Battery protection circuit, protection circuit board and battery

Abstract

The utility model discloses a protection circuit, protection circuit board and battery of battery, and protection circuit includes protection chip, the positive input of protection chip connects the positive output of battery, the negative input of protection chip connects the negative output of battery, the positive output of protection chip connects the positive input of external load, and the negative output of protection chip connects the negative input of external load, and the positive input of protection chip is connected with the negative input of protection chip through the first power switch. Through the first power switch between the positive input of protection chip and the negative input of protection chip, when the positive input and the negative input between external load are miscontacted short circuit, can be opened through the control first power switch, to open this first short circuit loop, thereby solved the short circuit protection function failure problem of existing protection circuit when the positive pole and the negative pole shell between the load short circuit.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a battery protection circuit, a protection circuit board, and a battery. Background Technology

[0002] Currently, the protection switch in the battery protection circuit is connected in series in the branch connecting the negative terminal of the load and the negative terminal of the battery. When a short circuit occurs between the positive and negative terminals of the load, this protection switch can be disconnected. However, when a short circuit occurs between the positive terminal of the load and the negative terminal of the battery, a circuit is formed where the positive terminal B+ of the battery passes through the output positive wire P+ and the negative terminal B- of the battery, and the current in the circuit does not pass through the protection switch, thus rendering the short-circuit protection function of the existing protection circuit ineffective. Summary of the Invention

[0003] This utility model provides a battery protection circuit, a protection circuit board, and a battery to solve the problem of short-circuit protection failure when existing protection circuits encounter a short circuit between the positive terminal of the load and the negative terminal of the battery casing.

[0004] In one embodiment, a battery protection circuit is provided, the protection circuit comprising:

[0005] A protection chip, wherein the positive input terminal of the protection chip is connected to the positive output terminal of the battery, the negative input terminal of the protection chip is connected to the negative output terminal of the battery, the positive output terminal of the protection chip is connected to the positive input terminal of an external load, and the negative output terminal of the protection chip is connected to the negative input terminal of an external load.

[0006] The positive input terminal of the protection chip is connected to the negative input terminal of the protection chip through a first power switch.

[0007] In one embodiment, the first power switch is encapsulated inside the protection chip, or the first power switch is disposed outside the protection chip.

[0008] In one embodiment, the negative output terminal of the battery is connected to the negative input terminal of the external load via a second power switch.

[0009] In one embodiment, a protection circuit board for a battery is provided, the protection circuit board having a protection circuit including:

[0010] A protection chip, wherein the positive input terminal of the protection chip is connected to the positive output terminal of the battery, the negative input terminal of the protection chip is connected to the negative output terminal of the battery, the positive output terminal of the protection chip is connected to the positive input terminal of an external load, and the negative output terminal of the protection chip is connected to the negative input terminal of an external load.

[0011] The positive input terminal of the protection chip is connected to the negative input terminal of the protection chip through a first power switch.

[0012] In one embodiment, the protection circuit board has a fan-shaped structure with an extended protrusion that is welded to the positive electrode cap of the battery.

[0013] In one embodiment, the positive output terminal of the battery is located at the top of the positive cap, the protection circuit board is located below the positive output terminal of the battery, and the positive and negative input terminals of the external load are located in the fan-shaped edge area of ​​the protection circuit board.

[0014] In one embodiment, the first power switch is encapsulated inside the protection chip, or the first power switch is disposed outside the protection chip.

[0015] In one embodiment, the negative output terminal of the battery is connected to the negative input terminal of the external load via a second power switch.

[0016] In one embodiment, a battery is provided, the battery including the aforementioned protection circuit board.

[0017] In one embodiment, the battery further includes: a housing, a cover assembly, and a winding core, the winding core being disposed inside the housing, the cover assembly covering the opening of the housing, and the protective circuit board being soldered to the top of the positive electrode cap of the cover assembly.

[0018] This utility model provides a battery protection circuit, a protection circuit board, and a battery. By connecting a first power switch in series between the positive and negative input terminals of the protection chip U1, when an external load's positive and negative input terminals accidentally short-circuit, forming a first short-circuit loop that passes sequentially through the first power switch, the positive and negative input terminals of the external load, and the negative output terminal of the battery, the first power switch can be controlled to disconnect this first short-circuit loop. This solves the problem of short-circuit protection failure in existing protection circuits when a short circuit occurs between the positive terminal of the load and the negative terminal of the battery casing. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1This is a schematic diagram of a protection circuit for a battery in one embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the internal circuit structure of a protection chip in one embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of the structure of a battery according to one embodiment of the present invention;

[0023] The labels are as follows:

[0024] 1. Cover assembly; 2. Positive electrode cap; 3. Protective circuit board; 4. Housing; 5. Extended protrusion; 6. Positive output terminal of the battery; 7. Negative output terminal of the battery. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model.

