Mobile power supply protection device and charging and discharging device

Abstract

The utility model relates to a mobile power supply protection device and a charging and discharging device. The device comprises a battery cell, a battery cell protection module and a control module. Triple protection is performed on the battery cell through the first protection unit, the second protection unit and the third protection unit in the battery cell protection module, and meanwhile, whether different protection units are started or not is controlled according to the control module, so that the battery cell is protected, over-charging or over-discharging of the battery is avoided, the battery of the mobile power supply is effectively protected, and the service life of the mobile power supply is prolonged. The problem that the battery of the mobile power supply cannot be effectively protected in the related technology is solved.

Description

Technical Field

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

[0002] As the functions of smart devices become increasingly powerful, people are becoming more and more dependent on smart mobile devices. However, the battery life of smart mobile devices has always been a bottleneck. Especially in modern society, people often need to use smart mobile devices, such as mobile phones, when going out, traveling, or attending business meetings. The problem of insufficient mobile phone power often brings a lot of inconvenience to people. The emergence of mobile power banks has provided convenience for solving this problem. Although it has made people's lives more convenient, battery protection of mobile power banks is particularly important due to long-term use and sharing by multiple people. If the battery is deeply overcharged or over-discharged, it will cause irreversible damage to the battery and even cause spontaneous combustion accidents of mobile power banks.

[0003] Currently, most of the mobile power supplies on the market use lithium battery protection chips to achieve battery overcharge and over-discharge protection. However, when the chip fails or the lithium battery protection chip is not properly selected, the overcharge protection voltage threshold will be too high or the over-discharge protection voltage threshold will be too low, so the battery cannot be effectively protected from overcharge and over-discharge.

[0004] In the related art, there is a problem that the battery of the mobile power source cannot be effectively protected, and no effective solution has been proposed yet. Utility Model Content

[0005] In view of this, it is necessary to provide a mobile power protection device and a charging and discharging device to solve the problem that the battery of the mobile power cannot be effectively protected in the related art.

[0006] In a first aspect, the utility model provides a mobile power supply protection device, characterized in that it comprises: a battery cell, a battery cell protection module and a control module; the battery cell protection module is connected to the control module and the battery cell respectively;

[0007] The battery cell protection module includes a first protection unit, a second protection unit and a third protection unit;

[0008] The input end of the first protection unit is connected to the charging input port of the mobile power supply; the first protection unit is connected to the second protection unit; the second protection unit is connected to the input and output ports of the control module; and the third protection unit is connected to the battery cell.

[0009] In one embodiment, the first protection unit includes an overvoltage protection circuit and a step-down switch; the overvoltage protection circuit is connected to the step-down switch; and the overvoltage protection circuit is connected to a charging input port of the mobile power supply.

[0010] In one embodiment, the second protection unit includes a charge-discharge chip and a charge-discharge switch built into the charge-discharge chip;

[0011] One end of the charge and discharge chip is connected to the overvoltage protection circuit, and the other end of the charge and discharge chip is connected to the discharge output port of the mobile power supply.

[0012] In one of the embodiments, the third protection unit includes a battery cell protection circuit and a detector; the detector is connected to the battery cell, and the detector is also connected to the battery cell protection circuit.

[0013] In one of the embodiments, the control module includes a battery voltage sampling circuit and a single chip microcomputer;

[0014] The battery voltage sampling circuit is connected to the single chip microcomputer; the single chip microcomputer is connected to the charging and discharging chip.

[0015] In one of the embodiments, the control module further includes a power chip;

[0016] The power chip is connected to the single chip microcomputer.

[0017] In one of the embodiments, the control module further includes a power control circuit;

[0018] The power control circuit is connected to the single chip microcomputer and is also connected to the power chip.

[0019] In one embodiment, the charge and discharge switch includes a front-stage switch and a rear-stage switch;

[0020] The front-stage switch is connected to the overvoltage protection circuit; the rear-stage switch is connected to the positive electrode of the battery cell.

[0021] In one of the embodiments, the single chip microcomputer is provided with a register for configuring the state of the front-stage switch and the state of the rear-stage switch.

[0022] In a second aspect, the utility model provides a charging and discharging device, comprising a mobile device and the mobile power supply protection device as described in the first aspect.

