Temperature protection circuit of battery pack

Abstract

The utility model relates to a temperature protection circuit of a battery pack. The temperature protection circuit of the battery pack comprises the battery pack and a protection module, the protection module comprises a first temperature control unit, a second temperature control unit and a third temperature control unit, the first temperature control unit is electrically connected with the battery pack, the second temperature control unit is electrically connected with the first temperature control unit, and the third temperature control unit is electrically connected with the second temperature control unit. According to the scheme provided by the invention, multiple protection can be provided for the lithium battery pack, so that the risk of explosion of the lithium battery pack caused by out-of-control temperature is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a temperature protection circuit for a battery pack. Background Art

[0002] At present, lithium battery packs are widely used in home appliances, automobiles, and industrial manufacturing.

[0003] In the prior art, lithium battery packs typically have only a single level of protection: a protection chip that sets a temperature threshold to protect the battery pack. If the protection chip fails, there is no alternative solution, and the battery pack faces the risk of temperature runaway and explosion. Therefore, this protection method is relatively simple. Utility Model Content

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a temperature protection circuit for a battery pack, which can provide multiple protections for the lithium battery pack, thereby reducing the risk of explosion of the lithium battery pack due to temperature runaway.

[0005] The purpose of this utility model is achieved through the following technical solutions:

[0006] In a first aspect, the present application provides a temperature protection circuit for a battery pack, comprising: a battery pack; a protection module, comprising a first temperature control unit, a second temperature control unit, and a third temperature control unit, wherein the first temperature control unit is electrically connected to the battery pack, the second temperature control unit is electrically connected to the first temperature control unit, and the third temperature control unit is electrically connected to the second temperature control unit.

[0007] The first temperature control unit includes a chip U1 and a resistor R1. The chip U1 is electrically connected to the battery pack. A first end of the resistor R1 is electrically connected to the chip U1, and a second end of the resistor R1 is grounded.

[0008] The first temperature control unit further includes a MOS transistor Q1 and a MOS transistor Q2 , and the MOS transistor Q1 and the MOS transistor Q2 are electrically connected to the chip U1 respectively.

[0009] The second temperature control unit includes a chip U2 and a resistor R2. The chip U2 is electrically connected to the chip U1. The MOS transistors Q1 and Q2 are also electrically connected to the chip U2, respectively. A first end of the resistor R2 is electrically connected to the chip U2, and a second end of the resistor R2 is grounded.

[0010] The second temperature control unit further includes a buzzer LS1 , and the buzzer LS1 is electrically connected to the chip U2 .

[0011] The second temperature control unit further includes a fuse F1 , which is electrically connected to the buzzer LS1 .

[0012] The third temperature control unit includes a resistor R3 and a resistor R4. The first end of the resistor R3 is electrically connected to the chip U2, and the second end of the resistor R3 is grounded. The first end of the resistor R4 is electrically connected to the chip U2, and the second end of the resistor R4 is grounded.

[0013] The protection module further includes a resistor R5 , a first end of the resistor R5 is electrically connected to the battery pack, and a second end of the resistor R5 is electrically connected to the chip U1 .

[0014] It also includes a first output end, which is electrically connected to the fuse F1.

[0015] It also includes a second output end, which is electrically connected to the MOS transistor Q2.

[0016] Compared with the prior art, the present invention has at least the following advantages:

[0017] This application provides triple all-round protection for the battery pack by setting up a first temperature control unit, a second temperature control unit and a third temperature control unit. The temperature thresholds corresponding to the first temperature control unit, the second temperature control unit and the third temperature control unit are all different, thereby reducing the risk of explosion of the battery pack due to temperature out of control. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following briefly introduces the drawings required for use in the embodiments.

[0019] Figure 1 This is a functional module diagram of a temperature protection circuit for a battery pack in one embodiment of the present invention;

[0020] Figure 2 This is a circuit diagram of a temperature protection circuit for a battery pack in one embodiment of the present invention. DETAILED DESCRIPTION

[0021] The following describes embodiments of the present application in more detail with reference to the accompanying drawings. Although the accompanying drawings illustrate embodiments of the present application, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. Rather, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0022] It should be understood that although the terms "first", "second", "third", etc. may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0023] Unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," and the like should be interpreted broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0024] Currently, lithium-ion battery packs typically have only a single level of protection: a protection chip that sets a temperature threshold to protect the battery pack. If the protection chip fails, there is no alternative, and the battery pack faces the risk of temperature runaway and explosion. This is a relatively simple protection method.