[0026] It should be understood that this invention can be embodied in various forms and should not be construed as being limited to the embodiments set forth herein. Rather, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of this invention to those skilled in the art. In the drawings, for clarity, the dimensions of layers and regions, as well as their relative dimensions, may be exaggerated. The same reference numerals denote the same elements throughout.

[0027] It should be understood that when an element or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, components, areas, layers, and / or portions, these elements, components, areas, layers, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, area, layer, or portion from another element, component, area, layer, or portion. Therefore, without departing from the teachings of this utility model, the first element, component, area, layer, or portion discussed below may be referred to as the second element, component, area, layer, or portion.

[0028] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used herein for convenience of description to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms are intended to also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, then the element or feature described as “below,” “under,” or “below” other elements or features will be oriented “above” other elements or features. Therefore, the exemplary terms “below” and “under” can include both above and below orientations. The device may be otherwise oriented (rotated 90 degrees or otherwise) and the spatial descriptive terms used herein will be interpreted accordingly.

[0029] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising” and / or “including,” when used in this specification, identify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0030] To fully understand this utility model, detailed structures and steps will be presented in the following description to illustrate the technical solution proposed by this utility model. Preferred embodiments of this utility model are described in detail below; however, in addition to these detailed descriptions, this utility model may have other embodiments.

[0031] In one embodiment, such as Figure 1 As shown, a battery protection circuit is provided, the protection circuit comprising:

[0032] The protection chip U1 has its positive input terminal VDD connected to the positive output terminal B+ of the battery, its negative input terminal GND connected to the negative output terminal B- of the battery, its positive output terminal VM connected to the positive input terminal P+ of an external load, and its negative output terminal GND connected to the negative input terminal P- of an external load.

[0033] The positive input terminal VDD of the protection chip U1 is connected to the negative input terminal VM of the protection chip U1 through a first power switch.

[0034] The operation of the aforementioned protection circuit includes:

[0035] When the positive and negative input terminals of an external load are accidentally short-circuited, a first short-circuit loop is formed, which passes through the first power switch, the positive and negative input terminals of the external load, and the negative output terminal of the battery in sequence. This first short-circuit loop can be broken by controlling the first power switch to turn off.

[0036] When the positive input terminal of the external load is accidentally short-circuited to the negative output terminal of the battery, a second short-circuit loop is formed, which passes through the first power switch, the positive input terminal of the external load, and the negative output terminal of the battery in sequence. This second short-circuit loop can be broken by controlling the first power switch to turn off.

[0037] The protection circuit of this embodiment connects a first power switch in series between the positive and negative input terminals of the protection chip U1. This allows the circuit to break the first short circuit loop when an external load's positive and negative input terminals accidentally short-circuit, causing the battery's positive output terminal to sequentially pass through the first power switch, the positive and negative input terminals of the external load, and the battery's negative output terminal. This solves the problem of short-circuit protection failure in existing protection circuits when a short circuit occurs between the positive terminal of the load and the battery's negative casing.

[0038] In one embodiment, the first power switch is encapsulated inside the protection chip U1, or the first power switch is disposed outside the protection chip U1.

[0039] Among them, such as Figure 2 The internal structure of the protection chip U1 shown includes a logic processing module, a temperature detection module, a drive module, an overcurrent detection module, and an overcharge / over-discharge detection module. The logic processing module is connected to the control terminal of the first power switch through the drive module. It is used to send a conduction drive signal to the control terminal of the first power switch to control the first power switch to conduct, so as to carry out the charging and discharging of the battery. Alternatively, when the logic processing module determines that a short circuit has occurred, it sends a shutdown drive signal to the control terminal of the first power switch through the drive module to control the first power switch to disconnect, thereby breaking the short circuit circuit.

[0040] Figure 2 In the middle, the logic processing module is connected to the temperature detection module, the overcurrent detection module, and the overcharge and over-discharge detection module respectively. It is used to detect the operating temperature through the temperature detection module, detect whether the conduction drive signal sent by the drive module is overcurrent through the overcurrent detection module, and detect whether the charging current or discharging current on the branch where the first power switch is located is overcharged or over-discharged through the overcharge and over-discharge detection module.

