A multi-string battery charging and discharging composite circuit

Abstract

A multi-string battery charging and discharging composite circuit includes a first charging protection module and at least one second charging protection module, the first charging protection module is connected across a first rechargeable battery, and a second charging protection module is connected across a second rechargeable battery; a control unit electrically connects the first charging protection module and the second charging protection module, or electrically connects two second charging protection modules, and the control unit enables the first rechargeable battery and the second rechargeable battery to switch between series or parallel states; a charging control module is connected in series between the negative pole of the first charging protection module and the negative pole of a 5V input power supply to connect the charging circuit; an output module couples the first charging protection module and the second charging protection module, and is connected to the positive pole of the second rechargeable battery and the negative pole of the first rechargeable battery to connect the discharge circuit. The present invention can realize parallel charging and series discharging functions by switching the connection state of the battery, and has charging and discharging protection functions.

Description

Technical Field

[0001] The present invention relates to the technical field of battery charging and discharging circuits, and in particular to a multi-string battery charging and discharging composite circuit. Background Art

[0002] With the popularity of USB-powered devices, 5V voltage is easier to obtain than DC 9V or DC 12V, so the TP4056 charging chip for charging single-cell lithium batteries is widely used in the market. However, for some electronic devices that use two or more strings of batteries, the required voltage for charging is higher than 5V. Generally, charging can only be done after the 5V input voltage is boosted; however, the boost circuit is complex, requires more peripheral components, is costly, and has large high-frequency interference.

[0003] Chinese invention CN201820317688 discloses a circuit that can realize parallel charging and series discharge of multiple battery groups, which includes a control system and at least two battery groups and the same number of charging modules as the rechargeable batteries. The charging modules are connected across the positive and negative electrodes of the battery groups corresponding to the charging modules to form a charging structure for the battery groups; switches are provided between adjacent battery groups, and each switch is used to connect or disconnect adjacent battery groups to form a series discharge structure or a parallel separate charging structure. However, the above scheme fails to solve the problem of overcurrent short circuit protection or over-discharge protection during the charging and discharging process, and there may be safety hazards during use. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the present invention provides a multi-string battery charging and discharging composite circuit, in which the connection relationship of the battery pack is changed to enable it to discharge or charge at a specific voltage; a protection circuit is set to prevent over-discharge, short circuit, over-temperature, over-charging and other phenomena from causing damage to the equipment. .

[0005] To achieve the above object, the technical solution of the present invention is:

[0006] A multi-string battery charging and discharging composite circuit comprises a first charging protection module and at least one second charging protection module, wherein the first charging protection module is connected across a first rechargeable battery, and a second charging protection module is connected across a second rechargeable battery;

[0007] Wherein, it also includes a control unit, the control unit is electrically connected to the first charging protection module and the second charging protection module, or electrically connected to the two second charging protection modules, and the control unit enables the first rechargeable battery and the second rechargeable battery to switch between series connection and parallel connection;

[0008] Among them, it also includes a charging control module electrically connected to the first charging protection module and connected to the 5V input power supply, and the charging control module is electrically connected to the negative electrode of the first rechargeable battery and the 5V input power supply to connect the charging circuit;

[0009] It also includes an output module, which couples the first charging protection module and the second charging protection module, and electrically connects the positive electrode of the second rechargeable battery and the negative electrode of the first rechargeable battery to connect the discharge circuit.

[0010] Through the scheme disclosed in the present invention, a multi-string battery charging and discharging composite circuit is provided, and the connection relationship between the first charging protection module and the second charging protection module can be switched by adjusting the control unit, thereby making the circuit suitable for 5V charging and series discharge of lithium batteries.

[0011] Furthermore, the first charging protection module includes a first charging module and a first protection module; the second charging protection module includes a second charging module and a second protection module.

[0012] Through the solution disclosed in the present invention, the charging or discharging state of the battery during use can be monitored, which is beneficial to improving the service life and safety of the product.

