CN222484323U - A protection circuit for a rechargeable battery - Google Patents

Abstract

The embodiment of the utility model discloses a protection circuit for a rechargeable battery, which relates to the technical field of charging and discharging of storage batteries, and comprises a first control chip, a second control chip, a charging module, a discharging module, a first overload protection device and a second overload protection device; the discharging module is respectively connected with the first overload protection device, the first control chip and a preset rechargeable battery, the charging module is respectively connected with the first control chip, the second overload protection device and the rechargeable battery, the preset charger is respectively connected with the first control chip and the second overload protection device, and the first overload protection device is connected with a preset discharging electrode. The method has the advantages that multiple protection is set up for battery charging and discharging, and the effect of improving the safety performance of the battery pack is achieved.

Description

Protection circuit for rechargeable battery

Technical Field

The utility model relates to the technical field of storage battery charging and discharging, in particular to a protection circuit for a rechargeable battery.

Background

The rechargeable battery has the advantages of economy, environmental protection, sufficient electric quantity, suitability for high power, long-time use and the like, and is deeply favored by consumers. On the one hand, when the battery is connected reversely, the result is quite serious, negative pressure formed by the reverse connection is easy to break down the power supply chip and explode, and on the other hand, the battery is over-charged and over-discharged to cause unrecoverable damage to the battery, so that the service life of the battery is seriously influenced.

Disclosure of utility model

The technical problem to be solved by the embodiment of the utility model is that potential safety hazards exist on the structure of the rechargeable battery, and the safety performance needs to be improved to ensure the safety of users.

In order to solve the above problems, an embodiment of the present utility model discloses a protection circuit for a rechargeable battery. The battery is charged and discharged to establish multiple protection, so that the effect of improving the safety performance of the battery pack is achieved.

The utility model provides a protection circuit for a rechargeable battery, which comprises a first control chip, a second control chip, a charging module, a discharging module, a first overload protection device and a second overload protection device, wherein the discharging module is respectively connected with the first overload protection device, the first control chip and a preset rechargeable battery, the charging module is respectively connected with the first control chip, the second overload protection device and the rechargeable battery, and a preset charger is respectively connected with the first control chip and the second overload protection device, and the first overload protection device is connected with a preset discharge electrode.

The charging module comprises a first MOS tube and a second MOS tube, wherein the first MOS tube is respectively connected with the first control chip, the second MOS tube and the rechargeable battery, and the second MOS tube is respectively connected with the second control chip and the second overload protection device.

The first MOS tube comprises a first source electrode, a first grid electrode and a first drain electrode, wherein the first source electrode is connected with the second MOS tube, the first grid electrode is connected with the first control chip, and the first drain electrode is connected with the rechargeable battery.

The second MOS tube comprises a second source electrode, a second grid electrode and a second drain electrode, wherein the second source electrode is connected with the second overload protection device, the second grid electrode is connected with the second control chip, and the second drain electrode is connected with the first MOS tube.

The further technical scheme is that the intelligent charger further comprises an identification module, wherein the identification module is respectively connected with the first control chip and the charger.

The further technical scheme is that the identification module comprises a switch and an anti-reverse connection unit, the switch is respectively connected with the anti-reverse connection unit and the first control chip, and the anti-reverse connection unit is connected with the charger.

The discharge module comprises a plurality of third MOS tubes connected in parallel.

The technical scheme is that the intelligent control system further comprises a third control chip, wherein the third control chip is connected with the first control chip.

The further technical scheme is that the first overload protection device is a fuse.

The further technical scheme is that the second overload protection device is a fuse.

Compared with the prior art, the technical effects achieved by the embodiment of the utility model include:

The battery charging has quadruple protection, namely, the first control chip directly controls the connection/disconnection of the charging module, the second control chip detects the voltage of the charging module, the charging module is disconnected when the voltage of the charging module exceeds a threshold value, the charging is stopped, the charger stops the battery charging according to the low level fed back by the circuit, and the fourth overload protection device prevents the circuit from overload.

