Charge / discharge protection circuit, power supply device, and electronic device

Abstract

The application provides a charging and discharging protection circuit, a power supply device and an electronic device. The charging and discharging protection circuit is applied to the power supply device. The power supply device comprises at least two battery groups connected in parallel. Each battery group corresponds to a charging and discharging protection circuit. Each charging and discharging protection circuit is coupled to the positive electrode and / or the negative electrode of the corresponding battery group. Each charging and discharging protection circuit comprises at least one detection module and at least one switch module. Each switch module corresponds to a detection module. Each detection module is used for detecting whether the corresponding battery group is charged by other battery groups and outputting a first control signal to the corresponding switch module when detecting that the corresponding battery group is charged. The switch module is disconnected in response to the first control signal, so as to disconnect the parallel circuit between the battery group and other battery groups. In the above manner, the charging and discharging protection circuit is arranged between the parallel battery groups, so as to control and isolate the parallel battery groups, to protect the power supply and meet the anti-explosion requirement.

Description

Technical Field

[0001] This application relates primarily to the field of power supply circuit technology, and in particular to charge and discharge protection circuits, power supply devices, and electronic equipment. Background Technology

[0002] For intrinsically safe explosion-proof walkie-talkies and mobile phones, the batteries also need to meet intrinsic safety requirements. This requires that both the battery cells and the battery protection board simultaneously meet intrinsic safety design standards. Consequently, intrinsically safe explosion-proof batteries have particularly high requirements for their cells. They must not ignite, smoke, explode, or leak when short-circuited at a resistance not exceeding 3mΩ under high-temperature conditions of 60°C, and the cell surface temperature must not exceed 130°C to be rated as T4. However, in reality, most cells supplied by manufacturers cannot meet these requirements, and high-capacity batteries are even rarer. Therefore, expanding the capacity of explosion-proof batteries by connecting small-capacity cells in series to form multiple battery packs, and then connecting these battery packs in parallel, is an inevitable trend for future explosion-proof batteries. However, how to meet explosion-proof requirements under these conditions is a problem that urgently needs to be solved. Summary of the Invention

[0003] The main purpose of this application is to provide a charge and discharge protection circuit, a power supply device, and electronic equipment to solve the problem that in a power supply circuit composed of parallel battery packs, when any one of the battery packs is abnormal or short-circuited, the parallel battery packs charge and discharge each other, causing a serious power supply failure.

[0004] To address the aforementioned problems, this application provides a charge / discharge protection circuit, a power supply device, and an electronic device. The charge / discharge protection circuit is applied to the power supply device, which includes at least two battery packs connected in parallel. Each battery pack corresponds to one charge / discharge protection circuit, and each charge / discharge protection circuit is coupled to the positive and / or negative terminal of the corresponding battery pack. Each charge / discharge protection circuit includes: at least one detection module; and at least one switching module, with each switching module corresponding to one detection module. Each detection module is used to detect whether the corresponding battery pack is being charged by other battery packs, and when it detects that the corresponding battery pack is being charged, it outputs a first control signal to the corresponding switching module. The switching module disconnects in response to the first control signal, thereby breaking the parallel circuit between the battery pack and other battery packs.

[0005] In one embodiment, the detection module includes: a current limiting unit coupled to a switching module; and a control unit coupled to the current limiting unit and the switching module. The switching module is coupled to the positive or negative terminal of the corresponding battery pack. The control unit detects the voltage difference on the switching module and determines whether the corresponding battery pack is being charged by other battery packs based on the voltage difference. When the corresponding battery pack is detected to be being charged, the control unit outputs a first control signal to the corresponding switching module. The switching module responds to the first control signal and disconnects, thus breaking the parallel circuit between the battery pack and other battery packs.

[0006] By combining a current limiting unit with a control unit, the voltage difference of the switching module is sampled, and the switching module is turned on and off according to the sampling result, so as to achieve isolation of the parallel circuit.

[0007] In one embodiment, the charge / discharge protection circuit further includes: an impedance unit coupled to a current limiting unit and a switching module, wherein the impedance unit and the switching module are coupled to the positive or negative terminal of the corresponding battery pack; the control unit is used to detect the voltage difference across the switching module to detect whether the corresponding battery pack is being charged by other battery packs; or, the control unit is used to detect the voltage difference across the impedance unit to detect whether the corresponding battery pack is being charged by other battery packs; or, the control unit is used to detect the voltage difference between the impedance unit and the switching module to detect whether the corresponding battery pack is being charged by other battery packs.

[0008] By setting impedance units, diverse voltage sampling can be achieved either individually or in conjunction with switching modules to meet sampling requirements under different conditions, thereby enabling the determination of the charging and discharging status of the battery pack and ultimately achieving isolation protection.