[0025] To address the above problems, an embodiment of the present application provides a temperature protection circuit for a battery pack, which can provide multiple protections for the lithium battery pack, thereby reducing the risk of explosion of the lithium battery pack due to temperature runaway.

[0026] The technical solutions of the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0027] See also Figure 1 A temperature protection circuit for a battery pack includes: a battery pack 100 and a protection module 200, the protection module 200 includes a first temperature control unit 210, a second temperature control unit 220 and a third temperature control unit 230, the first temperature control unit 210 is electrically connected to the battery pack 100, the second temperature control unit 220 is electrically connected to the first temperature control unit 210, and the third temperature control unit 230 is electrically connected to the second temperature control unit 220.

[0028] It should be noted that the battery pack 100 is a lithium battery pack, and the temperature thresholds of the first temperature control unit 210, the second temperature control unit 220, and the third temperature control unit 230 are all different. These temperature thresholds correspond to a protection mechanism. Thus, by configuring the first temperature control unit 210, the second temperature control unit 220, and the third temperature control unit 230, it is possible to ensure that the battery pack 100 is protected at various dangerous temperatures, thereby preventing the battery pack 100 from exploding.

[0029] See also Figure 2 In one embodiment, the first temperature control unit 210 includes a chip U1 and a resistor R1. The chip U1 is electrically connected to the battery pack 100. A first end of the resistor R1 is electrically connected to the chip U1, and a second end of the resistor R1 is grounded. Specifically, the first temperature control unit 210 also includes a MOS transistor Q1 and a MOS transistor Q2. The MOS transistors Q1 and Q2 are each electrically connected to the chip U1.

[0030] It should be noted that the chip U1 is an AFE chip, the resistor R1 is a thermistor, and the resistor R1 is used to collect the temperature of the battery pack 100 by measuring the temperature change of its resistance. The MOS tubes Q1 and Q2 act as switches.

[0031] See also Figure 2 In one embodiment, the second temperature control unit 220 includes a chip U2 and a resistor R2. The chip U2 is electrically connected to the chip U1. The MOS transistor Q1 and the MOS transistor Q2 are also electrically connected to the chip U2 respectively. The first end of the resistor R2 is electrically connected to the chip U2, and the second end of the resistor R2 is grounded.

[0032] It should be noted that the chip U2 is an MCU chip, and the resistor R2 is a thermistor. The resistor R2 is used to collect the temperature of the battery pack 100, and the temperature is collected by the characteristic that its resistance changes with temperature.

[0033] See also Figure 2 In one embodiment, the second temperature control unit 220 further includes a buzzer LS1 , which is electrically connected to the chip U2 .

[0034] It should be noted that the buzzer LS1 is used to emit a sound to warn that the battery pack has experienced temperature runaway.

[0035] See also Figure 2 In one embodiment, the second temperature control unit 220 further includes a fuse F1 , and the fuse F1 is electrically connected to the buzzer LS1 .

[0036] It should be noted that the fuse F1 is used to protect the circuit.

[0037] See also Figure 2In one embodiment, the third temperature control unit 230 includes a resistor R3 and a resistor R4, a first end of the resistor R3 is electrically connected to the chip U2, a second end of the resistor R3 is grounded, a first end of the resistor R4 is electrically connected to the chip U2, and a second end of the resistor R4 is grounded.

[0038] It should be noted that the resistor R3 and the resistor R4 are a thermistor switch, which is in an open state under normal circumstances. When the temperature reaches the threshold of the resistor R3 and the resistor R4, the resistor R3 and the resistor R4 will be in a closed state.

[0039] See also Figure 2 In one embodiment, the protection module 200 further includes a resistor R5 , a first end of the resistor R5 is electrically connected to the battery pack 100 , and a second end of the resistor R5 is electrically connected to the chip U1 .

[0040] It should be noted that the resistor R5 is a detection resistor used to detect current.

[0041] See also Figure 2 In one embodiment, a temperature protection circuit of a battery pack further includes a first output terminal electrically connected to the fuse F1. Specifically, a temperature protection circuit of a battery pack further includes a second output terminal electrically connected to the MOS tube Q2.

[0042] It should be noted that the first output terminal is the positive output terminal, and the second output terminal is the negative output terminal.

[0043] The circuit principle of this application is described below:

[0044] The discharge temperature range of the cells in a conventional battery pack is -20 degrees Celsius to 60 degrees Celsius, and the charging temperature is 0 degrees Celsius to 50 degrees Celsius. Furthermore, the chip U1 of the first temperature control unit is paired with a resistor R1. When the temperature collected by the resistor R1 is higher or lower than the set value, the chip U1 will drive the MOS tube Q1 and MOS tube Q2 to cut off the output of the battery pack. At the same time, the chip U2 will drive the buzzer LS1 to sound. Among them, the temperature setting value is flexibly set according to the cell discharge temperature range and the charging temperature range. Usually, the first-level discharge over-temperature protection is 60 degrees Celsius, and the charging over-temperature protection is 50 degrees Celsius.