The battery discharging has double protection, namely, the first control chip directly controls the connection/disconnection of the discharging module, and the second overload protection device prevents the overload of the circuit.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings required for the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present utility model, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic diagram of a protection circuit for a rechargeable battery according to an embodiment of the present utility model;

Fig. 2 is a schematic diagram of another protection circuit for a rechargeable battery according to an embodiment of the present utility model;

Fig. 3 is a circuit diagram of a second control chip U8 according to an embodiment of the present utility model;

Fig. 4 is a circuit diagram of a third control chip U5 according to an embodiment of the present utility model.

Reference numerals

The device comprises a first control chip U7, a second control chip U8, an identification module 1, a charging module 3, a discharging module 4, a first overload protection device 5, a second overload protection device 6, a first MOS tube Q40, a second MOS tube Q41, a third control chip U5, a rechargeable battery 91 and a charger 92.

Detailed Description

The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the drawings in the embodiments of the present utility model, in which like reference numerals represent like components. It will be apparent that the embodiments described below are only some, but not all, embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

It should be understood that the terms "comprises" and "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It is also to be understood that the terminology used in the description of the embodiments of the utility model herein is for the purpose of describing particular embodiments only and is not intended to be limiting of embodiments of the utility model. As used in the specification of the embodiments of the utility model and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

Referring to fig. 1-4, an embodiment of the present utility model provides a protection circuit for a rechargeable battery 91. The protection circuit for the rechargeable battery 91 comprises a first control chip U7, a second control chip U8, a charging module 3, a discharging module 4, a first overload protection device 5 and a second overload protection device 6, wherein the discharging module 4 is respectively connected with the first overload protection device 5, the first control chip U7 and a preset rechargeable battery 91, the charging module 3 is respectively connected with the first control chip U7, the second control chip U8, the second overload protection device 6 and the rechargeable battery 91, a preset charger 92 is respectively connected with the first control chip U7 and the second overload protection device 6, and the first overload protection device 5 is connected with a preset discharging electrode. The specific description of each component is as follows:

In the present embodiment, the charging module 3 is connected to the negative electrode (B-) of the rechargeable battery 91 and to the negative electrode (P-) of the charger 92, and the positive electrode of the rechargeable battery 91 is connected to the charger 92. The first control chip U7 and the second control chip U8 are respectively connected with the charging module 3, when the first control chip U7 outputs high voltage, the charging module 3 operates, the charger 92 is connected with the rechargeable battery 91 through the charging module 3, the rechargeable battery 91 is charged, when the first control chip U7 outputs low voltage, the charging module 3 stops operating, and the rechargeable battery 91 is stopped. The second control chip U8 is configured to detect a voltage of the charging module 3, and if the voltage value reaches a preset voltage value threshold, the second control chip U8 outputs a low level to control the charging module 3 to be turned off, and stops the operation of the charging module 3, thereby avoiding overcharging. The first control chip U7 outputs a high level to the charger 92 through the identification module 1 when the battery is not full, and the charger 92 charges the high level of the identification module 1 as an active signal. If the charger 92 receives a low level from the identification module 1, the charging of the battery is stopped. The second overload protection device 6 is connected in series between the charging module 3 and the charger 92, and when the charging current is greater than the preset current threshold value of the second overload protection device 6, the second overload protection device 6 is disconnected, so that the charging cut-off is realized. The charge protection of the rechargeable battery 91 is realized.

When the discharge voltage reaches the overdischarge voltage threshold of the first control chip U7, the first control chip U7 turns off the discharge module 4 to terminate the discharge. The first overload protection device 5 is connected in series between the discharging module 4 and the charger 92, and when the discharging current is greater than the preset current threshold value of the first overload protection device 5, the first overload protection device 5 is disconnected, so that the discharging is stopped. Discharge protection of the rechargeable battery 91 is achieved.

The preset discharge electrode comprises a discharge seat of the battery, and also refers to a negative electrode (P-) of the battery, and is used for supplying power to external equipment.

