A battery control system and a battery control method

Abstract

This invention discloses a battery control system and a battery control method. The battery control system includes an output interface, a charging control module, a discharging control module, a float charging control module, and a main control unit. The output interface includes a positive terminal, a negative terminal, and a detection port. The positive and negative terminals are used to connect to a charger or load. The positive terminal is connected to the positive terminal of the battery module. The detection port is used to connect to a detection line. The charging control module and the discharging control module are connected in series between the negative terminal and the negative terminal of the battery module to control the conduction or disconnection of the charging and discharging paths, respectively. One end of the float charging control module is connected to the positive terminal, and the other end is connected between the charging control module and the discharging control module and connected to the detection port. The main control unit is used to control the conduction or disconnection of the charging control module, the discharging module, and the float charging control module. This invention aims to solve the technical problem that lithium batteries are incompatible with lead-acid battery chargers in the prior art.

Description

Technical Field

[0001] This invention relates to the field of battery management technology, and more specifically to a battery control system and a battery control method. Background Technology

[0002] Fire emergency power supplies are widely used in fire emergency lighting, fire equipment power supply, and emergency evacuation systems, providing backup power to relevant equipment when the mains power fails or in the event of a sudden accident. Currently, lead-acid batteries are commonly used as energy storage units in fire emergency power systems. However, lead-acid batteries suffer from low energy density, large size and weight, short cycle life, and high maintenance costs. With the development of lithium battery technology, lithium batteries, due to their advantages of high energy density, long cycle life, and small size and weight, are gradually being used to replace lead-acid batteries, thus forming a lead-to-lithium conversion solution for fire emergency power systems.

[0003] However, existing fire emergency power systems are typically equipped with lead-acid battery chargers. Lead-acid battery chargers are generally designed according to the charging characteristics of lead-acid batteries, and their charging process usually includes a constant current charging stage, a constant voltage charging stage, and a float charging stage. When lithium batteries are used to replace lead-acid batteries, due to differences in charging characteristics and management methods between lithium and lead-acid batteries, existing lead-acid chargers may not be able to properly enter the float charging stage after detecting that the lithium battery is fully charged, and may even generate abnormal detection or alarms. Furthermore, if the lithium battery continues to receive float charging current while fully charged, there is a risk of overcharging, which may affect the battery's safety and lifespan.

[0004] Therefore, in the application of lead-to-lithium conversion in fire emergency power systems, how to make the system compatible with the original lead-acid battery charger when using lithium batteries to replace lead-acid batteries, and how to avoid continuing to charge the battery cells after the batteries are fully charged, while keeping the lead-acid charger in normal float charging mode, has become an urgent technical problem to be solved. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned technical deficiencies and propose a battery control system and battery control method to solve the technical problem that lithium batteries are incompatible with lead-acid battery chargers in the prior art.

[0006] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a battery control system connected to a battery module, comprising: an output interface including a positive terminal, a negative terminal, and a detection port, wherein the positive and negative terminals are used to connect to an external lead-acid charger or load, the positive terminal is also connected to the positive terminal of the battery module, and the detection port is used to connect to the detection line of the external lead-acid charger; a charging control module and a discharging control module, connected in series between the negative terminal and the negative terminal of the battery module, for controlling the conduction or disconnection of the charging path and the discharging path of the battery module respectively; a float charging control module, one end of which is connected to the positive terminal, and the other end of which is connected to the node between the charging control module and the discharging control module, so as to form a float charging current loop through the discharging control module and the negative terminal, and is connected to the detection port; and a main control unit electrically connected to the charging control module, the discharging control module, and the float charging control module, for controlling the conduction or disconnection of the charging control module, the discharging control module, and the float charging control module.

[0007] In some embodiments, the charging control module includes a charging switch and a first diode. The charging switch and the first diode are connected in parallel between the negative terminal of the battery module and the discharge control module. The anode of the first diode is connected to the side closer to the discharge control module, and the cathode is connected to the side closer to the battery module, so as to limit the current to be conducted only in the direction from the discharge module to the battery module.

