Battery cell group with balanced confluence and scooter battery module with battery cell group

Abstract

The invention belongs to the technical field of batteries, and provides a battery cell group with balanced confluence and a scooter battery module with the battery cell group, the battery cell group with balanced confluence comprises four brackets, two groups of 21700 battery cells and two groups of nickel sheets; the 21700 battery cell is fixed through the screw column structures of the four brackets; the two groups of nickel sheets adopt a symmetrical balanced confluence design, and the over-current path resistance difference value of each 21700 cell is less than or equal to 5%. According to the invention, a symmetrical and balanced confluence design is adopted, so that the current distribution uniformity between the battery cell groups is effectively improved, and the problems of overheating and damage of the battery cells caused by non-uniform current distribution are avoided; two groups of 21700 battery cells are stably fixed by the four brackets through screw column structures, so that the stability and the safety of the battery cell groups in the running process of the scooter are ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and particularly to a battery cell group with balanced busbars and a scooter battery module with such a battery cell group. Background Art

[0002] Traditional scooter battery modules adopt an asymmetric busbar design, resulting in significant differences in the current paths of the positive and negative nickel sheets. This design causes some battery cells to bear excessive loads (especially the battery cells near the protection board, which have a high current density), leading to abnormal local temperature rise, shortened service life, and insufficient stability of the overall endurance; in addition, the layout of multi-series and parallel battery packs (such as 13S5P) is too loose, and the battery cells are not arranged compactly enough, resulting in a space utilization rate more than 30% lower than the industry average level; the misaligned battery cells need to be cross-connected using flying wires, and the insulation of the solder joints depends on heat shrinkable sleeves or glue, which is prone to short circuits and even fires due to insulation failure. The common mold bracket is mainly fixed by glue or double-sided tape, unable to pass the 1.5-meter drop test, and the waterproof level of the plastic shell is also insufficient.

[0003] Therefore, it is necessary to provide a battery cell group with balanced busbars and a scooter battery module with such a battery cell group. Summary of the Invention

[0004] The present invention provides a battery cell group with balanced busbars and a scooter battery module with such a battery cell group. Through the balanced busbar design, the uniform distribution of current among the battery cells is realized, effectively avoiding the problem of battery cell overload in the traditional asymmetric busbar design, significantly reducing the abnormal local temperature rise, extending the service life of the battery cells, and at the same time improving the stability of the overall endurance; the battery cell group adopts a compact arrangement method, greatly improving the space utilization rate, and the space utilization rate is increased by more than 30% compared with the layout of traditional multi-series and parallel battery packs; in addition, the non-flying wire design is adopted between the battery cells, and all connections are through reliable welding and insulation treatment, avoiding the risk of short circuits and fires caused by insulation failure; a stable bracket fixing method is adopted between the battery cell group and the scooter battery module, without relying on glue or double-sided tape, and the shell design meets a high-level waterproof standard, ensuring stable operation in harsh environments.

[0005] The present invention provides a battery cell group with balanced busbars, including: four brackets, two groups of 21700 battery cells, and two groups of nickel sheets; the 21700 battery cells are fixed through the screw post structures of the four brackets; the two groups of nickel sheets adopt a symmetric balanced busbar design, and the overcurrent path resistance difference of each 21700 battery cell is ≤5%.

[0006] Further, the four brackets include bracket A, bracket B, bracket C and bracket D; the two groups of 21700 battery cells include a first group of 21700 battery cells and a second group of 21700 battery cells; the two groups of nickel sheets include a first group of nickel sheets and a second group of nickel sheets; The first group of 21700 battery cells are fixed through the screw columns of bracket A and bracket B with M2.3 self-tapping screws. The first group of nickel sheets are spot welded through the limit installation of bracket A and bracket B to form bracket A / B battery cell module-1; The second group of 21700 battery cells are fixed through the screw columns of bracket C and bracket D with M2.3 self-tapping screws. The second group of nickel sheets are spot welded through the limit installation of bracket C and bracket D to form bracket C / D battery cell module-2; The bracket A / B battery cell module-1 and the bracket C / D battery cell module-2 are fixed by the screw columns of the bracket B and the bracket C with M2.3 screws to form a 13S5P battery cell group.

