A battery management system

Abstract

The utility model relates to battery management technical field discloses a kind of battery management systems, by adopting modularization design, main control panel, discharge power board and charging power board are designed as independent module, the on-demand configuration of discharge power board and charging power board of different current specifications is realized;This design has remarkable beneficial effect: one is high flexibility, can be flexibly selected power board specification according to the charge-discharge demand of low-speed vehicle, without redesigning entire system, to reduce cost, shorten development cycle, accelerate product listing speed;Two is convenient to repair and upgrade, module independence makes only need to replace corresponding module when fault, without scrapping whole system, reduce repair cost and difficulty, system upgrade is also simpler, save time and cost;Three is system reliability promotion, the independence between each module reduces the risk of mutual interference, further improves the performance and service life of low-speed vehicle battery management system.

Description

Technical Field

[0001] This utility model relates to the field of battery management technology, and in particular to a battery management system. Background Technology

[0002] Low-speed vehicles (including electric tricycles, mobility scooters for the elderly, sanitation vehicles, sightseeing vehicles, etc.) have been widely used for short-distance travel and specific work scenarios due to their significant economic advantages and convenient and flexible use, providing convenient transportation solutions for people's daily life, work and leisure activities.

[0003] Currently, the prevailing approach for battery management systems in low-speed vehicles is an integrated design concept. Specifically, this involves integrating control, charging, and discharging functions onto a single circuit board. While this design is compact, it has limitations. For example, when different charging and discharging current specifications are required, the entire system often needs to be redesigned and manufactured. This not only increases costs but also extends the development cycle, preventing timely market launches and missing optimal marketing opportunities.

[0004] Furthermore, the integrated battery management system also faces significant challenges in subsequent maintenance and upgrades. Due to the high degree of integration of its various functional modules, a failure in any part necessitates the scrapping of the entire system. Additionally, system upgrades are difficult and time-consuming due to the limitations of the overall structure.

[0005] Therefore, it is both necessary and urgent to comprehensively and thoroughly improve and innovate existing battery management technologies.

[0006] The above information is provided as background information only to aid in understanding this utility model, and does not confirm or acknowledge whether any of the above content can be used as prior art relative to this utility model. Utility Model Content

[0007] This invention provides a battery management system to reduce system costs and improve system configuration flexibility and maintainability.

[0008] To achieve the above objectives, this utility model provides the following technical solution:

[0009] A battery management system includes a battery pack, a main control board, a discharge power board, and a charging power board; wherein,

[0010] The main control board is connected to the battery pack, the discharge power board and the charging power board respectively.

[0011] The discharge power board is connected to the negative terminal of the battery pack and the negative input terminal of the load, respectively.

[0012] The charging power board is connected to the negative terminal of the battery pack and the negative input terminal of the charger, respectively.

[0013] The positive terminal of the battery pack is connected to the positive input terminal of the load and the positive input terminal of the charger, respectively.

[0014] Furthermore, in the battery management system, the main control board includes a discharge interface J1 and a charging interface J2;

[0015] The main control board is connected to the discharge power board via the discharge interface J1, and to the charging power board via the charging interface J2.

[0016] Furthermore, in the battery management system, the discharge power board includes a discharge current detection resistor RSD, a discharge control switch QD, and a discharge board interface J3;

[0017] The discharge current detection resistor RSD is connected in series with the discharge control switch QD, the discharge current detection resistor RSD is connected to the negative terminal of the battery pack, and the discharge control switch QD is connected to the negative input terminal of the load.

[0018] The main control board is connected to the discharge board interface J3 through the discharge interface J1, and is used to monitor the discharge current information and control the discharge control switch QD to turn on or off.

[0019] Furthermore, in the battery management system, the discharge current detection resistor RSD includes a single high-power resistor or several low-power resistors connected in parallel;

[0020] The discharge control switch QD includes several NMOS transistors connected in parallel.

[0021] Furthermore, in the battery management system, the discharge power board also includes a backflow prevention switch (QC).