[0008] In some embodiments, the discharge control module includes a discharge switch and a second diode, which are connected in parallel between the charging control module and the negative terminal. The anode of the second diode is connected to the side closer to the charging control module, and the cathode is connected to the side closer to the negative terminal, so as to limit the current to conduct only in the direction from the charging control module to the negative terminal.

[0009] In some embodiments, the float charge control module includes a float charge resistor, a third diode, and a float charge switch arranged in series, and the float charge control module is connected between the positive terminal and the node between the charging control module and the discharging control module; the anode of the third diode is connected to the side closer to the positive terminal, and the cathode is connected to the side closer to the node, so as to limit the current to conduct only in the direction from the positive terminal to the node.

[0010] In some embodiments, the battery control system further includes a shunt, which is disposed between the battery module and the negative terminal. The main control unit determines the charging or discharging state of the battery based on the current signal detected by the shunt.

[0011] In some embodiments, the main control unit is electrically connected to the battery module and is used to detect the voltage or current of the battery module to determine the battery status.

[0012] Secondly, the present invention also provides a battery control method applied to the aforementioned battery control system, comprising: when the battery module has not reached a preset fully charged state, controlling the charging control module to be turned on, the float charging control module to be turned off, and the discharging control module to be turned on, so as to form a charging path from the positive terminal through the battery module, the charging control module, and the discharging control module to the negative terminal; when the battery module is detected to have reached a preset fully charged state, controlling the charging control module to be turned off, the float charging control module to be turned on, and the discharging control module to be turned on, so as to form a float charging current loop from the positive terminal through the float charging control module and the discharging control module to the negative terminal; when the battery module is detected to be discharging to an external load, controlling the float charging control module to be turned off, the charging control module to be turned on, and the discharging control module to be turned on, so as to form a discharging path from the battery module through the charging control module and the discharging control module to the negative terminal.

[0013] In some embodiments, when the battery module voltage is detected to be lower than a preset voltage threshold, the discharge control module is disconnected to stop the battery module from discharging externally.

[0014] In some embodiments, the state of the battery module is determined based on the voltage and current of the battery module.

[0015] In some embodiments, when the float charging current loop is formed, a detection signal is provided to the external lead-acid charger through the detection port so that the external lead-acid charger maintains the float charging operation state.

[0016] Compared with existing technologies, the battery control system and battery control method provided by this invention, by setting up a charging control module, a discharging control module, and a float charging control module in the battery control system, and having the main control unit coordinately control each module according to the working state of the battery module, enables the system to establish a normal charging path when the battery module is not fully charged, and to cut off the charging of the cells when the battery module reaches full charge, while establishing a float charging current loop bypassing the battery module, so that the external lead-acid charger still maintains float charging operation. Without changing the original lead-acid charger structure, this invention achieves compatible application of lithium battery systems with lead-acid charging equipment, not only avoiding the risk of overcharging the battery module and improving battery safety, but also ensuring the stability of the charger's operating state, thereby improving the overall reliability and adaptability of the fire emergency power supply system. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a battery control system according to one embodiment of the present invention; Figure 2 This is a schematic diagram of the parallel structure of a battery control system according to one embodiment of the present invention.

[0018] Explanation of reference numerals in the attached figures: 11. Positive terminal; 12. Negative terminal; 13. Detection port; 20. Charging control module; 21. Charging switch; 22. First diode; 30. Discharge control module; 31. Discharge switch; 32. Second diode; 40. Float charge control module; 41. Float charge switch; 42. Float charge resistor; 43. Third diode; 50. Main control unit; 60. Shunt; 70. Battery module. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0020] To address the technical problem that lithium batteries are incompatible with lead-acid battery chargers in the prior art, this invention provides a battery control system and a battery control method that can achieve the technical effect of preventing the battery cells from continuing to charge after the battery is fully charged, while maintaining the lead-acid charger in a normal float charging state.

