A power battery cell maintenance structure and a maintenance method

Abstract

The application discloses a power battery cell maintenance structure. A BMS and a plurality of single cells are fixed in a box body of a power battery. Collection lines are led out from two ends of each single cell. End portions of each collection line are connected with independent low-voltage sockets. Signal interfaces of the BMS are connected with the low-voltage sockets through signal lines. All the low-voltage sockets are fixed on the surface of the box body. Low-voltage plug groups matched with each low-voltage socket are fixed on a shell to form a low-voltage maintenance switch. Internal conductors connecting two low-voltage plugs are arranged in the shell. One of the low-voltage sockets connected with the internal conductors is connected with a battery single cell, and the other low-voltage socket is connected with the BMS. The low-voltage maintenance switch connects each single cell with one signal interface of the BMS. The improved battery is a simple and convenient maintenance battery PACK scheme, and has the characteristics of simple operation, convenient maintenance and quick after-sales.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of force batteries. BACKGROUND

[0002] Lithium-ion batteries are popular due to their high single-cell voltage and long cycle life. However, due to the material system and current production process, the capacity, internal resistance, and size of each battery cell cannot be completely identical when it is offline. Due to the high voltage platform and large capacity demand of current electric vehicles, the battery pack is composed of several to several hundred battery cells connected in series and parallel. Although these single cells are selected and the relevant parameters are unified as much as possible during grouping, the consistency of the charge capacity, corresponding voltage, and capacity curve of each single cell will change to some extent after actual operation of charging and discharging for a period of time, resulting in the inability of some single cells to be fully charged or discharged, and reducing the actual available power of the battery pack.

[0003] Current battery management systems (BMS) have equalization management, which reduces the differences between single cells. However, whether it is passive or active, the equalization effect between single cells is very limited. After a long time, the overall capacity of the power battery system will still decrease, and the simplest and most direct solution is to maintain some single cells and individually charge some single cells that are not fully charged.

[0004] The current power battery pack scheme is as follows Figure 4 As shown in the figure, multiple single cells are placed in the pack box, and the multiple single cells are connected to each other in series and parallel, and finally connected to the positive and negative output terminals of the pack box. The components for connecting the single cells include copper and aluminum bars or copper and aluminum wires, relays, fuses, and various electrical elements. In order to accurately monitor the voltage of each single cell, a collection line is drawn at both ends of each single cell and connected to the BMS in the pack box. In actual application, waterproof and dustproof are required, and the entire battery pack needs to meet the IP67 and above standards. Therefore, once the pressure difference between the single cells in the pack is too large, affecting the capacity of the entire pack system, and the BMS equalization cannot reduce the pressure difference. At this time, some low-voltage single cells in the pack need to be supplemented and maintained.

[0005] However, the current battery pack scheme does not have a convenient method for supplementing the single cells, and the sealed pack box needs to be opened, which inevitably increases the complexity of the operation. After opening the box, it is difficult to ensure that the airtightness and torque of the fixing parts of the battery pack after restoration meet the original factory requirements. SUMMARY

[0006] The technical problem to be solved by the present application is to realize a battery PACK scheme with simple maintenance, which needs to have the characteristics of simple operation, easy maintenance and being beneficial to quick after-sales.

[0007] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows: a power battery cell maintenance structure, a BMS and a plurality of single cells are fixed in the box body of the power battery, the two ends of each single cell are connected with a collection line, the end of each collection line is connected with an independent low-voltage socket, the signal interface of the BMS is connected with the low-voltage socket through a signal line, all the low-voltage sockets are fixed on the surface of the box body, a low-voltage maintenance switch is formed by a low-voltage plug group matched with each low-voltage socket and fixed on the shell, an internal conductor connecting two low-voltage plugs is arranged in the shell, one of the low-voltage sockets connected by the internal conductor is connected with a single cell, and the other low-voltage socket is connected with the BMS, and the low-voltage maintenance switch connects each single cell with a signal interface of the BMS.

[0008] The electrodes of each single cell in the box body are connected in series, parallel or series-parallel combination and then connected to the power battery electrode of the box body.

[0009] A socket area is arranged on one side of the box body, and all the low-voltage sockets are arranged in the socket area.

[0010] The socket area is a boss protruding from the surface of the box body, the low-voltage plug is fixed in the groove of the shell, the boss and the groove are male-female matched, and a sealing washer is arranged on the inner wall of the groove.

[0011] The cell maintenance device for maintaining and charging the single cells is provided with a low-voltage plug group for connecting with each low-voltage socket connected with the single cells, the low-voltage plug group is composed of low-voltage plugs fixed on the shell of the cell maintenance device, and each low-voltage plug is connected with a charging component inside the cell maintenance device.

[0012] The test tool / standby BMS for collecting parameter information of the single cells is provided with a low-voltage plug group for connecting with each low-voltage socket connected with the single cells, the low-voltage plug group is composed of low-voltage plugs fixed on the shell of the test tool / standby BMS, and each low-voltage plug is connected with a test component inside the test tool / standby BMS.

