Charging and discharging system and mobile equipment

Abstract

The utility model discloses a charging and discharging system and a mobile device, and relates to the technical field of power supply circuits. The charging and discharging system comprises at least two rechargeable batteries and at least two battery charging and discharging management modules, the battery charging and discharging management modules are in one-to-one correspondence with the rechargeable batteries, and each battery charging and discharging management module is connected with the corresponding rechargeable battery; and the at least two anti-backflow circuits are in one-to-one correspondence with the battery charging and discharging management modules, the anti-backflow circuits are arranged between the corresponding battery charging and discharging management modules and the load, and the anti-backflow circuits can be selectively switched on or switched off. According to the utility model, the current backflow phenomenon can be prevented.

Description

Technical Field

[0001] The utility model relates to the technical field of power supply circuits, in particular to a charging and discharging system and a mobile device. Background Art

[0002] For mobile devices such as outdoor camera equipment, they need to be powered by a battery pack. In the related art, a battery pack has a plurality of rechargeable batteries connected in series or in parallel.

[0003] However, when multiple rechargeable batteries are connected in parallel in a battery pack, battery backflow may occur between different rechargeable batteries. Utility Model Content

[0004] The main purpose of the utility model is to provide a charging and discharging system and a mobile device, aiming to solve the technical problem of current backflow when different rechargeable batteries are connected in parallel in the related art.

[0005] To achieve the above objectives, in a first aspect, the utility model provides a charging and discharging system, comprising:

[0006] At least two rechargeable batteries and at least two battery charge and discharge management modules, the battery charge and discharge management modules correspond to the rechargeable batteries one by one, and each battery charge and discharge management module is connected to the corresponding rechargeable battery; and

[0007] At least two backflow prevention circuits, the backflow prevention circuits correspond to the battery charge and discharge management modules one by one, the backflow prevention circuits are arranged between the corresponding battery charge and discharge management modules and the load, and the backflow prevention circuits can be selectively turned on or off.

[0008] In a possible embodiment, the charging and discharging system further includes:

[0009] At least two anti-reverse connection circuits are provided, the anti-reverse connection circuits correspond to the battery charge and discharge management modules one by one, and the anti-reverse connection circuits are arranged between the corresponding rechargeable batteries and the battery charge and discharge management modules.

[0010] In a possible embodiment, the reverse connection protection circuit includes:

[0011] a first MOS tube, wherein the drain of the first MOS tube is connected to the positive electrode of the rechargeable battery, the source of the first MOS tube is connected to the battery charge and discharge management module, the anode of the first body diode of the first MOS tube is connected to the drain of the first MOS tube, the cathode of the first body diode is connected to the source of the first MOS tube, and the first MOS tube is a P-channel MOS tube;

[0012] a first bias resistor, one end of which is connected to the source of the first MOS transistor, and the other end of which is connected to the gate of the first MOS transistor; and

[0013] A switch driving circuit, wherein a first end of the switch driving circuit is connected to the gate of the first MOS tube, a second end of the switch driving circuit is connected to the positive electrode of the rechargeable battery, a third end of the switch driving circuit is grounded, and the third end and the first end can be selectively turned on or off;

[0014] When the switch driving circuit detects that the rechargeable battery is positively connected, the third terminal is connected to the first terminal so that the gate of the first MOS tube is grounded.

[0015] In a possible embodiment, the switch driving circuit includes:

[0016] a second MOS tube, wherein the gate of the second MOS tube is the second end, the drain of the second MOS tube is the first end, and the source of the second MOS tube is the third end; the second MOS tube is an N-channel MOS tube, and the negative electrode of the rechargeable battery is grounded;

[0017] The second bias resistor is arranged between the positive electrode and the second end of the rechargeable battery.

[0018] In a possible embodiment, the switch driving circuit further includes a pull-down resistor, and the second end is grounded through the pull-down resistor;

[0019] The resistance of the pull-down resistor is greater than the resistance of the second bias resistor.

[0020] In a possible embodiment, the anti-reverse connection circuit further includes a first capacitor, one end of the first capacitor is connected to the source of the second MOS tube, and the other end of the first capacitor is connected to the gate of the second MOS tube.

[0021] In a possible embodiment, the anti-reverse connection circuit further includes a second capacitor, one end of the second capacitor is connected to the drain of the first MOS tube, and the other end of the second capacitor is connected to the gate of the first MOS tube.