The operation of the protection circuit for the secondary battery 91 is as follows:

And 1. The first control chip U7 outputs high voltage 11V when the battery is not full, the charging MOS tube Q40 and the MOS tube Q41 are opened for charging, the first control chip U7 outputs low voltage 0V after the battery voltage is full, the charging MOS tube Q40 and the MOS tube Q41 are closed, and the charging is stopped.

And 2. The second protection is that when the charging is performed, the first control chip U7 fails, and a certain cell voltage reaches the overcharge protection voltage V1 (4.225V) of the first control chip U7, so that the charging MOS tube Q40 and the MOS tube Q41 cannot be closed, and the charging is continued. When the voltage of a certain battery cell reaches the overcharge protection voltage value V2 (4.25V) of the second control chip U8, the control pin 14 (CO) of the second control chip U8 outputs the low-level control Q29, and the MOS transistor Q41 is closed.

And 3. The first control chip U7 outputs high level 3.3V to the charger 92 through the identification module 1 under the condition that the battery is not full, and the charger 92 is charged and is effective to charge the battery normally when the high level of the identification module 1 is received. When the first control chip U7 fails, the high level cannot be output through the identification module 1, and the charger 92 stops charging the battery.

And 4. The 4 th protection, namely, the charging output end is connected with a second overload protection device 6 in series, when the charging current is more than 3A, the second overload protection device 6 breaks the circuit after charging for a period of time, and the charging is stopped.

With continued reference to fig. 1-4, in this embodiment, the charging module 3 includes a first MOS transistor Q40 and a second MOS transistor Q41, where the first MOS transistor Q40 is connected to the first control chip U7, the second MOS transistor Q41 and the rechargeable battery 91, and the second MOS transistor Q41 is connected to the second control chip U8 and the second overload protection device 6, respectively.

The first MOS transistor Q40 includes a first source, a first gate, and a first drain, the first source is connected to the second MOS transistor Q41, the first gate is connected to the first control chip U7, and the first drain is connected to the rechargeable battery 91.

The second MOS transistor Q41 includes a second source, a second gate, and a second drain, where the second source is connected to the second overload protection device 6, the second gate is connected to the second control chip U8, and the second drain is connected to the first MOS transistor Q40.

In an embodiment, the first MOS transistor Q40 includes a first source, a first gate and a first drain, the first MOS transistor Q40 is an NMOS, the second MOS transistor Q41 includes a second source, a second gate and a second drain, and the second MOS transistor Q41 is an NMOS.

Further, the portable electronic device further comprises an identification module 1, wherein the identification module 1 is respectively connected with the first control chip U7 and the charger 92.

Specifically, the identification module 1 is configured to identify the charger 92, and output a high level of 3.3V to the charger 92 through the identification module 1 when the battery is not full, and the charger 92 is normally effective to charge the battery when the high level of the identification module 1 is received. When the first control chip U7 fails, the high level cannot be output through the identification module 1, and the charger 92 stops charging the battery. The charger 92 is prevented from overcharging the battery due to the failure of the first control chip U7 by the identification module 1.

Further, the identification module 1 includes a switch and an anti-reverse connection unit, the switch is connected to the anti-reverse connection unit and the first control chip U7, respectively, and the anti-reverse connection unit is connected to the charger 92.

Specifically, the switch includes a transistor Q43 and a transistor Q44, in an embodiment, a resistor is further connected between the transistor Q43 and the transistor Q44, the anti-reverse connection unit includes a diode D28, and a resistor is further connected between the transistor Q44 and the diode D28, so as to avoid excessive current of the circuit.

Further, the discharging module 4 includes a plurality of third MOS transistors connected in parallel.

Specifically, the third MOS tube comprises a MOS tube Q1, a MOS tube Q38, a MOS tube Q39 and a MOS tube Q42, and the MOS tube groups are formed by connecting a plurality of third MOS tubes in parallel for active current sharing, so that the difference of the Vgs discreteness is reduced to 1/Kv times, and after current sharing, current sharing and power consumption (temperature sharing) are realized, and input and output linearization is realized.

