CN216390559U

CN216390559U - Battery management circuit and energy storage system

Info

Publication number: CN216390559U
Application number: CN202122605184.2U
Authority: CN
Inventors: 周述宇
Original assignee: Shenzhen H&T Intelligent Control Co Ltd
Current assignee: Shenzhen H&T Intelligent Control Co Ltd
Priority date: 2021-10-27
Filing date: 2021-10-27
Publication date: 2022-04-26
Anticipated expiration: 2031-10-27

Abstract

The application discloses battery management circuit and energy storage system, this battery management circuit includes first switch module, second switch module, energy storage module and control module. The energy storage module is connected with the battery and used for charging when the battery is connected to output a first voltage. The first switch module is respectively connected with the energy storage module and the control module, and the first switch module is configured to be turned on when the first voltage is smaller than a first voltage threshold value and output a second voltage to the control module, so that the control module outputs a first control signal according to the second voltage. The second switch module is connected with the control module, the control module is connected with the battery, and the second switch module is configured to be disconnected according to the first control signal so as to enable the connection between the control module and the battery. Through the mode, when the battery is not used, the power consumption of the battery can be reduced to be nearly zero, so that the service life of the battery is prolonged.

Description

Battery management circuit and energy storage system

Technical Field

The present application relates to the field of battery technologies, and in particular, to a battery management circuit and an energy storage system.

Background

With the invention of lithium batteries, more and more products adopt lithium batteries for power supply, so that equipment for work and life of human beings is more and more convenient to use, but the working environment of the lithium batteries has strict requirements, the situation of overcharge and overdischarge cannot occur, otherwise the batteries are easily damaged and the batteries are easily exploded by fire.

In particular, when the lithium battery is not used, it is usually necessary to design the lithium battery with low power consumption so as to avoid the situation that the lithium battery is damaged due to overdischarge. At present, when a lithium battery is not used, a Micro Controller Unit (MCU) with low power consumption is usually selected to control the lithium battery to enter a sleep mode, so as to reduce the power consumption of the lithium battery.

However, this approach also does not achieve the reduction of the power consumption of the lithium battery to near zero when the lithium battery is not in use. Namely, the lithium battery still has certain power consumption, and the risk that the lithium battery is damaged due to overdischarge still exists.

SUMMERY OF THE UTILITY MODEL

The embodiment of the application aims to provide a battery management circuit and an energy storage system, which can reduce the power consumption of a battery to be nearly zero when the battery is not used so as to prolong the service life of the battery.

To achieve the above object, in a first aspect, the present application provides a battery management circuit, including:

the energy storage device comprises a first switch module, a second switch module, an energy storage module and a control module;

the energy storage module is connected with the battery and is used for charging when the battery is connected to the energy storage module so as to output a first voltage;

the first switch module is connected with the energy storage module and is used for being switched on when the first voltage is smaller than a first voltage threshold value so as to output a second voltage;

the control module is respectively connected with the first switch module, the second switch module and the battery, and is used for starting timing when receiving the second voltage, and if the timing duration is greater than or equal to the first duration, the second switch module is controlled to be disconnected so as to disconnect the connection between the control module and the battery.

In an optional manner, the control module includes a first switch unit, a first control unit, and a second control unit;

the first switch unit is respectively connected with the battery, the first control unit, the first switch module, the second switch module and the energy storage module, and the first switch unit is used for disconnecting when the second switch module is disconnected so as to disconnect the connection between the first control unit and the battery;

the first control unit is connected with the second control unit and is used for providing an input power supply for the second control unit;

the second control unit is connected with the first switch module and the second switch module, and is used for starting timing when receiving the second voltage, and controlling the second switch module to be disconnected if the timing duration is greater than or equal to the first duration.

In an optional mode, the first switching unit comprises a first switching tube and a first resistor;

the first end of the first switch tube is connected with the first switch module, the second switch module and the energy storage module respectively, the second end of the first switch tube is connected with the anode of the battery and the second switch module, and the third end of the first switch tube is connected with the power input end of the first control unit through the first resistor.

In an optional mode, the first switch module includes a second switch tube, a second resistor and a third resistor;

the first end of the second switch tube is connected with the energy storage module, the second end of the second switch tube is connected with the control module, the energy storage module and the second switch module, the third end of the second switch tube is connected with the first end of the second resistor, the second end of the second resistor is connected with the control module and the first end of the third resistor, and the second end of the third resistor is grounded.