[0022] In a possible embodiment, the charging and discharging system further includes:

[0023] The control module is connected to all the backflow prevention circuits and is used to detect the voltage of each backflow prevention circuit and control each backflow prevention circuit to be turned on or off according to the voltage.

[0024] In a possible embodiment, the backflow prevention circuit includes:

[0025] a third MOS tube, wherein the drain of the third MOS tube is connected to the corresponding battery charge and discharge management module, the gate of the third MOS tube is connected to the control module, the anode of the third body diode of the third MOS tube is connected to the drain of the third MOS tube, and the cathode of the third body diode is connected to the source of the third MOS tube;

[0026] A fourth MOS tube, a source of the fourth MOS tube is connected to the source of the third MOS tube, a drain of the fourth MOS tube is connected to the load, a gate of the fourth MOS tube is connected to the control module, an anode of a fourth body diode of the fourth MOS tube is connected to the drain of the fourth MOS tube, and a cathode of the fourth body diode is connected to the source of the fourth MOS tube.

[0027] In a second aspect, the utility model further provides a mobile device, which includes the charging and discharging system of the first aspect.

[0028] The utility model provides a charging and discharging system and a mobile device. The charging and discharging system comprises at least two rechargeable batteries and at least two battery charging and discharging management modules, the battery charging and discharging management modules correspond to the rechargeable batteries one by one, and each battery charging and discharging management module is connected to the corresponding rechargeable battery; at least two anti-backflow circuits, the anti-backflow circuits correspond to the battery charging and discharging management modules one by one, the anti-backflow circuits are arranged between the corresponding battery charging and discharging management modules and the load, and the anti-backflow circuits can be selectively turned on or off.

[0029] It can be seen that in the charging and discharging system provided by the utility model, multiple rechargeable batteries are connected in parallel to supply power to the load, but in addition to the battery charging and discharging management module, each branch where the rechargeable battery is located is also provided with an anti-backflow circuit that can be selectively turned on or off. Therefore, the utility model can isolate the rechargeable battery by putting the anti-backflow circuit in the off state, thereby preventing the occurrence of current backflow. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0031] Figure 1 This is a module schematic diagram of an embodiment of the charging and discharging system of the utility model;

[0032] Figure 2 It is a module schematic diagram of another embodiment of the charging and discharging system of the utility model;

[0033] Figure 3 It is a circuit diagram of the anti-reverse connection circuit in the charging and discharging system of the utility model;

[0034] Figure 4 The figure is a circuit diagram of the anti-backflow circuit in the charging and discharging system of the utility model.

[0035] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0037] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0038] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the utility model, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least two of the features. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the utility model.

[0040] See also Figure 1 The utility model provides a charging and discharging system, including at least two rechargeable batteries 10, at least two battery charging and discharging management modules 20 and at least two backflow prevention circuits 30.

[0041] The battery charge and discharge management modules 20 correspond one-to-one to the rechargeable batteries 10, and each battery charge and discharge management module 20 is connected to the corresponding rechargeable battery 10; the anti-backflow circuit 30 corresponds one-to-one to the battery charge and discharge management module 20, the anti-backflow circuit 30 is arranged between the corresponding battery charge and discharge management module 20 and the load, and the anti-backflow circuit 30 can be selectively turned on or off.

[0042] Specifically, in the charging and discharging system of this embodiment, multiple rechargeable and dischargeable batteries are connected in parallel, and in each branch where the rechargeable battery 10 is located, it also includes a battery charging and discharging management module 20 and an anti-backflow circuit 30. The rechargeable batteries 10 are all removable batteries, and any rechargeable battery 10 can be independently disassembled and assembled. It should be noted that each rechargeable battery 10 can be a single removable battery, or a battery pack composed of multiple single removable batteries connected in series or in parallel.

[0043] The battery charge and discharge management module 20 implements safe management of the charging process by monitoring and controlling parameters such as battery charging current and voltage. It can be understood that the charge and discharge system of this embodiment also includes a power interface, which is connected to the battery charge and discharge management module 20, so that an external power source can be connected to the battery charge and discharge management module 20 through the power interface, so that the battery charge and discharge management module 20 can use the external power source to power the corresponding rechargeable battery 10.