[0021] It should be noted that the battery control system and battery control method described in this invention are used for, but not limited to, battery management. For ease of explanation, this invention will only use the application of the battery control system and battery control method to battery management as an example. The principles of the battery control system and battery control method applied to other types of devices are essentially the same as those applied to battery management, and will not be elaborated here.

[0022] Please see Figure 1 , Figure 1 This is a schematic diagram of a battery control system according to one embodiment of the present invention. This battery control system is applied to the conversion of lead-acid batteries to lithium-ion batteries for fire emergency power supplies. It ensures compatibility with existing lead-acid battery chargers when lithium-ion batteries replace lead-acid batteries, prevents further charging of the battery cells after full charging, and simultaneously ensures the lead-acid charger maintains normal float charging operation. The system includes an output interface, a charging control module 20, a discharging control module 30, a float charging control module 40, and a main control unit 50.

[0023] The output interface is used to establish an electrical connection between the battery control system and external devices. The output interface includes a positive terminal 11 (P+) and a negative terminal 12 (P...). ) and detection port 13. Positive terminal 11 (P+) and negative terminal 12 (P Connect the positive (B+) and negative (B) terminals of the battery module 70 respectively. The detection port 13 is used to connect to an external lead-acid battery charger or load to realize the charging and discharging functions of the system; the detection port 13 is used to connect to the detection line of the external lead-acid charger to provide a detection signal to the external lead-acid charger, so that the lead-acid charger can determine the current charging state or float charging state of the system based on the detection signal.

[0024] The charging control module 20 and the discharging control module 30 are connected in series at the negative terminal (B) of the battery module 70. ) and negative extreme 12 (P The charging control module 20 and the discharging control module 30 are used to control the conduction or disconnection of the charging path and discharging path of the battery module 70, respectively. The charging control module 20 and the discharging control module 30 may each include switching devices, such as MOSFETs or other power switching devices, to control the conduction or disconnection of the charging path or discharging path of the battery module 70. When the charging control module 20 is turned on, an external lead-acid charger can charge the battery module 70 through the positive terminal 11 (P+); when the discharging control module 30 is turned on, the battery module 70 can charge through the negative terminal 12 (P... It provides electrical energy to external loads.

[0025] The float charge control module 40 is used to establish a float charge current loop after the battery module 70 reaches a fully charged state. One end of the float charge control module 40 is connected to the positive terminal 11 (P+), and the other end is connected to the node between the charging control module 20 and the discharging control module 30, so that when the float charge control module 40 is turned on, the current loop is established through the discharging control module 30 and the negative terminal 12 (P+). This forms a float charging current loop. Through this loop, once the battery module 70 is fully charged, charging to the cells ceases, while still providing a current path to the external lead-acid charger. This keeps the charger in the float charging phase, preventing abnormal detection or alarms. Furthermore, the float charging control module 40 is connected to the detection port 13 to provide corresponding detection signals to the external lead-acid charger during float charging.

[0026] The main control unit 50 is used to uniformly control all control modules of the system. The main control unit 50 is electrically connected to the charging control module 20, discharging control module 30, and float charging control module 40, respectively, and is used to control the conduction or disconnection of each module according to the working state of the battery module 70. For example, when the battery module 70 is in the charging stage but has not reached the preset fully charged state, the main control unit 50 controls the charging control module 20 and discharging control module 30 to remain on, while simultaneously turning off the float charging control module 40, so that the current flows from the positive terminal 11 (P+) through the battery module 70, charging control module 20, and discharging control module 30 to the negative terminal 12 (P... This enables normal charging of the battery module 70. When the main control unit 50 detects that the battery module 70 has reached the preset full charge state, it controls the charging control module 20 to disconnect and controls the float charging control module 40 to turn on, thereby establishing a charging connection from the positive terminal 11 (P+) through the float charging control module 40 and the discharge control module 30 to the negative terminal 12 (P+). The float charging current circuit is used to avoid continuing to charge the battery cell, while keeping the external lead-acid charger in float charging mode.