[0045] The second temperature control unit, chip U2, is paired with resistor R2. When the temperature sensed by resistor R2 is above or below a set value, chip U2 switches off MOS transistors Q1 and Q2. However, if MOS transistors Q1 and Q2 fail, chip U2 triggers fuse F1 to shut down the battery pack's input and output, while buzzer LS1 sounds an alarm. The set temperature here is 5 to 10 degrees Celsius higher than that of the first temperature control unit to expand the protection range. Furthermore, the temperature setting of chip U2 can be adjusted based on actual conditions.

[0046] Resistors R3 and R4 of the third temperature control unit have the same specifications and simultaneously collect the battery pack temperature. Since resistors R3 and R4 act as thermistor switches, when the temperature exceeds their thresholds, they close, forcibly disconnecting MOS transistors Q1 and Q2, thereby shutting off the battery's input and output. The temperature threshold for resistors R3 and R4 is 75 degrees Celsius.

[0047] Through the above settings, it can be ensured that the battery pack can trigger protection at different dangerous temperatures, thereby preventing the battery pack from exploding.

[0048] The scheme of the present application has been described in detail above with reference to the accompanying drawings. In the above embodiments, the descriptions of each embodiment have their own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments. Those skilled in the art should also be aware that the actions and modules involved in the description are not necessarily required for this application. In addition, it is understood that the steps in the method of the embodiment of the present application can be adjusted in sequence, merged and deleted according to actual needs, and the modules in the device of the embodiment of the present application can be merged, divided and deleted according to actual needs.

[0049] The embodiments of the present application have been described above. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, their practical applications, or improvements to the technology in the market, or to enable other persons skilled in the art to understand the embodiments disclosed herein.

Claims

1. A temperature protection circuit for a battery pack, characterized in that: include: Battery pack; The protection module includes a first temperature control unit, a second temperature control unit and a third temperature control unit, wherein the first temperature control unit is electrically connected to the battery pack, the second temperature control unit is electrically connected to the first temperature control unit, and the third temperature control unit is electrically connected to the second temperature control unit.

2. The temperature protection circuit of the battery pack according to claim 1, characterized in that: The first temperature control unit includes a chip U1 and a resistor R1. The chip U1 is electrically connected to the battery pack. A first end of the resistor R1 is electrically connected to the chip U1, and a second end of the resistor R1 is grounded.

3. The temperature protection circuit of the battery pack according to claim 2, characterized in that: The first temperature control unit further includes a MOS transistor Q1 and a MOS transistor Q2 , and the MOS transistor Q1 and the MOS transistor Q2 are electrically connected to the chip U1 respectively.

4. The temperature protection circuit of the battery pack according to claim 3, characterized in that: The second temperature control unit includes a chip U2 and a resistor R2. The chip U2 is electrically connected to the chip U1. The MOS transistors Q1 and Q2 are also electrically connected to the chip U2, respectively. A first end of the resistor R2 is electrically connected to the chip U2, and a second end of the resistor R2 is grounded.

5. The temperature protection circuit of the battery pack according to claim 4, characterized in that: The second temperature control unit further includes a buzzer LS1 , and the buzzer LS1 is electrically connected to the chip U2 .

6. The temperature protection circuit of the battery pack according to claim 5, characterized in that: The second temperature control unit further includes a fuse F1 , which is electrically connected to the buzzer LS1 .

7. The temperature protection circuit of the battery pack according to claim 5, characterized in that: The third temperature control unit includes a resistor R3 and a resistor R4. The first end of the resistor R3 is electrically connected to the chip U2, and the second end of the resistor R3 is grounded. The first end of the resistor R4 is electrically connected to the chip U2, and the second end of the resistor R4 is grounded.

8. The temperature protection circuit of the battery pack according to claim 6, characterized in that: The protection module further includes a resistor R5 , a first end of the resistor R5 is electrically connected to the battery pack, and a second end of the resistor R5 is electrically connected to the chip U1 .

9. The temperature protection circuit of the battery pack according to claim 6, characterized in that: It also includes a first output end, which is electrically connected to the fuse F1.

10. The temperature protection circuit of the battery pack according to claim 7, characterized in that: It also includes a second output end, which is electrically connected to the MOS transistor Q2.

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