[0007] Furthermore, the position of the welding point of each nickel sheet in the two groups of nickel sheets is set in the limiting groove of each bracket in the four brackets, and the distance between the welding point and the adjacent nickel sheet is ≥3mm.

[0008] Furthermore, EVA foam and epoxy board are respectively attached to both sides of bracket A and bracket D.

[0009] A scooter battery module comprises: a BMS mainboard, a battery compartment, 65 battery cells and a battery cell group with a balanced current collector; the 65 battery cells and the battery cell group are compactly arranged in a preset physical space of the battery compartment, and the physical space occupied by the battery cell group is the same as the physical space occupied by each of the 66 battery cells; the BMS mainboard is arranged in the battery compartment.

[0010] Furthermore, the BMS mainboard is fixed to the battery cell group through the positioning columns and screw columns of bracket A, bracket B, bracket C, and bracket D, using M2.3 self-tapping screws, and the distance between the BMS mainboard and the battery cell group is ≥2mm.

[0011] Furthermore, EVA foam is configured on the left and right sides of the BMS protection plate, and silicone waterproof rings are configured on the top and bottom; The silicone waterproof ring integrates a leakage sensor, a microprocessor and an alarm. The leakage sensor is used to collect the ambient humidity according to the set collection cycle; the microprocessor makes a threshold judgment on the ambient humidity. If it exceeds the set first humidity threshold for three consecutive times, the alarm is controlled to sound an alarm; if the ambient humidity is lower than the set second humidity threshold, the alarm is controlled to cancel the alarm.

[0012] Further, the second nickel sheet in the first group of nickel sheets and the first nickel sheet in the second group of nickel sheets are connected in series and parallel through the BMS main board; the second nickel sheet in the first group of nickel sheets is limit-mounted and spot-welded to bracket B; the first nickel sheet in the second group of nickel sheets is limit-mounted and spot-welded to bracket C; The first nickel sheet in the first group of nickel sheets and the second nickel sheet in the second group of nickel sheets are connected in series and parallel through the wire passing holes of brackets A, B, C, and D, and the number of flying wires ≤ 5; the first nickel sheet in the first group of nickel sheets is limit-mounted and spot-welded to bracket A; the second nickel sheet in the second group of nickel sheets is limit-mounted and spot-welded to bracket D.

[0013] Further, the BMS main board is built-in with a dynamic equalization algorithm, and the equalization current is set to ≥ 100 mA. The dynamic equalization algorithm performs the following steps: Real-time monitor the voltage of each battery cell, calculate the average voltage of the two groups of battery cells, and the maximum deviation between the battery cell voltage and the average voltage; When the maximum deviation is greater than or equal to the set deviation threshold, start active equalization, control the equalization current proportionally to ensure that the equalization current ≥ 100 mA; and sort in descending order according to the deviation value, and select the top 3 battery cells with the largest deviation to implement priority equalization to avoid excessive temperature rise caused by simultaneous equalization of multiple battery cells; the priority equalization is: perform cyclic equalization according to the set equalization time and rotation interval.

[0014] Further, the battery compartment is made of aluminum alloy and is internally provided with a multi-layer protection structure; the protection structure includes an insulating lining, a buffer layer, and a sealing strip.

[0015] Compared with the prior art, the present invention has the following advantages and beneficial effects: The battery cell group structure is compact. Through the equalization and busbar design, the voltage difference between battery cells is effectively reduced, and the safety and stability of the battery module are improved; at the same time, the use of M2.3 screws for locking and fixing ensures a firm connection between the battery cell group and the BMS main board, reducing the risk of connection loosening caused by vibration or external impact; in addition, the use of EVA foam and epoxy board further enhances the seismic resistance and insulation performance of the battery module; while the leakage sensor, microprocessor, and alarm integrated in the silicone waterproof ring can issue an alarm in time when the battery module leaks, effectively avoiding potential safety hazards.

