, so that the absolute value of the difference between the voltage value of this battery cell after discharge and the voltage values ​​of other battery cells is less than the voltage threshold.

[0066] In some embodiments, after the main control device receives the temperature value from the battery cell monitoring device, it can compare the temperature value with the temperature threshold. When the temperature value is greater than or equal to the temperature threshold, it indicates that the temperature of the corresponding area is high. Therefore, an alarm signal can be output to prompt the user that the temperature is high, so that the user can stop using the battery pack according to the alarm signal, thereby preventing the battery pack from burning out due to excessive temperature.

[0067] In some embodiments, the main control device may be disposed on the top of the battery pack, so as to achieve reasonable utilization of the space of the battery pack.

[0068] For a detailed description of the battery cell monitoring device, reference may be made to the above-mentioned related description.

[0069] See also Figure 5 , Figure 5 is a schematic diagram of the structure of another battery management system disclosed in the embodiment of the present application. Figure 5 The battery management system shown is composed of Figure 4 The battery management system shown is optimized. Figure 5 As shown, the main control device may include a main control module and an inductive communication harness, and the inductive communication harness is connected to the main control module.

[0070] The main control module can send voltage monitoring instructions to the inductive communication harness. The inductive communication harness can receive voltage monitoring instructions from the main control module, and then send voltage monitoring instructions to the battery cell monitoring device via NFC.

[0071] The inductive communication harness can also receive the voltage value of the battery cell in the battery pack from the battery cell monitoring device through NFC, and then send the voltage value of the battery cell in the battery pack to the main control module. The main control module can control the voltage balance of the battery cells in the battery pack according to the voltage value of the battery cell in the battery pack.

[0072] See also Figure 6 , Figure 6 is a cross-sectional schematic diagram of a battery monitoring system disclosed in an embodiment of the present application. Figure 6 As shown, part of the inductive communication harness can be arranged on the battery cell, the battery cell monitoring module can be arranged on the inductive communication harness and the battery cell, and the battery cell monitoring module is respectively connected to the positive pole and the negative pole of each battery cell.

[0073] The battery cell monitoring device or battery management system can be applied to all electronic devices provided with a large number of battery cells.

[0074] Exemplarily, the battery cell monitoring device or battery management system may be applied in an electric vehicle, that is, the electric vehicle may include the battery cell monitoring device or battery management system.

[0075] It should be understood that the connection in this application can be understood as an electrical connection.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery cell monitoring device, characterized in that: It includes a plurality of battery cell monitoring modules, each of which is respectively connected to a plurality of battery cells in a battery pack, the plurality of battery cell monitoring modules are connected to a main control device via NFC, and the plurality of battery cell monitoring modules are respectively arranged at positions corresponding to the plurality of battery cells; The first battery cell monitoring module is used to receive a voltage monitoring instruction from the main control device, monitor the voltage values ​​of the corresponding multiple battery cells according to the voltage monitoring instruction, and send the voltage values ​​of the corresponding multiple battery cells to the main control device via NFC. The first battery cell monitoring module is any battery cell monitoring module among the multiple battery cell monitoring modules.

2. The battery cell monitoring device according to claim 1, characterized in that: The second battery cell monitoring module is used to monitor the temperature value of the area corresponding to the multiple battery cells, and send the temperature value of the corresponding area to the main control device through NFC. The second battery cell monitoring module is a battery cell monitoring module among the multiple battery cell monitoring modules.

3. The battery cell monitoring device according to claim 2, characterized in that: The battery cell monitoring module includes a monitoring unit, a first multiplexer, a second multiplexer and an NFC communication unit, wherein: The monitoring unit is respectively connected to the first multiplexer, the second multiplexer and the NFC communication unit, and the first multiplexer and the second multiplexer are respectively connected to corresponding multiple battery cells; The NFC communication unit is used to receive a voltage monitoring instruction from the main control device via NFC; The monitoring unit is used to control the first multiplexer and the second multiplexer to select a first battery cell according to the voltage monitoring instruction, detect a voltage value of the first battery cell, obtain voltage values ​​of the corresponding multiple battery cells, and send the voltage values ​​of the corresponding multiple battery cells to the NFC communication unit, wherein the first battery cell is any one of the corresponding multiple battery cells; The NFC communication unit is further used to send the voltage values ​​corresponding to the multiple battery cells to the main control device via NFC.

4. The battery cell monitoring device according to claim 3, characterized in that: The battery cell monitoring module further includes a temperature detection unit, and the temperature detection unit is connected to the monitoring unit; The temperature detection unit is used to monitor the temperature value of the area where the multiple battery cells are located, and send the temperature value of the corresponding area to the monitoring unit; The monitoring unit is further used to send the temperature value of the corresponding area to the NFC communication unit; The NFC communication unit is further used to send the temperature value of the corresponding area to the main control device via NFC.

5. The battery cell monitoring device according to claim 1, characterized in that: The third battery cell monitoring module is used to receive a discharge instruction including a battery cell identification of a second battery cell from the main control device, and control the discharge of the second battery cell corresponding to the battery cell identification according to the discharge instruction. The third battery cell monitoring module is a battery cell monitoring module among the multiple battery cell monitoring modules, and the second battery cell is a battery cell among the multiple battery cells corresponding to the third battery cell monitoring module.

6. A battery management system, characterized in that: It comprises a main control device and a battery cell monitoring device as claimed in any one of claims 1 to 5; The main control device is used to send a voltage monitoring instruction to the battery cell monitoring device via NFC; The main control device is also used to receive the voltage values ​​of the cells in the battery pack from the cell monitoring device via NFC, and control the voltage balance of the cells in the battery pack according to the voltage values ​​of the cells in the battery pack.

7. The battery management system according to claim 6, characterized in that: The main control device is specifically used to compare the voltage values ​​of the battery cells in the battery pack, and when the voltage value of the second battery cell is greater than the voltage values ​​of more than half of the battery cells in the battery pack, send a discharge instruction to the third battery cell monitoring module corresponding to the second battery cell, and the discharge instruction includes the battery cell identification of the second battery cell.

8. The battery management system according to claim 6, characterized in that: The main control device is further used to receive the temperature value from the second battery cell monitoring module, and output an alarm signal when the temperature value is greater than a temperature threshold.

9. The battery management system according to claim 6, characterized in that: The main control device comprises a main control module and an inductive communication harness, wherein the inductive communication harness is connected to the main control module; The main control module is used to send the voltage monitoring instruction to the induction communication harness; The inductive communication harness is used to send the voltage monitoring instruction to the battery cell monitoring device via NFC; The inductive communication harness is further used to receive the voltage value of the battery cell in the battery pack from the battery cell monitoring device through NFC, and send the voltage value of the battery cell in the battery pack to the main control module; The main control module is further used to control the voltage balance of the battery cells in the battery pack according to the voltage values ​​of the battery cells in the battery pack.

10. An electric vehicle, characterized in that: It comprises a battery cell monitoring device as described in any one of claims 1 to 5, or a battery management system as described in any one of claims 6 to 9.

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