WO2023284781A1 - Battery pack management circuit and battery pack - Google Patents

Abstract

Embodiments of the present invention relate to the technical field of electronic power, and in particular, to a battery pack management circuit and a battery pack. The present invention provides a battery pack management circuit and a battery pack, comprising a main switch circuit, a first sampling circuit, a second sampling circuit, a discharge switch, a discharge unit, and a control unit. When the control unit outputs a first control signal to the main switch circuit and the first sampling circuit, the main switch circuit turns on a connection between the battery pack and an output port, and the first sampling circuit collects and outputs a voltage of the output port to a second end of the control unit; the control unit controls the second sampling circuit to operate when the voltage of the output port is not received, the second sampling circuit collects a voltage of the battery pack and outputs the voltage of the battery pack to a fourth end of the control unit, and the control unit outputs a discharge signal to the discharge switch according to the voltage of the battery pack to discharge the battery pack. In this circuit, the battery power and the discharge state are determined without communicating with a fuel gauge, such that the design is simple and the cost is low.

Description

A battery pack management circuit and battery pack

This application claims the priority of the Chinese patent application with the application number 2021107972358 and the application title "a battery pack management circuit and battery pack" submitted to the China Patent Office on July 14, 2021, the entire contents of which are incorporated herein by reference. Applying.

technical field

Embodiments of the present invention relate to the field of electronic power technology, and in particular to a battery pack management circuit and a battery pack.

Background technique

At present, with the application of high-rate lithium batteries more and more widely, the storage problem of high-rate lithium batteries has gradually become a focus of attention. Especially for high-rate lithium batteries, when they are stored with high power and long-term storage, if there is no scientific storage process, there will be battery swelling, which will accelerate the aging of the battery. Especially when multiple batteries are used in series, the aging batteries will further lead to the imbalance of battery power.

At present, conventional high-power storage solutions for lithium batteries generally use the method of communicating with the fuel gauge to determine the discharge state and power state of the battery, and then use the set program to discharge and store according to the power state. This method is not only complicated in design And the cost is high.

Contents of the invention

The purpose of the embodiments of the present invention is to provide a battery pack management circuit and a battery pack, which do not need to communicate with a fuel gauge to determine the battery power, and are simple in design and low in cost.

In the first aspect, a technical solution adopted in the embodiments of the present invention is to provide a battery pack management circuit, including: a main switch circuit, a first sampling circuit, a second sampling circuit, a discharge switch, a discharge unit, and a control unit;

The first end of the main switch circuit is connected to the first end of the battery pack, the second end of the main switch circuit is connected to the first end of the output port, and the third end of the main switch circuit is connected to the first end of the control unit. At one end, the control unit is used to output a first control signal to the main switch circuit, and the main switch circuit is used to connect the first end of the battery pack to the output port according to the first control signal the connection between the first ends of ;

The first end of the first sampling circuit is connected to the first end of the output port, the second end of the first sampling circuit is connected to the second end of the control unit, and the third end of the first sampling circuit connected to the first end of the control unit, the control unit is also used to output the first control signal to the first sampling circuit, and the first sampling circuit is used to collect the output the voltage of the output port, and output the voltage of the output port to the second terminal of the control unit;

The first terminal of the second sampling circuit is connected to the first terminal of the battery pack, the second terminal of the second sampling circuit is connected to the third terminal of the control unit, and the third terminal of the second sampling circuit Connect the fourth terminal of the control unit, the control unit is also used to control the second sampling circuit not to work when receiving the voltage of the output port, and for not receiving the voltage of the output port control the operation of the second sampling circuit so that the second sampling circuit collects the voltage of the battery pack and outputs the voltage of the battery pack to the fourth terminal of the control unit;

The first end of the discharge unit is connected to the first end of the battery pack, the second end of the discharge unit is connected to the first end of the discharge switch, and the second end of the discharge switch is connected to the output port. The second terminal, the third terminal of the discharge switch is connected to the fifth terminal of the control unit, and the control unit is also used to output a discharge signal to the discharge switch according to the voltage of the battery pack, and the discharge switch is used for and conducting the connection between the second end of the discharge unit and the second end of the output port according to the discharge signal, so as to discharge the battery pack.

In some embodiments, the control unit is configured to output a discharge signal to the discharge switch when the voltage of the battery pack is higher than a preset stored voltage value, and, when the voltage of the battery pack is lower than or equal to When the stored voltage value is preset, the second sampling circuit is controlled not to work.

In some embodiments, the first sampling circuit includes a first switch circuit and a first voltage divider circuit;

The first end of the first switch circuit is connected to the first end of the output port, the second end of the first switch circuit is connected to the first end of the first voltage divider circuit, and the first end of the first switch circuit The third end is connected to the first end of the control unit, the second end of the first voltage divider circuit is connected to the second end of the control unit, and the control unit is used to output the first control signal to the A first switch circuit, the first switch circuit is used to conduct the connection between the first end of the output port and the first end of the first voltage divider circuit according to the first control signal, so that the The first voltage dividing circuit collects the voltage of the output port and outputs the voltage of the output port to the control unit.

In some embodiments, the first switch circuit includes a first switch tube;

The first end of the first switch tube is connected to the first end of the output port, the second end of the first switch tube is connected to the first end of the first voltage divider circuit, and the first end of the first switch tube The third terminal is connected to the first terminal of the control unit.

In some embodiments, the first switching transistor is a first NMOS transistor;

The drain of the first NMOS transistor is connected to the first end of the output port, the source of the first NMOS transistor is connected to the first end of the first voltage divider circuit, and the gate of the first NMOS transistor Connect the first end of the control unit.

In some embodiments, the first voltage dividing circuit includes a first voltage dividing resistor and a second voltage dividing resistor;

The first terminal of the first voltage dividing resistor is connected to the second terminal of the first switch circuit, and the second terminal of the first voltage dividing resistor is connected to the second terminal of the control unit and the second terminal of the second dividing resistor respectively. The first terminal of the piezoresistor is grounded, and the second terminal of the second voltage dividing resistor is grounded.