In an optional manner, the second switch module includes a third switch tube, a fourth resistor, a fifth resistor, a sixth resistor, and a seventh resistor;

the first end of the third switch tube is connected with the first end of the fourth resistor and the first end of the fifth resistor, the second end of the fourth resistor is grounded, the second end of the fifth resistor is connected with the control module, the second end of the third switch tube is grounded, the third end of the third switch tube is connected with the first end of the sixth resistor, the second end of the sixth resistor is connected with the first end of the seventh resistor, the control module, the first switch module and the energy storage module, and the second end of the seventh resistor is connected with the battery and the control module.

In an optional manner, the energy storage module includes a voltage dividing unit, a second switching unit, and an energy storage unit;

the voltage division unit is respectively connected with the battery, the control module, the first switch module, the second switch module and the second switch unit, and the second switch unit is connected with the energy storage unit;

the energy storage unit is used for charging when the second switch unit is conducted so as to output the first voltage;

the voltage division unit is used for outputting a fourth voltage when the first voltage is smaller than a first voltage threshold, wherein the fourth voltage is used for controlling the first switch module to be conducted.

In an optional manner, the voltage dividing unit includes an eighth resistor and a ninth resistor;

the eighth resistor and the ninth resistor are connected in series to form a first branch circuit, a first end of the first branch circuit is connected with the control module, the first switch module and the second switch module, a second end of the first branch circuit is connected with the second switch unit, and a connecting point between the eighth resistor and the ninth resistor is connected with the first switch module.

In an alternative mode, the second switch unit includes a key;

the first end of the key is connected with the voltage dividing unit, and the second end of the key is connected with the energy storage unit.

In an optional mode, the energy storage unit comprises a first capacitor and a tenth resistor;

the first capacitor is connected with the tenth resistor in parallel, a first end of the first capacitor is connected with the second switch unit, and a second end of the capacitor is grounded.

In a second aspect, the present application provides an energy storage system comprising at least one battery and a battery management circuit as described above, the battery being connected to the battery management circuit.

The beneficial effects of the embodiment of the application are that: the battery management circuit provided by the application comprises a first switch module, a second switch module, an energy storage module and a control module. The energy storage module is connected with the battery, the first switch module is connected with the energy storage module, and the control module is respectively connected with the first switch module, the second switch module and the battery. If the battery is used, the energy storage module can be charged when the battery is connected to output a first voltage. When the first voltage is smaller than the first voltage threshold, the first switch module is conducted to output a second voltage. Then, the control module outputs a first control signal according to the second voltage after receiving the second voltage. The first control signal is used for controlling the second switch module to be disconnected so as to disconnect the control module from the battery when the battery is not used. At this moment, because the connection of battery and control module has been broken off, then the consumption of battery can be reduced to nearly zero to can reduce the risk that the battery damaged because of the overdischarge, be favorable to prolonging the life of battery.

Drawings

One or more embodiments are illustrated by way of example in the accompanying drawings, which correspond to the figures in which like reference numerals refer to similar elements and which are not to scale unless otherwise specified.

Fig. 1 is a schematic structural diagram of a battery management circuit according to an embodiment of the present disclosure;

fig. 2 is a schematic structural diagram of a battery management circuit according to another embodiment of the present disclosure;

fig. 3 is a schematic circuit structure diagram of a battery management circuit according to an embodiment of the present disclosure.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In recent years, with the appearance of lithium batteries, more and more products adopt lithium batteries for power supply, so that equipment for working and living of human beings is more and more convenient to use. However, the working environment of the lithium battery is strictly required, and overcharge and overdischarge cannot happen, otherwise, the battery is easily damaged and is easy to explode.

Therefore, when the lithium battery is not used, it is usually required to design the lithium battery with low power consumption so as to avoid the situation that the lithium battery is damaged due to overdischarge. For example, in an application scenario, a user activates a lithium battery only for checking the state of charge of the battery through an electronic component such as a display screen. And after the user looked over, the lithium cell had not been used this moment, if it still keeps the state that is activated, then the lithium cell is discharging always, has the risk that the lithium cell damaged because of putting excessively.

In the process of implementing the present application, the inventors of the present application found that: currently, in the related art, an MCU with low power consumption is usually selected to reduce the power consumption of the battery when the battery is not used. However, for this approach, on one hand, the price of such MCU is generally high, which results in increased cost; on the other hand, the MCU cannot achieve power consumption close to zero, i.e., the battery still has power consumption, i.e., there is still a risk of causing excessive discharge of the battery.