[0027] In this embodiment, a charging control module 20, a discharging control module 30, and a float charging control module 40 are set in the battery control system. The main control unit 50 controls each module according to the state of the battery module 70, so that the system can cut off the charging of the battery cells after the battery module 70 is fully charged, and at the same time establish a float charging current loop to maintain the float charging operation of the external lead-acid charger. In this way, when lithium batteries are used to replace lead-acid batteries, normal operation can be achieved without replacing the original lead-acid battery charger. This avoids the problem of overcharging lithium batteries and prevents abnormal detection or alarms of lead-acid chargers, realizing the compatible application of lithium batteries in lead-acid battery systems.

[0028] Please see Figure 2 , Figure 2 This is a schematic diagram of a parallel structure of a battery control system according to one embodiment of the present invention. In another embodiment, the battery control system can be applied to a scenario where multiple battery modules 70 are used in combination. Taking a series combination of two battery modules 70 as an example, the system includes a first battery module 70 and a second battery module 70, wherein the first battery module 70 has a positive electrode (B1+) and a negative electrode (B1). ), correspondingly setting the first positive terminal 11 (P1+) and the first negative terminal 12 (P1) The second battery module 70 has a positive electrode (B2+) and a negative electrode (B2). ), corresponding to setting the second positive terminal 11 (P2+) and the second negative terminal 12 (P2) Each battery control system is equipped with a charging control module 20, a discharging control module 30, a float charging control module 40, and a main control unit 50.

[0029] Between the first battery module 70 and the second battery module 70, the first positive terminal 11 (P1+) and the second negative terminal 12 (P2+) are connected. The two battery modules 70 are electrically connected, thus forming a connection between them; the output port of the entire system is the first negative terminal 12 (P1). The first positive terminal 11 (P2+) is used to connect to an external lead-acid charger or load to enable the charging and discharging functions of the overall system. Meanwhile, the detection port 13 remains connected to the detection line of the external lead-acid charger to provide a detection signal to the charger.

[0030] During system operation, during the charging phase, the external lead-acid charger provides charging current to multiple battery modules 70 through the system output port, completing the charging process of the corresponding battery module 70. After a battery module 70 reaches full charge, its corresponding float charge control module 40 can establish a float charge current loop, stopping the charging of that battery module 70 while maintaining the float charge operation of the charger, while other battery modules 70 that are not fully charged can continue to charge. During the discharging phase, multiple battery modules 70 can jointly supply power to an external load, and their respective discharge control modules 30 realize the conduction or disconnection of the discharge path according to the control of the main control unit 50.

[0031] In some embodiments of this application, the charging control module 20 includes a charging switch 21 and a first diode 22, which are connected in parallel in the current path between the battery module 70 and the negative terminal 12. The charging switch 21 is used to control whether the charging path of the battery module 70 is open, and is controlled to be open or closed by a control signal output by the main control unit 50.

[0032] The first diode 22 is connected in parallel with the charging switch 21. Its anode is located near the negative terminal 12, and its cathode is located near the negative terminal of the battery module 70, thus forming a unidirectional conduction path from the negative terminal 12 to the negative terminal of the battery module 70. In other words, when current flows into the system from the external charger, the current can enter the battery module 70 from the negative terminal 12 through this diode, but when the current attempts to flow from the battery module 70 to the negative terminal 12, it will be blocked by this diode.

[0033] During system operation, when the battery module 70 is in the normal charging phase, the main control unit 50 controls the charging switch 21 to close. At this time, the current mainly forms a charging circuit through the charging switch 21, and the battery module 70 can normally receive the charging current from the external lead-acid charger. When the charging switch 21 is in the closed state, the first diode 22 can still provide a unidirectional conduction path, allowing the current to flow through the diode in a predetermined direction, thereby ensuring that the circuit still has a stable current path under different operating states, while preventing the battery current from flowing back in the opposite direction.

[0034] In this embodiment, by setting up a parallel structure of charging switch 21 and first diode 22, it is possible to achieve controllable management of the charging path of battery module 70, and maintain the stability of the current path when the system working state is switched, thereby improving the reliability and safety of the entire battery control system.