[0022] The anti-backflow switch QC is connected in series between the discharge control switch QD and the negative input terminal of the load, and is controlled by the main control board.

[0023] Furthermore, in the battery management system, the backflow prevention switch QC includes several NMOS transistors connected in parallel.

[0024] Furthermore, in the battery management system, the charging power board includes a charging current detection resistor RSC, a charging control switch T2, and a charging board interface J4;

[0025] The charging current detection resistor RSC is connected in series with the charging control switch T2, and the charging current detection resistor RSC is connected to the negative terminal of the battery pack. The charging control switch T2 is connected to the negative input terminal of the charger.

[0026] The main control board is connected to the charging board interface J4 via the charging interface J2, and is used to monitor charging current information and control the charging control switch T2 to turn on or off.

[0027] Furthermore, in the battery management system, the charging current detection resistor RSC includes a single high-power resistor or several low-power resistors connected in parallel;

[0028] The charging control switch T2 includes several NMOS transistors connected in parallel.

[0029] Furthermore, the battery management system further includes a fuse protection unit;

[0030] The fuse protection unit is connected in series with the positive terminal of the battery pack.

[0031] Furthermore, in the battery management system, the main control board is used to control the discharge power board to stop discharging to the load when charging current information is detected.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] This utility model provides a battery management system that adopts a modular design, making the main control board, discharge power board, and charging power board independent modules. This allows for on-demand configuration of discharge and charging power boards with different current specifications. This design approach has significant advantages: First, it allows for flexible selection of appropriate discharge and charging power boards based on the different charging and discharging current requirements of low-speed vehicles, eliminating the need to redesign and manufacture the entire system. This significantly reduces system costs, shortens the development cycle, and enables products to be launched to the market more quickly, seizing the best market promotion opportunities. Second, in terms of maintenance and upgrades, the modular design ensures that each functional module is independent. When a part fails, only the corresponding module needs to be replaced, without scrapping the entire system, reducing maintenance costs and difficulty. Simultaneously, system upgrades are more convenient; only specific modules need to be upgraded or replaced, without large-scale adjustments to the overall structure, saving upgrade time and costs. Furthermore, the modular design improves system reliability. The independence between modules reduces the risk of mutual interference, further enhancing the performance and lifespan of the low-speed vehicle battery management system.

[0034] This invention has other features and advantages that will be apparent from or will be set forth in detail in the accompanying drawings and the following detailed description, which together serve to explain the particular principles of this invention. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a schematic diagram of the structure of a battery management system provided in an embodiment of the present invention;

[0037] Figure 2 This is one of the circuit principle diagrams of a battery management system provided in this utility model embodiment;

[0038] Figure 3 This is the second schematic diagram of the circuit principle of a battery management system provided in this embodiment of the present invention.

[0039] Figure label:

[0040] Battery pack 1, main control board 2, discharge power board 3, charging power board 4, load 5, charger 6, fuse protection unit 7. Detailed Implementation

[0041] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0042] Please refer to Figure 1 This utility model provides a battery management system with a compact structure and reasonable design. It is mainly composed of several core parts, including a battery pack 1, a main control board 2, a discharge power board 3, and a charging power board 4.

[0043] From the perspective of the connection relationship of each component, the main control board 2 plays a key role in the core regulation of the whole system. It is connected to the battery pack 1, the discharge power board 3 and the charging power board 4 respectively. It can obtain the status information of the battery pack 1 in real time and accurately, and at the same time effectively monitor and intelligently regulate the working status and data information of the discharge power board 3 and the charging power board 4.

[0044] The discharge power board 3 plays an important role in stabilizing the output of electrical energy from the battery pack 1. It is connected to the negative terminal of the battery pack 1 and the negative input terminal of the load 5, respectively. It can reasonably control the output power of electrical energy according to the actual needs of the load 5, so as to ensure that the load 5 can operate normally and stably.