Based on this, the embodiment of the present application provides a battery management circuit, which disconnects the battery from a control module in the battery management circuit to stop the battery from outputting electric energy, if the battery is not used within a preset time period after the battery is activated by a user, that is, the battery is used. Therefore, when the battery is not used, the power consumption of the battery is reduced to be close to zero, the situation of over-discharge of the battery can be avoided, and the service life of the battery is prolonged. Meanwhile, the conventional MCU can be used in the method, and compared with the MCU with low power consumption selected in the related technology, the method is low in cost.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a battery management circuit according to an embodiment of the present disclosure. As shown in fig. 1, the battery management circuit 100 includes a first switch module 10, a second switch module 20, an energy storage module 30 and a control module 40, and the battery management circuit 100 is configured to be connected to a battery 200.

The energy storage module 30 is connected to the battery 200, the first switch module 10 is connected to the energy storage module 30, and the control module 40 is connected to the first switch module 10, the second switch module 20, and the battery 200. Specifically, the first end of the first switch module 10 is connected to the first end of the second switch module 20, the first end of the energy storage module 30 and the first end of the control module 40, the second end of the first switch module 10 is connected to the second end of the control module 40, the third end of the first switch module 10 is connected to the second end of the energy storage module 30, the second end of the second switch module 20 is connected to the third end of the control module 40, and the third end of the second switch module 20 is connected to the fourth end of the control module 40 and the battery 200.

In this embodiment, the energy storage module 30 is used for charging when the battery 200 is connected to output a first voltage. The first switch module 10 is configured to be turned on when the first voltage is smaller than the first voltage threshold, so as to output a second voltage. The control module 40 is configured to output a first control signal according to the second voltage, specifically, start timing when the second voltage is received, and output the first control signal to control the second switch module 20 to be disconnected if the timed duration is greater than or equal to the first duration, so as to disconnect the connection between the control module 40 and the battery 200.

It can be understood that the first time period may be set according to practical application, and the embodiment of the present application does not limit this. For example, in one embodiment, the user activates the battery only for checking the charge of the battery 200, and the first time period may be set to a shorter time period, such as 1 minute, and the battery 200 is stopped outputting the electric energy, which is beneficial to saving the power consumption of the battery 200.

Specifically, when the battery 200 needs to be used, the connection between the battery 200 and the energy storage module 30 and the connection between the battery 200 and the control module 40 need to be established, so as to connect the battery 200 to the energy storage module 30 and the control module 40, that is, both the energy storage module 30 and the control module 40 are powered.

Then, the energy storage module 30 is charged, a first voltage is generated at the energy storage module 30, and the first voltage is input to the first switching module 10. When a voltage is smaller than a first voltage threshold, the first switch module 10 is turned on, and when the first voltage is larger than the first voltage threshold, the first switch module 10 is turned off. After the first switch module 10 is turned on, the first switch module 10 outputs a second voltage, and inputs the second voltage to the second terminal of the control module 40. After the control module 40 receives the second voltage, the connection between the energy storage module 30 and the battery 200 may be disconnected. Meanwhile, the control module 40 starts timing at the time when the control module 40 receives the second voltage. If the timed duration is greater than or equal to the first duration, the third terminal of the control module 40 outputs a first control signal to the second terminal of the second switch module 20 to control the second switch module 20 to turn off. After the second switching module 20 is disconnected, the control module 40 controls the disconnection between it and the battery 200.

It is thereby achieved that the battery 200 is disconnected from the energy storage module 30 and the control module 40 when the battery 200 is not in use, so that the power consumption of the battery 200 can be reduced to nearly zero. The battery 200 can be prevented from being damaged due to over-discharge, which is beneficial to improving the safety of power utilization and prolonging the service life of the battery 200. Furthermore, the battery 200 can provide relatively stable electric energy, which is beneficial to improving the stability of the operation of the battery management circuit 100.

The battery in the embodiment of the present application may be a lithium ion battery, a lithium metal battery, a lead-acid battery, a nickel-metal-insulated battery, a nickel-metal hydride battery, a lithium-sulfur battery, a lithium-air battery, a sodium ion battery, or the like, and is not limited herein. In terms of scale, the battery in the embodiment of the present application may be a single battery cell, may also be a battery module formed by connecting a plurality of single battery cells in series and/or in parallel, may also be a battery pack formed by connecting a plurality of battery modules in series and/or in parallel, and may also be a power supply device formed by connecting a plurality of battery packs in parallel, which is not limited herein, and is not limited herein.

