A waterproof protection circuit for a battery pack and a battery pack employing the same

Abstract

The utility model provides a waterproof protection circuit for battery package, its technical scheme's main points include: control circuit, on -off switch, high level VCC contact and water inlet detection contact, control circuit and on -off switch electricity are connected, on -off switch electricity is connected in the power supply circuit between high level VCC contact and anode pin, high level VCC contact and the anode electricity of power supply in battery package are connected, water inlet detection contact and control circuit electricity are connected, for when water is through water body and is connected high level VCC contact, make control circuit trigger, control on -off switch switches from the conduction state to the cut -off state, to cut off the power supply circuit between the power supply in battery package and anode pin, the utility model discloses can under the condition that battery package shell is waterlogged, cut off the power supply circuit between battery power supply and anode pin in time, guarantee that PCB circuit board whole is in low potential state, effectively solve the problem that battery package is easy to cause PCB circuit board to be scrapped and the electrolytic corrosion of anode pin because of shell waterlogging.

Description

Technical Field

[0001] This utility model relates to the field of power supply waterproofing technology, and in particular to a waterproof protection circuit for a battery pack and a battery pack using the circuit. Background Technology

[0002] Battery packs are widely used in portable power supplies and various portable electronic devices. A typical battery pack structure includes a casing, a battery power source, and a PCB circuit board, usually housed within the casing, for charge and discharge management. Furthermore, battery packs are typically used in various environmental conditions, including humid, rainy, or potentially water-contaminated environments. While the waterproofing process for the battery power source is relatively simple and mature, to avoid affecting the electrical connections of the pins on the PCB circuit board, it's impossible to directly apply a waterproof coating to the PCB circuit board and its pins using waterproof adhesive or paint. This results in the vast majority of battery packs on the market not being able to completely waterproof their PCB circuit boards and pins.

[0003] When water enters the battery pack casing or the entire battery pack falls into water, the PCB circuit board and its electronic components are easily burned out due to leakage or short circuit. Moreover, because impurities in the water have a certain resistance, leakage or electrolysis can occur through the water's resistance. The positive discharge and positive charging terminals of the battery pack are prone to electrolytic corrosion in the water because they are in a high-level state for a long time, which affects the performance and lifespan of the battery pack and also poses safety hazards. Therefore, since the PCB circuit board inside the existing battery pack is not waterproofed, water ingress can easily lead to the failure of the PCB circuit board and even the entire battery pack. Utility Model Content

[0004] To promptly cut off the power supply circuit between the battery and the positive terminal when water enters the battery pack casing, ensuring the entire PCB circuit board of the battery pack remains at a low potential, and effectively waterproofing the positive terminal of the battery pack, this invention addresses the problem of water ingress into the battery pack casing easily leading to the failure of the PCB circuit board or even the entire battery pack. The technical solution is as follows: A waterproof protection circuit for a battery pack protects components on a PCB circuit board inside the battery pack and their electrically connected positive terminal pins, preventing electrolytic corrosion of the positive terminal pins upon contact with water. The circuit includes a control circuit, a switching switch, a high-level VCC contact, and a water ingress detection contact. The control circuit is electrically connected to the switching switch, which is connected in the power supply circuit between the high-level VCC contact and the positive terminal pin. The high-level VCC contact is electrically connected to the positive terminal of the power supply inside the battery pack. The water ingress detection contact is electrically connected to the control circuit and, upon water ingress, connects the high-level VCC contact to the water, triggering the control circuit to switch the switching switch from an on state to an off state. This cuts off the power supply circuit between the highest potential of the power supply inside the battery pack and the positive terminal pin, thereby ensuring all components on the PCB circuit board are at a low potential.

[0005] Preferably, the control circuit includes a first switching unit and a second switching unit. The first switching unit is a MOSFET Q1, the second switching unit is a MOSFET Q2, and the on / off switch is a MOSFET Q3. The gate G of MOSFET Q1 is electrically connected to the water inlet detection contact and one end of resistor R1, and the other end of resistor R1 is grounded. The drain D of MOSFET Q1 is electrically connected to the gate G of MOSFET Q2, and the source S of MOSFET Q1 is grounded. The gate G of MOSFET Q2 is connected to the high-level VCC contact after series with resistor R2. The drain D of MOSFET Q2 is connected to the gate G of MOSFET Q3, and the source S of MOSFET Q2 is grounded. The source S of MOSFET Q3 is connected to the high-level VCC contact. The gate G of MOSFET Q3 is connected to the high-level VCC contact after series with resistor R3, and the drain D of MOSFET Q3 is electrically connected to the positive terminal.

