Storage battery protection circuit and electric equipment

Abstract

The embodiment of the utility model discloses a storage battery protection circuit and electric equipment. The storage battery protection circuit comprises a storage battery; the first connecting end of the safety unit is connected to the positive electrode of the storage battery; the protection loop is connected between the positive electrode of the storage battery and the second connecting end of the safety unit; the pre-discharge loop is connected between the positive electrode of the storage battery and the first connecting end of the safety unit and is also connected with the protection loop; the safety unit is configured to be disconnected from the storage battery when a fault occurs, the protection loop is configured to respond to disconnection of the safety unit to send a switching instruction to the pre-discharging loop, and the pre-discharging loop is configured to respond to the received switching instruction to be connected with the storage battery in series to form a loop and then discharge the storage battery. According to the application, the pre-discharge loop is connected between the storage battery and the safety unit, and the storage battery can be discharged after the safety unit is fused, so that the risk of short circuit, explosion or electrolyte leakage after the storage battery is permanently invalid is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of battery protection, in particular to a battery protection circuit and electrical equipment. Background Art

[0002] The laptop batteries currently on the market do not have the function of self-discharging after the protection fails, especially when the laptop battery has a high energy density and a high voltage, the risk is greater. When the battery is under high voltage, because the fuse burns out and the battery fails permanently and cannot self-discharge, the battery may short-circuit or even explode and other safety accidents. Especially for batteries with large capacity, once the above situation occurs, the consequences will be more serious. At the same time, the high voltage situation will also cause the electrolyte pressure inside the battery to increase, resulting in an increased risk of electrolyte leakage, which will not only affect the personal safety of the user, but also cause pollution and corrosion to the environment. Utility Model Content

[0003] The embodiments of the present application provide a battery protection circuit and an electrical device to solve the technical problem in the prior art that the battery cannot self-discharge after permanent failure, thus posing a potential safety hazard.

[0004] In order to solve the above technical problems, the embodiments of the present application disclose the following technical solutions:

[0005] In a first aspect, a battery protection circuit is provided, comprising:

[0006] Batteries;

[0007] A safety unit, wherein a first connection end of the safety unit is connected to the positive electrode of the battery;

[0008] A protection circuit, the protection circuit being connected between the positive electrode of the battery and the second connection end of the insurance unit;

[0009] A pre-discharge circuit, the pre-discharge circuit being connected between the positive electrode of the battery and the first connection end of the insurance unit, and the pre-discharge circuit being also connected to the protection circuit;

[0010] The insurance unit is configured to be disconnected from the battery when the battery fails, the protection circuit is configured to send a switch instruction to the pre-discharge circuit in response to the disconnection of the insurance unit, and the pre-discharge circuit is configured to discharge the battery after being connected in series with the battery to form a circuit in response to the received switch instruction.

[0011] In combination with the first aspect, the pre-discharge circuit includes a pre-discharge switch unit and a power consumption unit;

[0012] The pre-discharge switch unit has a pre-discharge output terminal, a pre-discharge input terminal and a pre-discharge signal terminal, the pre-discharge output terminal is connected to the positive electrode of the battery, the pre-discharge input terminal is connected to the first power consumption connection terminal of the power consumption unit, the second power consumption connection terminal of the power consumption unit is connected to the negative electrode of the battery, and the pre-discharge signal terminal is connected to the instruction output terminal of the protection circuit;

[0013] The instruction output terminal is configured to output a switch instruction, and the pre-discharge switch unit electrically connects the pre-discharge output terminal and the pre-discharge input terminal in response to the switch instruction received by the pre-discharge signal terminal.

[0014] In combination with the first aspect, the protection circuit includes a first protection unit and a second protection unit, the first protection unit has a first voltage input terminal and a first signal output terminal, and the second protection unit has a second voltage input terminal and a second signal output terminal;

[0015] The first voltage input terminal and the second voltage input terminal are connected to the positive electrode of the battery, and the first signal output terminal and the second signal output terminal are connected to the second connection terminal of the insurance unit;

[0016] Wherein, the instruction output end is located in the first protection unit.