In one embodiment, as shown in fig. 2, the control module 40 includes a first switch unit 41, a first control unit 42, and a second control unit 43. The first switch unit 41 is connected to the battery 200, the first control unit 42, the first switch module 10, the second switch module 20, and the energy storage module 30, the first control unit 42 is connected to the second control unit 43, and the second control unit 43 is connected to the first switch module 10 and the second switch module 20. Specifically, a first end of the first switch unit 41 is connected to the battery 200 and a third end of the second switch module 20, a second end of the first switch unit 41 is connected to the first end of the first switch module 10, the first end of the second switch module 20 and the first end of the energy storage module 30, a third end of the first switch unit 41 is connected to the first end of the first control unit 42, a second end of the first control unit 42 is connected to the first end of the second control unit 43, a second end of the second control unit 43 is connected to the third end of the first switch module 10, and a third end of the second control unit 43 is connected to the second end of the second switch module 20.

A second end of the first switch unit 41 is a first end of the control module 40, a second end of the second control unit 43 is a second end of the control module 40, a third end of the second control unit 43 is a third end of the control module 40, and a first end of the first switch unit 41 is a fourth end of the control module 40.

Specifically, the first switching unit 41 is configured to be opened when the second switching module 20 is turned off to disconnect the first control unit 42 from the battery 200. The first control unit 42 is used to provide input power to the second control unit 43. The second control unit 43 is configured to start timing when receiving the second voltage, and control the second switch module 20 to turn off if the timing duration is greater than or equal to the first duration.

In an embodiment, referring to fig. 3 in combination with fig. 2, the first switch unit 41 includes a first switch Q1 and a first resistor R1. The first switch Q1 is a PMOS transistor, for example.

A first end of the first switch tube Q1 is connected to the first switch module 10, the second switch module 20 and the energy storage module 30, a second end of the first switch tube Q1 is connected to the positive electrode of the battery 200 and the second switch module 20, and a third end of the first switch tube Q1 is connected to the power input VCC of the first control unit 42 through the first resistor R1.

In this embodiment, when the first switch Q1 is turned on, the positive electrode of the battery 200 is connected to the power input terminal VCC of the first control unit 42, and the first control unit 42 is powered. Conversely, when the first switching tube Q1 is turned off, the connection between the positive electrode of the battery 200 and the first control unit 42 is disconnected, and the first control unit 42 loses power. The first resistor R1 is used to limit the current to prevent the first control unit 42 from being damaged by the excessive current, so as to protect the first control unit 42.

In an embodiment, the first control unit 42 provides an input power to the power input terminal VDD of the second control unit 43 through the power output terminal REGOUT thereof, so that the second control unit 43 obtains a power supply voltage.

IN an embodiment, the input terminal IN1 of the second control unit 43 is used for inputting the second voltage, and outputs the first control signal from the output terminal OUT1 thereof to control the second switch module 20 to be turned off, or outputs the second control signal to control the second switch module 20 to be turned on.

In summary, in practical applications, when the battery 200 needs to be used, the first switch Q1 should be turned on to power the first control unit 42 and the second control unit 43. As is clear from the above embodiment, at this time, the input terminal IN1 of the second control unit 43 can input the second voltage, and the second control unit 43 starts timing when receiving the second voltage. If the timed duration is greater than or equal to the first duration, a first control signal is output from the output terminal OUT1 to control the second switching module 20 to be turned off, so that the first switching tube Q1 is turned off. Accordingly, both first control unit 42 and second control unit 43 lose power, and the power consumption of battery 200 is reduced to approximately 0.

It is understood that, when the timing duration of the second control unit 43 is less than the first duration, the second control unit 43 can output the second control signal through the output terminal OUT1 to control the second switch module 20 to be turned on. At this time, the second switch module 20 may output a fifth voltage, which enables the first switch Q1 to be kept turned on, so that the first control unit 42 and the second control unit 43 are kept powered, which is beneficial to maintaining the stable operation of the battery management circuit 100.

In one embodiment, the first switch module 10 includes a second switch transistor Q2, a second resistor R2, and a third resistor R3. The first end of the second switch tube Q2 is connected to the second end of the energy storage module 30, the second end of the second switch tube Q2 is connected to the first end of the control module 40, the first end of the energy storage module 30 and the first end of the second switch module 20, the third end of the second switch tube Q2 is connected to the first end of the second resistor R2, the second end of the second resistor R2 is connected to the second end of the control module 40 and the first end of the third resistor R3, and the second end of the third resistor R3 is grounded to GND. In this embodiment, the second switch Q2 is a PMOS transistor, for example.