[0023] The utility model provides a mobile power protection device and a charging and discharging device, which perform triple protection on the battery cell through the first protection unit, the second protection unit and the third protection unit in the battery cell protection module, and at the same time control whether to turn on different protection units according to the control module, thereby avoiding overcharging or over-discharging of the battery, thereby effectively protecting the battery of the mobile power supply, and solving the problem that the battery of the mobile power supply cannot be effectively protected in the related art. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic structural diagram of a mobile power protection device according to an embodiment of the present application;

[0025] Figure 2 is a schematic diagram of the structure of a control module in an embodiment of the present application;

[0026] Figure 3 is a schematic diagram of a mobile power supply device of this specific embodiment;

[0027] Figure 4 is a schematic diagram of a cell protection circuit in this specific embodiment;

[0028] Figure 5 Schematic diagram of a battery voltage sampling circuit in this specific embodiment.

[0029] Figure numerals: 11, battery cell; 12, battery cell protection circuit; 13, charging and discharging chip; 14, overvoltage protection circuit; 15, single-chip microcomputer; 16, power chip; 17, power control circuit; 18, battery voltage sampling circuit; 2, battery cell protection module; 3, control module; 21, first protection unit; 22, second protection unit; 23, third protection unit. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments provided in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application. In addition, it can also be understood that although the efforts made in this development process may be complex and lengthy, for ordinary technicians in the field related to the contents disclosed in the present application, some changes such as design, manufacturing or production based on the technical contents disclosed in the present application are only conventional technical means, and should not be understood as insufficient contents disclosed in the present application.

[0031] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those of ordinary skill in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0032] Unless otherwise defined, the technical terms or scientific terms involved in this application should be understood by people with ordinary skills in the technical field to which this application belongs. In this application, when an element is referred to as "provided on" another element, it can be directly provided on the other element or there can also be a centered element. When an element is considered to be "provided on" another element, it can be directly provided on the other element or there can be a centered element at the same time. When an element is considered to be "fixed on" another element, it can be directly fixed on the other element or there can be a centered element at the same time. The terms "first", "second", "third" and the like involved in this application are merely used to distinguish similar objects and do not represent a specific ordering of objects. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0033] refer to Figure 1 , Figure 1 Schematic diagram of the structure of the mobile power protection device of the embodiment of the present application. The utility model provides a mobile power protection device, such as Figure 1 As shown, the mobile power protection device includes: a battery cell 11, a battery cell protection module 2 and a control module 3; the battery cell protection module 2 is connected to the control module 3 and the battery cell 11 respectively; wherein the battery cell protection module 2 includes a first protection unit 21, a second protection unit 22 and a third protection unit 23; further, the input end of the first protection unit 21 is connected to the charging input port of the mobile power supply; the first protection unit 21 is connected to the second protection unit 22; the second protection unit 22 is connected to the input and output ports of the control module 3; the third protection unit 23 is connected to the battery cell 11.

[0034] Specifically, the mobile power protection device includes a battery cell 11, a battery cell protection module 2 and a control module 3; wherein the control module 3 is connected to the battery cell protection module 2 to send a control instruction to the battery cell protection module 2 to protect the battery cell 11, and the battery cell protection module 2 is connected to the battery cell 11 and protects the battery cell 11 according to the control instruction sent by the control module 3. More specifically, the battery cell protection module 2 includes a first protection unit 21, a second protection unit 22 and a third protection unit 23; the input end of the first protection unit 21 is connected to the charging input port of the mobile power supply, and is used to obtain the power supply voltage input to the charging input port. When the power supply voltage is too high, the first protection unit 21 acts as a first layer of protection to reduce the power supply voltage; the first protection unit 21 is connected to the second protection unit 22, and the second protection unit 22 is connected to the input and output ports of the control module 3. The second protection unit 22 receives the control instruction information of the control module 3, and acts as a second layer of protection according to the control instruction information; the third protection unit 23 is connected to the battery cell 11, and the third protection unit 23 collects the voltage and current of the battery cell 11, and then performs overcharge protection, over-discharge protection, overcurrent protection and short circuit protection on the battery cell 11.