[0013] The shell of the cell maintenance device and the shell of the test tool / standby BMS are provided with a boss structure matched with the groove of the shell, the low-voltage plug group of the cell maintenance device and the test tool / standby BMS is fixed in the boss structure,

[0014] The groove and the boss are provided with convex / concave structures for identifying the insertion direction.

[0015] A maintenance method based on the aforementioned power battery cell maintenance structure includes a single-cell charging method:

[0016] 1) Unplug the low-voltage maintenance switch and disconnect the BMS from the cell acquisition line;

[0017] 2) Insert the low-voltage plug of the battery cell maintenance equipment into the low-voltage socket;

[0018] 3) Recharge the battery cells directly using battery cell maintenance equipment;

[0019] 4) After the power supply is completed, unplug the battery cell maintenance equipment and install the low-voltage maintenance switch plug.

[0020] It also includes methods for collecting parameter information of individual battery cells:

[0021] 1) Unplug the low-voltage maintenance switch and disconnect the BMS from the cell acquisition line;

[0022] 2) Insert the low-voltage plug of the test fixture / spare BMS into the low-voltage socket;

[0023] 3) Collect individual cell parameter information using test fixtures / backup BMS;

[0024] 4) If the BMS inside the enclosure fails, replace the BMS inside the enclosure with a test fixture / spare BMS before starting the vehicle.

[0025] The main features of this invention compared to existing solutions are as follows:

[0026] 1. Existing solutions require opening the battery pack for cell charging and maintenance, which is labor-intensive and cannot guarantee the airtightness of the pack. However, the battery pack using this patented solution only requires unplugging the low-voltage maintenance switch; the charging equipment can be directly connected to the low-voltage socket via a tooling for direct charging. This is convenient and does not compromise the pack's airtightness.

[0027] 2. Not only can low-voltage cells be recharged and maintained through the low-voltage socket installed on the pack, but testing tools can also be used in after-sales maintenance to detect faults in the internal data acquisition harness of the pack or identify BMS faults. Attached Figure Description

[0028] The following is a brief explanation of the content and markings in each of the accompanying drawings in this specification:

[0029] Figure 1 This is a schematic diagram of the maintenance structure for a power battery cell.

[0030] Figure 2 A schematic diagram showing the connection to the battery cell maintenance equipment;

[0031] Figure 3 For connecting test tool / spare BMS schematic diagram;

[0032] Figure 4 For prior art power battery structure schematic diagram;

[0033] The marks in the above figures are as follows: 1, box; 2, low-voltage socket; 3, low-voltage plug; 4, low-voltage maintenance switch; 5, switch shell; 6, internal conductor; 7, cell maintenance equipment; 8, test tool / spare BMS. DETAILED DESCRIPTION

[0034] The specific embodiments of the present application will be further described below with reference to the accompanying drawings, and the shape, structure, mutual position and connection relationship between parts, the role and working principle of each part, the manufacturing process and the operation and use method of each component involved in the description will be further described in detail, so as to help the skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present application.

[0035] The power battery pack scheme is as shown in Figure 1 A plurality of single cells are placed in the pack box 1, and finally connected to the positive and negative output terminals on the pack box 1. The components for connecting the cells include copper, aluminum bars or copper, aluminum wires, relays, fuses and various electrical elements. In order to accurately monitor the voltage of each single cell, a collection line is led out at both ends of each single cell. The present application connects the collection line of the single cell to the outside of the pack box 1 through the low-voltage maintenance switch 4, and then connects the collection line into the inside of the box 1 through the conductor in the switch, and finally connects to the BMS in the box 1.

[0036] The low-voltage maintenance switch 4 is divided into two parts: a low-voltage socket 2 and a switch plug, and the low-voltage socket 2 and the plug cooperate with each other. The low-voltage socket 2 is fixed on the pack box 1, and the inside of the socket has a plurality of mutually isolated pin feet, and the plurality of pin feet can be divided into two parts, one part of which can lead out the collection line signal of the connected single cell in the battery pack outside the box 1. The other part of the pin feet is connected with the BMS in the pack. The plug part also has a plurality of pin feet, and the plurality of pin feet can also be divided into two parts, but the pin feet of the two parts are connected to each other through the conductor in the plug.

[0037] When the plug and the socket are separated, the cell collection in the pack and the BMS are completely disconnected. After the plug and the socket cooperate with each other, the BMS can completely collect all the single cell signals in the PACK.

[0038] Embodiment 1 of the present application: maintenance and power supply of the cells in the pack, as shown in Figure 2 :

[0039] 1、First pull out the plug of low voltage maintenance switch 4, disconnect BMS and cell acquisition line.

[0040] 2, The tooling harness is connected to the pin of low voltage socket 2, and the pin is directly connected to the two ends of a plurality of cells in the pack.

[0041] 3, After the cell maintenance device 7 is connected to the tooling harness, the cell is directly charged.

[0042] 4, After the charging is completed, the tooling harness is pulled out of the voltage socket, and the plug of the low voltage maintenance switch 4 is installed.