[0045] The charging power board 4 is mainly responsible for charging the battery pack 1. It is connected to the negative terminal of the battery pack 1 and the negative input terminal of the charger 6. During the charging process, the charging power board 4 can accurately adjust the charging current and voltage according to the charging state of the battery pack 1 and the output characteristics of the charger 6 to achieve a safe and efficient charging process.

[0046] The positive terminal of battery pack 1 is connected to the positive input terminal of load 5 and the positive input terminal of charger 6, forming a complete and closed circuit loop, ensuring the smooth flow of electrical energy between battery pack 1, load 5 and charger 6.

[0047] The modular design concept adopted in this embodiment of the invention is a highly innovative and forward-looking design approach. Specifically, the main control board 2, the discharge power board 3, and the charging power board 3 are carefully designed as independent modules. This modular design brings many significant and valuable benefits:

[0048] First, it demonstrates exceptional flexibility and adaptability in addressing the diverse charging and discharging current requirements of low-speed vehicles. Different types of low-speed vehicles, used in different scenarios, exhibit significant differences in their charging and discharging current specifications. The modular design of this invention allows for the flexible and precise selection of appropriate discharge power board 3 and charging power board 4 based on the specific charging and discharging current requirements of the low-speed vehicle. Unlike traditional designs, it eliminates the need to redesign and manufacture the entire system for different current specifications. This feature significantly reduces system development and production costs while substantially shortening the development cycle. This enables products to be launched to market faster, seizing optimal market opportunities and gaining a competitive edge in the fierce market competition.

[0049] Secondly, the advantages of modular design are even more evident in maintenance and upgrades. The independent design of each functional module allows maintenance personnel to quickly and accurately locate the faulty module when a part of the system malfunctions. Only the faulty module needs to be replaced, without scrapping the entire system. This not only significantly reduces maintenance costs but also simplifies maintenance, improves efficiency, reduces downtime due to equipment failure, and ensures the normal operation of low-speed vehicles. Furthermore, in terms of system upgrades, modular design makes the upgrade process more convenient and efficient. Only specific modules need to be upgraded or replaced, without large-scale adjustments or modifications to the overall structure. This greatly saves upgrade time and costs, allowing the system to keep pace with technological advancements and continuously improve its performance and functionality.

[0050] Furthermore, modular design plays a crucial role in improving system reliability. The independence between modules effectively reduces the risk of mutual interference and avoids the possibility of a cascading effect from a failure in one module to other modules. This design approach further enhances the overall performance of the low-speed vehicle battery management system, extends its lifespan, and provides users with a more stable and reliable battery management solution.

[0051] In one embodiment of this invention, one of the important functions of the main control board 2 is to control the discharge power board 3 to immediately stop discharging to the load 5 when charging current information is detected.

[0052] It should be noted that this design mechanism ensures that electrical energy can flow to battery pack 1 in a concentrated and efficient manner during the charging process, avoiding various problems that may be caused by simultaneous charging and discharging operations, and effectively ensuring the safety and stability of the entire battery management system.

[0053] It is particularly important to point out that current low-speed vehicle battery management systems have significant shortcomings and deficiencies. Regarding charge and discharge control, a common approach is a simultaneous charging and discharging design. Under this architecture, when battery pack 1 is charging, the system cannot effectively prevent discharge. This means that during charging, load 5 can continue to consume the energy of battery pack 1, leading to a significant reduction in charging efficiency. More seriously, this simultaneous charging and discharging can cause current disturbances within battery pack 1, resulting in excessive current surges and heat buildup, causing irreversible damage to battery pack 1, greatly shortening its lifespan, and creating serious safety hazards, increasing the probability of battery fires, explosions, and other dangerous accidents.