[0044] Exemplarily, the external power source may be a USB power source, which is connected to the battery charge and discharge management module 20 through a USB interface to provide power to the battery charge and discharge management module 20. The battery charge and discharge management module 20 is connected to the rechargeable battery 10 and is responsible for controlling the charging and discharging process of the battery. During the charging process of the external power source, when the USB power source supplies power to the rechargeable battery 10 through the USB interface, the power first enters the battery charge and discharge management module 20. The battery charge and discharge management module 20 monitors the voltage and current state of the rechargeable battery 10 to determine whether the rechargeable battery 10 needs to be charged. If the rechargeable battery 10 needs to be charged, the battery charge and discharge management module 20 controls its internal charging circuit to convert the power provided by the USB power source into a voltage and current suitable for charging the rechargeable battery 10. The converted power enters the rechargeable battery 10 through the output port of the charge and discharge management module to charge the rechargeable battery 10. Of course, if there is no rechargeable battery 10 connected to the branch or no rechargeable battery 10 is correctly connected to the charge and discharge system, the USB power source does not charge the rechargeable battery 10, but only provides power for the subsequent load.

[0045] The anti-backflow circuit 30 is used to provide anti-backflow protection for the branch where it is located, that is, to prevent the high-voltage and fully charged batteries in the multiple rechargeable batteries 10 from supplying power to the low-voltage and insufficiently charged batteries when powering the load, causing the temperature of the battery to be too high. In this embodiment, the anti-backflow circuit 30 can be selectively turned on or off. That is, when the anti-backflow circuit 30 is in the on state, the branch where it is located is normally connected to the charging and discharging system, and when the anti-backflow circuit 30 is in the off state, the branch where it is located is isolated from the charging and discharging system, thereby avoiding current backflow. That is, this embodiment can avoid mutual charging between batteries and avoid the safety hazards caused by high battery temperature due to internal circulation.

[0046] In this embodiment, it is possible to configure the priority consumption of the power of the rechargeable battery 10 with high voltage and sufficient power, such as configuring the anti-backflow circuit 30 of the corresponding branch with the highest value or the top preset position among all voltages to be turned on, while the anti-backflow circuits 30 of the other branches are turned off until the voltages of the rechargeable batteries 10 of all branches are basically the same. If the voltage difference between every two branches is within the preset threshold range, all the anti-backflow circuits 30 are controlled to be turned on, so that all branches supply power to the load at the same time.

[0047] In addition, in this embodiment, the charging and discharging system further includes a SOC module, which is connected to each battery charging and discharging management module 20 via an I2C line or an SPI line. In this way, the configuration of charging current, charging voltage, charging protection and other functions can be realized by configuring parameters through the SOC module.

[0048] Therefore, in the present embodiment, in the charge and discharge system provided, a plurality of rechargeable batteries 10 are connected in parallel to supply power to the load, but in addition to the battery charge and discharge management module 20, each branch is also provided with a selectively turned on or off anti-backflow circuit 30. Therefore, in the present embodiment, the anti-backflow circuit 30 is in the off state to isolate the rechargeable battery, thereby avoiding the occurrence of current backflow.

[0049] In addition, in this embodiment, by cutting off one or more backflow prevention circuits 30, not only the isolation of the rechargeable battery 10 can be achieved, but also automatic balancing between multiple rechargeable batteries 10 can be achieved, thereby improving the use flexibility and integration of the charging and discharging system.

[0050] In a possible embodiment, the charging and discharging system further includes at least two anti-reverse connection circuits 40 , the anti-reverse connection circuits 40 correspond one-to-one to the battery charging and discharging management modules 20 , and the anti-reverse connection circuits 40 are arranged between the corresponding rechargeable batteries 10 and the battery charging and discharging management modules 20 .

[0051] Specifically, see Figure 2, in this embodiment, an anti-reverse connection circuit 40 is further provided in each branch. When the positive and negative electrodes of the rechargeable battery 10 are correctly inserted into the battery compartment, it can be normally connected to the charge and discharge circuit through the anti-reverse connection circuit 40. On the contrary, when the positive and negative electrodes of the rechargeable battery 10 are not correctly inserted into the battery compartment, the anti-reverse connection circuit 40 becomes effective, isolating the reversely connected rechargeable battery 10 outside the charge and discharge system and protecting the charge and discharge system.