[0009] In one embodiment, the current limiting unit includes: a first current limiting circuit and a second current limiting circuit; wherein, when the control unit is used to detect the voltage difference across the switching module, a first terminal of the first current limiting circuit is coupled to a first terminal of the switching module, a second terminal of the first current limiting circuit is coupled to the control unit, a first terminal of the second current limiting circuit is coupled to a second terminal of the switching module, and a second terminal of the second current limiting circuit is coupled to the control unit; when the control unit is used to detect the voltage difference across the impedance unit, a first terminal of the first current limiting circuit is coupled to a first terminal of the impedance unit, a second terminal of the first current limiting circuit is coupled to the control unit, a first terminal of the second current limiting circuit is coupled to a second terminal of the impedance unit, and a second terminal of the second current limiting circuit is coupled to the control unit; when the control unit is used to detect the voltage difference between the impedance unit and the switching module, a first terminal of the first current limiting circuit is coupled to a first terminal of the impedance unit, a second terminal of the first current limiting circuit is coupled to the control unit, a first terminal of the second current limiting circuit is coupled to a second terminal of the switching module, and a second terminal of the second current limiting circuit is coupled to the control unit.

[0010] The switching module is coupled with the first and second current limiting circuits to achieve current limiting control and protect the downstream circuit components.

[0011] In one embodiment, the first current limiting circuit includes: a first resistor, a first end of which is coupled to a first end of a switching module or an impedance unit, and a second end of which is coupled to a control unit; a first capacitor, a first end of which is coupled to a second end of the first resistor, and a second end of which is grounded; and / or, the second current limiting circuit includes: a second resistor, a first end of which is coupled to a second end of a switching module or an impedance unit, and a second end of which is coupled to a control unit; a second capacitor, a first end of which is coupled to a second end of the second resistor, and a second end of which is grounded.

[0012] By setting a first resistor and a second resistor, current limiting can be achieved. On this basis, by setting a first capacitor and a second capacitor, filtering and energy storage can be achieved, so as to stabilize the current and avoid damage to circuit components caused by sudden current changes.

[0013] In one embodiment, the control unit includes: a comparator, a first input terminal and a second input terminal of the comparator coupled to a current limiting unit, and an output terminal of the comparator coupled to a switching module; wherein, when the comparator detects that the corresponding battery pack is being charged, it outputs a first control signal to the corresponding switching module, and the switching module disconnects in response to the first control signal to disconnect the parallel circuit between the battery pack and other battery packs.

[0014] By using a comparator to compare the voltage signals at both ends of the input circuit, a corresponding level control signal is output based on the comparison result, thereby controlling the on / off state of the switching module.

[0015] In one embodiment, the control unit further includes: a diode, the anode of which is coupled to the output of a comparator, and the cathode of which is coupled to a switching module.

[0016] By coupling a diode to the output of the comparator, the stability and reliability of the comparator can be improved, while protecting the components in the subsequent circuit from damage.

[0017] In one embodiment, the charge / discharge protection circuit includes: two detection modules; two switching modules, each switching module corresponding to one detection module; wherein, the switching module is connected in series to the positive or negative terminal of the corresponding battery pack, each detection module is used to detect whether the corresponding battery pack is being charged by other battery packs, and when the corresponding battery pack is detected to be being charged, it outputs a first control signal to the corresponding switching module, and the switching module disconnects in response to the first control signal to disconnect the parallel circuit between the battery pack and other battery packs.

[0018] By setting up two detection modules and two corresponding switch modules, the circuit can achieve multiple detection and multiple protection effects.

[0019] In one embodiment, the charge / discharge protection circuit further includes a charging module coupled to each switching module; wherein the charging module is configured to turn on each switching module when an external power source is connected, so that each battery pack is connected to the charging circuit.

[0020] By setting up a charging module, the function of charging the battery pack can be realized.

[0021] In one embodiment, the charging module includes: a charging port for coupling to an external power source; at least one charging diode, each charging diode corresponding to a switching module, the anode of each charging diode being coupled to the charging port, and the cathode of each charging diode being coupled to its corresponding switching module.

[0022] By setting up a charging port and a charging diode, the system achieves coupling with an external power source and protection during the charging process.

[0023] To address the aforementioned issues, this application also provides a power supply device comprising at least two battery packs connected in parallel, each battery pack corresponding to a charge / discharge protection circuit, each charge / discharge protection circuit being coupled to the positive or negative terminal of the corresponding battery pack, and the charge / discharge protection circuit being the charge / discharge protection circuit described in any of the embodiments described above.

[0024] To address the aforementioned problems, this application also provides an electronic device comprising: a power supply device, which is the power supply device described in any of the embodiments described above.

[0025] The charge / discharge protection circuit, power supply device, and electronic device provided in this application detect the charge / discharge of parallel battery packs through the charge / discharge protection circuit. When the parallel battery packs charge and discharge with each other, the switching module therein is used to isolate the parallel battery packs to protect the circuit from failure and meet the explosion-proof requirements of the power supply. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0027] Figure 1 This is a schematic diagram of the structure of the first embodiment of the charge / discharge protection circuit provided in this application;

[0028] Figure 2 This is a schematic diagram of the structure of the first embodiment of the detection module provided in this application;

[0029] Figure 3 This is a schematic diagram of the structure of the second embodiment of the detection module provided in this application;

[0030] Figure 4 This is a schematic diagram of the structure of the first embodiment of the current limiting unit provided in this application;

[0031] Figure 5 This is a schematic diagram of the structure of the second embodiment of the current limiting unit provided in this application;

[0032] Figure 6 This is a schematic diagram of the structure of the first embodiment of the control unit provided in this application;

[0033] Figure 7 This is a schematic diagram of the structure of the second embodiment of the control unit provided in this application;

[0034] Figure 8 This is a schematic diagram of the structure of the second embodiment of the charge / discharge protection circuit provided in this application;

[0035] Figure 9 This is a schematic diagram of the structure of the first embodiment of the charging module provided in this application;

[0036] Figure 10 This is a schematic diagram of the structure of the second embodiment of the charging module provided in this application;

[0037] Figure 11 This is a schematic diagram of the structure of an embodiment of the power supply device provided in this application;

[0038] Figure 12 This is a schematic diagram of the structure of an embodiment of the electronic device provided in this application.