[0017] In combination with the first aspect, the battery protection circuit further includes a fuse switch unit, the fuse switch unit having a fuse output end, a fuse input end and a fuse signal end, the fuse output end is connected to the second connection end of the insurance unit, the fuse input end is connected to the negative electrode of the battery, and the fuse signal end is connected to the first signal output end of the first protection unit;

[0018] The fuse switch unit electrically connects the fuse output terminal and the fuse input terminal in response to the fuse instruction received by the fuse signal terminal, so as to cause the fuse unit to fuse.

[0019] In combination with the first aspect, the battery protection circuit further includes a timing module, and the timing module is built into the first protection unit;

[0020] The timing module performs timing in response to the permanent failure state of the battery or the fuse state of the insurance unit monitored by the first protection unit, and outputs the switch instruction through the instruction output terminal after the timing value reaches a threshold.

[0021] In combination with the first aspect, the battery protection circuit further includes a charging switch unit and a discharging switch unit, wherein the charging switch unit has a charging input terminal, a charging output terminal and a charging signal terminal, and the discharging switch unit has a discharging input terminal, a discharging output terminal and a discharging signal terminal;

[0022] The charging input terminal is connected to the third connection terminal of the insurance unit, the charging output terminal is connected to the discharging output terminal, the charging signal terminal is connected to the third signal output terminal of the first protection unit, the discharging input terminal is an external electrode, and the discharging signal terminal is connected to the fourth signal output terminal of the first protection unit.

[0023] In combination with the first aspect, the first protection unit further includes a current input terminal and a current output terminal, wherein the current input terminal and the current output terminal are connected to the negative electrode of the battery, and a precision resistor is connected between the current input terminal and the current output terminal.

[0024] In combination with the first aspect, the pre-discharge switch unit, the fuse switch unit, the charge switch unit and the discharge switch unit all include any one of an N-type MOS tube, a P-type MOS tube and a relay.

[0025] In combination with the first aspect, the power consumption unit includes any one of a resistor, a load and a light source.

[0026] In a second aspect, the present application provides an electrical device, comprising a battery protection circuit as described in any one of the first aspects.

[0027] One of the above technical solutions has the following advantages or beneficial effects:

[0028] The present application provides a battery protection circuit, comprising: a battery; a safety unit, wherein the first connection end of the safety unit is connected to the positive electrode of the battery; a protection circuit, wherein the protection circuit is connected between the positive electrode of the battery and the second connection end of the safety unit; a pre-discharge circuit, wherein the pre-discharge circuit is connected between the positive electrode of the battery and the first connection end of the safety unit, and the pre-discharge circuit is also connected to the protection circuit; the safety unit is configured to disconnect from the battery when the battery fails, and the protection circuit is configured to send a switch instruction to the pre-discharge circuit in response to the disconnection of the safety unit, and the pre-discharge circuit is configured to form a circuit in series with the battery in response to the received switch instruction. The present application connects the safety unit, the pre-discharge circuit and the protection circuit to the battery, and the safety unit can disconnect from the battery when a short circuit or overcurrent occurs in the battery, thereby preventing the battery from damaging other components; the protection circuit can send a switch instruction to the pre-discharge circuit after detecting that the safety unit is disconnected from the battery, so that the prevention circuit is connected in series with the battery to form a circuit and then discharges the battery until the battery is empty, thereby avoiding the risk of further short circuit, explosion or electrolyte leakage after the battery fails permanently. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The technical solution and other beneficial effects of the present application will be made apparent by describing in detail the specific implementation methods of the present application in conjunction with the accompanying drawings.

[0030] Figure 1 A schematic diagram of the module connection structure provided in an embodiment of the present application;

[0031] Figure 2 A schematic diagram of the circuit structure provided in an embodiment of the present application.

[0032] Reference numerals:

[0033] 100 - battery, 200 - insurance unit, 300 - protection circuit, 310 - first protection unit, 311 - timing module, 320 - second protection unit, 400 - pre-discharge circuit, 410 - pre-discharge switch unit, 420 - power consumption unit, 500 - fuse switch unit, 600 - charging switch unit, 700 - discharge switch unit. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. In the description of the present application, it is necessary to understand that the orientation or position relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc. is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present application. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0035] Glossary:

[0036] "PCHG" is described as a pin in a battery management IC (such as the chip BQ40Z50). Specifically, the PCHG pin is one of the pins responsible for controlling battery charging. It receives an input signal and controls a charging-related output pin (such as CHG_EN) based on the state of the input signal. The specific function and use of the PCHG pin may vary depending on the specific battery management IC.