[0054] Another existing solution uses relays to control charging and discharging. However, the relay solution also has many drawbacks. In terms of size, relays themselves occupy a large space, which undoubtedly increases the difficulty and cost of layout for the space-constrained battery management system of low-speed vehicles. In terms of cost, as a mechanical control component, relays are relatively expensive to manufacture and are prone to mechanical wear and failure during use, further increasing maintenance costs. From a power consumption perspective, relays consume electrical energy to maintain the operation of their mechanical contacts, which undoubtedly increases the power consumption of the entire battery management system and reduces energy efficiency. Furthermore, the relay solution has a long system response time; there is a delay between detecting a charging signal and actually cutting off the discharge circuit. During this time, battery pack 1 may still be in an unsafe charging and discharging state, failing to ensure the safe operation of the system in a timely and effective manner.

[0055] In contrast, this embodiment of the invention cleverly avoids the problems existing in the above-mentioned existing solutions through the intelligent control function of the main control board 2, and provides a safer, more efficient and reliable solution for low-speed vehicle battery management.

[0056] Please refer to Figure 2 In one embodiment of this invention, the main control board 2 includes a discharge interface J1 and a charging interface J2.

[0057] The main control board 2 is connected to the discharge power board 3 through the discharge interface J1, and is connected to the charging power board 4 through the charging interface J2.

[0058] It should be noted that this separate port design provides the hardware foundation for solving the problems caused by simultaneous charging and discharging. It allows the charging and discharging circuits to be independent of each other and not interfere with each other, thereby fundamentally avoiding many drawbacks caused by simultaneous charging and discharging design and significantly improving the performance and safety of the entire battery management system.

[0059] It is understood that the main control board 2 should also include an MCU and necessary peripheral components such as a reference source, crystal oscillator, and memory. The specific function of these circuit designs is to ensure the normal operation of each function of the main control board 2. Given that these circuit designs have been implemented in the existing technology and are not the focus of this design, they will not be elaborated on here.

[0060] Please refer to this again. Figure 2 In one embodiment of this invention, the discharge power board 3 includes a discharge current detection resistor RSD, a discharge control switch QD, and a discharge board interface J3.

[0061] The discharge current sensing resistor RSD and the discharge control switch QD are connected in series to form a complete discharge control loop. In this loop, the other end of the discharge current sensing resistor RSD is connected to the negative terminal of battery pack 1 to ensure accurate acquisition of the current information during the discharge of battery pack 1; the other end of the discharge control switch QD is connected to the negative input terminal of load 5, thereby providing a stable power output channel for load 5.

[0062] The main control board 2 is connected to the discharge board interface J3 on the discharge power board 3 via its discharge interface J1. This connection method has two important functions: First, the main control board 2 can monitor the voltage signal across the discharge current detection resistor RSD in real time and accurately. Since the resistance value of the discharge current detection resistor RSD is known, according to Ohm's law, the discharge current of battery pack 1 can be accurately calculated by measuring the voltage across it, thus achieving a comprehensive understanding of the discharge current information. Second, the main control board 2 can issue precise control commands to the discharge control switch QD based on the real-time monitored discharge current information and the preset control strategy, flexibly controlling the on or off state of the discharge control switch QD. When the load 5 needs power supply, the main control board 2 controls the discharge control switch QD to be on, so that the battery pack 1 can discharge smoothly to the load 5; when abnormal conditions occur, such as excessive discharge current or low battery charge, the main control board 2 quickly controls the discharge control switch QD to be off, promptly cutting off the discharge circuit and protecting the battery pack 1 and the load 5 from damage.

[0063] In one embodiment of this invention, the specific selection and design of the discharge current detection resistor RSD and the discharge control switch QD are further optimized. The design of the discharge current detection resistor RSD fully considers the power requirements and heat dissipation requirements under different application scenarios. It can be a single high-power resistor, suitable for scenarios with relatively small discharge currents and less stringent cost and space requirements, offering advantages such as simple structure and low cost. Alternatively, it can be composed of several parallel low-power resistors, depending on actual needs. Using parallel low-power resistors not only meets the power requirements during high-current discharge but also distributes the current across multiple resistors, effectively reducing the heat generated by each resistor, improving the system's heat dissipation performance and reliability. It also increases design flexibility to a certain extent, facilitating adjustments to resistor values ​​and power according to specific requirements.