[0052] It is easy to understand that the anti-reverse connection circuit 40 generally can be composed of a single diode, a rectifier bridge structure or a single MOS transistor. However, such an anti-reverse connection circuit 40 only allows the battery to discharge externally. When the battery is the rechargeable battery 10 in the charge and discharge system, such an anti-reverse connection circuit 40 does not allow the current to flow reversely to charge the rechargeable battery 10, resulting in that the charge and discharge system still needs to configure other circuit modules. For this reason, this embodiment also provides an anti-reverse connection circuit 40 that can simultaneously realize the external discharge of the battery and allow the external power supply to charge the rechargeable battery 10. Please refer to Figure 3 , and the following will specifically elaborate on this.

[0053] The anti-reverse connection circuit 40 includes a first MOS transistor Q1, a first bias resistor R1, and a switch drive circuit. The drain of the first MOS transistor Q1 is connected to the positive electrode of the rechargeable battery 10, the source of the first MOS transistor Q1 is connected to the battery charge and discharge management module 20, the anode of the first body diode of the first MOS transistor Q1 is connected to the drain of the first MOS transistor Q1, and the cathode of the first body diode is connected to the source of the first MOS transistor Q1. One end of the first bias resistor R1 is connected to the source of the first MOS transistor Q1, and the other end of the first bias resistor R1 is connected to the gate of the first MOS transistor Q1. The first end of the switch drive circuit is connected to the gate of the first MOS transistor Q1, the second end of the switch drive circuit is connected to the positive electrode of the rechargeable battery 10, and the third end of the switch drive circuit is grounded, and the third end and the first end can be selectively conducted or cut off; wherein, when the switch drive circuit detects that the rechargeable battery 10 is correctly connected, the third end and the first end are conducted to ground the gate of the first MOS transistor Q1.

[0054] Specifically, the anti-reverse connection circuit 40 includes an input port and an output port. Among them, the input port is used to be connected to the positive electrode of the rechargeable battery 10, and the output port is connected to the battery charge and discharge management module 20. Please refer to Figure 3 , the input port is port VBAT, and the output port is port VBAT+. The first MOS transistor Q1 is a P-channel MOS transistor, and the conduction condition of the P-channel MOS transistor is that the gate voltage Vg < the source voltage Vs, and Vgs < Vgs(th). Generally, the Vgs(th) of the P-channel MOS transistor is usually a negative value.

[0055] During discharge, for example, the voltage of the rechargeable battery 10 is VBAT The potential of the VBAT port is V. BAT Since the anode of the first body diode of the first MOS transistor Q1 is connected to the drain of the first MOS transistor Q1, and the cathode of the first body diode is connected to the source of the first MOS transistor Q1, the VBAT port and the VBAT+ port are conducted through the first body diode of the first MOS transistor Q1, and the potential of the VBAT+ port is also V. BAT At this time, the gate voltage of the first MOS transistor Q1 is controlled by the switch driving circuit. The switch driving circuit has a first terminal, a second terminal, and a third terminal. Among them, the gate of the first MOS transistor Q1 is grounded through the first terminal and the third terminal. Thus, when the first terminal and the third terminal are conducted, the gate of the first MOS transistor Q1 is grounded. Therefore, the potential of the first MOS transistor Q1 is 0. And the first bias resistor R1 connects the gate and the source of the first MOS transistor Q1, thereby providing the bias voltage required for the normal operation of the first MOS transistor Q1. Therefore, V GSQ1 ≈ -V BAT , satisfying Vg < Vs and Vgs < Vgs(th), the first MOS transistor Q1 is turned on. And the second terminal of the switch driving circuit is connected to the positive electrode of the rechargeable battery 10, so that the switch driving circuit can detect whether the rechargeable battery 10 is correctly connected. When it is detected that the rechargeable battery 10 is correctly connected, the first terminal and the third terminal in the switch driving circuit are conducted.

[0056] During charging, since the rechargeable battery 10 is correctly connected, the first terminal and the third terminal are also conducted, and the gate of the first MOS transistor Q1 is grounded. At this time, the potential of the VBAT+ port is relatively high. And the first bias resistor R1 connects the gate and the source of the first MOS transistor Q1, thereby providing the bias voltage required for the normal operation of the first MOS transistor Q1. Thus, V GSQ1 ≈ -V BAT , satisfying Vg < Vs and Vgs < Vgs(th), the first MOS transistor Q1 is turned on.