In some embodiments, the second sampling circuit includes a second switch circuit and a second voltage divider circuit;

The first terminal of the second switch circuit is connected to the first terminal of the battery pack, the second terminal of the second switch circuit is connected to the first terminal of the second voltage divider circuit, and the second terminal of the second switch circuit The third terminal is connected to the third terminal of the control unit, the second terminal of the second voltage divider circuit is connected to the fourth terminal of the control unit, and the control unit is used to receive the voltage of the output port, Or, when the voltage of the battery pack is lower than or equal to the preset stored voltage value, a second control signal is output to the second switch circuit, so that the second switch circuit disconnects the first end of the battery pack and the connection between the first end of the second voltage divider circuit, the second voltage divider circuit does not work, and when the voltage of the output port is not received, the third control signal is output to the A second switch circuit, so that the second switch circuit conducts the connection between the first terminal of the battery pack and the first terminal of the second voltage dividing circuit, and the second voltage dividing circuit collects the the voltage of the battery pack, and output the voltage of the battery pack to the control unit.

In some embodiments, the second switch circuit includes a second switch tube and a third switch tube;

The first end of the second switch tube is connected to the first end of the battery pack, the second end of the second switch tube is connected to the first end of the second voltage divider circuit, and the second switch tube is connected to the first end of the second voltage divider circuit. The third end is connected to the first end of the third switch transistor, and the second end of the third switch transistor is connected to the third end of the control unit.

In some embodiments, the second switch transistor is a PMOS transistor, and the third switch transistor is a second NMOS transistor;

The source of the PMOS transistor is connected to the first end of the battery pack, the drain of the PMOS transistor is connected to the first end of the second voltage divider circuit, and the gate of the PMOS transistor is connected to the second NMOS The drain of the transistor, the gate of the second NMOS transistor is connected to the third terminal of the control unit, and the source of the second NMOS transistor is grounded.

In some embodiments, the second voltage dividing circuit includes a third voltage dividing resistor and a fourth voltage dividing resistor;

The first end of the third voltage dividing resistor is connected to the second end of the second switch circuit, and the second end of the third voltage dividing resistor is respectively connected to the fourth end of the control unit and the fourth dividing The first end of the piezoresistor, the second end of the fourth voltage dividing resistor is grounded.

In some embodiments, the battery pack management circuit further includes a first capacitor and a second capacitor, the first end of the first capacitor is connected to the first end of the second voltage dividing resistor, and the second end of the first capacitor The terminal is grounded, the first terminal of the second capacitor is connected to the first terminal of the fourth voltage dividing resistor, and the second terminal of the second capacitor is grounded.

In some embodiments, the discharge switch is a third NMOS transistor;

The drain of the third NMOS transistor is connected to the second end of the discharge unit, the source of the third NMOS transistor is connected to the second end of the output port, and the gate of the third NMOS transistor is connected to the The fifth terminal of the control unit.

In some embodiments, the discharge unit is a current limiting resistor;

The current limiting resistor is connected in series between the first end of the battery pack and the drain of the third NMOS transistor.

In some embodiments, it is characterized in that the battery pack management circuit further includes a first bias resistor, a second bias resistor and a third bias resistor;

The first end of the first bias resistor is connected to the gate of the second NMOS transistor, the second end of the first bias resistor is grounded, and the second bias resistor is connected in series with the source of the PMOS transistor and the PMOS transistor. The third bias resistor is connected in series between the source of the third NMOS transistor and the drain of the third NMOS transistor.

In some embodiments, the main switch circuit includes a fourth NMOS transistor and a fifth NMOS transistor;

The source of the fourth NMOS transistor is connected to the first end of the battery pack, the drain of the fourth NMOS transistor is connected to the drain of the fifth NMOS transistor, the source of the fifth NMOS transistor is connected to the second end of the output port, and the fourth NMOS transistor Both the gate of the NMOS transistor and the gate of the fifth NMOS transistor are connected to the control unit.

In a second aspect, an embodiment of the present invention provides a battery pack, including the battery pack management circuit according to any one of the first aspect.

Compared with the prior art, the beneficial effect of the present invention is: different from the situation of the prior art, the embodiment of the present invention provides a battery pack management circuit and a battery pack, including a main switch circuit, a first sampling circuit, a second sampling circuit circuit, discharge switch, discharge unit and control unit. When the control unit outputs the first control signal to the main switch circuit and the first sampling circuit, the main switch circuit conducts the connection between the battery pack and the output port, and the first sampling circuit collects and outputs the voltage of the output port to the first sampling circuit of the control unit. Two terminals: when the control unit does not receive the voltage of the output port, it controls the second sampling circuit to work, the second sampling circuit collects the voltage of the battery pack, and outputs the voltage of the battery pack to the fourth terminal of the control unit, and the control unit according to the battery The voltage of the battery pack outputs a discharge signal to the discharge switch to discharge the battery pack. In this circuit, there is no need to communicate with the fuel gauge to determine the battery power and discharge status, and the design is simple and low cost.

Description of drawings

One or more embodiments are exemplified by the pictures in the corresponding drawings, and these exemplifications do not constitute a limitation to the embodiments. Components/modules and steps with the same reference numerals in the drawings represent For similar elements/modules and steps, unless otherwise stated, the drawings in the drawings are not limited to scale.

FIG. 1 is a schematic structural block diagram of a battery pack management circuit provided by an embodiment of the present invention;

2 is a schematic structural block diagram of another battery pack management circuit provided by an embodiment of the present invention;

FIG. 3 is a schematic diagram of a circuit structure of a battery pack management circuit provided by an embodiment of the present invention;

Fig. 4 is a schematic circuit structure diagram of another battery pack management circuit provided by an embodiment of the present invention.

detailed description

The present invention will be described in detail below in conjunction with specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

In order to facilitate the understanding of the present application, the present application will be described in more detail below in conjunction with the accompanying drawings and specific embodiments. Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the technical field of this application. The terms used in the description of the present application are only for the purpose of describing specific embodiments, and are not used to limit the present application. The term "and/or" used in this specification includes any and all combinations of one or more of the associated listed items.

It should be noted that, if there is no conflict, various features in the embodiments of the present invention may be combined with each other, and all of them are within the protection scope of the present application. In addition, although the functional module division is performed in the schematic diagram of the device, in some cases, the division may be different from that in the device. In addition, words such as "first" and "second" used in this article do not limit the data and execution order, but only distinguish the same or similar items with basically the same function and effect.