Specifically, when the second switch Q2 is turned on, the second resistor R2 and the third resistor R3 perform a voltage dividing function to obtain a second voltage at a connection point between the second resistor R2 and the third resistor R3. When the second switch Q2 is turned off, the voltage at the connection point between the second resistor R2 and the third resistor R3 is 0. Therefore, when the battery 200 needs to be used, the second switch Q2 is controlled to be turned on to input the second voltage to the input terminal IN1 of the second control unit 43, so that the second control unit 43 can know that the battery 200 is used.

In an embodiment, the second switch module 20 includes a third switch transistor Q3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, and a seventh resistor R7. The first end of the third switching tube Q3 is connected to the first end of the fourth resistor R4 and the first end of the fifth resistor R, the second end of the fourth resistor R4 is connected to the GND, the second end of the fifth resistor R5 is connected to the third end of the control module 40, the second end of the third switching tube Q3 is connected to the GND, the third end of the third switching tube Q3 is connected to the first end of the sixth resistor R6, the second end of the sixth resistor R6 is connected to the first end of the seventh resistor R7, the first end of the control module 40, the first end of the first switching module 10 and the first end of the energy storage module 30, and the second end of the seventh resistor R7 is connected to the battery 200 and the fourth end of the control module 40. In this embodiment, the third switch Q3 is an NMOS transistor, for example.

Specifically, the fifth resistor R5 plays a role of current limiting to prevent the first terminal of the third switching tube Q3 from being damaged due to excessive input current. Meanwhile, the second resistor R5 and the fourth resistor R4 perform a voltage dividing function to divide the voltage output by the output terminal OUT1 of the second control unit 43, wherein when the divided voltage of the fourth resistor R4 is greater than the on voltage of the third switching tube Q3, the third switching tube Q3 is turned on, and otherwise, the third switching tube Q3 is turned off. It can be seen that the voltage division of the voltage of the first control signal output by the output terminal OUT1 of the second control unit 43 over the fourth resistor R4 should be smaller than the turn-on voltage of the third switching tube Q3, and the voltage division of the voltage of the second control signal over the fourth resistor R4 should be larger than the turn-on voltage of the third switching tube Q3.

The seventh resistor R7 also functions as a current limiting device to prevent the first terminal of the first switch Q1 from being damaged by excessive input current. Meanwhile, the sixth resistor R6 and the seventh resistor R7 perform a voltage division function to divide the voltage output by the battery 200, wherein when the divided voltage of the seventh resistor R7 is greater than the on-state voltage of the first switch tube Q1, the first switch tube Q1 is turned on, and otherwise, the first switch tube Q1 is turned off. It is understood that, in this embodiment, the divided voltage of the seventh resistor R7 is the fifth voltage outputted by the second switch module 20 in the above embodiment.

In an embodiment, the energy storage module 30 includes a voltage dividing unit 31, a second switching unit 32, and an energy storage unit 33. The voltage dividing unit 31 is connected to the battery 200, the control module 30, the first switch module 10, the second switch module 20, and the second switch unit 32 is connected to the energy storage unit 33. Specifically, a first end of the voltage dividing unit 31 is connected to a first end of the first switch module 10, a first end of the second switch module 20, and a first end of the control module 40, a second end of the voltage dividing unit 31 is connected to a second end of the first switch module 10, a third end of the voltage dividing unit 31 is connected to a first end of the second switch unit 32, and a second end of the second switch unit 32 is connected to a first end of the energy storage unit 33.

The first end of the voltage dividing unit 31 is the first end of the energy storage module 30, and the second end of the voltage dividing unit 31 is the second end of the energy storage module 30.

Specifically, the energy storage unit 33 is configured to be charged when the second switching unit 32 is turned on to output the first voltage. The voltage dividing unit 31 is configured to output a fourth voltage when the first voltage is smaller than the first voltage threshold, where the fourth voltage is used to control the first switch module 10 to be turned on.

In one embodiment, the voltage divider 31 includes an eighth resistor R8 and a ninth resistor R9. The eighth resistor R8 and the ninth resistor R9 are connected in series to form a first branch, a first end of the first branch is connected to the first end of the control module 40, the first end of the first switch module 10, and the first end of the second switch module 20, a second end of the first branch is connected to the second switch unit 32, and a connection point between the eighth resistor R8 and the ninth resistor R9 is connected to the third end of the first switch module 10.