[0039] Icon labels:

[0040] 100. Charge / discharge protection circuit; 200. Power supply unit; 300. Electronic equipment; 10. Battery pack; 20. Detection module; 21. Current limiting unit; 210. First current limiting circuit; 211. Second current limiting circuit; 22. Control unit; 220. Comparator; 221. Diode; 30. Switching module; 40. Impedance unit; 50. Charging module; 51. Charging port; 52. Charging diode. Detailed Implementation

[0041] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It is understood that the specific embodiments described herein are only for explaining this application and not for limiting it. Furthermore, it should be noted that, for ease of description, only the parts related to this application are shown in the accompanying drawings, not all structures. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0042] The terms "first," "second," etc., used in this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0043] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0044] See Figure 1 As shown, Figure 1 This is a schematic diagram of the structure of the first embodiment of the charge / discharge protection circuit provided in this application. The charge / discharge protection circuit 100 is applied to a power supply device 200, which includes at least two battery packs 10 connected in parallel. Each battery pack 10 corresponds to a charge / discharge protection circuit 100. Each charge / discharge protection circuit 100 is coupled to the positive and / or negative terminal of the corresponding battery pack 10. Each charge / discharge protection circuit 100 includes: at least one detection module 20; at least one switch module 30, and each switch module 30 corresponds to one detection module 20. Each detection module 20 is used to detect whether the corresponding battery pack 10 is being charged by other battery packs 10, and outputs a first control signal to the corresponding switch module 30 when it detects that the corresponding battery pack 10 is being charged. The switch module 30 disconnects in response to the first control signal to disconnect the parallel circuit between the battery pack 10 and other battery packs 10.

[0045] Each battery pack 10 may include multiple battery cells connected in series (not shown in the figure), and the corresponding number and capacity parameters can be set according to the actual situation without specific limitations. In a specific embodiment, two parallel battery packs 10 are completely identical in capacity, voltage and function, and are connected in parallel to form an external circuit.

[0046] Regarding the configuration of the charge / discharge protection circuit 100, multiple charge / discharge protection circuits 100 can be configured on the same side. That is, in one embodiment, multiple charge / discharge protection circuits 100 are uniformly configured between the negative terminals; in another embodiment, they are uniformly configured between the positive terminals. In other embodiments, multiple charge / discharge protection circuits 100 can coexist between both the positive and negative terminals. The number of charge / discharge protection circuits 100 configured on the positive or negative terminals can be set according to actual conditions and is not specifically limited.

[0047] Understandably, a charge-discharge protection circuit 100 is provided between the positive and / or negative terminals of the parallel-connected battery pack 10 to provide electrical isolation, so that the parallel-connected battery packs 10 are isolated from each other and cannot charge or discharge each other without the application of other controls.

[0048] In the above manner, the charging and discharging protection circuit 100 is used to detect the charging and discharging of the parallel battery pack 10, and the switching module 30 therein is used to isolate the parallel battery pack 10 to avoid mutual charging and discharging between the parallel battery packs 10, so as to protect the circuit from failure and meet the explosion-proof requirements of the power supply.

[0049] In one embodiment, the direction of the current is detected by the detection module 20 to determine whether the corresponding battery pack 10 is being charged by other battery packs 10; specifically, to Figure 1 Taking the detection module 20 on the left as an example, the charge and discharge protection circuits 100 are all set between the negative terminals of the parallel battery pack 10. Figure 1 When the battery pack 10 on the right side wants to charge the battery pack 10 on the left side, the current direction on the left-side switch module 30 is from left to right. That is, the voltage at the left end of the left-side switch module 30 is higher than the voltage at the right end. The current direction is determined based on the positive and negative relationship of the voltage difference, thereby controlling the on / off state of the switch module 30 to achieve isolation of the parallel battery packs 10 and complete the charging and discharging protection. Similarly, the detection module 20 and switch module 30 on the right side also realize current direction detection and complete the on / off control of the switch module 30.

[0050] Among them, the two battery packs 10 connected in parallel can discharge to the outside together, such as Figure 1As shown, taking the charge / discharge protection circuit 100 located between the negative terminals of the battery pack 10 as an example, when the battery pack 10 discharges externally, the current in the left battery pack 10 flows from the upper positive terminal to the load, and then through the load from... Figure 1 The bottom load interface flows to the switch module 30 and then back to the negative terminal of the battery pack 10. Similarly, the right side of the battery pack 10 discharges externally.