[0016] Other features and advantages of the present invention will be described in the following specification, and, in part, will become apparent from the specification or will be understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained by the structures specifically pointed out in the written specification and the drawings.

[0017] The technical solutions of the present invention will be further described in detail below through the drawings and embodiments. Description of the Drawings

[0018] The accompanying drawings are used to provide a further understanding of the present invention and form a part of the specification. They are used together with the embodiments of the present invention to explain the present invention and do not constitute a limitation to the present invention. In the drawings: Figure 1 It is a schematic structural diagram of a battery cell group with balanced busbars; Figure 2 It is a schematic structural diagram of the connection between a battery cell, a nickel sheet and a bracket; Figure 3 It is a schematic structural diagram of a battery module for a scooter. Detailed implementation manners

[0019] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to explain and illustrate the present invention and are not used to limit the present invention.

[0020] The present invention provides a battery cell group with balanced busbars, as Figure 1 shown, including: four brackets, two groups of 21700 battery cells, and two groups of nickel sheets; the 21700 battery cells are fixed through the screw post structures of the four brackets; the two groups of nickel sheets adopt a symmetric balanced busbar design, and the resistance difference of the current-carrying path of each 21700 battery cell is ≤5%.

[0021] The working principle of the above technical solution is as follows: the 21700 battery cells in the battery cell group are fixed through the screw post structures of the four brackets, ensuring the stability and structural strength of the battery cell group; the two groups of nickel sheets adopt a symmetric balanced busbar design, which makes the current distribution in the battery cell group more uniform, effectively avoiding the problems of local overheating and excessive current; the strict control of the resistance difference of the current-carrying path of each 21700 battery cell (≤5%) further improves the working efficiency and safety of the battery cell group; during specific operation, when the battery module needs to discharge, the current is evenly distributed to each battery cell through the nickel sheets, ensuring that each battery cell can discharge at a similar rate; similarly, during the charging process, the current can also evenly flow back to each battery cell through the nickel sheets, avoiding the performance differences and safety hazards of the battery cells caused by uneven current distribution.

[0022] The beneficial effects of the above technical solution are as follows: adopting the solution provided in this embodiment can significantly improve the working efficiency and safety of the battery cell group; the battery cells in the battery cell group are fixed through a stable bracket structure, and the nickel sheets adopt a symmetric balanced busbar design, making the current distribution more uniform, thereby extending the service life of the battery cells and reducing the failure rate caused by local overheating or excessive current.

[0023] In one embodiment, as Figure 2 shown, the four brackets include bracket A, bracket B, bracket C and bracket D; the two groups of 21700 battery cells include the first group of 21700 battery cells and the second group of 21700 battery cells; the two groups of nickel sheets include the first group of nickel sheets and the second group of nickel sheets; The first group of 21700 batteries are locked and fixed by M2.3 self-tapping screws through the screw posts of bracket A and bracket B. The first group of nickel sheets are installed and spot-welded by the limits of bracket A and bracket B to assemble and form the bracket A / B battery module-1; The second group of 21700 batteries are locked and fixed by M2.3 self-tapping screws through the screw posts of bracket C and bracket D. The second group of nickel sheets are installed and spot-welded by the limits of bracket C and bracket D to assemble and form the bracket C / D battery module-2; The bracket A / B battery module-1 and the bracket C / D battery module-2 are locked and fixed by M2.3 screws through the screw posts of bracket B and bracket C to assemble and form a 13S5P battery pack.