Specifically, the eighth resistor R8 may function as a current limiting function to prevent the first terminal of the second switch Q2 from being damaged due to excessive input current. Meanwhile, the eighth resistor R8 and the ninth resistor R9 perform a voltage division function to divide the voltage output by the battery 200. When the divided voltage of the eighth resistor R8 is greater than the turn-on voltage of the second switch Q2, the second switch Q2 is turned on, and otherwise, the second switch Q2 is turned off. It is understood that, in this embodiment, the divided voltage of the eighth resistor R8 is the fourth voltage output by the voltage dividing unit 31 in the above embodiment.

In one embodiment, the second switch unit 32 includes a key K1. The first end of the key K1 is connected with the voltage dividing unit 31, and the second end of the key K1 is connected with the energy storage unit 33.

Specifically, when the key K1 is pressed, the energy storage unit 33 is connected to the battery 200, and the energy storage unit 33 is charged. When the button K1 is released, the connection between the energy storage unit 33 and the battery 200 is broken, and the energy storage unit 30 discharges.

In one embodiment, the energy storage unit 33 includes a first capacitor C1 and a tenth resistor R10. The first capacitor C1 is connected in parallel with the tenth resistor R10, the first end of the first capacitor C1 is connected to the second switch unit 32, and the second end of the first capacitor C1 is grounded GND.

Specifically, when the key K1 is pressed, the first capacitor C1 is charged by the divided voltage of the output voltage of the battery 200 across the tenth resistor R10. When the key K1 is turned off, the first capacitor C1 discharges through the tenth resistor R10.

In one embodiment, as shown in fig. 3, the battery management circuit 100 further includes a clamping module 50, wherein the clamping module includes a first zener diode DW1 and a second zener diode DW 2. An anode of the first zener diode DW1 is connected to the first end of the first switch tube Q1, the second end of the second switch tube Q2, and a cathode of the second zener diode DW2, a cathode of the first zener diode DW1 is connected to the second end of the first switch tube Q1 and the anode of the battery 200, and an anode of the second zener diode DW2 is connected to the first end of the second switch tube Q2.

In this embodiment, the first zener diode DW1 is used to clamp the voltage between the first terminal and the second terminal of the first switch transistor Q1 (i.e., the fifth voltage) to prevent the voltage between the first terminal and the second terminal of the first switch transistor Q1 from being too large to damage the first switch transistor Q1, so as to improve the stability of the first switch transistor Q1. The second zener diode DW2 is used to clamp a voltage (i.e., a fourth voltage) between the first terminal and the second terminal of the second switching tube Q2, so as to prevent the voltage between the first terminal and the second terminal of the second switching tube Q2 from being too large to damage the second switching tube Q2, thereby improving the stability of the second switching tube Q2.

In one embodiment, the battery management circuit 100 further includes a filtering module 60. The filtering module 60 includes an eleventh resistor R11 and a second capacitor C2. A first end of the eleventh resistor R11 is connected to the positive electrode of the battery 200, a second end of the eleventh resistor R11 is connected to a first end of the second capacitor C2 and the first voltage detection terminal VC1 of the first control unit 42, and a second end of the second capacitor C2 is connected to the negative electrode of the battery 200 and the second voltage detection terminal VC2 of the first control unit 42.

Specifically, the eleventh resistor R11 and the second capacitor C2 are used for filtering out high frequency interference signals in the voltage output by the battery 200, so that the first control unit 42 can detect a relatively stable voltage. The first voltage detection terminal VC1 and the second voltage detection terminal VC2 are used for detecting voltages at two ends of the battery 200 to obtain the electric quantity of the battery 200.

It is understood that, in this embodiment, the power of one battery 200 is obtained as an example. In other embodiments, if the electric quantities of N batteries 200 need to be detected, a corresponding filtering module 60 may be disposed for each battery 200, where N is a positive integer.

In one embodiment, the battery management circuit 100 further includes a third switch module 70 and a first diode D1. The third switching module 70 includes a fourth switching tube Q4 and a fifth switching tube Q5. A first end of the fourth switching tube Q4 is connected to the first control end DSG of the first control unit 42, a second end of the fourth switching tube Q4 is connected to the negative electrode of the battery 200, a third end of the fourth switching tube Q4 is connected to the third end of the fifth switching tube Q5 and the port S4, a first end of the fifth switching tube Q5 is connected to the second control end CHG of the first control unit 42, a second end of the fifth switching tube Q5 is connected to the port S3, an anode of the first diode D1 is connected to the port S2, and a cathode of the first diode D1 is connected to the first end of the fifth resistor R5 and the output end OUT1 of the second control unit 43. At the same time, the positive electrode of the battery 200 is also connected to the port S1. In this embodiment, the fourth switch Q4 is exemplified by an NMOS transistor, and the fifth switch Q5 is exemplified by a PMOS transistor.