[0037] PF (Permanent Failure) means that the battery can no longer be used after the battery fuse blows.

[0038] The specific implementation methods of the present application are further described below through the examples:

[0039] like Figure 1 and Figure 2 As shown, an embodiment of the present application provides a battery protection circuit, including: a battery 100; a safety unit 200, wherein a first connection end of the safety unit 200 is connected to the positive electrode of the battery 100; a protection circuit 300, wherein the protection circuit 300 is connected between the positive electrode of the battery 100 and the second connection end of the safety unit 200; a pre-discharge circuit 400, wherein the pre-discharge circuit 400 is connected between the positive electrode of the battery 100 and the first connection end of the safety unit 200, and the pre-discharge circuit 400 is also connected to the protection circuit 300; the safety unit 200 is configured to be disconnected from the battery 100 when the battery 100 fails, and the protection circuit 300 is configured to send a switch instruction to the pre-discharge circuit 400 in response to the disconnection of the safety unit 200, and the pre-discharge circuit 400 is configured to be connected in series with the battery 100 to form a circuit in response to the received switch instruction. The battery protection circuit provided by the present application connects the insurance unit 200, the pre-discharge circuit 400 and the protection circuit 300 to the battery 100. When the battery 100 is short-circuited or over-current occurs, the insurance unit 200 can be disconnected from the battery 100, thereby preliminarily avoiding the excessive amount of electricity in the battery 100 and damaging other components; further, after monitoring that the insurance unit 200 is disconnected from the battery 100, the protection circuit 300 can send a switch command to the pre-discharge circuit 400, and the pre-discharge circuit 400 is turned on after receiving the switch command, and is connected in series with the battery 100 to form a discharge circuit. The discharge circuit can discharge the battery 100 until the battery 100 is emptied, thereby avoiding the risk of further short circuit, explosion or electrolyte leakage after the battery 100 fails permanently.

[0040] Specifically, the battery 100 is also called a storage battery or an energy storage battery, which is a device that can convert chemical energy into electrical energy. The battery 100 includes a rechargeable battery that can store electrical energy in an electrochemical reaction and release electrical energy to supply electronic equipment or electrical equipment when needed. In general, the battery 100 is composed of one or more battery cells, each of which is composed of a positive electrode, a negative electrode and an electrolyte. The positive electrode and the negative electrode are separated by an electrolyte to form a battery for chemical reactions. When the battery 100 is charged, an external power source provides electrical energy to the battery 100, a chemical reaction occurs, and the electrical energy is converted into chemical energy and stored. When the battery 100 is connected to an electronic device or an electrical device, the stored chemical energy is converted into electrical energy and supplied to the device for use. The battery 100 can generally be charged and discharged multiple times, which is more economical and environmentally friendly than disposable batteries. The battery 100 is widely used in various scenarios, including car batteries, home emergency power supplies, solar and wind energy storage systems, portable electronic devices, etc. Common types of batteries 100 include lead-acid batteries 100, lithium-ion batteries, nickel-cadmium batteries, nickel-metal hydride batteries, etc. Different types of batteries 100 differ in capacity, voltage, cycle life, and applicable scenarios.