[0043] The second embodiment of the present patent: troubleshooting of internal faults of the pack. Specifically as Figure 3 .

[0044] If similar voltage acquisition abnormality problems occur in the running project of the vehicle, the vehicle will generally be prohibited from high voltage and parked due to safety considerations. If it cannot be solved quickly, it needs to be towed to the repair shop for after-sales maintenance. The battery pack using the patent solution can be quickly diagnosed to reduce maintenance costs. The solution is as follows:

[0045] 1, After the voltage acquisition abnormality problem occurs, pull out the plug of the low voltage maintenance switch 4, disconnect the BMS and the cell acquisition line.

[0046] 2, The test tool is connected to the pin of the low voltage socket 2 through the harness, and the pin is directly connected to the two ends of a plurality of cells in the pack.

[0047] 3, The test tool can quickly locate whether the voltage acquisition fault is caused by the acquisition line or the BMS.

[0048] 4, If the BMS is faulty, a spare BMS is used to replace the BMS in the pack to start the vehicle, and the vehicle is self-walked from the parking place to the repair shop, reducing the after-sales cost generated by the towing service.

[0049] The above describes the present application in conjunction with the drawings, and it is obvious that the specific implementation of the present application is not limited by the above method. Any non-essential improvement or direct application of the concept and technical solution of the present application to other occasions is within the protection scope of the present application.

Claims

1. A power battery cell maintenance structure, a BMS and a plurality of single cells are fixed in the box of a power battery, both ends of each single cell are led out with a collection line, characterized in that: The end of each of the collection lines is connected to an independent low-voltage socket, the signal interface of the BMS is connected to the low-voltage socket through a signal line, all the low-voltage sockets are fixed on the surface of the box, a low-voltage maintenance switch is formed by a low-voltage plug group matched with each low-voltage socket and fixed on a shell, an internal conductor connecting two low-voltage plugs is arranged in the shell, one of the low-voltage sockets connected by the internal conductor is connected to a battery monomer, and the other low-voltage socket is connected to the BMS, the low-voltage maintenance switch connects each monomer battery to one signal interface of the BMS, the electrodes of each monomer battery in the box are connected in series, parallel or series-parallel combination and then connected to the electrodes of the power battery of the box, and a socket area is arranged on one side of the box, and all the low-voltage sockets are arranged in the socket area. The low-voltage socket has a plurality of mutually isolated pin feet.

2. The power cell maintenance structure of claim 1, wherein: The socket area is a boss protruding from the surface of the box, the low-voltage plug is fixed in a groove of the shell, the boss and the groove are male-female matched, and a sealing washer is arranged on the inner wall of the groove.

3. The power cell maintenance structure of claim 2, wherein: The battery cell maintenance device for maintaining and supplementing power of the monomer battery cell is provided with a low-voltage plug group for connecting with each low-voltage socket connected to the monomer battery cell, the low-voltage plug group is composed of low-voltage plugs fixed on the shell of the battery cell maintenance device, and each low-voltage plug is connected to a charging component inside the battery cell maintenance device.

4. The power cell maintenance structure of claim 3, wherein: The test tool / standby BMS for collecting parameter information of the monomer battery cell is provided with a low-voltage plug group for connecting with each low-voltage socket connected to the monomer battery cell, the low-voltage plug group is composed of low-voltage plugs fixed on the shell of the test tool / standby BMS, and each low-voltage plug is connected to a test component inside the test tool / standby BMS.

5. The power cell maintenance structure according to claim 3 or 4, characterized in that: The shell of the battery cell maintenance device and the shell of the test tool / standby BMS are provided with boss structures matched with the grooves of the shells, and the low-voltage plug groups of the battery cell maintenance device and the test tool / standby BMS are fixed in the boss structures.

6. The power cell maintenance structure of claim 5, wherein: The groove and the boss are provided with convex / concave structures for identifying the insertion direction.

7. A maintenance method based on the power battery cell maintenance structure according to any one of claims 1-6, characterized in that, The method for supplementing power of the monomer battery cell comprises the following steps: 1) pulling out the plug of the low-voltage maintenance switch, disconnecting the BMS from the battery cell collection line; 2) inserting the low-voltage plug of the battery cell maintenance device into the low-voltage socket; 3) directly supplementing power of the battery cell through the battery cell maintenance device; 4) pulling out the battery cell maintenance device after the power supplementing is completed, and installing the plug of the low-voltage maintenance switch.

8. The method of maintenance according to claim 7, characterized in that, The method for collecting parameter information of the monomer battery cell comprises the following steps: 1) pulling out the plug of the low-voltage maintenance switch, disconnecting the BMS from the battery cell collection line; 2) inserting the low-voltage plug of the test tool / standby BMS into the low-voltage socket; 3) collecting parameter information of the monomer battery through the test tool / standby BMS; 4) directly using the test tool / standby BMS to replace the BMS in the box when the BMS in the box is faulty, and starting the vehicle.

Images