[0064] The discharge control switch QD employs a design using several NMOS transistors connected in parallel. NMOS transistors offer advantages such as fast switching speed, low on-resistance, and convenient control. Using multiple NMOS transistors in parallel further reduces on-resistance, minimizes power loss during conduction, and improves the system's energy conversion efficiency. Simultaneously, the parallel design increases the current carrying capacity of the discharge control switch QD, enabling it to better handle high-current discharge demands and ensuring stable and reliable operation under various conditions. Furthermore, this design enhances system redundancy; if one NMOS transistor fails, the others connected in parallel continue to function normally, ensuring the continuity of discharge control and strengthening the overall reliability and stability of the battery management system.

[0065] Please refer to this again. Figure 2 In one embodiment of this invention, the discharge power board 3 is further optimized based on the original design, and a key component, the anti-backflow switch tube QC, is added, which greatly improves the safety and stability of the entire battery management system during the discharge process.

[0066] From the circuit connection perspective, the anti-backflow switch QC is connected in series between the discharge control switch QD and the negative input terminal of the load 5. The anti-backflow switch QC ensures that current can only flow from battery pack 1 to the load 5 through the discharge control switch QD, and absolutely prevents reverse flow. That is, it prevents the load 5 from backflowing current into battery pack 1 under certain operating conditions (such as the presence of other power sources or load characteristics that cause current reversal).

[0067] Once the main control board 2 detects any risk or indication of backflow, it immediately sends a shutdown command to the anti-backflow switch QC, quickly cutting off the path of the backflow current and effectively protecting the battery pack 1 from damage. This real-time, proactive control method greatly improves the system's response speed and protection capabilities, providing a solid guarantee for the safe operation of the battery pack 1.

[0068] In one embodiment of this invention, the specific selection and design of the backflow prevention switch QC were thoroughly considered and optimized. The backflow prevention switch QC employs a design using several NMOS transistors connected in parallel. As a high-performance semiconductor device, the NMOS transistor possesses numerous advantages suitable for backflow prevention control. It features fast switching speed, enabling it to respond to control commands from the main control board 2 in a very short time, achieving rapid turn-on and turn-off operations, thereby effectively preventing backflow current. Simultaneously, the NMOS transistor has low on-resistance, reducing power loss in the on-state, improving the system's energy conversion efficiency, reducing heat generation, and contributing to the long-term stable operation of the system.

[0069] The parallel design of several NMOS transistors further amplifies these advantages. The parallel design significantly increases the current carrying capacity of the reverse current protection switch (QC), enabling it to easily handle high-current reverse current situations and ensuring reliable operation under various complex load conditions. Furthermore, the parallel structure improves system redundancy; if one NMOS transistor fails or degrades in performance, the other parallel NMOS transistors can still function normally, ensuring the continuity of the reverse current protection function and preventing the entire system from losing its protection capability due to the failure of a single component. This highly reliable and high-performance design provides strong support for the safe and stable operation of the battery management system during discharge.

[0070] Please refer to this again. Figure 2 In one embodiment of this example, the charging power board 4 includes a charging current detection resistor RSC, a charging control switch T2, and a charging board interface J4.

[0071] In terms of circuit connection, the charging current sensing resistor RSC and the charging control switch T2 are connected in series to form a complete charging control loop. Specifically, the other end of the charging current sensing resistor RSC is connected to the negative terminal of battery pack 1, which allows it to sense the current change of battery pack 1 in real time during the charging process; the other end of the charging control switch T2 is connected to the negative input terminal of charger 6, thereby establishing a charging path between charger 6 and battery pack 1.