[0024] The working principle of the above technical solution is as follows: Each battery in the battery pack is fixed and connected through the brackets and nickel sheets, realizing the stable combination and power transmission between the batteries; Bracket A and bracket B jointly carry the first group of 21700 batteries, and realize the series or parallel connection between the batteries through the first group of nickel sheets to form the bracket A / B battery module-1; Similarly, bracket C and bracket D carry the second group of 21700 batteries and are connected through the second group of nickel sheets to form the bracket C / D battery module-2; These two modules are then connected through the screw posts of bracket B and bracket C to form an integral 13S5P battery pack; In this battery pack, the design of balanced current collection ensures the voltage and current balance of each battery during operation, avoiding the performance degradation of the battery module caused by the performance differences of the batteries; The balanced current collection system may include a balanced circuit and a bus bar. The balanced circuit is responsible for monitoring and adjusting the voltage of each battery to ensure that the voltage difference between the batteries is within the allowable range; The bus bar then aggregates and outputs the electrical energy of the battery pack for use by the scooter battery module.

[0025] The beneficial effects of the above technical solution are as follows: By adopting the solution provided in this embodiment, the design of the battery pack not only improves the overall performance of the battery module, but also enhances its safety and reliability.

[0026] In one embodiment, the positions of the solder joints of each nickel sheet in the two groups of nickel sheets are all set in the limit grooves of each of the four brackets, and the distance between the solder joint and its adjacent nickel sheet is ≥3mm.

[0027] The working principle of the above technical solution is as follows: The solder joints are designed in the limiting grooves of the bracket. Such a layout not only ensures the stability of the solder joints but also effectively prevents the risk of solder joint damage or short circuit that may occur during the assembly and use of the battery module. At the same time, the distance of ≥3 mm maintained between the solder joints and the adjacent nickel sheets reduces the electrical interference or short circuit problems that may be caused by the too-close distance between the nickel sheets, further enhancing the safety and reliability of the battery module. When the battery cell group works in the scooter battery module, the current is transmitted from the battery cell to the battery cell through the nickel sheet, forming a complete circuit loop. The solder joint, as the key node connecting the battery cell and the nickel sheet, its stability and safety are directly related to the working efficiency of the entire battery module. By setting the solder joint in the limiting groove of the bracket and strictly controlling the distance between the solder joint and the adjacent nickel sheet.

[0028] The beneficial effects of the above technical solution are as follows: By adopting the solution provided in this embodiment, the design of the battery cell group ensures the stability and efficiency of the current during transmission, and also improves the service life and safety of the battery module.

[0029] In one embodiment, EVA foam and epoxy board are respectively pasted on both sides of bracket A and bracket D.

[0030] The working principle of the above technical solution is as follows: EVA foam is mainly used for buffering and fixing between the battery cell group and the shell of the scooter battery module. It has good elasticity and shock absorption performance, and can effectively absorb the vibration and impact that the battery module may encounter during use, protect the battery cell group from external forces, and ensure the stability of current transmission and the safety of the battery module. The epoxy board, due to its excellent insulation performance and mechanical strength, is used as an isolation layer between the battery cell group and the external environment. It can effectively prevent the direct contact between the battery cell group and the shell, avoid the risk of electrical short circuit, and at the same time provide a solid support structure for the battery cell group.

[0031] The beneficial effects of the above technical solution are as follows: By adopting the solution provided in this embodiment, not only the overall stability of the battery module is enhanced, but also its safety and reliability are further improved.

[0032] A scooter battery module, as Figure 3 shown, includes: a BMS main board, a battery compartment, 65 battery cells, and a battery cell group with balanced busbars; The 65 battery cells and the battery cell group are compactly arranged in the preset physical space of the battery compartment, and the physical space occupied by the battery cell group is the same as that of each of the 66 battery cells; The BMS main board is configured in the battery compartment.

[0033] The working principle of the above technical solution is as follows: The BMS main board, as the core component of the battery management system, is responsible for monitoring, managing, and protecting the battery cell group. It can detect key parameters such as the voltage, current, and temperature of each battery cell in real time, ensuring the balance and safety of the battery cell group during the charging and discharging process. When an abnormal parameter of a certain battery cell is detected, the BMS main board will quickly activate the protection mechanism, such as cutting off the power supply or adjusting the charging and discharging strategy, to prevent the battery cell from overcharging, over-discharging, or overheating, thereby extending the service life of the battery module; in addition, through the balanced busbar design of the battery cell group, the current is evenly distributed among the battery cells. During the charging and discharging process, the balanced busbar device can automatically adjust the charging and discharging current of each battery cell to ensure the stability and efficiency of the overall performance of the battery cell group.