Further, the device also comprises a third control chip U5, and the third control chip U5 is connected with the first control chip U7.

Specifically, the third control chip U5 includes a memory control chip connected to the first control chip U7 for storing the decision logic of the first control chip U7.

Further, the first overload protection device 5 is a fuse.

Specifically, the first overload protection device 5 is usually a fuse with a current threshold of 25A, and when the discharge current is greater than 25A or short-circuits, the first overload protection device 5 opens the circuit and the discharge is cut off. Discharge protection of the rechargeable battery 91 is achieved.

Further, the second overload protection device 6 is a fuse.

Specifically, the second overload protection device 6 is usually a fuse with a current threshold of 3A, and when the charging current is greater than 3A, the temperature-controlled fuse is opened and the charging is stopped after charging for a period of time. The charge protection of the rechargeable battery 91 is realized.

In the foregoing embodiments, the descriptions of the embodiments are focused on, and for those portions of one embodiment that are not described in detail, reference may be made to the related descriptions of other embodiments.

In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present utility model and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present utility model, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the present utility model, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, connected, detachably connected, or integrally formed, mechanically connected, electrically connected, directly connected, indirectly connected via an intervening medium, or in communication between two elements or in an interaction relationship between two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present utility model, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.

In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present utility model. In this specification, schematic representations of the above terms should not be understood as necessarily being directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, one skilled in the art can combine and combine the different embodiments or examples described in this specification.

It will be apparent to those skilled in the art that various modifications and variations can be made to the present utility model without departing from the spirit or scope of the utility model. Thus, it is intended that the present utility model also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

While the utility model has been described with reference to certain preferred embodiments, it will be understood by those skilled in the art that various changes and substitutions of equivalents may be made and equivalents will be apparent to those skilled in the art without departing from the scope of the utility model. Therefore, the protection scope of the utility model is subject to the protection scope of the claims.

Claims (10)

1. The protection circuit for the rechargeable battery is characterized by comprising a first control chip, a second control chip, a charging module, a discharging module, a first overload protection device and a second overload protection device;

The discharging module is respectively connected with the first overload protection device, the first control chip and a preset rechargeable battery;

The charging module is respectively connected with the first control chip, the second overload protection device and the rechargeable battery;

The preset charger is respectively connected with the first control chip and the second overload protection device, and the first overload protection device is connected with a preset discharge electrode.

2. The protection circuit for a rechargeable battery according to claim 1, wherein the charging module comprises a first MOS transistor and a second MOS transistor, the first MOS transistor is respectively connected to the first control chip, the second MOS transistor and the rechargeable battery, and the second MOS transistor is respectively connected to the second control chip and the second overload protection device.

3. The protection circuit for a rechargeable battery according to claim 2, wherein the first MOS transistor includes a first source, a first gate, and a first drain, the first source is connected to the second MOS transistor, the first gate is connected to the first control chip, and the first drain is connected to the rechargeable battery.

4. The protection circuit for a rechargeable battery according to claim 2, wherein the second MOS transistor includes a second source, a second gate, and a second drain, the second source is connected to the second overload protection device, the second gate is connected to the second control chip, and the second drain is connected to the first MOS transistor.

5. The protection circuit for a rechargeable battery according to claim 1, further comprising an identification module connected to the first control chip and the charger, respectively.

6. The protection circuit for a rechargeable battery according to claim 5, wherein the identification module includes a switch and an anti-reverse unit, the switch being connected to the anti-reverse unit and the first control chip, respectively, the anti-reverse unit being connected to the charger.

7. The protection circuit for a rechargeable battery according to claim 1, wherein the discharging module comprises a plurality of third MOS transistors connected in parallel.

8. The protection circuit for a rechargeable battery according to claim 1, further comprising a third control chip connected to the first control chip.

9. The protection circuit for a rechargeable battery according to claim 1, wherein the first overload protection device is a fuse.

10. The protection circuit for a rechargeable battery according to claim 1, wherein the second overload protection device is a fuse.