In the first aspect, the embodiment of the present invention provides a battery pack management circuit, please refer to FIG. 1, the battery pack management includes: a main switch circuit 10, a first sampling circuit 20, a second sampling circuit 30, a discharge switch 40, and a control unit 50 and discharge unit 60. The first end of the main switch circuit 10 is connected to the first end B+ of the battery pack 200, the second end of the main switch circuit 10 is connected to the first end PACK+ of the output port 300, and the third end of the main switch circuit 10 is connected to the first end of the control unit 50. At one end, the control unit 50 is used to output the first control signal to the main switch circuit 10, and the main switch circuit 10 is used to conduct the connection between the first terminal B+ of the battery pack 200 and the first terminal PACK+ of the output port 300 according to the first control signal. connection between. The first end of the first sampling circuit 20 is connected to the first end PACK+ of the output port 300, the second end of the first sampling circuit 20 is connected to the second end of the control unit 50, and the third end of the first sampling circuit 20 is connected to the control unit 50 The control unit 50 is also used to output the first control signal to the first sampling circuit 20, the first sampling circuit 20 is used to collect the voltage of the output port 300 according to the first control signal, and output the voltage of the output port 300 to The second terminal of the control unit 50 . The first terminal of the second sampling circuit 30 is connected to the first terminal B+ of the battery pack 200, the second terminal of the second sampling circuit 30 is connected to the third terminal of the control unit 50, and the third terminal of the second sampling circuit 30 is connected to the control unit 50 The fourth end of the control unit 50 is also used to control the second sampling circuit 30 not to work when receiving the voltage of the output port 300, and to control the second sampling circuit 30 to work when the voltage of the output port 300 is not received. so that the second sampling circuit 30 collects the voltage of the battery pack 200 and outputs the voltage of the battery pack 200 to the fourth terminal of the control unit 50 . The first terminal of the discharge unit 60 is connected to the first terminal B+ of the battery pack 200, the second terminal of the discharge unit 60 is connected to the first terminal of the discharge switch 40, and the second terminal of the discharge switch 40 is connected to the second terminal PACK- of the output port 300. , the third terminal of the discharge switch 40 is connected to the fifth terminal of the control unit 50, the control unit 50 is also used to output a discharge signal to the discharge switch 40 according to the voltage of the battery pack 200, and the discharge switch 40 is used to conduct the discharge unit 60 according to the discharge signal The second terminal of the output port 300 is connected to the second terminal PACK- to discharge the battery pack 200 .

Specifically, the battery pack 200 may be a parallel battery pack, a series battery pack or a series-parallel combination battery pack, which includes at least one high-rate battery cell, and the high-rate battery cell is a battery cell with a discharge rate exceeding 1C. Generally, the first terminal B+ of the battery pack 200 is the positive pole of the battery pack, the second terminal B- of the battery pack 200 is the negative pole of the battery pack, the first terminal PACK+ of the output port 300 is the positive pole of the output port, and the second terminal B- of the output port 300 is the positive pole of the output port. The two terminals PACK- is the negative pole of the output port, the second terminal B- of the battery pack 200 is usually connected to the second terminal PACK- of the output port 300, the second terminal PACK- of the output port 300 is usually a ground terminal, and the output port 300 Usually used to connect loads. In practical applications, other components can be connected in series during the connection process between the second end of the battery pack and the second end of the output port. For example, the sampling resistor is connected in series between the second end of the battery pack and the second end of the output port. The sampling resistor is also connected to the control unit, the sampling resistor is used to collect the main loop current and output the main loop current to the control unit, and the control unit is used to control the charging and discharging state of the battery pack according to the main loop current, The specific connection process and control process can refer to the prior art, and are not limited here.

In the battery pack management circuit 100, when the battery pack is turned on, first, the first terminal of the control unit 50 outputs a first control signal to the main switch circuit 10 and the first sampling circuit 20, so that the main switch circuit 10 is turned on. The connection between the battery pack 200 and the output port 300 enables the first sampling circuit 20 to collect and output the voltage of the output port 300 to the second terminal of the control unit 50, and then the control unit 50 receives the voltage of the output port to control the second terminal. The sampling circuit 30 does not work, so that the second sampling circuit 30 is in a standby state. When the battery pack is in the shutdown state, the control unit 50 outputs a fourth control signal to the main switch circuit 10 and the first sampling circuit 20, so that the main switch circuit 10 disconnects the battery pack 200 from the output port 300, and at the same time makes the first sampling circuit The circuit 20 is not working. At this time, the control unit 50 cannot receive the voltage of the output port 300, so it controls the second sampling circuit 30 to work; then, the second sampling circuit 30 collects the voltage of the battery pack 200, and outputs the voltage of the battery pack 200 To the fourth end of the control unit 50, the control unit 50 outputs a discharge signal to the discharge switch 40 according to the voltage of the battery pack 200, so that the discharge switch 40 conducts between the second end of the discharge unit 10 and the second end of the output port 300 In this way, the first terminal B+ of the battery pack 200, the discharge unit 60, the second terminal PACK- of the output port 300, and the second terminal B- of the battery pack 200 constitute a discharge circuit, thereby discharging the battery pack 200. In the battery pack management circuit 100 , the power state of the battery can be determined without communicating with the fuel gauge, and discharge can be performed according to the power state. The structure design is simple and the production cost is relatively low.

Further, in some of these embodiments, the control unit is further configured to output a discharge signal to the discharge switch when the voltage of the battery pack is higher than a preset stored voltage value, and for the voltage of the battery pack to be lower than or equal to a preset When storing the voltage value, the second sampling circuit is controlled not to work. By setting a preset value of the storage voltage, when the power of the battery pack is discharged to the preset value, or when the power of the battery pack is lower than or equal to the preset value, the control unit can control the second sampling circuit not to work, thus, Enables the system to be in a low power consumption state.