[0051] In one embodiment, such as Figure 2 As shown, Figure 2 This is a schematic diagram of the structure of the first embodiment of the detection module provided in this application; wherein, the detection module 20 includes: a current limiting unit 21 and a control unit 22; the current limiting unit 21 is coupled to the switch module 30; the control unit 22 is coupled to the current limiting unit 21 and the switch module 30; wherein, the switch module 30 is coupled to the negative terminal of the corresponding battery pack 10, the control unit 22 is used to detect the voltage difference on the switch module 30, and detect whether the corresponding battery pack 10 is being charged by other battery packs 10 according to the voltage difference, and outputs a first control signal to the corresponding switch module 30 when it is detected that the corresponding battery pack 10 is being charged, and the switch module 30 disconnects in response to the first control signal to disconnect the parallel circuit between the battery pack 10 and other battery packs 10.

[0052] In the above embodiment, the current limiting unit 21 is coupled to the switch module 30. It can be understood that the control unit 22 can sample the voltage value at both ends of the switch module 30 and determine the charging and discharging state of the battery pack 10 based on the sampled value, so as to complete the control of the switch module and realize the isolation between the parallel battery packs 10.

[0053] In one embodiment, such as Figure 3 As shown, Figure 3 This is a schematic diagram of the second embodiment of the charge / discharge protection circuit provided in this application; the charge / discharge protection circuit further includes: an impedance unit 40, which is coupled to a current limiting unit 21 and a switching module 30, and the impedance unit 40 and the switching module 30 are coupled to the positive or negative terminal of the corresponding battery pack, wherein, Figure 3 Only the impedance unit 40 and the switch module 30 are shown coupled to the negative terminal of the corresponding battery pack. In this embodiment, the control unit 22 can continue to detect the voltage difference across the switch module 30 to detect whether the corresponding battery pack 10 is being charged by other battery packs 10; or, the control unit 22 can detect the voltage difference across the impedance unit 40 to detect whether the corresponding battery pack 10 is being charged by other battery packs 10; or, the control unit 22 can detect the voltage difference between the impedance unit 40 and the switch module 30 to detect whether the corresponding battery pack 10 is being charged by other battery packs 10.

[0054] Understandably, by setting the impedance unit 40, diverse voltage sampling can be achieved by sampling alone or in combination with the switch module 30, to meet the sampling requirements under different conditions, so as to complete the judgment of the charging and discharging state of the battery pack 10 and thus complete the isolation protection. That is, the battery pack 10 can be judged as to whether it is being charged by other battery packs 10 by detecting the voltage difference between the two sides of the switch module 30, or between the two sides of the impedance unit 40, or the voltage difference between the impedance unit 40 and the switch module 30.

[0055] In one embodiment, such as Figure 4 As shown, Figure 4 This is a schematic diagram of the structure of the first embodiment of the current limiting unit provided in this application; the current limiting unit 21 includes: a first current limiting circuit 210 and a second current limiting circuit 211; wherein, when the control unit 22 is used to detect the voltage difference on the switching module 30, the first end of the first current limiting circuit 210 is coupled to the first end of the switching module 30, and the second end of the first current limiting circuit 210 is coupled to the control unit 22; the first end of the second current limiting circuit 211 is coupled to the second end of the switching module 30, and the second end of the second current limiting circuit 211 is coupled to the control unit 22; when the control unit 22 is used to detect the voltage difference across the impedance unit 40, the first end of the first current limiting circuit 210 is coupled to the second end of the switching module 30, and the second end of the second current limiting circuit 211 is coupled to the control unit 22; One end of the first current limiting circuit 210 is coupled to the first end of the impedance unit 40, and the second end of the first current limiting circuit 210 is coupled to the control unit 22. The first end of the second current limiting circuit 211 is coupled to the second end of the impedance unit 40, and the second end of the second current limiting circuit 211 is coupled to the control unit 22. When the control unit 22 is used to detect the voltage difference between the impedance unit 40 and the switching module 30, the first end of the first current limiting circuit 210 is coupled to the first end of the impedance unit 40, the second end of the first current limiting circuit 210 is coupled to the control unit 22, the first end of the second current limiting circuit 211 is coupled to the second end of the switching module 30, and the second end of the second current limiting circuit 211 is coupled to the control unit 22. Figure 4 The diagram illustrates the use of control unit 22 to detect the voltage difference on switch module 30. See reference [link / reference] for details. Figure 4 The first terminal of the first current limiting circuit 210 is coupled to the first terminal of the switch module 30, and the second terminal of the first current limiting circuit 210 is coupled to the control unit 22; the first terminal of the second current limiting circuit 211 is coupled to the second terminal of the switch module 30, and the second terminal of the second current limiting circuit 211 is coupled to the control unit 22; wherein, the switch module 30 is coupled to the positive or negative terminal of the corresponding battery pack 10, and the control unit 22 detects the voltage difference on the switch module 30, and detects whether the corresponding battery pack 10 is being charged by other battery packs 10 based on the voltage difference.