[0041] like Figure 2 As shown, in the embodiment of the present application, the insurance unit 200 includes a fuse F1, which is used for overcurrent protection, short circuit protection and fire extinguishing protection of the battery 100. As a safety device, the fuse F1 is mainly used to protect the circuit of the battery 100 from damage by overcurrent. When the current in the circuit exceeds the rated current of the fuse F1, the fuse F1 will melt, cut off the circuit, and prevent excessive current from flowing through the circuit, thereby protecting the battery 100 and other circuit components. At the same time, if a short circuit occurs in the circuit, that is, the wires or components in the circuit come into contact, causing the current to flow directly through the short circuit point, the fuse F1 can respond quickly, melt and cut off the circuit, and prevent abnormal current from flowing through the circuit and the battery, thereby avoiding damage to the battery 100 and other equipment. In extreme cases, if the battery 100 or the circuit fails and causes dangerous situations such as overheating, overcharging or short circuit, the fusing action of the fuse F1 can prevent the current from continuing to flow, reducing the risk of fire. After the fuse F1 melts, the circuit is cut off, the probability of fire is reduced, and a time window for fire extinguishing and accident handling is provided. Therefore, the fuse F1, as an important safety device, is mainly used to protect the circuit and the battery from damage caused by abnormal conditions such as overcurrent and short circuit, thereby improving the safety and reliability of the battery and the circuit.

[0042] In the embodiment of the present application, the protection circuit is used to provide protection for the circuit of the battery 100 to ensure that the current supply can be cut off in time when an abnormality or failure occurs in the circuit of the battery 100 to protect the safety of the battery and other devices. This includes overcharge protection, under-discharge protection, short circuit protection, and overcurrent protection.

[0043] In the embodiment of the present application, the pre-discharge circuit 400 is used to be connected after the battery 100 fails permanently, so as to release the electric energy in the battery 100, so as to prevent the battery 100 from permanently failing, which may cause the electrochemical reaction inside the battery 100 to fail to proceed normally, thereby causing the voltage of the battery 100 to drop abnormally. After the pre-discharge circuit 400 releases the electric energy in the battery 100, it helps to prevent the battery from continuing to discharge in a failed state, avoiding damage to the battery or other safety risks. In addition, the failed battery 100 may generate excessive heat or release harmful gases during the continued discharge process, increasing the risk of safety accidents. The pre-discharge circuit 400 reduces the possibility of safety accidents by releasing the electric energy in the battery 100. Therefore, through the pre-discharge circuit 400, even if the battery 100 fails permanently, the discharge process of the battery 100 can be controlled to avoid excessive discharge and safety risks, thereby improving the safety of use.

[0044] like Figure 1 and Figure 2 As shown, in the embodiment of the present application, the pre-discharge circuit 400 includes a pre-discharge switch unit 410 and a power consumption unit 420; the pre-discharge switch unit 410 has a pre-discharge output terminal, a pre-discharge input terminal and a pre-discharge signal terminal, the pre-discharge output terminal is connected to the positive electrode of the battery 100, the pre-discharge input terminal is connected to the first power consumption connection terminal of the power consumption unit 420, the second power consumption connection terminal of the power consumption unit 420 is connected to the negative electrode of the battery 100, and the pre-discharge signal terminal is connected to the instruction output terminal of the protection circuit 300; wherein the instruction output terminal is configured to output a switch instruction, and the pre-discharge switch unit 410 electrically connects the pre-discharge output terminal and the pre-discharge input terminal in response to the switch instruction received by the pre-discharge signal terminal. Specifically, as Figure 2 As shown, the pre-discharge switch unit 410 is a fourth MOS tube Q4; wherein the pre-discharge output end is the drain of the fourth MOS tube Q4, the pre-discharge input end is the source of the fourth MOS tube Q4, and the pre-discharge signal end is the gate of the fourth MOS tube Q4. When the gate receives a high level, the source and drain of the fourth MOS tube Q4 are turned on. At this time, the battery 100 is short-circuited, and the power consumption unit 420 consumes power from the battery 100.

[0045] like Figure 2As shown, in the embodiment of the present application, the power consumption unit 420 is a resistor R, and the resistance value of the resistor R is not less than 10kΩ. It can be imagined that the role of the resistor R is to consume the power of the battery 100, so when the resistance value of the resistor R is selected to be larger, such as 15kΩ, 20kΩ, 50kΩ, etc., the power of the battery 100 can be exhausted faster, and if the resistance value of the resistor R is selected to be smaller, such as 8kΩ, 6kΩ, 3kΩ, 1kΩ, etc., the power of the battery 100 is slowly exhausted, thereby avoiding the danger of excessive heating of the resistor R.