In some embodiments, please refer to FIG. 2 , the first sampling circuit 20 includes a first switch circuit 21 and a first voltage divider circuit 22. Wherein, the first end of the first switch circuit 21 is connected to the first end PACK+ of the output port 300, the second end of the first switch circuit 21 is connected to the first end of the first voltage dividing circuit 22, and the third end of the first switch circuit 21 Terminal connected to the first terminal of the control unit 50, the second terminal of the first voltage divider circuit 22 is connected to the second terminal of the control unit 50, the control unit 50 is used to output the first control signal to the first switch circuit 21, the first switch circuit 21 is used to conduct the connection between the first end PACK+ of the output port 300 and the first end of the first voltage divider circuit 22 according to the first control signal, so that the first voltage divider circuit 22 collects the 300 voltage of the output port, and The voltage of the output port 300 is output to the control unit 50 .

In the battery pack management circuit, when the battery pack is in the power-on state, the control unit 50 will output the first control signal to the first switch circuit 21, and the first switch circuit 21 will conduct the first terminal PACK+ of the output port 300 and the first The connection between the first ends of the voltage divider circuit 22, then, the first voltage divider circuit 22 will collect the voltage of the output port, and output the voltage of the output port to the control unit 50, and the control unit 50 receives the voltage of the output port, Then the second sampling circuit 30 is controlled not to work. When the battery pack is in the shutdown state, the control unit 50 will output the fourth control signal to the first switch circuit 21, and the first switch circuit 21 will disconnect the first terminal PACK+ of the output port 300 and the first voltage divider circuit according to the fourth control signal 22, at this time, the first voltage divider circuit 22 is not working, then the first voltage divider circuit 22 will not collect the voltage of the output port, and the control unit 50 will control the second sampling circuit 30 to work.

In some embodiments, please continue to refer to FIG. 2 , the second sampling circuit 30 includes a second switch circuit 31 and a second voltage divider circuit 32 . Wherein, the first terminal of the second switch circuit 31 is connected to the first terminal B+ of the battery pack 200, the second terminal of the second switch circuit 31 is connected to the first terminal of the second voltage dividing circuit 32, and the third terminal of the second switch circuit 31 terminal is connected to the third terminal of the control unit 50, the second terminal of the second voltage divider circuit 32 is connected to the fourth terminal of the control unit 50, and the control unit 50 is used to receive the voltage of the output port 300, or the voltage of the battery pack 200 When it is lower than or equal to the preset storage voltage value, output the second control signal to the second switch circuit 31, so that the second switch circuit 31 disconnects the first terminal B+ of the battery pack 200 and the first terminal B+ of the second voltage dividing circuit 32. The connection between the terminals, so that the second voltage divider circuit 32 does not work, and when the voltage of the output port 300 is not received, the third control signal is output to the second switch circuit 31, so that the second switch circuit 31 The connection between the first terminal B+ of the battery pack 200 and the first terminal of the second voltage dividing circuit 32 is turned on, and the second voltage dividing circuit 32 collects the voltage of the battery pack and outputs the voltage of the battery pack to the control unit 50 .

In the battery pack management circuit, when the battery pack is turned on, the control unit 50 outputs a first control signal to the main switch circuit 10 and the first sampling circuit 20, and the first sampling circuit 20 collects the voltage of the output port 300 and outputs to the second terminal of the control unit 50, and then, the control unit 50 receives the voltage of the output port 300, and then outputs a second control signal to the second switch circuit 31, and the second switch circuit 31 disconnects the first terminal B+ of the battery pack 200 and the connection between the first end of the second voltage dividing circuit 32 , so that the second voltage dividing circuit 32 does not collect the voltage of the battery pack 200 . When the battery pack is in the shutdown state, the control unit 50 outputs the fourth control signal to the main switch circuit 10 and the first sampling circuit 20, and the first sampling circuit 20 does not work. At this time, the control unit 50 cannot receive the voltage of the output port 300 , then output the third control signal to the second switch circuit 31, and then the second switch circuit 31 conducts the connection between the first terminal B+ of the battery pack 200 and the first terminal of the second voltage dividing circuit 32, and the second dividing The voltage circuit 32 collects the voltage of the battery pack, and outputs the voltage of the battery pack 300 to the control unit 50 through the second terminal of the second voltage divider circuit 32 . Next, if the voltage of the battery pack 300 is higher than the preset stored voltage value, the control unit 50 outputs a discharge signal to the discharge switch 40, and the discharge switch 40 conducts between the second end of the discharge unit and the second end of the output port according to the discharge signal. connection between the battery packs, so that the battery pack is discharged, and the voltage of the battery pack is reduced to a preset storage voltage value; if the voltage of the battery pack is lower than or equal to the preset storage voltage value, the control unit 50 outputs a second control signal to the second switch The circuit 31 disconnects the connection between the first terminal B+ of the battery pack 200 and the first terminal of the second voltage dividing circuit 32, so that the second voltage dividing circuit 32 does not work, so that the second sampling circuit 30 is in a standby state, Can reduce the power consumption of the system.

In some of these embodiments, please refer to FIG. 3 , the first switch circuit 21 includes a first switch tube Q1, wherein the first end of the first switch tube Q1 is connected to the first end PACK+ of the output port, and the first switch tube Q1 The second terminal is connected to the first terminal of the first voltage divider circuit 22 , and the third terminal of the first switching transistor Q1 is connected to the first terminal A1 of the control unit 50 . Specifically, please continue to refer to FIG. 3 , the first switching transistor Q1 is a first NMOS transistor, wherein the drain of the first NMOS transistor Q1 is connected to the first terminal PACK+ of the output port, and the source of the first NMOS transistor Q1 is connected to the first The first end of the voltage divider circuit 22 and the gate of the first NMOS transistor Q1 are connected to the first end A1 of the control unit 50 . In practical applications, the first switching transistor may also be a PMOS transistor, a triode or any other suitable switching device, which is not limited to the limitation in this embodiment.