[0056] In the above embodiment, the current limiting unit 21 includes a first current limiting circuit 210 and a second current limiting circuit 211. The two current limiting circuits are respectively coupled to the two ends of the switching module 30 to limit the circuit current and prevent the large input current from damaging other components in the circuit. On this basis, the current magnitude can be adjusted by the first current limiting circuit 210 and / or the second current limiting circuit 211 to accurately control the current to complete the sampling of the voltage across the two ends of the switching module 30. The sampling result is output to the control unit 22 to determine whether the corresponding battery pack 10 is being charged by other battery packs 10 based on the sampling result, and control the switching module 30 to complete the isolation between the parallel battery packs 10.

[0057] In one embodiment, such as Figure 5 As shown, Figure 5 This is a schematic diagram of the structure of the second embodiment of the current limiting unit provided in this application; wherein, the first current limiting circuit 210 includes: a first resistor R1, a first capacitor C1, a second resistor R2 and a second capacitor C2, the first end of the first resistor R1 is coupled to the first end of the switch module 30 or the first end of the impedance unit 40, and the second end of the first resistor R1 is coupled to the control unit 22; the first end of the first capacitor C1 is coupled to the second end of the first resistor R1, and the second end of the first capacitor C1 is grounded; and / or, the second current limiting circuit 211 includes: the first end of the second resistor R2 is coupled to the second end of the switch module 30 or the second end of the impedance unit 40, and the second end of the second resistor R2 is coupled to the control unit 22; the first end of the second capacitor C2 is coupled to the second end of the second resistor R2, and the second end of the second capacitor C2 is grounded.

[0058] It is understandable that by setting the first resistor R1 and the second resistor R2, the current limiting function can be achieved. On this basis, by setting the first capacitor C1 and the second capacitor C2, the filtering and energy storage functions can be achieved, so as to stabilize the current and avoid damage to the circuit components caused by sudden current changes.

[0059] In one embodiment, such as Figure 6 As shown, Figure 6 This is a schematic diagram of the structure of the first embodiment of the control unit provided in this application; the control unit 22 includes: a comparator 220, the first input terminal and the second input terminal of the comparator 220 are coupled to the current limiting unit 21, and the output terminal of the comparator 220 is coupled to the switch module 30; wherein, when the comparator 220 detects that the corresponding battery pack 10 is being charged, it outputs a first control signal to the corresponding switch module 30, and the switch module 30 disconnects in response to the first control signal to disconnect the parallel circuit between the battery pack 10 and other battery packs 10.

[0060] In the above embodiment, the voltage signals at both ends of the input circuit are compared by using comparator 220, and a corresponding level control signal is output according to the comparison result. The switching module 30 is then controlled to turn on or off by the level control signal.

[0061] In other embodiments, the comparator 220 can be replaced by schemes including but not limited to operational amplifiers and reference voltage sources. When the charge / discharge protection circuit 100 is located at the positive terminal of the battery pack 10, the scheme is similar; only the non-inverting and inverting input terminals of the comparator 220 need to be swapped, which will not be elaborated further here.

[0062] Understandably, regarding voltage balance for the parallel battery pack 10:

[0063] Since comparator 220 only needs to amplify the DC signal, its bandwidth is close to 0, so the amplification factor can theoretically be infinitely large. In one embodiment, to account for interference and false triggering, the amplification factor is set to 2000 times. Taking the voltage difference across the impedance unit 40 as an example, when the external load current is 10mA, the output voltage is 0.7V (corresponding to a voltage drop of 0.35mV across the impedance unit 40), which can drive the switch module 30 to open (for example, the resistance of the reference impedance unit 40 is 60mΩ, and the resistance of the switch module 30 is 5mΩ). Since the negative terminal voltages of the parallel battery packs 10 are approximately equal, and the voltage detection point of comparator 220 is a common terminal, the two battery packs 10 may theoretically have a voltage difference of 0.35mV, resulting in a state of uncertainty about which one to open. However, when the voltage difference is greater than 0.35mV, the other current sensing circuit can always be opened to form a current shunt, thereby achieving steady-state balance of the battery cells. (PS: For series connection of battery cells, the voltage matching point is strictly controlled by a 10mV difference, so a 0.35mV voltage difference has almost no impact on the 10-cell battery pack.)

[0064] In one embodiment, such as Figure 7 As shown, Figure 7 This is a schematic diagram of the second embodiment of the control unit provided in this application; the control unit 22 also includes: a diode 221, the anode of the diode 221 is coupled to the output terminal of the comparator 220, and the cathode of the diode 221 is coupled to the switch module 30.

[0065] By coupling diode 221 to the output of comparator 220, the stability and reliability of comparator 220 are improved, and at the same time, the components in the subsequent circuit are protected from damage.