[0072] The main control board 2 is connected to the charging board interface J4 on the charging power board 4 via the charging interface J2. This connection design has a dual key function: Firstly, the main control board 2 can use this connection to monitor the voltage signal across the charging current sensing resistor RSC in real time and with precision. Since the resistance value of the charging current sensing resistor RSC is predetermined and precisely known, according to Ohm's law (I=U / R, where I is current, U is voltage, and R is resistance), the real-time charging current of battery pack 1 can be accurately calculated by precisely measuring the voltage across it, thus achieving comprehensive and accurate control of the charging current information. Secondly, the main control board 2 can issue precise control commands to the charging control switch T2 based on the real-time charging current information and the pre-set charging strategy and safety threshold, flexibly controlling the on or off state of the charging control switch T2. During normal charging, when the charging current is within a safe range, the main control board 2 controls the charging control switch T2 to remain on, so that the charger 6 can continuously charge the battery pack 1. Once an abnormality in the charging current is detected, such as overcurrent or short circuit, the main control board 2 will quickly issue a shutdown command to immediately cut off the charging circuit, preventing the battery pack 1 from being damaged due to overcharging or abnormal current, and ensuring the safety and reliability of the charging process.

[0073] In one specific embodiment of this example, the selection and design of the charging current sensing resistor RSC were carefully considered and optimized. Taking into account the different requirements for charging power and current sensing accuracy in different application scenarios, the charging current sensing resistor RSC also provides two flexible design schemes: a single high-power resistor scheme and a scheme using several low-power resistors connected in parallel.

[0074] In addition, the charging control switch T2 also adopts a design scheme of several NMOS transistors connected in parallel, which aims to achieve efficient and reliable control of the charging process.

[0075] In summary, the charging power board 4 in this embodiment, through its carefully designed circuit structure and rationally selected key components, achieves accurate monitoring and reliable control of the charging process of the battery pack 1. Working together with other components such as the main control board 2, it jointly constructs a safe, efficient, and intelligent battery management system.

[0076] Please refer to Figure 3 In one embodiment of this invention, a fuse protection unit 7 is introduced to further enhance the safety protection level of the entire battery management system. This fuse protection unit 7 is connected in series in the positive output path of the battery pack 1 in the system circuit, protecting the battery pack 1 and the entire system.

[0077] From the perspective of working principle and function, the fuse protection unit 7 achieves its protection function based on the characteristics of a fuse. A fuse is an overcurrent protection device, mainly composed of a fusible element and a fuse tube. Under normal operating conditions, the fusible element allows the current of the battery pack 1 to pass smoothly, providing a stable power supply to the load 5. At this time, the fusible element is in a conductive state and will not hinder the normal operation of the circuit. However, when an abnormal situation occurs in the circuit, such as a short circuit or overload, causing the current to increase sharply and exceed the rated current value set by the fuse protection unit 7, the fusible element will quickly melt due to overheating.

[0078] Once the fuse melts, the circuit will be immediately cut off, effectively preventing excessive current from continuing to flow through battery pack 1 and load 5. This rapid circuit disconnection action can quickly limit the damage of fault current to battery pack 1, preventing serious consequences such as overheating, fire, or even explosion caused by overcurrent. At the same time, it also avoids equipment damage caused by excessive current surges for load 5, extending the service life of the load.

[0079] In practical applications, the selection and design of the fuse protection unit 7 requires comprehensive consideration of various factors. For example, based on factors such as the rated current and maximum allowable current of the battery pack 1 and the operating characteristics of the load 5, a fuse with an appropriate rated current must be accurately selected to ensure that the fuse will not malfunction under normal operating current and can melt reliably and promptly in the event of an overcurrent fault. Furthermore, the fuse's fusing characteristic curve must match the system's protection requirements. Different application scenarios may require fuses with different fusing characteristics, such as fast-blow or slow-blow types, to achieve precise circuit protection.

[0080] In summary, this embodiment introduces a fuse protection unit 7, which works in conjunction with components such as the main control board 2, discharge power board 3, and charging power board 4 to form a multi-layered, comprehensive safety protection system. The main control board 2, through intelligent monitoring and control, can monitor the real-time operating status of the battery pack 1 and load 5, taking timely measures when abnormalities are detected. The discharge power board 3 and charging power board 4 ensure the safe input and output of electrical energy by precisely controlling the charging and discharging process. The fuse protection unit 7, as the last line of defense, quickly cuts off the circuit in the event of extreme overcurrent, providing a solid and reliable guarantee for the safe and stable operation of the entire battery management system.