[0013] Furthermore, the chip used in the first charging module and the second charging module is TP4056, and both are connected to a diode to block the reverse current occurring during the charging and discharging process; the model of the diode is SS34.

[0014] Through the solution disclosed in the present invention, connecting a diode to the TP4056 chip helps to block the reverse current that occurs during the battery charging and discharging process, effectively preventing different charging protection modules from interfering with each other during charging and discharging, and improving the stability of the product.

[0015] Furthermore, the charging control module uses a dual NMOS device 8205A.

[0016] Furthermore, the chip used by the first protection module and the second protection module is DW01.

[0017] Furthermore, the TEMP pin of the TP4056 chip of the first charging module is electrically connected to an NTC.

[0018] Through the solution disclosed in the present invention, an NTC is connected to the TEMP pin of the TP4056 chip, so that the product has a temperature monitoring function and improves the safety of the product.

[0019] Furthermore, the CHRG and STDBY pins of the TP4056 chip of the first charging module are respectively connected to the first LED and the second LED of different colors.

[0020] Through the solution disclosed in the present invention, LED lights of different colors are respectively connected to the CHRG and STDBY pins of the TP4056 chip, so as to indicate the charging status of the battery.

[0021] Furthermore, the control unit is a single-pole double-throw switch or a double-pole double-throw switch, and the types include but are not limited to: a button switch, a knob switch, a push button switch, and a relay.

[0022] Furthermore, the control unit can be cascaded in multiple stages, thereby simultaneously changing the connection relationship between the first charging protection module and all the second charging protection modules.

[0023] The solution disclosed in the present invention discloses a control method for the product when multiple batteries need to be charged.

[0024] The charging control module is connected to a 5V power supply through a transistor, the first LED and the second LED are connected to a common anode, and the anode is electrically connected to the base of the transistor of the charging control module.

[0025] Compared with the prior art, the advantages of the present invention are: only by switching the control switch and changing the connection state of the battery, it can be charged with 5V and the battery pack can provide a higher output voltage, which can be extended to the scenario where multiple batteries are connected in series to provide voltage; the first charging protection module and all second charging protection modules add a protection circuit on the basis of realizing battery charging, which can monitor the state of the battery during charging and discharging, avoid the occurrence of dangers such as short circuit and overheating, and help to improve the safety and life of the product; LED lights can also be connected to the product to further enhance the product experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the implementation manner will be briefly introduced below. Obviously, the drawings described below are only some implementation manners of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 A circuit diagram for charging two batteries of the present invention;

[0028] Figure 2 A circuit diagram for charging three batteries of the present invention;

[0029] Figure 3 The first charging protection module of the present invention;

[0030] Figure 4 Two second charging protection modules of the present invention;

[0031] Figure 5 The output module of the present invention is suitable for discharging two batteries;

[0032] Figure 6 The output module of the present invention is suitable for discharging three batteries;

[0033] Figure 7 Two control units of the present invention;

[0034] Figure 8 The charging control module of the present invention;

[0035] Fig. 9 A schematic diagram of connecting the CHRG and STDBY pins of the TP4056 chip of the present invention to an LED;

[0036] Fig.10 This is a schematic diagram of connecting the TEMP pin of the TP4056 chip of the present invention to the NTC. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0038] Reference to "embodiment" or "implementation" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiment or implementation may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0039] In this specification, for the sake of convenience, the words and phrases indicating the orientation or positional relationship such as "middle", "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like are used to illustrate the positional relationship of the constituent elements with reference to the drawings. This is only for the convenience of describing this specification and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation of the present disclosure. The positional relationship of the constituent elements is appropriately changed according to the orientation of the constituent elements being described. Therefore, it is not limited to the words and phrases described in the specification, and can be appropriately replaced according to the circumstances.