[0006] Preferably, MOSFET Q2 is of the same type as MOSFET Q1, and MOSFET Q3 is of the opposite type to MOSFET Q1. MOSFET Q3 is a P-channel MOSFET, while MOSFETs Q2 and Q1 are N-channel MOSFETs.

[0007] Preferably, the waterproof protection circuit has a waterproof insulating layer and the high-level VCC contact and the water ingress detection contact are exposed and conductive.

[0008] Preferably, a plurality of conductive probes are electrically connected to the water ingress detection contact, and the probes are respectively disposed inside the outer casing of the battery pack and located around the positive terminal or the high-level VCC contact.

[0009] Preferably, the high-level VCC contact and the water ingress detection contact are made of corrosion-resistant conductive metal or alloy, or the surfaces of the high-level VCC contact and the water ingress detection contact are coated with conductive adhesive for isolating air.

[0010] Preferably, the waterproof protection circuit is installed on the existing PCB circuit board inside the battery pack and is located in the power supply circuit for charging and discharging the battery pack, or a separate circuit board is installed and electrically connected to the power supply circuit between the power source inside the battery pack and the existing PCB circuit board.

[0011] A battery pack employing the aforementioned waterproof protection circuit includes: a battery pack shell, a PCB circuit board, and a battery power supply. The PCB circuit board is provided with a charge / discharge management circuit for controlling the charging and discharging of the battery power supply, and also includes a discharge positive terminal, a charging positive terminal, a negative terminal, and a ground terminal.

[0012] Preferably, waterproof paint or waterproof adhesive is applied to the locations on the PCB circuit board where the discharge positive terminal, charging positive terminal, and negative terminal are excluded; waterproof paint or waterproof adhesive is applied to the waterproof protection circuit, and the high-level VCC contact and the water ingress detection contact are exposed and conductive.

[0013] Compared with the prior art, the beneficial effects of this utility model are as follows: This utility model features a simple structure and reliable function. Compared with the existing battery pack circuit structure, it includes a control circuit, an on / off switch, a high-level VCC contact, and a water ingress detection contact. When water enters the battery pack, the water connects to the high-level VCC contact, triggering the control circuit. This causes the on / off switch to switch from an on state to an off state, promptly cutting off the power supply circuit between the battery pack's power source and the positive terminal. This ensures the battery pack's PCB circuit board is at a low potential, preventing damage to electronic components due to leakage or short circuits. It also effectively prevents electrolytic corrosion of the positive terminal, providing effective waterproof protection for the PCB circuit board and positive terminal. This solves the problem of water ingress into the battery pack's casing causing damage to the PCB circuit board and even the entire battery pack. Furthermore, after the water inside the battery pack's casing is cleaned, the waterproof protection circuit automatically restores the PCB circuit board to a powered state, allowing the battery pack to continue operating and effectively extending its lifespan. Attached Figure Description

[0014] The objects, features, and advantages of exemplary embodiments of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings. In the drawings, several embodiments of the present invention are shown by way of example and not limitation, and like or corresponding reference numerals denote like or corresponding parts in the description, wherein: Figure 1 This is a circuit block diagram of the battery pack as a whole, incorporating the waterproof protection circuit. Figure 2 This is the overall circuit diagram of the battery pack incorporating the waterproof protection circuit; Figure 3 This is the circuit diagram of the waterproof protection circuit; Figure 4 This is a schematic diagram of the circuit structure of a battery pack in the prior art; In the diagram: 1 is the control circuit; 2 is the on / off switch; 3 is the high-level VCC contact; 4 is the water inlet detection contact; 5 is the first switching unit; 6 is the second switching unit. 11 is the battery pack casing; 12 is the PCB circuit board; 13 is the battery power supply; 14 is the charge / discharge management circuit; 15 is the positive discharge pin; 16 is the positive charging pin; 17 is the negative pin; 18 is the grounding terminal. Detailed Implementation

[0015] The technical features of this utility model will be further described in detail below with reference to the accompanying drawings, so that those skilled in the art can understand them.