[0035] Through the above-mentioned device, a control instruction is sent to the battery cell protection module 2 through the control module 3, and then the battery cell protection module 2 is controlled to protect the battery cell 11; at the same time, through the first protection unit 21, the second protection unit 22 and the third protection unit 23 in the battery cell protection module 2, the battery cell 11 is triple-protected, thereby effectively protecting the battery of the mobile power supply, thereby solving the problem that the battery of the mobile power supply cannot be effectively protected in the related art.

[0036] In some of the embodiments, the first protection unit 21 includes an overvoltage protection circuit 14 and a step-down switch; the overvoltage protection circuit 14 is connected to the step-down switch; and the overvoltage protection circuit 14 is connected to a charging input port of the mobile power supply.

[0037] Specifically, the first protection unit 21 includes an overvoltage protection circuit 14 and a step-down switch, which are connected to each other; wherein the overvoltage protection circuit 14 detects the power supply voltage of the charging input port, and when the power supply voltage is too high, the step-down switch is turned on to reduce the power supply voltage to a preset voltage value, thereby performing the first layer of protection for the battery cell 11.

[0038] In some embodiments, the second protection unit 22 includes a charge and discharge chip 13 and a charge and discharge switch built into the charge and discharge chip 13; one end of the charge and discharge chip 13 is connected to the overvoltage protection circuit 14, and the other end of the charge and discharge chip 13 is connected to the discharge output port of the mobile power supply.

[0039] Specifically, the second protection unit 22 includes a charge and discharge chip 13, which has a built-in charge and discharge switch; the charge and discharge chip 13 is connected to the overvoltage protection circuit 14. When the first protection unit 21 reduces the power supply voltage of the charging input port to a preset voltage value, the reduced voltage is input into the second protection unit 22. In the charging state, the charge and discharge switch is turned on, and the charge and discharge chip 13 charges the battery cell 11; in the discharging state, the charge and discharge switch is turned on, and the battery cell 11 is boosted by the charge and discharge chip 13 to provide a discharge output power supply for an external load; more specifically, when charging is completed, the charge and discharge switch in the charge and discharge chip 13 is turned off, and the battery cell 11 is subjected to a second level of protection through the charge and discharge chip 13 of the second protection unit 22.

[0040] In some of the embodiments, the third protection unit 23 includes a battery cell protection circuit 12 and a detector; the detector is connected to the battery cell 11 , and the detector is also connected to the battery cell protection circuit 12 .

[0041] Specifically, when the second protection unit 22 confirms that the charging and discharging of the battery cell 11 is started, the detector in the third protection unit 23 detects the voltage and current of the battery cell 11, and transmits the detected voltage and current of the battery cell 11 to the battery cell protection circuit 12. When the battery cell protection circuit 12 detects that the voltage reaches a preset protection threshold, the charging and discharging operation of the battery cell 11 is stopped, thereby performing the third level of protection on the battery cell 11.

[0042] In some of these embodiments, reference Figure 2 , Figure 2 1 is a schematic diagram of the structure of the control module 3 of the embodiment of the present application. The control module 3 includes a battery voltage sampling circuit 18, a single chip microcomputer 15, a power chip 16 and a power control circuit 17; the battery voltage sampling circuit 18 is connected to the single chip microcomputer 15; the single chip microcomputer 15 is connected to the charge and discharge chip 13. The power chip 16 is connected to the single chip microcomputer 15. The power control circuit 17 is connected to the single chip microcomputer 15 and is also connected to the power chip 16.

[0043] Specifically, the single-chip microcomputer 15 in the control module 3 is connected to the charge and discharge chip 13 of the second protection unit 22 in the battery protection module 2, and is also connected to the battery voltage sampling circuit 18. The battery voltage sampling circuit 18 obtains the voltage of the battery and sends it to the single-chip microcomputer 15. The single-chip microcomputer 15 controls the charging and discharging of the charge and discharge chip 13 through the voltage of the battery; the power chip 16 is connected to the power pin of the single-chip microcomputer 15 to provide power to the single-chip microcomputer 15; the power control circuit 17 is connected to the single-chip microcomputer 15 and the power chip 16 to control whether the power chip 16 outputs power to the single-chip microcomputer 15; more specifically, the opening and closing of the charge and discharge switch in the second protection unit 22 is controlled by the single-chip microcomputer 15, thereby controlling the charging and discharging of the charge and discharge chip 13.