[0040] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] This solution discloses a multi-string battery charging and discharging composite circuit, including a Figure 3 The first charging protection module shown in FIG. Figure 4In the second charging protection module shown, a rechargeable battery is connected across the first charging protection module and the second charging protection module, which may be a 3.7V lithium battery;

[0042] It also includes a control unit, which is electrically connected to the first charging protection module and the second charging protection module, or electrically connected to two second charging protection modules; the control unit can switch the connection state of the first charging protection module and the second charging protection module connected thereto, that is, series connection or parallel connection, so that the first charging protection module and all the second charging protection modules can be connected to the circuit in the same connection relationship at the same time;

[0043] It also includes a charging control module electrically connected to the first charging protection module, and the charging control module is electrically connected to the negative electrode of the first rechargeable battery and a 5V input power supply to connect the charging circuit.

[0044] The output module is also included, which is connected to the positive electrode of the second rechargeable battery and the negative electrode of the first rechargeable battery to connect the discharge circuit. A circuit connection method of the output module is as follows Figure 5 shown.

[0045] In some embodiments, Figure 1 As shown, the solution of the present invention includes a first charging protection module and a second charging protection module.

[0046] In some embodiments, the first charging protection module includes a first charging module and a first protection module, and the second charging protection module includes a second charging module and a second protection module, wherein both the first charging module and the second charging module use the TP4056 chip, and the input 5V voltage passes through the diode SS34 and then connected to the VCC pin and the CE pin, which is beneficial to blocking the reverse current generated during the battery charging and discharging process, thereby improving the stability of the product.

[0047] In some embodiments, the TEMP pin of the TP4056 chip is electrically connected to an NTC, such as Fig.10 As shown, temperature monitoring is achieved during battery charging.

[0048] In some embodiments, the CHRG and STDBY pins of the TP4056 chip are respectively connected to a first LED and a second LED of different colors. Fig. 9 As shown, the product has an indication function.

[0049] In some embodiments, Figure 8As shown, the charging control module is connected to a 5V power supply through a transistor; the first LED and the second LED are connected to a common anode to form a logic AND gate circuit, and the anode is electrically connected to the base of the transistor of the charging control module. After the TP4056 has an over-temperature fault, the CHRG and STDBY pins are both set to a high level, and the LED anode is at a high level; in a normal state, charging only has a CHRG low level or only a STDBY low level, and the LED anode is at a low level. In this way, whether the fault is transmitted to the charging control module through the LED anode, thereby realizing the monitoring of faults such as over-temperature and overvoltage.

[0050] In some embodiments, the first charging protection module includes a first charging module and a first protection module, and the second charging protection module includes a second charging module and a second protection module, wherein both the first protection module and the second protection module use chip DW01, so that the product can realize over-discharge protection and over-current protection functions.

[0051] Specifically: In the first charging protection module, if Figure 1 As shown, the OD1 pin of the DW01 chip U1 is electrically connected to the gate of the NMOS tube Q3 of the output module; the CSI pin is electrically connected to the P-end of the output module through the resistor R6; the VDD pin is electrically connected to the positive electrode BAT1+ of the first rechargeable battery bridged by the first charging protection module through the resistor R2; the VSS pin is electrically connected to the negative electrode BAT1- of the first rechargeable battery; the VDD pin and the VSS pin are electrically connected through the capacitor C2;

[0052] In the second charging protection module, Figure 1 As shown, the OD2 pin of the DW01 chip U3 is electrically connected to the gate of the NMOS tube Q1 of the output module; the OC2 pin is connected to the gate of the NMOS tube Q8 of the charging control module; the CSI pin is electrically connected to the negative electrode BAT2- of the second rechargeable battery bridged by the second charging protection module through the resistor R13; the VDD pin is electrically connected to the positive electrode BAT2+ of the second rechargeable battery through the resistor R10; the VSS pin is electrically connected to the negative electrode BAT2- of the second rechargeable battery; the VDD pin and the VSS pin are electrically connected through the capacitor C6;