[0035] Furthermore, in some embodiments, the discharge control module 30 includes a discharge switch 31 and a second diode 32, which are connected in parallel on the current path between the battery module 70 and the negative terminal 12, for managing the current path when the battery module 70 supplies power to an external load. The discharge switch 31 is used to controllably turn the discharge path on or off, and is turned on or off by a control signal output by the main control unit 50, thereby controlling whether the battery module 70 can output electrical energy to an external load.

[0036] The second diode 32 is connected in parallel with the discharge switch 31. Its anode is connected to the side near the negative terminal of the battery module 70, and its cathode is connected to the side near the negative terminal 12, thus forming a unidirectional conduction path in the circuit from the battery module 70 to the negative terminal 12. When the battery module 70 supplies power to an external load, the current can flow along the direction from the negative terminal of the battery module 70 to the negative terminal 12; and when a reverse current trend occurs in the external circuit, the diode can block the reverse current to prevent the current from flowing back into the battery module 70.

[0037] During actual system operation, when the battery module 70 needs to supply power to an external load, the main control unit 50 controls the discharge switch 31 to be in the conducting state. At this time, the current mainly forms a low-impedance discharge path through the discharge switch 31, thereby reducing power loss and improving power supply efficiency. During certain state switching phases, such as when the system transitions from charging to discharging, or when the main control unit 50 controls and adjusts the switching devices, the second diode 32 can provide an auxiliary conduction path, allowing the current to maintain flow in a predetermined direction, thus preventing voltage fluctuations or system abnormalities caused by momentary circuit interruptions. Furthermore, this diode can also prevent the load-side current from flowing back into the battery module 70, thereby further improving the stability and safety of the battery system operation.

[0038] In one embodiment, the float charge control module 40 includes a float charge switch 41, a float charge resistor 42, and a third diode 43, which are connected in series along the current path. One end of the float charge control module 40 is connected to the positive terminal 11, and the other end is connected to the node between the charging control module 20 and the discharging control module 30, thereby enabling the establishment of a current path bypassing the battery module 70 in the system when needed.

[0039] The float charge switch 41 is used to control whether the float charge path is open or closed. The main control unit 50 outputs a control signal to control its opening or closing. When the float charge switch 41 is in the closed state, the float charge path is cut off, and the system operates in the normal charging or discharging mode. When the float charge switch 41 is turned on by the main control unit 50, the float charge control module 40 can participate in forming the float charge current loop in the system.

[0040] The float charging resistor 42 is used to limit and regulate the current in the float charging path, keeping the current through the path within a small range. For example, in some implementations, the resistor can be set to tens to hundreds of ohms, so that the current through the float charging circuit is much smaller than the normal charging current of the battery, thus avoiding further charging of the cell while maintaining the minimum operating current required by the external charger.

[0041] The anode of the third diode 43 is connected to the side closest to the positive terminal 11, and the cathode is connected to the node between the charging control module 20 and the discharging control module 30, thus forming a unidirectional conduction path from the positive terminal 11 to this node. With this structure, current can only flow from the positive terminal 11 to this node, and cannot flow in the opposite direction from the node to the positive terminal 11, thereby ensuring the stability of the current direction in the float charging path and preventing reverse current from occurring when the system switches between different operating states.

[0042] During actual system operation, when the main control unit 50 detects that the battery module 70 has reached the preset full charge state, it can shut down the charging control module 20 and turn on the float charge switch 41. At this time, the current will no longer pass through the battery module 70, but will flow from the positive terminal 11 through the float charge switch 41, the float charge resistor 42, and the third diode 43 to the node between the charging control module 20 and the discharge control module 30, and then return to the negative terminal 12 through the discharge control module 30, thus forming a float charge current loop. Through this float charge current loop, the external lead-acid charger can still detect the existence of the current path and maintain the float charge working state, while the battery module 70 will not continue to receive charging current, thereby avoiding overcharging of the battery cells.