[0046] like Figure 1 and Figure 2 As shown, in the embodiment of the present application, the protection circuit 300 includes a first protection unit 310 and a second protection unit, the first protection unit 310 has a first voltage input terminal and a first signal output terminal, and the second protection unit has a second voltage input terminal and a second signal output terminal; the first voltage input terminal and the second voltage input terminal are connected to the positive electrode of the battery 100, and the first signal output terminal and the second signal output terminal are connected to the second connection terminal of the insurance unit 200; wherein the command output terminal is located in the first protection unit 310. Specifically, the first protection unit 310 is a fuel gauge Gauge, wherein the first voltage input terminal is the first voltage pins VC1 and VC2 of the fuel gauge Gauge, and the first signal output terminal is the fuse signal pin FUSE. It can be understood that the fuel gauge provides a first layer of protection for the battery 100. In the first layer of protection, when the battery voltage exceeds the safety range or the overcharge limit value, the fuel gauge will cut off the current supply to prevent the battery from overcharging and reduce the damage to the battery caused by overcharging. At the same time, when the battery voltage drops below the safety range or below the under-discharge protection setting value, the fuel gauge will cut off the current supply to prevent the battery from over-discharging and avoid battery damage or irreversible reactions inside the battery.

[0047] like Figure 2 As shown, the second protection unit is a secondary protection chip 2 nd IC, wherein the second voltage input terminal is a secondary protection chip 2 nd The second voltage pins VC3 and VC4 of the IC, and the second signal output terminal is the signal output pin CO. It can be understood that the secondary protection chip 2 nd IC provides a second layer of protection for the circuit of the battery 100. In the second layer of protection, the second voltage pins VC3 and VC4 monitor the voltage of the battery 100. When the voltage of the battery 100 is too high, the secondary protection chip 2 nd The IC will quickly cut off the circuit (i.e. blow the fuse) to prevent excessive voltage from damaging other components in the circuit; at the same time, when the current in the circuit exceeds the rated value, the secondary protection chip 2 ndThe IC will cut off the current supply or trigger an alarm to prevent excessive current from damaging the circuit or other equipment. Through the combination of the first layer of protection and the second layer of protection, multiple protection mechanisms can be provided for the battery 100 circuit to ensure that the current supply can be cut off in time when an abnormality or failure occurs in the battery 100 circuit to protect the safety of the battery and other equipment.

[0048] like Figure 1 and Figure 2 As shown, in the embodiment of the present application, the battery protection circuit also includes a fuse switch unit 500, which has a fuse output terminal, a fuse input terminal and a fuse signal terminal. The fuse output terminal is connected to the second connection terminal of the insurance unit 200, the fuse input terminal is connected to the negative electrode of the battery 100, and the fuse signal terminal is connected to the first signal output terminal of the first protection unit 310; the fuse switch unit 500 electrically connects the fuse output terminal and the fuse input terminal in response to the fuse instruction received by the fuse signal terminal, so as to fuse the insurance unit 200. Specifically, the fuse switch unit 500 is a third MOS tube Q3, wherein the fuse output terminal is the drain of the third MOS tube Q3, the fuse input terminal is the source of the third MOS tube Q3, and the fuse signal terminal is the gate of the third MOS tube Q3. When the electric meter Gauge detects a current or electric quantity exceeding the set threshold, a high level signal is sent to the gate of the third MOS tube Q3 through the fuse signal pin FUSE (i.e., the first signal output terminal); or, the secondary protection chip 2 nd When the IC detects that the battery 100 is over-voltage, it sends a high-level signal to the gate of the third MOS tube Q3 through the signal output pin CO (i.e., the second signal output terminal). The gate of the third MOS tube Q3 is turned on after receiving the high-level signal. The turned-on third MOS tube Q3 will instantly form a low-resistance path through the fuse F1. At this time, a high current will flow through the fuse F1, generating high temperature, causing the fuse F1 to blow quickly and cut off the circuit. This process can effectively protect other components in the circuit from damage due to overcurrent or overload. It can be understood that the third MOS tube Q3, as a control switch between the fuel gauge Gauge and the fuse F1, has the characteristic of fast response. When the fuel gauge Gauge and the secondary protection chip 2 nd When the IC detects that the fuse needs to be blown, it can quickly send a high-level signal to the third MOS tube Q3, and the third MOS tube Q3 is quickly turned on, so that the fuse F1 can be blown immediately. This fast response feature helps to quickly cut off the current under abnormal conditions in the circuit to protect the safety and reliability of other key components.