[0053] The aforementioned charging control module is as follows Figure 8 As shown, the charging control module uses a field effect tube 8205A, wherein the G1 pin is electrically connected to the OC1 pin of the DW01 chip U1 of the first charging protection module through the NMOS tube Q8; the G2 pin is connected to the 5V voltage through R11 and the transistor Q7, and the G2 pin is electrically connected to the negative electrode BAT1- of the first rechargeable battery through R12; the S1 pin is electrically connected to the negative electrode BAT1- of the first rechargeable battery; and the S2 pin is connected to the GND of the input power supply;

[0054] Among them, by default, the G2 pin of the field effect tube 8205A is pulled down by R12 to a low level, so that the field effect tube 8205A is disconnected; when the 5V voltage is connected, the G2 pin of 8205A is pulled up by R11 to a high level, so that the field effect tube 8205A is turned on;

[0055] When TP4056 has over-temperature or other faults, the CHRG and STDBY pins are set to high level. Fig. 9 The LED anode A pin in the charging module is at a high level, where the A pin is connected to the base of the PNP transistor Q7 of the charging module control module. The transistor Q7 is disconnected, and then the G2 pin of 8205A is at a low level, and 8205A is disconnected, thereby controlling the disconnection of the charging circuit and stopping charging;

[0056] In the normal charging state, only CHRG is at a low level or only STDBY is at a low level, the voltage of the LED anode A pin is low, the charging mode control module PNP transistor Q7 is turned on, and then the G2 pin of 8205A is at a high level, 8205A is turned on, and the charging circuit is turned on.

[0057] Based on the above settings, when the voltage of the battery connected across the first charging protection module exceeds 4.25V, OC1 outputs a low level, and the signal is transmitted to the G1 pin of the charging control module, thereby turning off the field effect tube 8205A and stopping the battery charging; similarly, when the battery connected across the second charging protection module is overcharged, OC2 is at a low level, and the gate Q8 connected to the NMOS tube Q8 is disconnected, causing the G1 pin of 8205A to be low, and 8205A is disconnected to stop charging.

[0058] When the battery outputs an overcurrent when connected in series or the battery voltage across the first charging protection module is too low, OD1 outputs a low level, so that the NMOS tube Q3 on the output module electrically connected to OD1 is disconnected, the gate of the PMOS tube Q4 is set to a high level, the PMOS tube Q4 is disconnected, the gate of the NMOS tube Q5 is set to a low level, the NMOS tube Q5 is disconnected, and the series output stops;

[0059] When the voltage of the battery connected across the second charging protection module is too low, OD2 outputs a low level, the PMOS tube Q1 on the output module is turned on, the gate of the PMOS tube Q4 is set to a high level, the PMOS tube Q4 is disconnected, the gate of the NMOS tube Q5 is set to a low level, the NMOS tube Q5 is disconnected, and the series output stops.

[0060] In some embodiments, the control unit is a single-pole double-throw switch, including but not limited to: a button switch, a knob switch, a push button switch, and a relay; and the common terminal 2 pin is electrically connected to the negative electrode BAT2- of the second rechargeable battery, wherein the normally closed terminal 3 pin is electrically connected to the negative electrode BAT1- of the first rechargeable battery bridged by the first charging protection module, and the other normally open terminal 1 pin is electrically connected to the positive electrode BAT1+ of the first rechargeable battery bridged by the first charging protection module, specifically: Figure 7 As shown, the common terminal 2 pin of the control unit SW1 is electrically connected to BAT2-, wherein the normally closed terminal 3 pin is electrically connected to BAT1-, and the other normally open terminal 1 pin is electrically connected to BAT1+; in some embodiments, the control unit can be a double-pole double-throw switch.

[0061] In some embodiments, the solution of the present invention includes a first charging protection module and multiple second charging protection modules. In this case, the product also includes multiple control units for connecting a first charging protection module and multiple second charging protection modules in sequence to form a series or parallel structure.