[0057] Therefore, compared with the anti-reverse connection circuits such as diodes and rectifier bridges in the related art, the first MOS transistor Q1 is used in this embodiment. The current can flow from the input port to the output port during discharge, and can also flow from the output port to the input port during charging. In addition, the impedance of the first MOS transistor Q1 is much lower than that of the diode, which can effectively reduce the impedance of the charging and discharging system and improve the battery life of the load.

[0058] It is understandable that the switch driving circuit can control the first terminal and the second terminal to be conductive through an external control signal when detecting that the rechargeable battery 10 is positively connected, or the first terminal and the second terminal are conductive through a circuit structure. Therefore, the switch driving circuit can be a device such as a MOS tube or an IGBT (Insulate-Gate Bipolar Transistor).

[0059] In addition, it is worth mentioning that, since the third terminal of the switch driving circuit is grounded in the above structure, it is applicable to devices that do not share the negative electrode of the battery. Of course, for mobile devices such as outdoor cameras, the negative electrodes of multiple parallel rechargeable batteries 10 can also share a negative electrode of the battery, and it is common that the negative electrode of each rechargeable battery 10 is connected to the battery pack shell. Therefore, in a possible embodiment, the switch driving circuit includes a second MOS tube Q2 and a second bias resistor R3, the gate of the second MOS tube Q2 is the second terminal, the drain of the second MOS tube Q2 is the first terminal, and the source of the second MOS tube Q2 is the third terminal; the second MOS tube Q2 is an N-channel MOS tube, and the negative electrode of the rechargeable battery 10 is grounded. The second bias resistor R3 is arranged between the positive electrode and the second terminal of the rechargeable battery 10.

[0060] At this time, in this embodiment, when the common negative electrodes of multiple rechargeable batteries 10 are connected in parallel, the reverse-connected rechargeable batteries 10 are isolated from the charging and discharging system by utilizing the conduction characteristics of the N-channel MOS tube. Figure 3 , the specific working process of the second MOS tube Q2 is as follows:

[0061] Still taking the voltage of the rechargeable battery 10 as V BAT For example, when the rechargeable battery 10 is correctly inserted, the potential of the port VBAT is V BAT Since the anode of the first body diode of the first MOS tube Q1 is connected to the drain of the first MOS tube Q1, and the cathode of the first body diode is connected to the source of the first MOS tube Q1, the port VBAT+ and the port VBAT are turned on through the first body diode of the first MOS tube Q1, and the potential of the port VBAT+ is also V BAT Since the gate of the second MOS transistor Q2 is connected to the positive electrode of the rechargeable battery 10, the gate potential of the second MOS transistor Q2 is approximately V BAT The source of the second MOS tube Q2 is grounded, with a potential of 0, and the second bias resistor R3 connects the gate of the second MOS tube Q2 to the source, thereby providing the bias voltage required for the normal operation of the second MOS tube Q2. The V GS ≈V BAT , satisfying V GS >V GS(th), the second MOS transistor Q2 is saturated and turned on. Therefore, the gate of the first MOS transistor Q1 is grounded, and the potential of the first MOS transistor Q1 is 0. And the first bias resistor R1 connects the gate and the source of the first MOS transistor Q1, thereby providing the bias voltage required for the normal operation of the first MOS transistor Q1. Therefore, V GSQ1 ≈ -V BAT , satisfying Vg < Vs and Vgs < Vgs(th), the first MOS transistor Q1 is turned on.

[0062] Conversely, when the rechargeable battery 10 is inserted reversely, the potential of the port VBAT is -V BAT , the first body diode of the first MOS transistor Q1 is cut off and turned off, and the port VBAT+ has no potential. Similarly, the gate potential of the second MOS transistor Q2 is approximately -VBAT, and the V GS ≈ -VBAT, which is less than V GS (th), the second MOS transistor Q2 is cut off and turned off. The first MOS transistor Q1 does not form a loop, and the first MOS transistor Q1 is cut off and turned off, that is, the first body diode and the first MOS transistor Q1 of the first MOS transistor Q1 are both cut off and turned off to achieve the function of preventing reverse connection.