[0044] In some embodiments, the charge and discharge switch includes a front switch and a rear switch; the front switch is connected to the overvoltage protection circuit 14; the rear switch is connected to the positive electrode of the battery cell 11. The single chip 15 is provided with a register for configuring the state of the front switch and the state of the rear switch.

[0045] Specifically, the charging and discharging chip 13 has a built-in charging circuit, and the front stage of the charging and discharging chip 13 has a switch, which connects the overvoltage protection circuit 14 and the charging circuit, and the single-chip microcomputer 15 can configure the state of the front stage switch by configuring the register of the charging and discharging chip 13. The back stage of the charging and discharging chip 13 also has a switch, which connects the charging circuit and the positive electrode of the battery cell 11, and the single-chip microcomputer 15 can configure the state of the back stage switch by configuring the register of the charging and discharging chip 13.

[0046] The present embodiment is described and illustrated by means of specific examples below.

[0047] Figure 3 Schematic diagram of a mobile power supply device according to this specific embodiment. Figure 3 The device includes a battery cell 11, a battery cell protection circuit 12, a charge and discharge chip 13, an overvoltage protection circuit 14, a single chip computer 15, a power chip 16, a power control circuit 17 and a battery voltage sampling circuit 18.

[0048] The battery cell 11 stores electric energy when the mobile power supply is in a charging state, and provides power for the internal circuit of the mobile power supply and the external load in a discharging state. The battery cell 11 is provided with two parameters: a charging cut-off voltage and a discharging cut-off voltage. The battery cell protection circuit 12 is connected to the battery cell 11 to provide safety protection for the battery cell 11, and plays the role of overcharge protection, over-discharge protection, overcurrent protection, and short circuit protection by collecting the voltage and current of the battery cell 11. The charging and discharging chip 13 is connected to the battery cell 11 and the subsequent single-chip microcomputer 15. In the charging state, the charging and discharging chip 13 opens the internal charging circuit to charge the battery cell 11. In the discharging state, the battery cell 11 provides a discharge output power supply to the external load after being boosted by the charging and discharging chip 13. The overvoltage protection circuit 14 is connected to the charging and discharging chip 15. The single-chip microcomputer 15 is connected to the input port of the single-chip microcomputer 13. When the input power voltage of the charging port is too high, the step-down switch is turned on and the power voltage is reduced to a preset power voltage value, thereby protecting the charging and discharging chip 13 from being damaged by the excessively high power voltage; the single-chip microcomputer 15 is connected to the charging and discharging chip 13 and the battery voltage sampling circuit 18. The single-chip microcomputer 15 obtains the battery voltage through the battery voltage sampling circuit 18, and controls the charging and discharging of the charging and discharging chip 13 according to the battery voltage; the power chip 16 is connected to the power pin of the single-chip microcomputer 15 to provide power to the single-chip microcomputer 15; the power control circuit 17 is connected to the single-chip microcomputer 15 and the power chip 16. The power control circuit 17 controls whether the power chip 16 outputs power to the single-chip microcomputer 15.

[0049] In one possible embodiment, when the mobile power source is charged and discharged, the battery voltage is first sampled through the battery voltage sampling circuit 18 connected to the single-chip microcomputer 15, and the battery voltage is obtained and sent to the single-chip microcomputer 15; when the single-chip microcomputer 15 obtains the battery voltage, the power input and power output of the charge and discharge chip 13 are set to be turned on and off through the communication interface; secondly, the single-chip microcomputer 15 turns on and off the charging function and the discharging function of the charge and discharge chip 13 through the communication interface; further, the battery cell protection circuit 12 can also collect the battery voltage in real time, and when the battery cell 11 voltage reaches the overcharge protection voltage and over-discharge protection voltage of the lithium battery protection chip, it will also trigger the lithium battery protection chip to start protection and disconnect the negative electrode of the battery cell 11 from the system ground. Through the above triple protection, the safety of the battery cell 11 of the mobile power source is greatly improved, the occurrence of overcharge and over-discharge events is avoided, and the safety and reliability of the mobile power source are improved.