[0043] In one embodiment, the battery control system further includes a shunt 60. The shunt 60 is positioned in the current path between the battery module 70 and the negative terminal 12 to detect the current flowing through that path. The shunt 60 can be constructed using a low-resistance precision resistor, such as a milliohm resistor, to achieve current detection by generating a small voltage drop when current flows through it. This voltage signal can be acquired by the main control unit 50 to determine the current operating state of the battery module 70.

[0044] In terms of structural connection, the shunt 60 can be placed in the current path between the negative terminal of the battery module 70 and the charging control module 20 and discharging control module 30, so that regardless of whether the battery module 70 is in a charging or discharging state, the current flowing through the battery module 70 must pass through the shunt 60. With this arrangement, the main control unit 50 can obtain the current information of the battery module 70 in real time, thereby monitoring and judging the operating status of the system.

[0045] During system operation, when an external lead-acid charger provides charging current to the battery module 70, the current flows into the system from the positive terminal 11, passes through the battery module 70, and then flows to the negative terminal 12 via the shunt 60. At this time, a voltage signal proportional to the current magnitude is generated across the shunt 60, and the main control unit 50 can determine whether the system is in a charging state based on this voltage signal. Conversely, when the battery module 70 supplies power to an external load, the current flows from the battery module 70 to the negative terminal 12 and then through the shunt 60 to the external circuit. At this time, the current direction detected by the shunt 60 is opposite to that in the charging state, and the main control unit 50 can determine whether the system is in a discharging state based on this.

[0046] In one embodiment, the main control unit 50 is electrically connected to the battery module 70 and is used to monitor and determine the operating status of the battery module 70. The main control unit 50 can be connected to the positive and negative terminals of the battery module 70 through a voltage sampling line to obtain the voltage signal across the battery module 70; at the same time, the main control unit 50 can also combine with a current detection device (e.g., a shunt 60) to obtain the current information of the battery module 70, thereby realizing comprehensive monitoring of the operating status of the battery module 70.

[0047] During system operation, the main control unit 50 can determine the battery status based on the detected voltage and current information of the battery module 70. For example, when the voltage of the battery module 70 gradually increases and the current direction is in the charging direction, it can be determined that the system is in the charging stage; when the voltage of the battery module 70 reaches a preset threshold and the charging current gradually decreases, it can be determined that the battery module 70 is close to or has reached a fully charged state; when the current direction is detected to flow from the battery module 70 to the external load, it can be determined that the system is in the discharging state. Based on the above judgment results, the main control unit 50 can further control the charging control module 20, the discharging control module 30, and the float charging control module 40 to turn on or off, thereby achieving coordinated control of the charging, discharging, and float charging processes of the battery module 70.

[0048] On the other hand, this application also provides a battery control method. This method is applied to the aforementioned battery control system, whereby the main control unit 50 coordinates and controls the charging control module 20, discharging control module 30, and float charging control module 40, enabling the battery control system to form corresponding current paths under different operating states. The method includes the following steps.

[0049] First, when the battery module 70 has not reached the preset fully charged state, the main control unit 50 controls the charging control module 20 to be in the conducting state, while keeping the float charging control module 40 closed and controlling the discharging control module 30 to be in the conducting state. In this state, the current provided by the external lead-acid charger enters the system through the positive terminal 11, flows through the battery module 70 into the charging control module 20, and then through the discharging control module 30 to the negative terminal 12, thus forming a complete charging current path, enabling the battery module 70 to normally receive charging current. During this stage, the float charging control module 40 remains closed, allowing the current to mainly flow through the battery module 70 to achieve normal charging of the battery module 70.

[0050] Secondly, when the main control unit 50 detects that the battery module 70 has reached a preset fully charged state, the main control unit 50 controls the charging control module 20 to shut down and simultaneously controls the float charging control module 40 to turn on, while keeping the discharging control module 30 in a conducting state. In this state, the current no longer passes through the battery module 70, but flows from the positive terminal 11 through the float charging control module 40 to the node between the charging control module 20 and the discharging control module 30, and then through the discharging control module 30 to the negative terminal 12, thus forming a float charging current loop that bypasses the battery module 70. Through this float charging loop, the external lead-acid charger can still detect the existence of a current path in the system, thereby maintaining its float charging operation mode, while the battery module 70 will not continue to receive charging current, thus avoiding overcharging of the battery cells.