In some of these embodiments, please refer to FIG. 3 again, the first voltage dividing circuit 22 includes a first voltage dividing resistor Rp1 and a second voltage dividing resistor Rp2, wherein the first end of the first voltage dividing resistor Rp1 is connected to the first switch The second end of the circuit 21 and the second end of the first voltage dividing resistor Rp1 are respectively connected to the second end of the control unit 50 and the first end of the second voltage dividing resistor Rp2, and the second end of the second voltage dividing resistor Rp2 is grounded. Specifically, the first end of the first voltage dividing resistor Rp1 is connected to the source of the first NMOS transistor Q1. When the first NMOS transistor Q1 is turned on and turned on, the first voltage dividing circuit 22 can collect the voltage of the output port, and The voltage of the output port is output to the control unit 50 through the second terminal of the first voltage dividing resistor Rp1. In practical applications, the number and resistance value of the voltage dividing resistors of the first voltage dividing circuit 22 can be freely set, and in addition, a series connection between the second end of the first voltage dividing resistor Rp1 and the second end of the control unit 50 can also be made. The digital-to-analog converter is not limited to the limitation in this embodiment. It should be noted that in FIG. 3 and FIG. 4 , DGND represents the digital ground of the battery management circuit, that is, the ground of the control unit, which is different from the ground of the second terminal PACK- of the output port.

In order to filter the collected output port voltage, in some embodiments, the battery pack management circuit further includes a first filter circuit, and the first filter circuit is connected in series with the second terminal of the first voltage divider circuit and the first terminal of the control unit. between the two ends. Specifically, referring to FIG. 3 again, the first filter circuit is a first capacitor C1, wherein the first end of the first capacitor C1 is respectively connected to the second end of the first voltage dividing resistor Rp1 and the second end of the control unit 50, The second end of the first capacitor C1 is grounded. By setting the first capacitor C1, the output port voltage output by the first voltage divider circuit 22 can be filtered to prevent clutter from affecting the system operation and ensure system reliability. In practical applications, the first capacitor can be replaced by an inductor or any other suitable filter circuit, which is not limited to the limitation in this embodiment.

In some of these embodiments, please refer to FIG. 3 , the second switch circuit 31 includes a second switch tube Q2 and a third switch tube Q3; the first terminal of the second switch tube Q2 is connected to the first terminal B+ of the battery pack, and the second The second end of the switch tube Q2 is connected to the first end of the second voltage divider circuit 32, the third end of the second switch tube Q2 is connected to the first end of the third switch tube Q3, and the second end of the third switch tube Q3 is connected to the control The third end of unit 50.

Specifically, in some of these embodiments, the second switching transistor Q2 is a PMOS transistor, and the third switching transistor Q3 is a second NMOS transistor; the source of the PMOS transistor Q2 is connected to the first terminal B+ of the battery pack, and the drain of the PMOS transistor Q2 The pole is connected to the first end of the second voltage dividing circuit 32, the gate of the PMOS transistor Q2 is connected to the drain of the second NMOS transistor Q3, the gate of the second NMOS transistor Q3 is connected to the third end of the control unit 50, and the gate of the second NMOS transistor Q3 is connected to the third end of the control unit 50. The source of Q3 is grounded.

In the battery pack management circuit, when the battery pack is in the power-on state, the first sampling circuit 20 outputs the voltage of the output port to the control unit 50, and the control unit 50 outputs a low-level second control signal to the second NMOS transistor Q3. Gate, the second NMOS transistor Q3 is not turned on, at this time, the PMOS transistor Q2 is not turned on, the second voltage divider circuit 32 does not collect the voltage of the battery pack, that is, the second sampling circuit 30 is in a standby state. When the battery pack is in the shutdown state, the first sampling circuit 20 does not collect the voltage of the output port, and the control unit 50 cannot receive the voltage of the output port. At this time, the control unit 50 outputs a high-level third control signal to the second The gate of the second NMOS transistor Q3, the second NMOS transistor Q3 is turned on, and the gate of the PMOS transistor Q2 is grounded, so that the PMOS transistor Q2 is turned on. Then, the first terminal B+ of the battery pack and the second voltage dividing circuit 32 Conductive connection between the first ends, the second voltage divider circuit 32 collects the voltage of the battery pack, and outputs the voltage of the battery pack to the control unit 50, and the control unit 50 performs subsequent control according to the voltage of the battery pack . If the voltage of the battery pack is greater than the preset stored voltage value, the control unit 50 controls the battery pack to discharge, and if the voltage of the battery pack is less than or equal to the preset stored voltage value, the control unit 50 outputs a low-level second control signal The signal is sent to the gate of the second NMOS transistor Q3, so that the second NMOS transistor Q3 is turned off, so that the PMOS transistor Q2 is turned off, and then the second voltage divider circuit 32 does not work, and the system enters a low power consumption state. In practical applications, the second switch tube and the third switch tube may be other types of MOS tubes, triodes, or any other suitable switching devices, which are not limited to the limitations in this embodiment.

In some of these embodiments, the second voltage dividing circuit 32 includes a third voltage dividing resistor Rp3 and a fourth voltage dividing resistor Rp4; wherein, the first end of the third voltage dividing resistor Rp3 is connected to the second end of the second switch circuit 31 , the second end of the third voltage dividing resistor Rp3 is respectively connected to the fourth end of the control unit 50 and the first end of the fourth voltage dividing resistor Rp4, and the second end of the fourth voltage dividing resistor Rp4 is grounded. Specifically, the first end of the third voltage dividing resistor Rp3 is connected to the drain of the PMOS transistor Q2. When the PMOS transistor Q2 is turned on and turned on, the second voltage dividing circuit 32 can collect the voltage of the battery pack, and through the third dividing The second end of the piezoresistor Rp3 outputs the voltage of the battery pack to the control unit 50 . In practical applications, the number and resistance value of the voltage dividing resistors of the second voltage dividing circuit 32 can be freely set. In addition, a series connection between the second terminal of the third voltage dividing resistor Rp3 and the fourth terminal of the control unit 50 can also be performed. The digital-to-analog converter is not limited to the limitation in this embodiment.

In order to filter the collected output port voltage, in some embodiments, the battery pack management circuit further includes a second filter circuit, and the second filter circuit is connected in series with the second terminal of the second voltage divider circuit and the first terminal of the control unit. between the four ends. Specifically, please continue to refer to FIG. 3, the second filter circuit is a second capacitor C2, wherein the first end of the second capacitor C2 is connected to the fourth end of the control unit 50, and the second end of the second capacitor C2 is grounded, by setting The second capacitor C2 can filter the battery pack voltage output by the second voltage divider circuit 32 to prevent clutter from affecting the system operation and ensure system reliability. In practical applications, the second capacitor can be replaced by an inductor or any other suitable filter circuit, which is not limited to the limitation in this embodiment.