[0050] Figure 4 is a schematic diagram of the cell protection circuit 12 in this specific embodiment; Figure 4, the battery cell protection circuit 12 includes a resistor R10, a power supply BT1, a capacitor C11 and a lithium battery protection chip U2; illustratively, the resistance of the resistor R10 here is 1KΩ, the accuracy of the resistor R10 is 5%, the capacitance of the capacitor C11 is 0.1μf, the voltage of the power supply BT1 is 3.7V, the current is 5AH, and the lithium battery protection chip U2 uses the chip XB8886G; wherein, the positive electrode of the power supply BT1 is connected to the positive electrode BAT+ of the battery cell 11, the negative electrode of the power supply BT1 is connected to the negative electrode BAT- of the battery cell 11, BAT+ connects the resistor R10 to the pin 6 of the lithium battery protection chip U2, the pin 6 of the lithium battery protection chip U2 is also connected to the capacitor C11, the other end of the capacitor C11 is connected to the negative electrode BAT- of the battery cell 11, the pins 5, 7 and 8 of U2 are also connected to the negative electrode BAT- of the battery cell 11, and the pins 1, 2, 3, and 4 of U2 are connected to the system ground. When the voltage of the battery cell 11 collected by the battery cell protection circuit 12 reaches the overcharge and over-discharge protection threshold of the lithium battery protection chip U2, the lithium battery protection chip U2 will disconnect the connection between the negative electrode of the battery cell 11 and the system ground, that is, disconnect the pins 5, 7, 8 of the lithium battery protection chip U2 from the pins 1, 2, 3, and 4. Among them, the pins 5, 7, and 8 of the lithium battery protection chip U2 are the ground pins GND of the chip, that is, connected to the negative electrode of the power supply; the pin 6 of the lithium battery protection chip U2 is the power supply voltage pin VDD; the pins 1, 2, 3, and 4 of the lithium battery protection chip U2 are the pins VM of the chip's adjustable power supply voltage, and the pin VM represents the negative electrode of the battery pack, and the internal FET switch connects this end to GND; the pin EPAD of the lithium battery protection chip U2 is an exposed gasket, which must be connected to the GND of the XB8886G with a large amount of metal. Exemplarily, when the voltage of the battery cell 11 collected by the battery cell protection circuit 12 does not reach the overcharge and overdischarge protection threshold of the lithium battery protection chip U2, pins 5, 7, and 8 of the lithium battery protection chip U2 are connected to pins 1, 2, 3, and 4.

[0051] Figure 5 is a schematic diagram of the battery voltage sampling circuit 18 in this specific embodiment; Figure 5 , the battery voltage sampling circuit 18 includes a resistor R41, a resistor R42 and a capacitor C38; illustratively, the resistance of the resistor R41 is 200KΩ, the accuracy of the resistor R41 is ±1%, the resistance of the resistor R42 is 100KΩ, the accuracy of the resistor R42 is ±5%, the capacitance of the capacitor C38 is 100nF, and the accuracy is ±10%; VBAT is the positive electrode of the battery cell 11, VBAT is connected to the sampling resistor R41 and then connected to the sampling resistor R42, the other end of R42 is connected to the system ground, the two ends of the capacitor C38 are respectively connected to the two ends of R42, and one end of the capacitor C38 is connected to the ADC (Analog to Digital Converter) pin of the microcontroller 15, that is, Figure 5 The BATADC shown in .

[0052] The following specifically describes the implementation of the triple overcharge protection and triple over-discharge protection of the battery cell 11 through the above-mentioned battery cell protection circuit 12 and the battery voltage protection circuit.