[0066] Regarding the issue of insufficient current (e.g., less than 10mA) causing the voltage to fail to drive the switch module 30 to open:

[0067] Understandable, combined Figure 5 and Figure 6 As shown, at this time, the switch module 30 is off. Due to the voltage drop of the body diode 221, a voltage difference of about 0.7V will be generated. This 0.7V voltage difference will immediately trigger the comparator 220 to restart the switch module 30. At this time, the circuit is in a cycle of repeated conduction-off-conduction. Since the current is very small at this time, the large capacitor at the host end can completely filter out the ripple caused by this part of the switch. Combining the mathematical relationship Q=CU=It, where Q is the charge value, C is the capacitance value, U is the voltage value, I is the current value, and t is the time; for example, the host capacitor is 20uF, the current is calculated as 10mA, and t is the sum of the operational amplifier response time and RC delay time, which is about 2us. The energy storage of the capacitor can be used to obtain the host voltage change δV==It / C=2mV>0.35mV. Therefore, for the host, the voltage fluctuation is about 2mV. If the current is greater than 10mA, such as during transmission, reception, or standby, this fluctuation does not exist, so it has almost no impact on the host performance.

[0068] Furthermore, regarding the impact of a stationary battery on the OCV of the fuel gauge:

[0069] Among them, the open circuit voltage (OCV) of the battery refers to the potential difference between the positive and negative terminals of the battery when it is under no-load (i.e., no current flows through it). OCV is an important parameter in battery performance evaluation, as it reflects the equilibrium state of the internal chemical reactions of the battery.

[0070] As analyzed in the above embodiment, a 0.1uF capacitor is placed at the fuel gauge terminal. Combined with the fuel gauge current of 50uA and the mathematical formula Q=CU=It, where t is the sum of the operational amplifier response time and RC delay time, which is approximately 2us, and considering the energy storage of the capacitor, the fuel gauge voltage change δV=It / C=1mV>0.35mV can be obtained. Therefore, the voltage fluctuation for the fuel gauge is about 1mV, which will not produce a 1% difference for the OCV algorithm. The fuel gauge itself has an error of 3%, so its impact on the fuel gauge detection result is negligible.

[0071] In one embodiment, the charge / discharge protection circuit 100 includes: two detection modules 20; two switch modules 30, each switch module 30 corresponding to one detection module 20; wherein, the switch module 30 is connected in series to the positive or negative terminal of the corresponding battery pack 10, each detection module 20 is used to detect whether the corresponding battery pack 10 is being charged by other battery packs 10, and when it detects that the corresponding battery pack 10 is being charged, it outputs a first control signal to the corresponding switch module 30, and the switch module 30 disconnects in response to the first control signal to disconnect the parallel circuit between the battery pack 10 and other battery packs 10.

[0072] In the above embodiments, the charge / discharge protection circuit 100 implements multiple protection functions by using two detection modules 20 and corresponding switching modules 30, wherein any one of the corresponding detection modules 20 and switching modules 30 performs the same function in the circuit. In another embodiment, the two detection modules 20 may have different functions to make different levels of judgment on the control state of the circuit. For example, when determining the current direction, different thresholds are set based on different voltage differences on the left and right sides to achieve step-by-step switching and complete multiple protection.

[0073] In some other embodiments, the detection module 20 and the corresponding switch module 30 can be configured as a group. Therefore, multiple groups can be included in the circuit to achieve multiple protections for the circuit. The number is not specifically limited and can be set according to the actual situation. For example, one group, two groups, three groups, etc.

[0074] In conjunction with the solutions in the above embodiments, in one embodiment, such as Figure 8 As shown, Figure 8 This is a schematic diagram of the structure of the second embodiment of the charge / discharge protection circuit provided in this application; Figure 8 In this embodiment, two detection modules 20 and corresponding switch modules 30 are used. Taking the battery pack 10 on the left side in the other embodiments as an example, U1 and U2 are comparators 220, and D1 and D2 are diodes 221. One detection module 20 includes a first current limiting circuit 210 and a second current limiting circuit 211. The first current limiting circuit 210 includes a third resistor R3 and a third capacitor C3. The second current limiting circuit 211 includes a fourth resistor R4 and a fourth capacitor C4. The other detection module 20 also includes a first current limiting circuit 210 and a second current limiting circuit 211. The first current limiting circuit 210 includes a fifth resistor R5 and a fifth capacitor C5. The second current limiting circuit 211 includes a sixth resistor R6 and a sixth capacitor C6. The two detection modules 20 correspond to the first switch S1 and the second switch S2 (i.e., switch modules 30), and resistor RS1 is an impedance unit 40.

[0075] like Figure 3 As shown, when the right battery pack 10 charges the left battery pack 10, the current flows through the corresponding impedance unit 40 from left to right, meaning the voltage on the left is higher than that on the right. Figure 8 As shown, assuming the charging current is I, the internal resistances of the first switch S1 and the second switch S2 are Z1 and Z2 respectively, and the internal resistance of resistor RS1 is Z3. Then, according to Ohm's law, the mathematical relationship between the input terminals V+ and V- of U1 can be determined as follows:

[0076] (V+)-(V-)=V(DET_A1+)-V(DET_A1-)=-I*(Z1+Z2+Z3).

[0077] Where V(DET_A1+) is the voltage value of the first input terminal, and V(DET_A1-) is the voltage value of the second input terminal.

[0078] The voltage difference obtained using the above formula is negative, so U1 outputs a low level to control the first switch S1 to close. Understandably, the control logic is similar for the battery pack 10 on the right and the charge / discharge protection circuit 100, thus enabling the parallel battery packs 10 to charge and discharge each other.