[0034] The beneficial effects of the above technical solution are as follows: By adopting the solution provided in this embodiment, not only the energy density and power output of the battery module are improved, but also the performance difference between the battery cells is reduced, and the cycle life of the battery module is extended.

[0035] In one embodiment, the BMS main board is fixedly locked on the battery cell group by the positioning posts and screw posts of bracket A, bracket B, bracket C, and bracket D using M2.3 self-tapping screws, and the distance between the BMS main board and the battery cell group is ≥2 mm.

[0036] The working principle of the above technical solution is as follows: Through fixation, the BMS main board ensures a stable connection with the battery cell group, and at the same time maintains an appropriate distance, which is beneficial for heat dissipation and preventing short circuits; during the operation of the scooter battery module, the BMS main board continuously monitors the state of the battery cell group. Through high-precision sensors and data acquisition circuits, it obtains the voltage, current, and temperature information of the battery cell group in real time. After being processed by the microprocessor on the main board, these information are used to judge whether the working state of the battery cell group is normal. Once an abnormality is found, such as too high or too low voltage of a certain battery cell, too large current, or too high temperature, the BMS main board will immediately activate the preset protection strategy, such as adjusting the charging and discharging current, cutting off the power supply, or triggering an alarm, to ensure the safe operation of the battery module; in addition, under the monitoring of the BMS main board, the balanced busbar device automatically adjusts the charging and discharging current between the battery cells, further improving the overall performance and stability of the battery module.

[0037] The beneficial effects of the above technical solution are as follows: By adopting the solution provided in this embodiment, it can effectively avoid the performance degradation and safety hazards of the battery module caused by the imbalance between the battery cells inside the battery cell group, and extend the service life of the battery module; at the same time, through the real-time monitoring and protection strategy of the BMS main board, abnormal situations can be discovered and processed in the first time, significantly improving the safety and reliability of the battery module; in addition, the application of the balanced busbar device not only improves the overall performance of the battery module, but also enables the scooter battery module to maintain a stable energy output in a complex and changeable riding environment, providing lasting and stable power support for the scooter.

[0038] In one embodiment, EVA foam is arranged on both the left and right sides of the BMS protection board, and silicone rubber waterproof rings are arranged on both the upper and lower surfaces; The silicone rubber waterproof ring is integrated with a leakage sensor, a microprocessor and an alarm. The leakage sensor is used to collect the ambient humidity according to a set collection period; the microprocessor determines the threshold of the ambient humidity. If the ambient humidity exceeds the set first humidity threshold for three consecutive times, it controls the alarm to give an alarm prompt; if the ambient humidity is less than the set second humidity threshold, it controls the alarm to cancel the alarm.

[0039] The working principle of the above technical solution is as follows: When the scooter battery module is in a complex and changeable riding environment, it is inevitable to encounter wet conditions such as rain and mud. At this time, as a buffer and shock-proof material, the EVA foam can effectively protect the BMS protection board from external impacts. At the same time, its excellent sealing performance can also block the penetration of moisture to a certain extent. The silicone rubber waterproof ring further enhances the waterproof effect. Its soft material and tight fitting design ensure that moisture cannot easily penetrate into the BMS protection board; the leakage sensor integrated on the silicone rubber waterproof ring, like a pair of vigilant eyes, continuously monitors the humidity change of the surrounding environment. Once the ambient humidity exceeds the preset safe range, the microprocessor will quickly respond and determine the threshold of the humidity values collected three times continuously. If the determination result confirms the existence of a leakage risk, the microprocessor will immediately activate the alarm mechanism and give a clear alarm prompt through the alarm to remind the user to take measures in time to avoid damage to the battery module due to moisture intrusion; on the contrary, if the ambient humidity gradually decreases to the safe range, that is, less than the set second humidity threshold, the microprocessor will control the alarm to cancel the alarm and restore the normal monitoring state. This intelligent monitoring and alarm mechanism not only improves the safety performance of the scooter battery module, but also provides a more convenient and reliable user experience.