[0041] Figure 2The first power switch shown is packaged inside the protection chip U1. Compared to the first power switch being located outside the protection chip U1, the relatively smaller wiring design reduces the internal resistance of the protection chip U1 and reduces heat loss.

[0042] In one embodiment, the negative output terminal of the battery is connected to the negative input terminal of the external load via a second power switch. The second power switch is located in the connection branch between the negative output terminal of the battery and the negative input terminal of the external load, and can selectively disconnect the first power switch and / or the second power switch to break the short circuit when a short circuit occurs between the negative and positive input terminals of the external load.

[0043] In one embodiment, such as Figure 3 As shown, a battery protection circuit board 3 is provided, the protection circuit board 3 having a protection circuit, the protection circuit including:

[0044] The protection chip U1 has its positive input terminal connected to the positive output terminal 6 of the battery, its negative input terminal connected to the negative output terminal 7 of the battery, its positive output terminal connected to the positive input terminal of an external load, and its negative output terminal connected to the negative input terminal of an external load.

[0045] The positive input terminal of the protection chip U1 is connected to the negative input terminal of the protection chip U1 through a first power switch.

[0046] Among them, the protection circuit board 3 can be a PCB (printed circuit board), which can be a single-layer board, a double-layer board or a multi-layer board. The protection circuit is printed in the circuit layer of the single-layer board, or printed in the double-sided circuit layer of the double-layer board, or printed in one or more circuit layers of the multi-layer board.

[0047] In this embodiment, the battery protection circuit board 3 connects a first power switch in series between the positive and negative input terminals of the protection chip U1. This allows the circuit to be broken when an external load's positive and negative input terminals accidentally short-circuit, creating a first short-circuit loop that passes sequentially through the first power switch, the positive and negative input terminals of the external load, and the negative output terminal 7 of the battery. This solves the problem of short-circuit protection failure in existing protection circuits when a short circuit occurs between the positive terminal of the load and the negative terminal of the battery.

[0048] In one embodiment, the protection circuit board 3 has a fan-shaped structure, and an extended protrusion 5 is provided on the fan-shaped structure. The extended protrusion 5 is welded to the positive electrode cap 2 of the battery.

[0049] Among them, such as Figure 3 The battery shown has a protective circuit board 3 with a fan-shaped structure. The extended protrusion 5 on the fan-shaped structure can be made of nickel sheet. The nickel sheet and the positive electrode cap 2 of the battery are welded using laser welding technology, which makes the welding more solid, the production simpler, and the production efficiency higher.

[0050] The protection circuit board 3 of this embodiment has the following advantages:

[0051] First, because the protection circuit board 3 adopts a fan-shaped structure, it reserves the possibility of directly welding the nickel sheet as the extension protrusion 5 of the circuit board to the battery cell, resulting in lower contact resistance and lower temperature rise.

[0052] Secondly, because the protection circuit board 3 adopts a fan-shaped structure, the nickel sheet extending from the circuit board can be made with a single-sided gold plating process, which further reduces the contact internal resistance, ensures that the battery can be charged and discharged at high current, and also effectively reduces the temperature rise and improves the battery charge and discharge rate.

[0053] Third, because the protection circuit board 3 adopts a fan-shaped structure, the battery cell has more space to dissipate heat directly through the positive electrode cap 2, without being blocked by the circuit board substrate, resulting in better heat dissipation.

[0054] In one embodiment, the positive output terminal 6 of the battery is located on top of the positive cap 2, the protection circuit board 3 is located below the positive output terminal 6 of the battery, and the positive input terminal and negative input terminal of the external load are located in the fan-shaped edge area of ​​the protection circuit board 3.

[0055] Among them, such as Figure 3 As shown, since the positive output terminal 6 of the battery is located above the protection circuit board 3, and the positive and negative input terminals of the external load are located in the fan-shaped edge area of ​​the protection circuit board 3, the protection chip U1 of the protection circuit board 3 can connect the positive output terminal 6 of the battery and the positive input terminal of the external load with the shortest possible traces. The internal resistance of the protection circuit board 3 is smaller, which helps to reduce the heat generation of the components.

[0056] In one embodiment, the first power switch is encapsulated inside the protection chip U1, or the first power switch is disposed outside the protection chip U1.