[0063] Therefore, the reverse connection prevention circuit 40 of the charge and discharge system provided in this embodiment can be applied to multiple rechargeable batteries sharing a common negative electrode. In addition, the second bias resistor R3 in this embodiment can also be used to prevent the positive electrode of the rechargeable battery 10 from being directly connected to the grounded negative electrode and causing a short circuit.

[0064] In a possible embodiment, the reverse connection prevention circuit 40 further includes a first capacitor. One end of the first capacitor is connected to the gate of the second MOS transistor Q2, and the other end of the first capacitor is connected to the source of the second MOS transistor Q2.

[0065] In this embodiment, after the rechargeable battery 10 is correctly connected, the rechargeable battery 10 charges the first capacitor. When the voltage of the first capacitor is charged to the turn-on voltage required for the second MOS transistor Q2 to turn on, the second MOS transistor Q2 is turned on.

[0066] In a possible embodiment, the switch driving circuit further includes a pull-down resistor R2, and the second end is grounded through the pull-down resistor R2; wherein, the resistance value of the pull-down resistor R2 is greater than the resistance value of the second bias resistor R3.

[0067] Specifically, in this embodiment, the resistance value of the pull-down resistor R2 is greater than that of the second bias resistor R3, so as to avoid too large a voltage drop of the second bias resistor R3 and ensure that V GS >V GS (th) can be achieved. Of course, in order to further ensure that V GS >V GS(th) It can be achieved that the resistance of the pull-down resistor R2 is much larger than the second bias resistor R3.

[0068] In a possible embodiment, the anti-reverse connection circuit 40 further includes a second capacitor, one end of the second capacitor is connected to the drain of the first MOS transistor Q1 , and the other end of the second capacitor is connected to the gate of the first MOS transistor Q1 .

[0069] In this embodiment, after the rechargeable battery 10 is positively connected and the second MOS transistor Q2 is turned on, the rechargeable battery 10 charges the second capacitor. When the voltage of the second capacitor is charged to the turn-on voltage required for the first MOS transistor Q1 to be turned on, the first MOS transistor Q1 is turned on.

[0070] For example, when the rechargeable battery 10 is positively connected, the port VBAT and the port VBAT+ are turned on through the first body diode of the first MOS tube Q1, and the potential of the port VBAT+ is also V BAT At this time, in order to prevent the port VBAT+ from charging the second capacitor through the first bias resistor R1, the other end of the second capacitor is connected to the source of the second MOS tube Q2.

[0071] In a possible embodiment, the charging and discharging system further includes a control module 50, which is connected to all the backflow prevention circuits 30 and is used to detect the voltage of each backflow prevention circuit 30 and control each backflow prevention circuit 30 to be turned on or off according to the voltage.

[0072] Specifically, all the backflow prevention circuits 30 are connected to the control module 50. In this way, at any time, the backflow prevention circuit 30 is in the on state or the off state controlled by the control module 50. Specifically, the control module 50 can monitor the voltage of each branch where the backflow prevention circuit 30 is located, and according to the numerical values ​​of all voltages, control the backflow prevention circuit 30 corresponding to the voltage with abnormal value to switch to the off state, while the backflow prevention circuit 30 of the remaining branches remains in the on state and is powered normally. Exemplarily, the control module 50 can monitor the input voltage of each anti-backflow circuit 30.

[0073] The aforementioned numerical abnormality may be that the difference between the corresponding voltage and the voltage of the other branch is greater than a preset value. Alternatively, when there are only two branches, the aforementioned numerical abnormality may also be the larger value or the smaller value. For example, please refer to Figure 4, taking two branches as an example, VIN1 is the input voltage of the anti-backflow circuit 30 of branch 1, and VIN2 is the input voltage of the anti-backflow circuit 30 of branch 2. The control module 50 monitors the values ​​of VIN1 and VIN2. When VIN1>VIN2, the control module 50 controls the anti-backflow circuit 30 of branch 1 to be turned on, while the anti-backflow circuit 30 of branch 2 is turned off, and the load is powered by VIN1 as a whole. Conversely, when VIN2>VIN1, the control module 50 controls the anti-backflow circuit of branch 1 to be turned off, while the anti-backflow circuit of branch 2 is turned on, and the load is powered by VIN1 as a whole. Of course, when the voltage difference between VIN1 and VIN2 is less than the set threshold, the control module 50 controls the anti-backflow circuit of branch 1 and the anti-backflow circuit of branch 2 to be turned on at the same time to power the load at the same time.