[0051] Furthermore, when the system detects that the battery module 70 is supplying power to an external load, the main control unit 50 controls the float charging control module 40 to shut down, while keeping the charging control module 20 and discharging control module 30 on. In this state, the electrical energy released by the battery module 70 flows through the charging control module 20 and discharging control module 30 to the negative terminal 12, and provides power to the load through the external circuit, thus forming a discharge path for the battery module 70 to supply power to the external load. Through coordinated control of the on / off states of each control module, the system can switch between the three operating modes of charging, float charging, and discharging, thereby achieving effective management of the operating state of the battery module 70.

[0052] In this embodiment, after the battery module 70 reaches full charge, the charging of the battery cell can be cut off in time, and a float charging current loop can be established to maintain the float charging working state of the external lead-acid charger. This enables compatibility with the original charging equipment in the application scenario of lithium battery replacing lead-acid battery, and improves the stability and safety of system operation.

[0053] Furthermore, in one embodiment, when the main control unit 50 detects that the voltage of the battery module 70 is lower than a preset voltage threshold, the main control unit 50 controls the discharge control module 30 to shut down, thereby stopping the battery module 70 from discharging externally and providing over-discharge protection for the battery module 70. Specifically, the main control unit 50 can detect the voltage signal across the battery module 70 in real time through a voltage sampling line and compare the detected voltage value with a preset voltage threshold. When the voltage of the battery module 70 is detected to drop below the preset threshold, it indicates that the remaining charge of the battery module 70 is low, and continued discharge may adversely affect the internal cells of the battery module 70.

[0054] In this situation, the main control unit 50 outputs a control signal to the discharge control module 30, causing the discharge switch 31 to switch from the on state to the off state, thereby cutting off the discharge path between the battery module 70 and the negative terminal 12, and stopping the battery module 70 from supplying power to the external load. In this way, the battery module 70 can be effectively prevented from continuing to discharge when the power is too low, thus preventing over-discharge of the battery cell.

[0055] In one embodiment, the state of the battery module 70 is determined based on a comprehensive assessment of its voltage and current. The main control unit 50 can acquire the voltage signal across the battery module 70 in real time via a voltage sampling line and obtain the current information of the battery module 70 via a current detection device. The main control unit 50 determines the current operating state of the battery module 70 based on the detected voltage value and the magnitude and direction of the current.

[0056] When the voltage of battery module 70 is detected to be within the normal operating range and the current flows from the external power source to battery module 70, the system can be determined to be in a charging state. When the voltage of battery module 70 reaches the preset full charge voltage and the charging current gradually decreases to near the preset threshold, the battery module 70 can be determined to be at or near full charge. When the current flows from battery module 70 to the external load, the system can be determined to be in a discharging state. Furthermore, when the voltage of battery module 70 drops below the preset voltage threshold, it can be further determined that battery module 70 may have entered an over-discharge state, thereby triggering corresponding protection control.

[0057] In one embodiment, when the main control unit 50 detects that the battery module 70 has reached a preset fully charged state, it controls the charging control module 20 to shut down and turns on the float charging control module 40, thereby forming a float charging current loop in the system from the positive terminal 11 through the float charging control module 40 and the discharge control module 30 to the negative terminal 12. After this loop is established, a stable current path still exists in the system, allowing the external lead-acid charger to continue to output a small current to the system.

[0058] Simultaneously, detection port 13 is connected to the detection line of an external lead-acid charger to provide the charger with a detection signal corresponding to the current state of the system. For example, in some common lead-acid chargers, the charger detects the battery terminal voltage or circuit status through the detection line to determine whether the system is currently in the float charging stage. Once the float charging current circuit is established, detection port 13 can provide the corresponding voltage or circuit signal to the external lead-acid charger, enabling the charger to detect that the system is in a normal float charging operating state.