[0062] by Figure 2 Take the circuit with three batteries as an example, where: the common terminal 2 pin of the control unit SW1 is electrically connected to BAT2-, one of the normally closed terminals 3 pins is electrically connected to BAT1-, and the other normally open terminal 1 pin is electrically connected to BAT1+; the common terminal 2 pin of the control unit SW2 is electrically connected to BAT3-, one of the normally closed terminals 3 pins is electrically connected to BAT1-, and the other normally open terminal 1 pin is electrically connected to BAT2+. By analogy, the connection relationship between all control units and adjacent first charging protection modules and second charging protection modules can be obtained in the case of charging multiple batteries; in some embodiments, for the case of charging multiple batteries, the control units can be cascaded in multiple stages, so that the connection relationship between the first charging protection module and all second charging protection modules can be changed at the same time.

[0063] For a product including a first charging protection module and multiple second charging protection modules, it is necessary to expand its output module to Figure 2 Taking the circuit with three batteries as an example, one circuit connection method of the output module is as follows Figure 6 shown.

[0064] The technical means disclosed in the scheme of the present invention are not limited to the technical means disclosed in the above-mentioned implementation mode, but also include technical schemes composed of any combination of the above-mentioned technical features. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications are also regarded as the protection scope of the present invention.

Claims

1. A multi-string battery charging and discharging composite circuit, characterized in that: The device comprises a first charging protection module and at least one second charging protection module, wherein the first charging protection module is connected across a first rechargeable battery, and the second charging protection module is connected across a second rechargeable battery; Wherein, it also includes a control unit, the control unit is electrically connected to the first charging protection module and the second charging protection module, or electrically connected to two of the second charging protection modules, and the control unit enables the first rechargeable battery and the second rechargeable battery to switch between a series connection state and a parallel connection state; Among them, it also includes a charging control module electrically connected to the first charging protection module and connected to a 5V input power supply, wherein the charging control module is electrically connected to the negative electrode of the first rechargeable battery and the 5V input power supply to connect the charging circuit; It also includes an output module, which couples the first charging protection module and the second charging protection module, and electrically connects the positive electrode of the second rechargeable battery and the negative electrode of the first rechargeable battery to connect the discharge circuit.

2. The multi-string battery charging and discharging composite circuit according to claim 1, characterized in that: The first charging protection module includes a first charging module and a first protection module; the second charging protection module includes a second charging module and a second protection module.

3. The multi-string battery charging and discharging composite circuit according to claim 2, characterized in that: The chip used in the first charging module and the second charging module is TP4056, and both are connected with diodes to block the reverse current occurring during the charging and discharging process; the model of the diode is SS34.

4. The multi-string battery charging and discharging composite circuit according to claim 1, characterized in that: The charging control module uses a dual NMOS device 8205.

5. The multi-string battery charging and discharging composite circuit according to claim 2, characterized in that: The chip used by the first protection module and the second protection module is DW01.

6. The multi-string battery charging and discharging composite circuit according to claim 2, characterized in that: The TEMP pin of the TP4056 chip of the first charging module is electrically connected to the NTC.

7. The multi-string battery charging and discharging composite circuit according to claim 3, characterized in that: The CHRG and STDBY pins of the TP4056 chip of the first charging module are respectively connected to a first LED and a second LED of different colors.

8. The multi-string battery charging and discharging composite circuit according to claim 1, characterized in that: The control unit is a single-pole double-throw switch or a double-pole double-throw switch, and the types include but are not limited to: a button switch, a knob switch, a push button switch, and a relay.

9. The multi-string battery charging and discharging composite circuit according to claim 8, characterized in that: The control unit can be cascaded in multiple stages, thereby simultaneously changing the connection relationship between the first charging protection module and all the second charging protection modules.

10. The multi-string battery charging and discharging composite circuit according to claim 7, characterized in that: The charging control module is connected to a 5V power supply through a transistor, the first LED and the second LED are connected to a common anode, and the anode is electrically connected to the base of the transistor of the charging control module.

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