[0040] The beneficial effects of the above technical solution are as follows: By adopting the solution provided in this embodiment, the adaptability and durability of the scooter battery module in a complex and changeable environment can be significantly improved; through the double protection of the EVA foam and the silicone rubber waterproof ring, the potential threat of the external humid environment to the BMS protection board is effectively isolated, and the service life of the battery module is greatly extended; at the same time, the integrated leakage sensor and the intelligent monitoring and alarm mechanism realize the real-time and accurate control of the battery module state. Once an abnormal situation is detected, it can quickly respond, thus ensuring the safe and stable operation of the scooter battery module.

[0041] In one embodiment, the second nickel sheet in the first group of nickel sheets and the first nickel sheet in the second group of nickel sheets are connected in series and parallel through the BMS main board; the second nickel sheet in the first group of nickel sheets is limit-mounted and spot-welded on the bracket B; the first nickel sheet in the second group of nickel sheets is limit-mounted and spot-welded on the bracket C; The first nickel sheet in the first group of nickel sheets and the second nickel sheet in the second group of nickel sheets are wired and bus-connected in series and parallel through the wire passing holes of bracket A, bracket B, bracket C, and bracket D, and the number of jumper wires ≤ 5; the first nickel sheet in the first group of nickel sheets is limit-mounted and spot-welded on bracket A; the second nickel sheet in the second group of nickel sheets is limit-mounted and spot-welded on bracket D.

[0042] The working principle of the above technical solution is as follows: The second nickel sheet in the first group of nickel sheets and the first nickel sheet in the second group of nickel sheets achieve series and parallel connection between the battery cells after precise bus connection processing by the BMS main board, thereby ensuring the balanced distribution of current inside the battery module. At the same time, these two nickel sheets are respectively limit-mounted and spot-welded on bracket B and bracket C. This fixing method not only improves the connection stability but also effectively avoids the problem of poor contact caused by vibration during the scooter's driving; on the other hand, the first nickel sheet in the first group of nickel sheets and the second nickel sheet in the second group of nickel sheets are cleverly wired through the wire passing holes on bracket A, bracket B, bracket C, and bracket D, and finally achieve bus connection in series and parallel. This design greatly reduces the number of jumper wires, making the wiring of the entire battery cell group more concise and compact. It not only improves the space utilization rate of the battery module but also helps to reduce the short-circuit risk that may be caused by too many jumper wires; these two nickel sheets are also limit-mounted and spot-welded on the corresponding bracket A and bracket D, further enhancing the connection reliability. The beneficial effects of the above technical solution are as follows: By adopting the solution provided in this embodiment, efficient and balanced bus connection of the battery cells inside the scooter battery module is achieved. During the use of the scooter, the battery module can stably provide electrical energy to ensure the normal driving of the scooter, and at the same time, it also brings a safer and more reliable user experience to users.

[0043] In one embodiment, the BMS main board is built-in with a dynamic equalization algorithm, and the equalization current is set to ≥ 100 mA. The dynamic equalization algorithm performs the following steps: Real-time monitor the voltage of each battery cell, calculate the average voltage of the two groups of battery cells, and the maximum deviation between the battery cell voltage and the average voltage. When the maximum deviation is greater than or equal to the set deviation threshold, start active equalization, control the equalization current proportionally to ensure that the equalization current ≥ 100 mA; and arrange them in descending order according to the deviation value, and select the top 3 battery cells with the largest deviation to perform priority equalization to avoid excessive temperature rise caused by simultaneous equalization of multiple battery cells; the priority equalization is: perform cyclic equalization according to the set equalization time and rotation interval.