[0049] like Figure 1 and Figure 2As shown, in the embodiment of the present application, the battery protection circuit also includes a timing module 311, which is built into the first protection unit 310; the timing module 311 performs timing in response to the permanent failure state of the battery 100 or the fuse state of the insurance unit 200 monitored by the first protection unit 310, and outputs a switch instruction through the instruction output terminal after the timing value reaches the threshold. Specifically, the switch instruction is used to control the conduction of the fourth MOS tube Q4. After the source and drain of the fourth MOS tube Q4 are turned on, the battery 100 is short-circuited at this time, and the resistor R consumes power to the battery 100. It can be understood that a permanently failed battery 100 or a blown fuse F1 may cause the battery 100 to be unable to charge and supply power normally. In this case, disconnecting the battery 100 from the load can prevent the battery 100 from continuing to discharge. However, in some cases, when the battery 100 has a minor safety event such as overcharge, over-discharge, overcurrent, short circuit, etc., the fuel gauge Gauge will also disconnect the corresponding charge and discharge switch, and the fuel gauge Gauge will resume closing the switch after the safety event is resolved, and the battery 100 can continue to be used. Therefore, in order to avoid the occurrence of the above-mentioned safety event, the fuel gauge Gauge immediately turns on the fourth MOS tube Q4 and causes the battery 100 to be exhausted. The embodiment of the present application sets a timing module 311 for timing, and after the timing value exceeds the threshold (the maximum time for the safety event to be resolved), the switch control instruction of the fourth MOS tube Q4 is issued. Generally speaking, the recovery time of the above-mentioned minor safety events is 1 hour, so the threshold in the timing module 311 is 1 hour. In some other embodiments of the present application, the threshold of the timing module 311 can also be greater than or less than 1 hour, and the size of the specific threshold can be selected according to the duration of the safety event to be resolved, and the embodiment of the present application will not be listed in detail here.

[0050] like Figure 1 and Figure 2As shown, in the embodiment of the present application, the battery protection circuit further includes a charging switch unit 600 and a discharging switch unit 700. The charging switch unit 600 has a charging input terminal, a charging output terminal and a charging signal terminal, and the discharging switch unit 700 has a discharging input terminal, a discharging output terminal and a discharging signal terminal; the charging input terminal is connected to the third connection terminal of the insurance unit 200, the charging output terminal is connected to the discharging output terminal, the charging signal terminal is connected to the third signal output terminal CHG of the first protection unit 310, the discharging input terminal is an external electrode, and the discharging signal terminal is connected to the fourth signal output terminal DSG of the first protection unit 310. Specifically, the charging switch unit 600 is a first MOS tube Q1, wherein the charging input terminal is the source of the first MOS tube Q1, the charging output terminal is the drain of the first MOS tube Q1, and the charging signal terminal is the gate of the first MOS tube Q1; the discharging switch unit 700 is a second MOS tube Q2, the discharging input terminal is the source of the second MOS tube Q2, the discharging output terminal is the drain of the second MOS tube Q2, and the discharging signal terminal is the gate of the second MOS tube Q2. It can be understood that the first MOS transistor Q1 and the second MOS transistor Q2 are connected in series between the positive electrode of the battery 100 and the positive power supply terminal P+ in a manner of connecting the drain electrodes. Figure 2 As shown, when charging or discharging is performed, the first MOS tube Q1 and the second MOS tube Q2 are turned on at the same time; when charging stops, the first MOS tube Q1 is turned off; when discharging stops, the second MOS tube Q2 is turned off.