In some of these embodiments, please refer to FIG. 3 , the discharge switch 40 is a third NMOS transistor Q6; the drain of the third NMOS transistor Q6 is connected to the second end of the discharge unit 60, and the source of the third NMOS transistor Q6 is connected to the output port. The second terminal PACK- of the third NMOS transistor Q6 is connected to the fifth terminal of the control unit 50 . When the voltage of the battery pack is higher than the preset stored voltage value, the control unit 50 outputs a high-level discharge signal to the gate of the third NMOS transistor Q6, so that the third NMOS transistor Q6 is turned on, thereby turning on the first discharge unit of the discharge unit. The connection between the two terminals and the second terminal of the output port makes the battery pack in a discharge state; when the voltage of the battery pack is lower than or equal to the preset storage voltage value, or the voltage of the battery pack is discharged to the preset storage voltage value, The control unit 50 outputs a low-level signal to the gate of the third NMOS transistor Q6, so that the third NMOS transistor Q6 is disconnected, thereby disconnecting the connection between the second end of the discharge unit and the second end of the output port, and disconnecting Battery pack discharge circuit. In practical applications, the discharge switch can be a PMOS transistor, a triode or any other suitable switching devices, and the number of switches of the discharge switch can be set according to actual needs, which is not limited here.

Further, in some of these embodiments, please refer to FIG. 3 again, the discharge unit 60 is a current limiting resistor Rf, and the current limiting resistor Rf is connected in series between the first terminal B+ of the battery pack and the drain of the third NMOS transistor Q6 , by setting the current-limiting resistor Rf to act as a discharge unit, the power of the battery pack can be consumed and the discharge current can be limited. In practical applications, the number and resistance value of the current limiting resistor Rf can be set according to actual needs, and the discharge unit can adopt any other circuit structure that can consume battery power, which is not limited here.

In order to improve the reliability of the system, in some embodiments, please continue to refer to FIG. 3 , the battery pack management circuit further includes a first bias resistor R1, a second bias resistor R2 and a third bias resistor R3; wherein, the first The first end of a bias resistor R1 is connected to the gate of the second NMOS transistor Q3, the second end of the first bias resistor R1 is grounded, and the second bias resistor R2 is connected in series with the source of the PMOS transistor Q2 and the PMOS transistor Q2 The third bias resistor R3 is connected in series between the source of the third NMOS transistor Q6 and the drain of the third NMOS transistor Q6. By setting the bias resistor, it can prevent the MOS transistor from being affected by the noise signal and cause malfunction, thereby improving the reliability of the system.

In some of these embodiments, please refer to FIG. 3 , the main switch circuit 10 includes a fourth NMOS transistor Q4 and a fifth NMOS transistor Q5; wherein, the source of the fourth NMOS transistor Q4 is connected to the first terminal B+ of the battery pack, and the fourth NMOS transistor Q4 The drain of the NMOS transistor Q4 is connected to the drain of the fifth NMOS transistor Q5, the source of the fifth NMOS transistor Q5 is connected to the second terminal PACK+ of the output port, and the gate of the fourth NMOS transistor Q4 is connected to the first terminal A1 of the control unit 50. , the gate of the fifth NMOS transistor Q5 is connected to the sixth terminal A2 of the control unit 50 . In this way, the normal charging and discharging of the battery pack can be realized through two MOS tubes connected in reverse series, and since the fourth NMOS transistor Q4 and the fifth NMOS transistor Q5 each have a body diode, current backflow can be prevented, and the battery pack can be charged and discharged. can be more secure. In practical applications, the switch tube type and quantity of the main switch circuit 10 can be set according to actual needs, and the first terminal A1 of the control unit 50 and the sixth terminal A6 of the control unit 50 can be the same port of the control unit 50, or for the control The different ports of the unit 50 are not limited to the limitations in this embodiment.

In some of these embodiments, referring to FIG. 4, the control unit may include a first controller U1 and a second controller U2. Then, the first terminal of the aforementioned control unit and the sixth terminal of the control unit are the first control unit respectively. The two ports of the controller U1, the second terminal to the fifth terminal of the control unit can be the four ports of the second controller U2, and the connection methods refer to the above description, and will not be repeated here. The first controller U1 and the second controller U2 can use STM8, STM16, STM32 series microcontroller processors, and of course all other microcontroller processors that can be used to receive and output data can also be used. Specifically, the second controller U2 can use an STM8L050J3 chip, and the power supply VCC of the second controller U2 is set according to the user manual. Generally, VCC is 3.3V. In the battery pack management circuit, by setting two controllers, the power consumption of the system can be further reduced. For example, when the battery pack is in a shutdown state, the first controller can be set to enter the standby state, and only the second controller work, thereby saving energy.

The specific working process of the battery pack management circuit provided by the present invention will be described in detail below with the circuit diagram shown in FIG. 4 .

When the battery pack is in the power-on state, first, the first controller U1 outputs a high-level first control signal to the gate of the fourth NMOS transistor Q4 and the gate of the fifth NMOS transistor Q5 of the main switch circuit 10, usually the first The driving voltage of a control signal is higher than the voltage of the first terminal B+ of the battery pack. At this time, both the fourth NMOS transistor Q4 and the fifth NMOS transistor Q5 are closed, and the battery pack and the output port are conducted. Then, the first terminal of the output port The voltage of one terminal PACK+ is equal to the voltage of the first terminal B+ of the battery pack; and because the high-level first control signal is output to the first NMOS transistor Q1 at the same time, the first NMOS transistor Q1 is in a closed state, and the second controller U2 pin 8 of the first voltage dividing resistor Rp1 can detect the output port voltage output by the second end of the first voltage dividing resistor Rp1. At this time, the second controller U2 judges that the current battery pack is in the power-on state; then, the second controller U2 outputs a low level The second control signal of the second control signal is sent to the gate of the second NMOS transistor Q3, and the second NMOS transistor Q3 is disconnected. At this time, the gate of the PMOS transistor Q2 is not grounded, and the PMOS transistor Q2 is disconnected. The second voltage divider circuit 32 cannot collect battery battery pack voltage, the second controller U2 cannot detect the battery pack voltage, and the second controller U2 is in a standby state.