[0053] The specific implementation of triple overcharge protection is as follows: the positive electrode VBAT of the battery cell 11 is divided by two sampling resistors R41 and R42, filtered by capacitor C38, and connected to the ADC sampling pin BATADC of the microcontroller 15. The relationship between the sampling pin BATADC and the voltage of the battery cell 11 is expressed by the formula:

[0054] VBATADC=VBAT*R42 / (R41+R42)

[0055] Among them, VBAT is the voltage value of the battery cell 11, R41 and R42 are the resistance values ​​respectively, and VBATADC is the voltage value of the ADC sampling pin of the single-chip microcomputer 15. During the charging process, the BATADC pin of the single-chip microcomputer 15 will monitor the voltage VBAT of the battery cell 11 in real time; at the same time, the charging cut-off voltage threshold of the charge and discharge chip 13 is set to V1 through the communication interface. When the single-chip microcomputer 15 detects that VBAT=V1, the first level of protection is turned on, that is, the single-chip microcomputer 15 controls the charge and discharge chip 13 through the communication interface to turn off the power supply voltage input. At this time, the charge and discharge chip 13 cannot charge the battery cell 11 after reducing the voltage through the internal step-down circuit; if the first level of protection fails, the single-chip microcomputer 15 detects that the voltage VBAT of the battery cell 11 ≥V1 through the battery voltage sampling circuit 18, and turns on the second level of protection. The single-chip microcomputer 15 sets the charge and discharge through the communication interface. The electric chip 13 turns off the charging function, that is, disconnects the connection between the charging and discharging chip 13 and the battery cell 11; if both the first-level protection and the second-level protection fail, the charging and discharging chip 13 still turns on the charging function, and the positive electrode VBAT of the battery cell 11 is connected to the power pin 6 of the lithium battery protection chip U2 through the resistor R10. Since the lithium battery protection chip U2 has a built-in voltage sampling circuit and a comparison circuit, when the voltage VBAT reaches the overcharge protection threshold V2 of the lithium battery cell 11, that is, V2>V1, the lithium battery protection chip will disconnect the connection between the negative electrode of the battery and the system ground. At this time, the charging circuit is cut off, and the battery cell 11 cannot be charged further, thereby achieving the purpose of the third-level overcharge protection.

[0056] The specific implementation of triple over-discharge protection is as follows: the positive electrode VBAT of the battery cell 11 is divided by two sampling resistors R41 and R42, and then connected to the ADC sampling pin BATADC of the single-chip microcomputer 15 after filtering by the capacitor C38, and then the voltage value VBATADC of the ADC sampling pin BATADC is obtained. During the discharge process, the BATADC pin of the single-chip microcomputer 15 will monitor the voltage VBAT of the battery cell 11 in real time, and at the same time set the discharge cut-off voltage threshold of the charge and discharge chip 13 to V3 through the communication interface. When the single-chip microcomputer 15 detects that VBAT=V3, the first level of protection is turned on, and the single-chip microcomputer 15 controls the charge and discharge chip 13 to turn off the power output through the communication interface. At this time, the charge and discharge chip 13 cannot boost the output voltage through the internal boost circuit; when the first level of discharge protection fails, the single-chip microcomputer 15 detects that the voltage VBAT of the battery cell 11 is ≤V3 through the battery voltage sampling circuit 18, and then the second level of discharge protection is turned on, and the single-chip microcomputer 15 sets the charge and discharge chip 13 through the communication interface. 13 turns off the discharge function, that is, disconnecting the connection between the charge and discharge chip 13 and the battery cell 11; if both the first-level discharge protection and the second-level discharge protection fail, the charge and discharge chip 13 still turns on the discharge function, and the positive electrode VBAT of the battery cell 11 is connected to the power pin 6 of the lithium battery protection chip U2 through the resistor R10. Since the lithium battery protection chip U2 has a built-in voltage sampling circuit and a comparison circuit, when the voltage VBAT reaches the over-discharge protection threshold V4 of the lithium battery protection cell 11, that is, V4<V3, the lithium battery protection chip will disconnect the connection between the negative electrode of the battery and the system ground. At this time, the discharge circuit is cut off, and the battery cell 11 cannot continue to discharge to the outside, thereby achieving the purpose of the third-level over-discharge protection.