[0059] In this embodiment, even if the battery module 70 has reached full charge and no longer accepts charging current, the external lead-acid charger can still maintain its float charging mode without entering an abnormal state or generating an alarm due to the inability to detect a load or current loop. For example, in some fire emergency power systems, if the charger cannot detect the float charging loop, it may mistakenly determine that the battery is not connected or that the system is faulty, thereby affecting the normal operation of the system. Providing the corresponding detection signal to the charger through the detection port 13 can effectively avoid the above situation.

[0060] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A battery control system, connected to a battery module, characterized in that, include: The output interface includes a positive terminal, a negative terminal, and a detection port. The positive terminal and the negative terminal are used to connect to an external lead-acid charger or load. The positive terminal is also connected to the positive terminal of the battery module. The detection port is used to connect to the detection line of the external lead-acid charger. A charging control module and a discharging control module are connected in series between the negative terminal and the negative terminal of the battery module, and are used to control the conduction or disconnection of the charging path and the discharging path of the battery module, respectively. The float charge control module has one end connected to the positive terminal and the other end connected to the node between the charging control module and the discharging control module, so as to form a float charge current loop with the negative terminal through the discharging control module and connect to the detection port; The main control unit is electrically connected to the charging control module, the discharging control module, and the float charging control module, and is used to control the on or off of the charging control module, the discharging control module, and the float charging control module.

2. The battery control system according to claim 1, characterized in that, The charging control module includes a charging switch and a first diode, wherein the charging switch and the first diode are connected in parallel between the negative terminal of the battery module and the discharge control module. The anode of the first diode is connected to the side closer to the discharge control module, and the cathode is connected to the side closer to the battery module, so as to limit the current to conduct only in the direction from the discharge module to the battery module.

3. The battery control system according to claim 2, characterized in that, The discharge control module includes a discharge switch and a second diode, which are connected in parallel between the charging control module and the negative terminal. The anode of the second diode is connected to the side closer to the charging control module, and the cathode is connected to the side closer to the negative terminal, so as to limit the current to conduct only in the direction from the charging control module to the negative terminal.

4. The battery control system according to claim 3, characterized in that, The float charge control module includes a float charge resistor, a third diode, and a float charge switch arranged in series, and the float charge control module is connected between the positive terminal and the node between the charging control module and the discharging control module. The anode of the third diode is connected to the side closer to the positive terminal, and the cathode is connected to the side closer to the node, so as to limit the current to conduct only in the direction from the positive terminal to the node.

5. The battery control system according to claim 4, characterized in that, The battery control system also includes a shunt, which is disposed between the battery module and the negative terminal. The main control unit determines the charging or discharging state of the battery based on the current signal detected by the shunt.

6. The battery control system according to claim 1, characterized in that, The main control unit is electrically connected to the battery module and is used to detect the voltage or current of the battery module to determine the battery status.

7. A battery control method, applied to the battery control system according to any one of claims 1 to 6, characterized in that, include: When the battery module has not reached the preset full charge state, the charging control module is turned on, the float charging control module is turned off, and the discharging control module is turned on, so as to form a charging path from the positive terminal through the battery module, the charging control module, and the discharging control module to the negative terminal. When the battery module is detected to have reached the preset full charge state, the charging control module is disconnected, the float charging control module is turned on, and the discharging control module is turned on, so as to form a float charging current loop from the positive terminal through the float charging control module and the discharging control module to the negative terminal. When the battery module is detected discharging to an external load, the float charging control module is disconnected, the charging control module is turned on, and the discharging control module is turned on to form a discharge path from the battery module through the charging control module and the discharging control module to the negative terminal.

8. The battery control method according to claim 7, characterized in that, When the battery module voltage is detected to be lower than the preset voltage threshold, the discharge control module is disconnected to stop the battery module from discharging externally.

9. The battery control method according to claim 7, characterized in that, The state of the battery module is determined based on the voltage and current of the battery module.

10. The battery control method according to claim 7, characterized in that, When the float charging current loop is formed, a detection signal is provided to the external lead-acid charger through the detection port so that the external lead-acid charger maintains the float charging working state.

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