When the battery pack is in the shutdown state, first, the first controller U1 outputs a fourth low-level control signal to the gate of the fourth NMOS transistor Q4, the gate of the fifth NMOS transistor Q5, and the gate of the first NMOS transistor Q1. pole, then the fourth NMOS transistor Q4, the fifth NMOS transistor Q5 and the first NMOS transistor Q1 are all disconnected, and the second voltage divider circuit 22 cannot collect the output port voltage, so pin 8 of the second controller U2 cannot detect the first At this time, the second controller U2 determines that the battery pack is in the shutdown state. Then, after a period set by the user through the program, the second controller U2 outputs a high-level third control signal to the gate of the second NMOS transistor Q3, the second NMOS transistor Q3 is closed, and the gate of the PMOS transistor Q2 is grounded. The PMOS transistor Q2 is closed, the second voltage divider circuit 32 can collect the voltage of the battery pack, the second controller U2 can detect the divided voltage of the second end of the third divider resistor Rp3, and then calculate the corresponding voltage of the battery pack.

If the voltage of the battery pack is lower than or equal to the preset stored voltage value, no discharge process is performed, the second controller U2 outputs a low-level second control signal to the gate of the second NMOS transistor Q3, and the second NMOS transistor Q3 is turned off. At this time, the PMOS transistor Q2 is disconnected, the second controller U2 cannot detect the voltage of the battery pack, and the second controller U2 is in a standby state. If the voltage of the battery pack is greater than the preset storage voltage value, discharge processing will be performed. At this time, the second controller U2 controls the discharge signal of pin 1 from low level to high level, and the third NMOS transistor Q6 is closed, so that the battery pack The first terminal B+ of the battery discharges through the current-limiting resistor Rf. During the discharge process, the second controller U2 always detects the voltage value of the battery pack. Once the voltage value of the battery pack is lower than or equal to the preset storage voltage value, it is considered that the discharge is completed. Finally, the second controller U2 outputs a low-level second control signal to the gate of the second NMOS transistor Q3 to turn off the operation of the second sampling circuit, so that the second controller U2 enters a low power consumption state.

In summary, the battery pack management circuit can determine the battery power state without communicating with the fuel gauge, and can discharge according to the power state, with a simple structural design. Moreover, the circuit is constructed by using conventional electronic devices and a simple microprocessor, which is easy to design, low in production cost and high in cost performance.

In a second aspect, an embodiment of the present invention further provides a battery pack, which includes the battery pack management circuit according to any one of the first aspect. The battery pack can determine the power state of the battery pack without communicating with the fuel gauge, and can discharge according to the power state, has a simple structure design and relatively low production cost.

An embodiment of the present invention provides a battery pack management circuit and a battery pack, including a main switch circuit, a first sampling circuit, a second sampling circuit, a discharge switch, a discharge unit and a control unit. When the control unit outputs the first control signal to the main switch circuit and the first sampling circuit, the main switch circuit conducts the connection between the battery pack and the output port, and the first sampling circuit collects and outputs the voltage of the output port to the first sampling circuit of the control unit. Two terminals: when the control unit does not receive the voltage of the output port, it controls the second sampling circuit to work, the second sampling circuit collects the voltage of the battery pack, and outputs the voltage of the battery pack to the fourth terminal of the control unit, and the control unit according to the battery The voltage of the battery pack outputs a discharge signal to the discharge switch to discharge the battery pack. In this circuit, there is no need to communicate with the fuel gauge to determine the battery power and discharge status, and the design is simple and low cost.

It should be noted that the device embodiments described above are only illustrative, and the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physically separated. A unit can be located in one place, or it can be distributed to multiple network units. Part or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, not to limit them; under the idea of the present invention, the technical features in the above embodiments or different embodiments can also be combined, The steps may be performed in any order, and there are many other variations of the different aspects of the invention as described above, which have not been presented in detail for the sake of brevity; although the invention has been described in detail with reference to the preceding examples, those of ordinary skill in the art The skilled person should understand that it is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the various implementations of the present invention. The scope of technical solutions.

Claims (16)

1. A battery pack management circuit, characterized by comprising: a main switch circuit, a first sampling circuit, a second sampling circuit, a discharge switch, a discharge unit and a control unit;

   The first end of the main switch circuit is connected to the first end of the battery pack, the second end of the main switch circuit is connected to the first end of the output port, and the third end of the main switch circuit is connected to the first end of the control unit. At one end, the control unit is used to output a first control signal to the main switch circuit, and the main switch circuit is used to connect the first end of the battery pack to the output port according to the first control signal the connection between the first ends of the

   The first end of the first sampling circuit is connected to the first end of the output port, the second end of the first sampling circuit is connected to the second end of the control unit, and the third end of the first sampling circuit connected to the first end of the control unit, the control unit is also used to output the first control signal to the first sampling circuit, and the first sampling circuit is used to collect the output the voltage of the output port, and output the voltage of the output port to the second terminal of the control unit;

   The first terminal of the second sampling circuit is connected to the first terminal of the battery pack, the second terminal of the second sampling circuit is connected to the third terminal of the control unit, and the third terminal of the second sampling circuit Connect the fourth terminal of the control unit, the control unit is also used to control the second sampling circuit not to work when receiving the voltage of the output port, and for not receiving the voltage of the output port control the operation of the second sampling circuit so that the second sampling circuit collects the voltage of the battery pack and outputs the voltage of the battery pack to the fourth terminal of the control unit;

   The first end of the discharge unit is connected to the first end of the battery pack, the second end of the discharge unit is connected to the first end of the discharge switch, and the second end of the discharge switch is connected to the output port. The second terminal, the third terminal of the discharge switch is connected to the fifth terminal of the control unit, and the control unit is also used to output a discharge signal to the discharge switch according to the voltage of the battery pack, and the discharge switch is used for and conducting the connection between the second end of the discharge unit and the second end of the output port according to the discharge signal, so as to discharge the battery pack.
2. The battery pack management circuit according to claim 1, wherein the control unit is configured to output a discharge signal to the discharge switch when the voltage of the battery pack is higher than a preset stored voltage value, and, when When the voltage of the battery pack is lower than or equal to the preset stored voltage value, the second sampling circuit is controlled not to work.
3. The battery pack management circuit according to claim 2, wherein the first sampling circuit comprises a first switch circuit and a first voltage divider circuit;