[0057] In one specific embodiment, the charging input of the mobile power supply is a 5V power supply, and the input range of the charge and discharge chip 13 is 4.65V to 6V. When the input power is greater than 6V, the overvoltage protection circuit 14 will clamp the input power at 5.5V to ensure that it does not exceed the input range of the charge and discharge chip 13, thereby protecting the charge and discharge chip 13 from damage by overvoltage. The charge and discharge chip 13 has a built-in charging circuit. There is a switch in the front stage of the charge and discharge chip 13, which connects the overvoltage protection circuit 14 and the charging circuit. The single-chip microcomputer 15 can configure the state of the front-stage switch by configuring the register of the charge and discharge chip 13. There is also a switch in the rear stage of the charge and discharge chip 13, which connects the charging circuit and the positive pole of the battery cell 11. The single-chip microcomputer 15 can configure the state of the rear-stage switch by configuring the register of the charge and discharge chip 13. During normal charging, the single-chip computer 15 will turn on both the pre-stage switch and the post-stage switch of the charge-discharge chip 13. The charge-discharge chip 13 will step down the input 5V power supply to 3V~4.2V and then charge the battery cell 11. When the single-chip computer 15 obtains through the battery voltage sampling circuit 18 that the battery voltage has reached 4.2V, that is, the battery is fully charged, the pre-charge switch and the post-charge switch of the charge-discharge chip 13 will be turned off respectively, thereby stopping the charging of the battery cell 11. If both the first-level overcharge protection and the second-level overcharge protection fail, that is, after the battery voltage reaches 4.2V, the pre-charge switch and the post-charge switch of the charge-discharge chip 13 are not turned off, and the battery continues to charge. When the battery voltage continues to charge to 4.25V, the lithium protection chip of the battery protection circuit 12 detects that the battery voltage has reached the overcharge protection threshold of 4.25V, and the negative electrode of the battery will be disconnected from the system ground. At this time, the charging of the battery cell 11 will also be stopped, which plays the role of the third-level protection.

[0058] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0059] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present invention and are not intended to limit the present invention. As long as they are within the spirit of the present invention, appropriate changes and modifications to the above embodiments are within the scope of protection required by the present invention.

Claims

1. A mobile power protection device, characterized in that: include: Battery cells, battery cell protection modules and control modules; The battery cell protection module is connected to the control module and the battery cell respectively; The battery cell protection module includes a first protection unit, a second protection unit and a third protection unit; The input end of the first protection unit is connected to the charging input port of the mobile power supply; the first protection unit is connected to the second protection unit; the second protection unit is connected to the input and output ports of the control module; The third protection unit is connected to the battery cell.

2. The mobile power protection device according to claim 1, characterized in that: The first protection unit includes an overvoltage protection circuit and a step-down switch; the overvoltage protection circuit is connected to the step-down switch; and the overvoltage protection circuit is connected to the charging input port of the mobile power supply.

3. The mobile power protection device according to claim 2, characterized in that: The second protection unit includes a charge and discharge chip and a charge and discharge switch built into the charge and discharge chip; One end of the charge and discharge chip is connected to the overvoltage protection circuit, and the other end of the charge and discharge chip is connected to the discharge output port of the mobile power supply.

4. The mobile power protection device according to claim 1, characterized in that: The third protection unit includes a battery cell protection circuit and a detector; the detector is connected to the battery cell, and the detector is also connected to the battery cell protection circuit.

5. The mobile power protection device according to claim 3, characterized in that: The control module includes a battery voltage sampling circuit and a single chip microcomputer; The battery voltage sampling circuit is connected to the single chip microcomputer; the single chip microcomputer is connected to the charging and discharging chip.

6. The mobile power protection device according to claim 5, characterized in that: The control module also includes a power chip; The power chip is connected to the single chip microcomputer.

7. The mobile power protection device according to claim 6, characterized in that: The control module also includes a power control circuit; The power control circuit is connected to the single chip microcomputer and is also connected to the power chip.

8. The mobile power protection device according to claim 5, characterized in that: The charge and discharge switch comprises a front-stage switch and a rear-stage switch; The front-stage switch is connected to the overvoltage protection circuit; the rear-stage switch is connected to the positive electrode of the battery cell.

9. The mobile power protection device according to claim 8, characterized in that: The single chip microcomputer is provided with a register for configuring the state of the front-stage switch and the state of the rear-stage switch.

10. A charging and discharging device, characterized in that: It comprises a mobile device and a mobile power protection device according to any one of claims 1 to 9.

Images