[0044] The working principle of the above technical solution is as follows: The BMS main board can real-time monitor the voltage status of each battery cell in the scooter battery module through the built-in dynamic equalization algorithm. First, the system calculates the average value of all battery cell voltages and finds the battery cell with the largest deviation from the average voltage, and determines this maximum deviation value. Once this maximum deviation value exceeds the preset deviation threshold, it means that there is an imbalance in the battery cell voltages in the battery module. At this time, the BMS main board will immediately activate the active equalization function. During the active equalization process, the BMS main board controls the magnitude of the equalization current according to a preset ratio to ensure that the equalization current always remains at a level of ≥100 mA to ensure the equalization efficiency. At the same time, to avoid the problem of excessive temperature rise that may be caused by simultaneous equalization of multiple battery cells, the system selects the top three battery cells with the largest deviation values in the order from largest to smallest voltage deviation of the battery cells for priority equalization. This priority equalization strategy can not only effectively reduce the temperature difference inside the battery module, but also ensure that the equalization process is more efficient and safe. Specifically, the priority equalization is a cyclic equalization carried out according to the set equalization time and rotation interval. During the equalization time, the selected battery cells will perform charge transfer through a specific equalization circuit to achieve voltage equalization. When the set equalization time is reached, the system switches to the next battery cell for equalization until the top three battery cells with the largest deviation values have completed one round of equalization. Then, the system repeats this cyclic equalization process according to the set rotation interval to ensure the continuous equalization of the battery cell voltages inside the battery module.

[0045] The beneficial effects of the above technical solution are as follows: By adopting the solution provided in this embodiment, the voltage equalization efficiency and safety of the scooter battery module can be significantly improved. By real-time monitoring the battery cell voltages and dynamically adjusting the equalization current, it is ensured that each battery cell can be timely and effectively equalized, thus avoiding the degradation of battery performance and potential safety hazards caused by uneven battery cell voltages. In addition, through the priority equalization strategy, the temperature difference inside the battery module is further reduced, the service life of the battery is extended, and the overall performance and user experience of the scooter are improved.

[0046] In one embodiment, the battery compartment is made of aluminum alloy and is provided with a multi-layer protection structure inside; the protection structure includes an insulating lining, a buffer layer, and a sealing strip.

[0047] The working principle of the above technical solution is as follows: The battery compartment made of aluminum alloy has good heat dissipation performance and high mechanical strength, which can effectively protect the battery cell group from external impacts and damage; the insulating lining is located between the battery cell group and the inner wall of the battery compartment, playing the role of electrical isolation to prevent safety accidents caused by short circuits in the battery cell group. The buffer layer is arranged around the battery cell group and is made of an elastic material, which can absorb and disperse impact energy to further protect the safety of the battery cell group; the sealing strip is used for the sealing of the battery compartment to prevent impurities such as moisture and dust from entering the interior of the battery compartment, ensuring that the battery cell group works in a good environment; when the scooter battery module works, the battery cell group will generate a certain amount of heat, and the aluminum alloy battery compartment can quickly conduct the heat away to keep the temperature inside the battery module stable; at the same time, the multi-layer protection structure can effectively isolate the battery cell group from the external environment, preventing the battery cell group from being interfered and damaged by the outside world.

[0048] The beneficial effects of the above technical solution are as follows: By adopting the solution provided in this embodiment, not only the safety and reliability of the battery module are improved, but also the service life of the battery is extended.

[0049] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these changes and modifications.

Claims

1. A battery cell group with balanced current bus, characterized in that: include: Four brackets, two groups of 21700 battery cells, and two groups of nickel sheets; the 21700 battery cells are fixed by the screw column structure of the four brackets; the two groups of nickel sheets adopt a symmetrical balanced confluence design, and the resistance difference of the overcurrent path of each 21700 battery cell is ≤5%.