[0074] In addition, in this embodiment, the control module 50 can also control the state of the anti-backflow circuit 30 of multiple branches to realize automatic balancing of the system. Specifically, the control module 50 is configured to preferentially consume the power of the rechargeable battery 10 with high voltage and sufficient power, such as controlling the anti-backflow circuit 30 of the branch with the highest value or the top preset position among all voltages to be turned on, while the anti-backflow circuit 30 of the other branches is turned off until the voltage of the rechargeable battery 10 of all branches is basically the same. If the voltage difference between every two branches is within the preset threshold range, all the anti-backflow circuits 30 are controlled to be turned on, so that all branches can supply power to the load at the same time.

[0075] Therefore, in the present embodiment, in the provided charging and discharging system, the states of all the backflow prevention circuits 30 are controlled by the control module 50, so that under the control of the control module 50, some branches can be isolated from the charging and discharging system. Therefore, in the present embodiment, the control module 50 controls one or more backflow prevention circuits 30 to be cut off, and at the same time, the isolation of a single rechargeable battery 10 and the automatic balance between multiple rechargeable batteries 10 are realized, thereby improving the use flexibility of the charging and discharging system.

[0076] In a possible embodiment, the backflow prevention circuit 30 includes a third MOS transistor and a fourth MOS transistor.

[0077] Among them, the drain of the third MOS tube is connected to the corresponding battery charge and discharge management module 20, the gate of the third MOS tube is connected to the control module 50, the anode of the third body diode of the third MOS tube is connected to the drain of the third MOS tube, and the cathode of the third body diode is connected to the source of the third MOS tube; the source of the fourth MOS tube is connected to the source of the third MOS tube, the drain of the fourth MOS tube is connected to the load, the gate of the fourth MOS tube is connected to the control module 50, and the anode of the fourth body diode of the fourth MOS tube is connected to the drain of the fourth MOS tube, and the cathode of the fourth body diode is connected to the source of the fourth MOS tube.

[0078] For example, see Figure 4 , taking two branches as an example, the output end of the entire charge and discharge system is VOUT. VIN1 is the input voltage of the anti-backflow circuit of branch 1, and VIN2 is the input voltage of the anti-backflow circuit of branch 2. The control module 50 monitors the voltages of VIN1 and VIN2. When VIN1>VIN2, the control module 50 controls the MOS tube Q3 and MOS tube Q4 of branch 1 to be turned on, while the MOS tube Q5 and MOS tube Q6 of branch 2 are turned off, and the load is powered by VIN1 as a whole. On the contrary, when VIN2>VIN1, the control module 50 controls the MOS tube Q3 and MOS tube Q4 of branch 1 to be turned off, while the MOS tube Q5 and MOS tube Q6 of branch 2 are turned on, and the load is powered by VIN1 as a whole. Of course, when the voltage difference between VIN1 and VIN2 is less than the set threshold, the control module 50 controls the MOS tube Q3 and MOS tube Q4 of branch 1, and the MOS tube Q5 and MOS tube Q6 of branch 2 to be turned on at the same time, and power the load at the same time.

[0079] Specifically, in the anti-backflow circuit 30, the anode of the third body diode is connected to the drain of the third MOS tube, the cathode of the third body diode is connected to the source of the third MOS tube, and the anode of the fourth body diode of the fourth MOS tube is connected to the drain of the fourth MOS tube, and the cathode of the fourth body diode is connected to the source of the fourth MOS tube. In this way, when the third MOS tube and the fourth MOS tube are both cut off, the third body diode can prevent the voltage of other branches from backflowing through the fourth body diode.

[0080] Of course, the third MOS transistor and the fourth MOS transistor in this embodiment may be P-channel MOS transistors or N-channel MOS transistors, and this embodiment does not limit this.

[0081] In a second aspect, the utility model further provides a mobile device, which includes a charging and discharging system.

[0082] Specifically, the mobile device of this embodiment can be a mobile device such as a mobile phone, a power bank, a camera, etc. The specific structure of the charging and discharging system refers to the above embodiment. Since this mobile device adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here one by one.