[0081] Although this invention frequently uses terms such as main control board, discharge power board, and load, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of this invention; interpreting them as any additional limitation would contradict the spirit of this invention.

[0082] Finally, it should be noted that although the above embodiments have been described in the text and drawings of this utility model, this should not limit the scope of patent protection of this utility model. Any technical solutions resulting from equivalent structural or procedural substitutions or modifications made based on the essential concept of this utility model and utilizing the content described in the text and drawings of this utility model, as well as the direct or indirect application of the technical solutions of the above embodiments to other related technical fields, are all included within the scope of patent protection of this utility model.

Claims

1. A battery management system, characterized in that, The system includes a battery pack (1), a main control board (2), a discharge power board (3), and a charging power board (4); wherein, The main control board (2) is connected to the battery pack (1), the discharge power board (3) and the charging power board (4) respectively; The discharge power plate (3) is connected to the negative terminal of the battery pack (1) and the negative input terminal of the load (5) respectively; The charging power board (4) is connected to the negative terminal of the battery pack (1) and the negative input terminal of the charger (6) respectively; The positive terminal of the battery pack (1) is connected to the positive input terminal of the load (5) and the positive input terminal of the charger (6), respectively.

2. The battery management system according to claim 1, characterized in that, The main control board (2) includes a discharge interface J1 and a charging interface J2; The main control board (2) is connected to the discharge power board (3) through the discharge interface J1, and is connected to the charging power board (4) through the charging interface J2.

3. The battery management system according to claim 2, characterized in that, The discharge power board (3) includes a discharge current detection resistor RSD, a discharge control switch QD, and a discharge board interface J3; After the discharge current detection resistor RSD is connected in series with the discharge control switch QD, the discharge current detection resistor RSD is connected to the negative terminal of the battery pack (1), and the discharge control switch QD is connected to the negative input terminal of the load (5). The main control board (2) is connected to the discharge board interface J3 through the discharge interface J1, and is used to monitor the discharge current information and control the discharge control switch QD to turn on or off.

4. The battery management system according to claim 3, characterized in that, The discharge current detection resistor RSD includes a single high-power resistor or several low-power resistors connected in parallel. The discharge control switch QD includes several NMOS transistors connected in parallel.

5. The battery management system according to claim 3, characterized in that, The discharge power board (3) also includes a backflow prevention switch tube (QC); The anti-backflow switch QC is connected in series between the discharge control switch QD and the negative input terminal of the load (5), and is controlled by the main control board (2).

6. The battery management system according to claim 5, characterized in that, The backflow prevention switch QC includes several NMOS transistors connected in parallel.

7. The battery management system according to claim 3 or 5, characterized in that, The charging power board (4) includes a charging current detection resistor RSC, a charging control switch T2, and a charging board interface J4. After the charging current detection resistor RSC is connected in series with the charging control switch T2, the charging current detection resistor RSC is connected to the negative terminal of the battery pack (1), and the charging control switch T2 is connected to the negative input terminal of the charger (6). The main control board (2) is connected to the charging board interface J4 through the charging interface J2, and is used to monitor the charging current information and control the charging control switch T2 to turn on or off.

8. The battery management system according to claim 7, characterized in that, The charging current sensing resistor RSC includes a single high-power resistor or several low-power resistors connected in parallel. The charging control switch T2 includes several NMOS transistors connected in parallel.

9. The battery management system according to claim 1, characterized in that, The system also includes a fuse protection unit (7); The fuse protection unit (7) is connected in series with the positive electrode of the battery pack (1).

10. The battery management system according to claim 1, characterized in that, The main control board (2) is used to control the discharge power board (3) to stop discharging to the load (5) when the charging current information is detected.

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