[0051] like Figure 1 and Figure 2 As shown, in the embodiment of the present application, the first protection unit 310 also includes a current input terminal and a current output terminal, the current input terminal and the current output terminal are connected to the negative pole of the storage battery 100, and a precision resistor RS is connected between the current input terminal and the current output terminal. Specifically, the current input terminal is the current input pin SRP in the fuel gauge Gauge, and the current output terminal SRN is the current output pin SRN of the fuel gauge Gauge. Connecting the current input pin SRP and the current output pin SRN to the circuit of the storage battery 100 realizes the monitoring of the current size of the storage battery 100 by the fuel gauge Gauge. The precision resistor RS measures the current passing through the fuel gauge Gauge by measuring the voltage drop between the input pin and the output pin of the fuel gauge Gauge. According to Ohm's law, when current passes through a resistor, a specific voltage drop will be generated at both ends of the resistor. By measuring this voltage drop and using the accurate resistance value of the precision resistor RS, the current value passing through the fuel gauge Gauge can be calculated. At the same time, by designing and selecting an appropriate resistance value, the size of the current in the circuit of the storage battery 100 can also be controlled.

[0052] like Figure 1 and Figure 2As shown, in the embodiment of the present application, the pre-discharge switch unit 410, the fuse switch unit 500, the charging switch unit 600 and the discharge switch unit 700 all include any one of an N-type MOS tube, a P-type MOS tube and a relay. Specifically, in the embodiment of the present application, the pre-discharge switch unit 410, the fuse switch unit 500, the charging switch unit 600 and the discharge switch unit 700 are all used as switches, that is, the pre-discharge switch unit 410, the fuse switch unit 500, the charging switch unit 600 and the discharge switch unit 700 realize the conduction of the other two ends after receiving a certain signal, thereby realizing the corresponding function. Therefore, the N-type MOS tube, the P-type MOS tube and the relay can also play the same function. In the above example, the embodiment of the present application provides a solution in which the pre-discharge switch unit 410, the fuse switch unit 500, the charging switch unit 600 and the discharge switch unit 700 use an N-type MOS tube. When necessary, other embodiments of the present application can be replaced by P-type MOS tubes or relays. When P-type MOS tubes or relays are used as replacements, the connection relationship in the circuit will be changed accordingly. How to change the embodiments of the present application is not described in detail here. Of course, in some other embodiments of the present application, the pre-discharge switch unit 410, the fuse switch unit 500, the charging switch unit 600 and the discharge switch unit 700 can also use other devices with the same function to realize the switching effect, and the embodiments of the present application are not listed here.

[0053] like Figure 1 and Figure 2 As shown, in the embodiment of the present application, the power consumption unit 420 includes any one of a resistor, a load and a light source. Specifically, the main function of the power consumption unit 420 is to consume the power of the battery 100, so all components that can meet the power consumption requirements can meet the requirements. The resistors, loads and light sources listed in the embodiment of the present application are only selected from some of the components that can meet the conditions. In some other embodiments of the present application, the power consumption unit 420 can also use other components that can consume power.

[0054] The present application also provides an electrical device, including a battery protection circuit as provided in any of the above items. When the electrical device adopts the above battery protection circuit, when the battery 100 fails permanently or the fuse F1 blows, the fourth MOS tube Q4 can be turned on in time, so as to exhaust the power of the battery 100, and avoid the short circuit, explosion or electrolyte leakage of the battery 100 to damage the electrical device. It is understandable that the electrical devices referred to in the present application include but are not limited to notebooks, mobile phones, tablet computers, electric cars, electric bicycles, etc.

[0055] The above is a detailed introduction to a battery protection circuit and electrical equipment provided in the embodiments of the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the technical solution and its core idea of ​​the present application. Ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with equivalents; and these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the present application.

Claims

1. A battery protection circuit, characterized in that: include: Battery (100); A safety unit (200), wherein a first connection end of the safety unit (200) is connected to the positive electrode of the storage battery (100); A protection circuit (300), the protection circuit (300) being connected between the positive electrode of the storage battery (100) and the second connection end of the insurance unit (200); A pre-discharge circuit (400), the pre-discharge circuit (400) being connected between the positive electrode of the storage battery (100) and the first connection end of the insurance unit (200), and the pre-discharge circuit (400) being also connected to the protection circuit (300); The insurance unit (200) is configured to disconnect from the storage battery (100) when the storage battery (100) fails, the protection circuit (300) is configured to send a switch instruction to the pre-discharge circuit (400) in response to the disconnection of the insurance unit (200), and the pre-discharge circuit (400) is configured to discharge the storage battery (100) after being connected in series with the storage battery (100) to form a circuit in response to the received switch instruction.