[0083] The above are only optional embodiments of the present invention, and the protection scope of the present invention is not limited thereto. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the protection scope of the present invention.

Claims

1. A charging and discharging system, characterized in that: include: at least two rechargeable batteries and at least two battery charge and discharge management modules, wherein the battery charge and discharge management modules correspond to the rechargeable batteries one by one, and each of the battery charge and discharge management modules is connected to the corresponding rechargeable battery; and At least two backflow prevention circuits, each of which corresponds to the battery charge and discharge management module one by one, are arranged between the corresponding battery charge and discharge management module and the load, and can be selectively turned on or off.

2. The charging and discharging system according to claim 1, characterized in that: The charging and discharging system further comprises: At least two anti-reverse connection circuits, the anti-reverse connection circuits correspond to the battery charge and discharge management modules one by one, and the anti-reverse connection circuits are arranged between the corresponding rechargeable batteries and the battery charge and discharge management modules.

3. The charging and discharging system according to claim 2, characterized in that: The anti-reverse connection circuit comprises: a first MOS transistor, wherein the drain of the first MOS transistor is connected to the positive electrode of the rechargeable battery, the source of the first MOS transistor is connected to the battery charge and discharge management module, the anode of the first body diode of the first MOS transistor is connected to the drain of the first MOS transistor, the cathode of the first body diode is connected to the source of the first MOS transistor, and the first MOS transistor is a P-channel MOS transistor; a first bias resistor, one end of which is connected to the source of the first MOS transistor, and the other end of which is connected to the gate of the first MOS transistor; and A switch driving circuit, wherein a first end of the switch driving circuit is connected to the gate of the first MOS transistor, a second end of the switch driving circuit is connected to the positive electrode of the rechargeable battery, a third end of the switch driving circuit is grounded, and the third end and the first end can be selectively turned on or off; Wherein, when the switch driving circuit detects that the rechargeable battery is positively connected, the third terminal is connected to the first terminal to ground the gate of the first MOS tube.

4. The charging and discharging system according to claim 3, characterized in that: The switch driving circuit comprises: a second MOS tube, wherein the gate of the second MOS tube is the second end, the drain of the second MOS tube is the first end, and the source of the second MOS tube is the third end; the second MOS tube is an N-channel MOS tube, and the negative electrode of the rechargeable battery is grounded; A second bias resistor is disposed between the positive electrode of the rechargeable battery and the second end.

5. The charging and discharging system according to claim 4, characterized in that: The switch driving circuit further includes a pull-down resistor, and the second end is grounded through the pull-down resistor; Wherein, the resistance of the pull-down resistor is greater than the resistance of the second bias resistor.

6. The charging and discharging system according to claim 4, characterized in that: The anti-reverse connection circuit also includes a first capacitor, one end of the first capacitor is connected to the source of the second MOS tube, and the other end of the first capacitor is connected to the gate of the second MOS tube.

7. The charging and discharging system according to claim 3, characterized in that: The anti-reverse connection circuit also includes a second capacitor, one end of the second capacitor is connected to the drain of the first MOS tube, and the other end of the second capacitor is connected to the gate of the first MOS tube.

8. The charging and discharging system according to any one of claims 1 to 7, characterized in that: The charging and discharging system further comprises: A control module is connected to all the anti-backflow circuits and is used to detect the voltage of each anti-backflow circuit and control each anti-backflow circuit to be turned on or off according to the voltage.

9. The charging and discharging system according to claim 8, characterized in that: The anti-backflow circuit comprises: a third MOS tube, wherein the drain of the third MOS tube is connected to the corresponding battery charge and discharge management module, the gate of the third MOS tube is connected to the control module, the anode of the third body diode of the third MOS tube is connected to the drain of the third MOS tube, and the cathode of the third body diode is connected to the source of the third MOS tube; a fourth MOS tube, wherein a source of the fourth MOS tube is connected to the source of the third MOS tube, a drain of the fourth MOS tube is connected to the load, a gate of the fourth MOS tube is connected to the control module, an anode of a fourth body diode of the fourth MOS tube is connected to the drain of the fourth MOS tube, and a cathode of the fourth body diode is connected to the source of the fourth MOS tube.

10. A mobile device, characterized in that: The mobile device comprises the charging and discharging system according to any one of claims 1 to 9.

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