[0079] When the entire parallel battery pack 10 discharges externally, such as Figure 3 As shown, for the left battery pack 10, the entire current path is from... Figure 3 The end connected to the load discharges to the load, and then through the load from... Figure 3 The flow returns from the end connected to the load, and then flows back to the battery pack 10 through the switch module 30, impedance unit 40, etc.

[0080] Combination Figure 8 As shown, at this time, the current I will generate a voltage drop δV = (V+) - (V-) = I*(Z1+Z2+Z3) > 0 across the first switch S1, the second switch S2, and the resistor RS1;

[0081] When the current I is large enough that δV > Vth, U1 outputs a high level, controlling the first switch S1 to turn on. Similarly, the same applies to the second switch S2, and... Figure 3 The control principle of the battery pack 10 on the right is similar, so I won't go into too much detail here.

[0082] For the power supply device 200 in the above embodiments, when charging in a non-explosion-proof environment, the battery can be charged by an external charger, as follows:

[0083] In one embodiment, such as Figure 9 As shown, Figure 9 This is a schematic diagram of the structure of the first embodiment of the charging module provided in this application; the charge and discharge protection circuit 100 further includes: a charging module 50, which is coupled to each switching module 30; wherein, the charging module 50 is configured to turn on each switching module 30 when an external power source is connected, so that each battery pack 10 is connected to the charging circuit.

[0084] In one embodiment, such as Figure 10 As shown, Figure 10This is a schematic diagram of the structure of the second embodiment of the charging module provided in this application; the charging module 50 includes: a charging port 51, which is used to couple to an external power source; at least one charging diode 52, each charging diode 52 corresponding to a switching module 30, the anode of each charging diode 52 being coupled to the charging port 51, and the cathode of each charging diode 52 being coupled to its corresponding switching module 30.

[0085] During the charging process, the first switch S1 and the second switch S2 close and conduct, directly connecting the two parallel battery packs 10. However, since an external charger is connected at this time, the charger's voltage is always higher than the voltage of either battery pack. According to Kirchhoff's Law (KCL), there is no possibility of mutual charging between the cells of the two battery packs 10. Therefore, this solution ensures that the parallel battery packs 10 do not charge each other, can discharge together to an external load, and can charge the battery packs 10 using an external charger. It does not affect the performance of the host device or the fuel gauge, effectively increasing battery capacity and improving product range and low-temperature discharge capability.

[0086] The above solution overcomes the limitations of high-capacity explosion-proof battery cell technology at the circuit level by using small-capacity cells with lower explosion-proof certification requirements. These cells, combined with the solution presented in this application, can be used to construct a high-capacity battery. This effectively increases battery capacity and extends product range while meeting explosion-proof requirements. Furthermore, the high-capacity explosion-proof battery significantly improves low-temperature discharge performance, enhancing the reliability of explosion-proof products in cold northern regions.

[0087] To address the aforementioned problems, this application also provides a power supply device 200, such as... Figure 11 As shown, Figure 11 This is a schematic diagram of a power supply device according to an embodiment of the present application; the power supply device 200 includes at least two battery packs 10 connected in parallel, each battery pack 10 corresponds to a charge-discharge protection circuit 100, and each charge-discharge protection circuit 100 is coupled to the positive or negative terminal of the corresponding battery pack 10. The charge-discharge protection circuit 100 is the charge-discharge protection circuit 100 described in any of the above embodiments.

[0088] To address the aforementioned problems, this application also provides an electronic device 300, such as... Figure 12 As shown, Figure 12 This is a schematic diagram of an embodiment of the electronic device provided in this application; the electronic device 300 includes: a power supply device 200, which is the power supply device 200 as described in any of the above embodiments.

[0089] The charge / discharge protection circuit, power supply device, and electronic equipment provided in this application detect the charge / discharge of parallel battery packs through the charge / discharge protection circuit. The switching module within the circuit isolates the parallel battery packs from each other, preventing mutual charging and discharging between the parallel battery packs. This protects the circuit from malfunctions and meets the explosion-proof requirements of the power supply. It has near-forward conduction and reverse cutoff effects, can withstand high power transmission, and generates relatively little heat. It can use multiple small-capacity cells in parallel instead of a single large-capacity cell. Multiple detection modules and corresponding switching modules can be used to achieve multiple layers of protection for the parallel battery packs, providing on / off isolation. Furthermore, a charging module is integrated to realize the charging process of the battery packs and meet their charging needs.

[0090] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A charge / discharge protection circuit, characterized in that, The power supply device includes at least two battery packs connected in parallel, each battery pack corresponding to one charge / discharge protection circuit, each charge / discharge protection circuit being coupled to the positive and / or negative terminal of the corresponding battery pack, and each charge / discharge protection circuit including: At least one detection module; At least one switching module, and each of the switching modules corresponds to one of the detection modules; Each of the detection modules is used to detect whether the corresponding battery pack is being charged by other battery packs, and when the corresponding battery pack is detected to be being charged, it outputs a first control signal to the corresponding switch module. The switch module responds to the first control signal to disconnect, thereby disconnecting the parallel circuit between the battery pack and other battery packs.