[0057] In this embodiment, the protection circuit board 3 is particularly suitable for button batteries and small cylindrical batteries. Adding a protection circuit to the battery facilitates processing, improves production safety, reduces battery temperature rise, and increases battery charge and discharge rates. Furthermore, it fully considers improvements in both structure and electronics, ensuring the feasibility and reliability of the circuit board design. This design structure and circuit are relatively simple and can be mass-produced.

[0058] In one embodiment, the negative output terminal 7 of the battery is connected to the negative input terminal of the external load via a second power switch.

[0059] In one embodiment, a battery is provided, the battery including the aforementioned protection circuit board 3.

[0060] like Figure 3 As shown, this battery is particularly suitable for button cells and small cylindrical batteries. The design incorporates a protection circuit board 3, located at the positive terminal of the battery, eliminating the need for steps such as bending the protection board and simplifying processing. Furthermore, the protection board employs a fan-shaped structure design, allowing laser welding of the positive electrode casing and the extended nickel sheet on the board, resulting in a stronger weld, simpler production, and higher efficiency. Simultaneously, the fan-shaped structure of the protection circuit board 3 provides greater heat dissipation space for the battery, eliminating the need for insulating tape, increasing the heat dissipation coefficient of the positive electrode, and preventing heat buildup on the board, effectively reducing the overall temperature rise of the battery. Moreover, due to the fan-shaped structure design, the nickel sheet connecting the protection board and the cell can be gold-plated on one side, significantly improving the battery's charge and discharge rate.

[0061] In one embodiment, such as Figure 3 As shown, the battery may further include: a casing 4, a cover assembly 1, and a winding core (not shown in the figure). The winding core is installed inside the casing 4, the cover assembly 1 covers the opening of the casing 4, and the protective circuit board 3 is soldered to the top of the positive electrode cap 2 of the cover assembly 1. The cover assembly 1 includes the positive electrode cap 2 and the protective circuit board 3. This battery solves the problems of adding a protective circuit to button batteries and small cylindrical batteries, improving processing convenience, production safety, reducing battery temperature rise, and increasing battery charge / discharge rate; furthermore, the design structure and circuit of this battery are relatively simple, allowing for mass production.

[0062] The above-described embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model, and should all be included within the protection scope of this utility model.

Claims

1. A battery protection circuit, characterized in that, The protection circuit includes: A protection chip, wherein the positive input terminal of the protection chip is connected to the positive output terminal of the battery, the negative input terminal of the protection chip is connected to the negative output terminal of the battery, the positive output terminal of the protection chip is connected to the positive input terminal of an external load, and the negative output terminal of the protection chip is connected to the negative input terminal of an external load. The positive input terminal of the protection chip is connected to the negative input terminal of the protection chip through a first power switch.

2. The protection circuit according to claim 1, characterized in that, The first power switch is either encapsulated inside the protection chip or disposed outside the protection chip.

3. The protection circuit according to claim 1, characterized in that, The negative output terminal of the battery is connected to the negative input terminal of the external load via a second power switch.

4. A battery protection circuit board, characterized in that, The protection circuit board has a protection circuit, which includes: A protection chip, wherein the positive input terminal of the protection chip is connected to the positive output terminal of the battery, the negative input terminal of the protection chip is connected to the negative output terminal of the battery, the positive output terminal of the protection chip is connected to the positive input terminal of an external load, and the negative output terminal of the protection chip is connected to the negative input terminal of an external load. The positive input terminal of the protection chip is connected to the negative input terminal of the protection chip through a first power switch.

5. The protective circuit board according to claim 4, characterized in that, The protection circuit board has a fan-shaped structure with an extended protrusion that is welded to the positive electrode cap of the battery.

6. The protective circuit board according to claim 5, characterized in that, The positive output terminal of the battery is located on top of the positive cap, the protection circuit board is located below the positive output terminal of the battery, and the positive and negative input terminals of the external load are located in the fan-shaped edge area of ​​the protection circuit board.

7. The protective circuit board according to claim 4, characterized in that, The first power switch is either encapsulated inside the protection chip or disposed outside the protection chip.

8. The protective circuit board according to claim 4, characterized in that, The negative output terminal of the battery is connected to the negative input terminal of the external load via a second power switch.

9. A battery, characterized in that, The battery includes a protection circuit board as described in any one of claims 4 to 8.

10. The battery according to claim 9, characterized in that, The battery further includes: a casing, a cover assembly, and a winding core, wherein the winding core is installed inside the casing, the cover assembly covers the opening of the casing, and the protective circuit board is soldered to the top of the positive electrode cap of the cover assembly.

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