2. The battery cell group with balanced current bus according to claim 1, characterized in that: The four brackets include bracket A, bracket B, bracket C and bracket D; the two groups of 21700 battery cells include a first group of 21700 battery cells and a second group of 21700 battery cells; the two groups of nickel sheets include a first group of nickel sheets and a second group of nickel sheets; The first group of 21700 battery cells are fixed through the screw columns of bracket A and bracket B with M2.3 self-tapping screws. The first group of nickel sheets are spot welded through the limit installation of bracket A and bracket B to form bracket A / B battery cell module-1; The second group of 21700 battery cells are fixed through the screw columns of bracket C and bracket D with M2.3 self-tapping screws. The second group of nickel sheets are spot welded through the limit installation of bracket C and bracket D to form bracket C / D battery cell module-2; The bracket A / B battery cell module-1 and the bracket C / D battery cell module-2 are fixed by the screw columns of the bracket B and the bracket C with M2.3 screws to form a 13S5P battery cell group.

3. The battery cell group with balanced bus according to claim 1, characterized in that: The position of the welding point of each nickel sheet in the two groups of nickel sheets is set in the limiting groove of each bracket in the four brackets, and the distance between the welding point and the adjacent nickel sheet is ≥3mm.

4. The battery cell group with balanced current bus according to claim 1, characterized in that: EVA foam and epoxy board are respectively attached to both sides of bracket A and bracket D.

5. A scooter battery module, characterized in that: include: A BMS mainboard, a battery compartment, 65 battery cells and a battery cell group with balanced bus as described in any one of claims 1-4; the 65 battery cells and the battery cell group are compactly arranged in a preset physical space of the battery compartment, and the physical space occupied by the battery cell group is the same as the physical space occupied by each of the 66 battery cells; the BMS mainboard is configured in the battery compartment.

6. A scooter battery module according to claim 5, characterized in that: The BMS mainboard is fixed to the battery cell group through the positioning columns and screw columns of bracket A, bracket B, bracket C, and bracket D, using M2.3 self-tapping screws. The distance between the BMS mainboard and the battery cell group is ≥2mm.

7. A scooter battery module according to claim 5, characterized in that: The left and right sides of the BMS protection plate are equipped with EVA foam, and the top and bottom are equipped with silicone waterproof rings; The silicone waterproof ring integrates a leakage sensor, a microprocessor and an alarm. The leakage sensor is used to collect the ambient humidity according to the set collection cycle; the microprocessor makes a threshold judgment on the ambient humidity. If it exceeds the set first humidity threshold for three consecutive times, the alarm is controlled to sound an alarm; if the ambient humidity is lower than the set second humidity threshold, the alarm is controlled to cancel the alarm.

8. A scooter battery module according to claim 5, characterized in that: The second nickel sheet in the first group of nickel sheets and the first nickel sheet in the second group of nickel sheets are connected in series and in parallel via the BMS mainboard; the second nickel sheet in the first group of nickel sheets is spot welded on the bracket B; the first nickel sheet in the second group of nickel sheets is spot welded on the bracket C; The first nickel sheet in the first group of nickel sheets and the second nickel sheet in the second group of nickel sheets are routed and connected in series through the wire holes of bracket A, bracket B, bracket C, and bracket D, and the number of flying wires is ≤5; the first nickel sheet in the first group of nickel sheets is spot welded on bracket A for limiting installation; the second nickel sheet in the second group of nickel sheets is spot welded on bracket D for limiting installation.

9. A scooter battery module according to claim 5, characterized in that: The BMS mainboard has a built-in dynamic balancing algorithm. The balancing current is set to ≥100mA. The dynamic balancing algorithm performs the following steps: Monitor the voltage of each battery cell in real time, and calculate the average voltage of the two groups of battery cells, as well as the maximum deviation between the battery cell voltage and the average voltage; When the maximum deviation is greater than or equal to the set deviation threshold, active balancing is started and the balancing current is proportionally controlled to ensure that the balancing current is ≥100mA. The cells are arranged in descending order according to the deviation value, and the first three cells with the largest deviations are selected for priority balancing to avoid excessive temperature rise caused by balancing multiple cells at the same time. Priority balancing is: cyclic balancing according to the set balancing time and rotation interval.

10. A scooter battery module according to claim 5, characterized in that: The battery compartment is made of aluminum alloy and has a multi-layer protective structure inside; the protective structure includes an insulating lining, a buffer layer and a sealing strip.

Images