   The first end of the first switch circuit is connected to the first end of the output port, the second end of the first switch circuit is connected to the first end of the first voltage divider circuit, and the first end of the first switch circuit The third end is connected to the first end of the control unit, the second end of the first voltage divider circuit is connected to the second end of the control unit, and the control unit is used to output the first control signal to the A first switch circuit, the first switch circuit is used to conduct the connection between the first end of the output port and the first end of the first voltage divider circuit according to the first control signal, so that the The first voltage dividing circuit collects the voltage of the output port and outputs the voltage of the output port to the control unit.
4. The battery pack management circuit according to claim 3, wherein the first switch circuit comprises a first switch tube;

   The first end of the first switch tube is connected to the first end of the output port, the second end of the first switch tube is connected to the first end of the first voltage divider circuit, and the first end of the first switch tube The third terminal is connected to the first terminal of the control unit.
5. The battery pack management circuit according to claim 4, wherein the first switch tube is a first NMOS tube;

   The drain of the first NMOS transistor is connected to the first end of the output port, the source of the first NMOS transistor is connected to the first end of the first voltage divider circuit, and the gate of the first NMOS transistor Connect the first end of the control unit.
6. The battery pack management circuit according to claim 3, wherein the first voltage dividing circuit comprises a first voltage dividing resistor and a second voltage dividing resistor;

   The first terminal of the first voltage dividing resistor is connected to the second terminal of the first switch circuit, and the second terminal of the first voltage dividing resistor is connected to the second terminal of the control unit and the second terminal of the second dividing resistor respectively. The first terminal of the piezoresistor is grounded, and the second terminal of the second voltage dividing resistor is grounded.
7. The battery pack management circuit according to claim 2, wherein the second sampling circuit comprises a second switch circuit and a second voltage divider circuit;

   The first terminal of the second switch circuit is connected to the first terminal of the battery pack, the second terminal of the second switch circuit is connected to the first terminal of the second voltage divider circuit, and the second terminal of the second switch circuit The third terminal is connected to the third terminal of the control unit, the second terminal of the second voltage divider circuit is connected to the fourth terminal of the control unit, and the control unit is used to receive the voltage of the output port, Or, when the voltage of the battery pack is lower than or equal to the preset stored voltage value, a second control signal is output to the second switch circuit, so that the second switch circuit disconnects the first end of the battery pack and the connection between the first end of the second voltage divider circuit, the second voltage divider circuit does not work, and when the voltage of the output port is not received, the third control signal is output to the A second switch circuit, so that the second switch circuit conducts the connection between the first terminal of the battery pack and the first terminal of the second voltage dividing circuit, and the second voltage dividing circuit collects the the voltage of the battery pack, and output the voltage of the battery pack to the control unit.
8. The battery pack management circuit according to claim 7, wherein the second switch circuit comprises a second switch tube and a third switch tube;

   The first end of the second switch tube is connected to the first end of the battery pack, the second end of the second switch tube is connected to the first end of the second voltage divider circuit, and the second switch tube is connected to the first end of the second voltage divider circuit. The third end is connected to the first end of the third switch transistor, and the second end of the third switch transistor is connected to the third end of the control unit.
9. The battery pack management circuit according to claim 8, wherein the second switch tube is a PMOS tube, and the third switch tube is a second NMOS tube;

   The source of the PMOS transistor is connected to the first end of the battery pack, the drain of the PMOS transistor is connected to the first end of the second voltage divider circuit, and the gate of the PMOS transistor is connected to the second NMOS The drain of the transistor, the gate of the second NMOS transistor is connected to the third terminal of the control unit, and the source of the second NMOS transistor is grounded.
10. The battery pack management circuit according to claim 7, wherein the second voltage dividing circuit comprises a third voltage dividing resistor and a fourth voltage dividing resistor;

    The first end of the third voltage dividing resistor is connected to the second end of the second switch circuit, and the second end of the third voltage dividing resistor is respectively connected to the fourth end of the control unit and the fourth dividing The first end of the piezoresistor, the second end of the fourth voltage dividing resistor is grounded.
11. The battery pack management circuit according to claim 6 or 10, wherein the battery pack management circuit further comprises a first capacitor and a second capacitor, the first end of the first capacitor is connected to the second voltage dividing resistor The first terminal, the second terminal of the first capacitor is grounded, the first terminal of the second capacitor is connected to the first terminal of the fourth voltage dividing resistor, and the second terminal of the second capacitor is grounded.
12. The battery pack management circuit according to claim 2, wherein the discharge switch is a third NMOS transistor;

    The drain of the third NMOS transistor is connected to the second end of the discharge unit, the source of the third NMOS transistor is connected to the second end of the output port, and the gate of the third NMOS transistor is connected to the The fifth terminal of the control unit.
13. The battery pack management circuit according to claim 12, wherein the discharge unit is a current limiting resistor;

    The current limiting resistor is connected in series between the first end of the battery pack and the drain of the third NMOS transistor.
14. The battery pack management circuit according to claim 5, 9, 12 or 13, wherein the battery pack management circuit further comprises a first bias resistor, a second bias resistor and a third bias resistor;

    The first end of the first bias resistor is connected to the gate of the second NMOS transistor, the second end of the first bias resistor is grounded, and the second bias resistor is connected in series with the source of the PMOS transistor and the PMOS transistor. The third bias resistor is connected in series between the source of the third NMOS transistor and the drain of the third NMOS transistor.
15. The battery pack management circuit according to claim 2, wherein the main switch circuit comprises a fourth NMOS transistor and a fifth NMOS transistor;

    The source of the fourth NMOS transistor is connected to the first end of the battery pack, the drain of the fourth NMOS transistor is connected to the drain of the fifth NMOS transistor, the source of the fifth NMOS transistor is connected to the second end of the output port, and the fourth NMOS transistor Both the gate of the NMOS transistor and the gate of the fifth NMOS transistor are connected to the control unit.
16. A battery pack, characterized by comprising the battery pack management circuit according to any one of claims 1-15.

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