2. The charge / discharge protection circuit according to claim 1, characterized in that, The detection module includes: A current limiting unit, wherein the current limiting unit is coupled to the switching module; A control unit, which is coupled to the current limiting unit and the switching module; The switch module is coupled to the positive or negative terminal of the corresponding battery pack. The control unit is used to detect the voltage difference on the switch module and detect whether the corresponding battery pack is being charged by other battery packs based on the voltage difference. When the corresponding battery pack is detected to be being charged, the control unit outputs the first control signal to the corresponding switch module. The switch module responds to the first control signal to disconnect, thereby disconnecting the parallel circuit between the battery pack and other battery packs.

3. The charge / discharge protection circuit according to claim 2, characterized in that, The charge / discharge protection circuit also includes: An impedance unit is coupled to the current limiting unit and the switching module, wherein the impedance unit and the switching module are coupled to the positive or negative terminal of the corresponding battery pack. The control unit is used to detect the voltage difference on the switching module in order to detect whether the corresponding battery pack is being charged by other battery packs. Alternatively, the control unit is used to detect the voltage difference across the impedance unit in order to detect whether the corresponding battery pack is being charged by other battery packs. Alternatively, the control unit is used to detect the voltage difference between the impedance unit and the switching module to detect whether the corresponding battery pack is being charged by other battery packs.

4. The charge / discharge protection circuit according to claim 3, characterized in that, The current limiting unit includes: First current limiting circuit; Second current limiting circuit; Wherein, when the control unit is used to detect the voltage difference on the switching module, the first end of the first current limiting circuit is coupled to the first end of the switching module, the second end of the first current limiting circuit is coupled to the control unit, the first end of the second current limiting circuit is coupled to the second end of the switching module, and the second end of the second current limiting circuit is coupled to the control unit; When the control unit is used to detect the voltage difference across the impedance unit, the first end of the first current limiting circuit is coupled to the first end of the impedance unit, the second end of the first current limiting circuit is coupled to the control unit, the first end of the second current limiting circuit is coupled to the second end of the impedance unit, and the second end of the second current limiting circuit is coupled to the control unit. When the control unit is used to detect the voltage difference between the impedance unit and the switching module, the first end of the first current limiting circuit is coupled to the first end of the impedance unit, the second end of the first current limiting circuit is coupled to the control unit, the first end of the second current limiting circuit is coupled to the second end of the switching module, and the second end of the second current limiting circuit is coupled to the control unit.

5. The charge / discharge protection circuit according to claim 4, characterized in that, The first current limiting circuit includes: A first resistor, the first end of which is coupled to the first end of the switching module or the first end of the impedance unit, and the second end of which is coupled to the control unit. A first capacitor, the first terminal of which is coupled to the second terminal of the first resistor, and the second terminal of the first capacitor is grounded; And / or, the second current limiting circuit includes: The second resistor has a first end coupled to the second end of the switching module or the second end of the impedance unit, and the second end of the second resistor is coupled to the control unit. The second capacitor has its first terminal coupled to the second terminal of the second resistor, and its second terminal is grounded.

6. The charge / discharge protection circuit according to claim 2, characterized in that, The control unit includes: The comparator has its first and second input terminals coupled to the current limiting unit, and its output terminal coupled to the switching module. When the comparator detects that the corresponding battery pack is being charged, it outputs a first control signal to the corresponding switch module. The switch module disconnects in response to the first control signal to break the parallel circuit between the battery pack and other battery packs.

7. The charge / discharge protection circuit according to claim 6, characterized in that, The control unit further includes: A diode, wherein the anode of the diode is coupled to the output of the comparator, and the cathode of the diode is coupled to the switching module.

8. The charge / discharge protection circuit according to claim 1, characterized in that, The charge / discharge protection circuit includes: Two detection modules; Two switching modules, each of which corresponds to one of the detection modules; The switch module is connected in series to the positive or negative terminal of the corresponding battery pack. Each detection module is used to detect whether the corresponding battery pack is being charged by other battery packs. When the corresponding battery pack is detected to be being charged, the detection module outputs a first control signal to the corresponding switch module. The switch module disconnects in response to the first control signal to disconnect the parallel circuit between the battery pack and other battery packs.

9. The charge / discharge protection circuit according to any one of claims 1-8, characterized in that, The charge / discharge protection circuit also includes: A charging module, wherein the charging module is coupled to each of the switch modules; The charging module is configured to turn on each of the switching modules when an external power source is connected, so that each of the battery packs is connected to the charging circuit.

10. The charge / discharge protection circuit according to claim 9, characterized in that, The charging module includes: A charging port for coupling to an external power source; At least one charging diode, each charging diode corresponding to one of the switching modules, the anode of each charging diode being coupled to the charging port, and the cathode of each charging diode being coupled to the corresponding switching module.

11. A power supply device, characterized in that, The power supply device includes at least two battery packs connected in parallel, each battery pack corresponding to a charge-discharge protection circuit, each charge-discharge protection circuit being coupled to the positive or negative terminal of the corresponding battery pack, and the charge-discharge protection circuit being the charge-discharge protection circuit as described in any one of claims 1-10.

12. An electronic device, characterized in that, The electronic device includes: A power supply device, wherein the power supply device is the power supply device as described in claim 11.

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