In this embodiment, the interface S1 may be used for the positive pole of the external device, wherein the external device includes a charging device and a power consuming device. When the interface S1 is connected to the charging device, the interface S3 is used to connect the negative electrode of the charging device, and when the interface S1 is connected to the electric device, the interface S4 is used to connect the negative electrode of the electric device. The interface S2 is used for inputting a high level signal through the external device when the external device is connected, so that the third switch Q3 and the first switch Q1 are turned on, and the first control unit 42 and the second control unit 43 are powered on.

Then, if a charging device is connected to charge the battery 200, the first control terminal DSG outputs a control signal to control the fourth switching transistor Q4 to be turned on, and the second output terminal CHG outputs a control signal to control the fifth switching transistor Q5 to be turned on, so that a loop is formed between the battery 200 and the charging device, and the battery 200 is charged. If the electric equipment is connected to supply power by using the battery 200, the fourth switching tube Q4 is controlled to be turned on by the control signal output by the first control terminal DSG, so that a loop can be formed between the electric equipment and the battery, and the battery 200 is used for providing power supply voltage for the electric equipment.

It should be noted that, in the embodiment of the present application, each switching tube may be a switching device such as a triode, an MOS tube, or an IGBT switching tube. The switching tubes may be the same or different.

Take the first switch Q1 as an example. If the first switch tube Q1 is a triode, the base of the triode is the first end of the first switch tube Q1, the emitter of the triode is the second end of the first switch tube Q1, and the collector of the triode is the third end of the first switch tube Q1. If the first switch transistor Q1 is an MOS transistor, the gate of the MOS transistor is the first end of the first switch transistor Q1, the source of the MOS transistor is the second end of the first switch transistor Q1, and the drain of the MOS transistor is the third end of the first switch transistor Q1. If the first switch tube Q1 is an IGBT switch tube, the gate of the IGBT switch tube is the first end of the first switch tube Q1, and the emitter of the IGBT switch tube is the third end of the first switch tube Q1, which is the collector of the IGBT switch tube at the second end of the first switch tube Q1.

For a better understanding of the present application, the operating principle of the circuit arrangement shown in fig. 3 is described below.

When the battery management circuit 100 does not access an external device, the battery 200 is activated for checking the power of the battery 200. First, the key K1 is pressed to make the battery 200, the seventh resistor R7, the eighth resistor R8, the ninth resistor R9, the key K1 and the first capacitor C1 form a loop, the first capacitor C1 is charged, and a first voltage is generated across the first capacitor C1 and gradually increases.

When the first voltage is smaller than the first voltage threshold, the difference between the voltage of the battery 200 and the first voltage is large, and a large voltage division can be obtained at the seventh resistor R7 and the eighth resistor R8, that is, the fourth voltage is obtained at both ends of the seventh resistor R7, and the fifth voltage is obtained at both ends of the eighth resistor R8.

On the one hand, the fourth voltage turns on the first switch Q1, and the first control unit 42 and the second control unit 43 are powered. The first control unit 42 obtains the electric quantity of the battery 200 through the first voltage detection terminal VC1 and the second voltage detection terminal VC2, and transmits the electric quantity to the third control unit 43 through the connection line SDA and the connection line SCL. The third control unit 43 can control the corresponding display device to display the power of the battery 200 for the user to view.

On the other hand, the fifth voltage turns on the second switch Q2, and the battery 200, the seventh resistor R7, the second switch Q2, the second resistor R2 and the third resistor R3 form a loop to output the second voltage value at the input terminal IN1 of the second control unit 43. The third control unit 43 starts timing and outputs the second control signal (in this case, a high level signal) from the output terminal OUT1 to turn on the third switch Q3. At this time, the battery 200, the seventh resistor R7, the sixth resistor R6 and the third switching tube Q3 form a loop to maintain the fourth voltage across the seventh resistor R7, so that the first switching tube Q1 is kept conducting.

When the first voltage increases to be greater than or equal to the first voltage threshold, since the difference between the voltage of the battery 200 and the first voltage is small, at this time, the fifth voltage across the eighth resistor R8 decreases to be close to 0V, and the fourth voltage across the seventh resistor R7 is maintained due to the loop of the battery 200, the seventh resistor R7, the sixth resistor R6, and the third switching tube Q3. Therefore, the second switch Q2 is turned off, and the first switch Q1 is still turned on, so as to keep the first control unit 42 and the second control unit 43 powered, and continue to display the power of the battery 200.