2. The battery protection circuit according to claim 1, characterized in that: The pre-discharge circuit (400) comprises a pre-discharge switch unit (410) and a power consumption unit (420); The pre-discharge switch unit (410) has a pre-discharge output terminal, a pre-discharge input terminal and a pre-discharge signal terminal, the pre-discharge output terminal is connected to the positive electrode of the storage battery (100), the pre-discharge input terminal is connected to the first power consumption connection terminal of the power consumption unit (420), the second power consumption connection terminal of the power consumption unit (420) is connected to the negative electrode of the storage battery (100), and the pre-discharge signal terminal is connected to the command output terminal of the protection circuit (300); The instruction output terminal is configured to output a switch instruction, and the pre-discharge switch unit (410) electrically connects the pre-discharge output terminal and the pre-discharge input terminal in response to the switch instruction received by the pre-discharge signal terminal.

3. The battery protection circuit according to claim 2, characterized in that: The protection circuit (300) comprises a first protection unit (310) and a second protection unit (320), the first protection unit (310) having a first voltage input terminal and a first signal output terminal, and the second protection unit (320) having a second voltage input terminal and a second signal output terminal; The first voltage input terminal and the second voltage input terminal are connected to the positive electrode of the storage battery (100), and the first signal output terminal and the second signal output terminal are connected to the second connection terminal of the insurance unit (200); Wherein, the instruction output terminal is located in the first protection unit (310).

4. The battery protection circuit according to claim 3, characterized in that: The battery protection circuit further comprises a fuse switch unit (500), the fuse switch unit (500) having a fuse output end, a fuse input end and a fuse signal end, the fuse output end being connected to the second connection end of the insurance unit (200), the fuse input end being connected to the negative electrode of the battery (100), and the fuse signal end being connected to the first signal output end of the first protection unit (310); The fuse switch unit (500) electrically connects the fuse output terminal and the fuse input terminal in response to a fuse instruction received by the fuse signal terminal, so as to cause the fuse unit (200) to fuse.

5. The battery protection circuit according to claim 3, characterized in that: The battery protection circuit further comprises a timing module (311), wherein the timing module (311) is built into the first protection unit (310); The timing module (311) performs timing in response to the permanent failure state of the storage battery (100) or the fuse state of the insurance unit (200) monitored by the first protection unit (310), and outputs the switch instruction through the instruction output terminal after the timing value reaches a threshold value.

6. The battery protection circuit according to claim 5, characterized in that: The battery protection circuit further comprises a charging switch unit (600) and a discharging switch unit (700), wherein the charging switch unit (600) has a charging input terminal, a charging output terminal and a charging signal terminal, and the discharging switch unit (700) has a discharging input terminal, a discharging output terminal and a discharging signal terminal; The charging input terminal is connected to the third connection terminal of the insurance unit (200), the charging output terminal is connected to the discharging output terminal, the charging signal terminal is connected to the third signal output terminal of the first protection unit (310), the discharging input terminal is an external electrode, and the discharging signal terminal is connected to the fourth signal output terminal of the first protection unit (310).

7. The battery protection circuit according to claim 4, characterized in that: The first protection unit (310) further comprises a current input terminal and a current output terminal, wherein the current input terminal and the current output terminal are connected to the negative electrode of the storage battery (100), and a precision resistor is connected between the current input terminal and the current output terminal.

8. The battery protection circuit according to claim 7, characterized in that: The pre-discharge switch unit (410), the fuse switch unit (500), the charge switch unit (600) and the discharge switch unit (700) all include any one of an N-type MOS tube, a P-type MOS tube and a relay.

9. The battery protection circuit according to claim 2, characterized in that: The power consumption unit (420) includes any one of a resistor, a load and a light source.

10. An electrical device, characterized in that: The invention comprises a battery protection circuit as claimed in any one of claims 1 to 9.

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