Then, when the timing of the second control unit 43 is greater than or equal to the first time duration, the output terminal OUT1 of the second control unit 43 outputs the first control signal (in this case, a low level signal) to turn off the third switch Q3. At this time, the fourth voltage across the seventh resistor R7 also decreases to 0, and the first switching tube Q1 is turned off. The first control unit 42 is disconnected from the battery 200 before, and both the first control unit 42 and the second control unit 43 lose power.

Thus, in the above manner, the process of inquiring the electric quantity of the battery 200 is realized. Also, after the user checks, it is possible to control the disconnection between the battery 200 and the first control unit 41 after a certain period of time so as to reduce the power consumption of the battery 200 to approximately 0. Damage to the battery 200 due to over-discharge can be avoided, which is advantageous for extending the service life of the battery 200.

Meanwhile, in this embodiment, in the event of an abnormal situation where the key K1 is pressed all the time, the power consumption of the battery 200 can be kept close to 0 by selecting a suitable type for the electronic components in the battery management circuit 100.

For example, in one embodiment, key K1 cannot be turned off after being pressed due to a failure of key K1, i.e., key K1 remains pressed. At this time, the first capacitor C1 is always charged until the voltage across it is the same as the voltage across the tenth resistor R10. And the voltage division of the seventh resistor R7 due to the difference V0 between the voltage of the battery 200 and the voltage across the tenth resistor R10 is the fourth voltage. And the voltage division of the difference V0 between the voltage of the battery 200 and the voltage across the tenth resistor R10 on the eighth resistor R8 is the fifth voltage.

Therefore, in order to keep the power consumption of the battery 200 close to 0, the first switch Q1 and the third switch Q3 are controlled to be kept off when the battery 200 is not used, i.e., the fourth voltage should be less than the on-state voltage of the first switch Q1, and the fifth voltage should be less than the on-state voltage of the second switch Q2. Then, the difference V0 is controlled to be smaller, so as to control the fourth voltage and the fifth voltage to be smaller. Then, the voltage across the tenth resistor R10 may be increased to decrease the difference V0, while the output voltage of the battery 200 remains unchanged. In other words, by selecting the resistor with a larger resistance value as the tenth resistor R10, the first switch tube Q1 can be kept disconnected from the second switch tube Q2 in the abnormal situation that the key K1 is pressed all the time.

Therefore, when the battery 200 is not used, the power consumption of the battery 200 can be kept close to 0, so that the battery 200 is prevented from being damaged due to over-discharge, and the service life of the battery 200 is prolonged.

The embodiment of the present application further provides an energy storage system, where the energy storage system includes at least one battery and the battery management circuit in any embodiment of the present application, and the battery is connected to the battery management circuit.

In one embodiment, the energy storage system is a battery pack.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; within the context of the present application, where technical features in the above embodiments or in different embodiments can also be combined, the steps can be implemented in any order and there are many other variations of the different aspects of the present application as described above, which are not provided in detail for the sake of brevity; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery management circuit, comprising:

the first switch module is respectively connected with the energy storage module and the control module, and is configured to be turned on when the first voltage is smaller than a first voltage threshold value, and output a second voltage to the control module, so that the control module outputs a first control signal according to the second voltage;

the second switch module is connected with the control module, the control module is connected with the battery, and the second switch module is disconnected according to the first control signal so as to disconnect the control module from the battery.

2. The battery management circuit of claim 1,

the control module comprises a first switch unit, a first control unit and a second control unit;

the second control unit is connected with the first switch module and the second switch module, and the second control unit is used for outputting the first control signal according to the second voltage so as to control the second switch module to be switched off.

3. The battery management circuit of claim 2,

the first switch unit comprises a first switch tube and a first resistor;

4. The battery management circuit of claim 1,

the first switch module comprises a second switch tube, a second resistor and a third resistor;

5. The battery management circuit of claim 1,

the second switch module comprises a third switch tube, a fourth resistor, a fifth resistor, a sixth resistor and a seventh resistor;

6. The battery management circuit of claim 1,

the energy storage module comprises a voltage division unit, a second switch unit and an energy storage unit;

7. The battery management circuit of claim 6,

the voltage division unit comprises an eighth resistor and a ninth resistor;

8. The battery management circuit of claim 6,

the second switch unit comprises a key;

9. The battery management circuit of claim 6,

the energy storage unit comprises a first capacitor and a tenth resistor;

10. An energy storage system comprising at least one battery and a battery management circuit according to any of claims 1 to 9, the battery being connected to the battery management circuit.