[0016] A waterproof protection circuit for a battery pack is provided to protect the components on the PCB circuit board inside the battery pack and the positive terminal pin that is electrically connected to them, and to prevent the positive terminal pin from being electrolytically corroded by water. Its circuit structure is as follows: Figures 1-3 As shown, it includes: a control circuit 1, an on / off switch 2, a high-level VCC contact 3, and a water ingress detection contact 4. The control circuit 1 is electrically connected to the on / off switch 2. The on / off switch 2 is electrically connected in the power supply circuit between the high-level VCC contact 3 and the positive terminal. The high-level VCC contact 3 is electrically connected to the positive terminal of the power supply in the battery pack. The water ingress detection contact 4 is electrically connected to the control circuit 1 and is used to connect the high-level VCC contact 3 through the water body when water enters, so that the control circuit 1 is triggered and controls the on / off switch 2 to switch from the on state to the off state, so as to cut off the power supply circuit between the highest potential of the power supply in the battery pack and the positive terminal, thereby so that all components on the PCB circuit board are in a low potential state. The circuit structure of existing battery packs is as follows Figure 4 As shown, compared with the existing battery pack circuit structure, the water ingress detection contact 4 in this waterproof protection circuit can connect to the high-level VCC contact 3 through the water body when water enters, triggering the control circuit 1 and controlling the on / off switch 2 to switch from the on state to the off state. This promptly cuts off the power supply circuit between the battery pack's power supply and the positive terminal, thereby ensuring that the battery pack's PCB circuit board is in a low potential state. This prevents electronic components on the PCB circuit board from being damaged due to leakage or short circuits, and also effectively prevents electrolytic corrosion of the battery pack's positive terminal. This achieves effective waterproof protection for the battery pack's PCB circuit board and positive terminal, solving the problem that the battery pack is easily damaged by water entering the outer casing, leading to the scrapping of the PCB circuit board or even the entire battery pack.

[0017] Specifically, such as Figure 2or Figure 3 As shown, the control circuit 1 includes a first switching unit 5 and a second switching unit 6. The first switching unit 5 is a MOSFET Q1, the second switching unit 6 is a MOSFET Q2, and the on / off switch 2 is a MOSFET Q3. The gate G of MOSFET Q1 is electrically connected to the water inlet detection contact 4 and one end of resistor R1, respectively. The other end of resistor R1 is grounded. The drain D of MOSFET Q1 is electrically connected to the gate G of MOSFET Q2, and the source S of MOSFET Q1 is grounded. The gate G of MOSFET Q2 is connected to the high-level VCC contact 3 after being connected in series with resistor R2. The drain D of MOSFET Q2 is connected to the gate G of MOSFET Q3, and the source S of MOSFET Q2 is grounded. The source S of MOSFET Q3 is connected to the high-level VCC contact 3. The gate G of MOSFET Q3 is connected to the high-level VCC contact 3 after being connected in series with resistor R3, and the drain D of MOSFET Q3 is electrically connected to the positive terminal.

[0018] The operation of this waterproof protection circuit when water enters the battery pack is as follows: When the battery pack is in normal use, there is no conductive connection between the water ingress detection contact 4 and the high-level VCC contact 3. At this time, the gate G of MOSFET Q1 is at a low level, which keeps MOSFET Q1 in the off state. The gate G of MOSFET Q2 is at a high level and the gate G of MOSFET Q3 is at a low level, which makes MOSFET Q2 and MOSFET Q3 in the on state. When water enters the battery pack, the water ingress detection contact 4 and the high-level VCC contact 3 are electrically connected through the water, causing the gate G of MOSFET Q1 to go high and turn on MOSFET Q1. At this time, the gate G of MOSFET Q2 is pulled low, turning off MOSFET Q2. Subsequently, the gate G of MOSFET Q3 is pulled high, turning off MOSFET Q3. This timely interruption of the high-potential output from the positive terminal of the battery power supply to the positive terminal pin cuts off the power supply circuit between the battery power supply and the positive terminal pin, ensuring that the entire PCB circuit board of the battery pack is in a low-potential state. This prevents damage to electronic components on the PCB circuit board due to leakage or short circuit, and also effectively prevents electrolytic corrosion of the positive terminal pin of the battery pack, thus achieving effective waterproof protection for the PCB circuit board and the positive terminal pin of the battery pack.

[0019] Furthermore, the specific reset process of this waterproof protection circuit is as follows: After the water inside the battery pack casing is cleaned and the battery pack is manually confirmed to be dry, the conductive connection between the water ingress detection contact 4 and the high-level VCC contact 3 is broken, causing the gate G of MOSFET Q1 to go low and MOSFET Q1 to return to the off state. At this time, the gate G of MOSFET Q2 is pulled high again, and MOSFET Q2 returns to the on state. Meanwhile, the gate G of MOSFET Q3 is pulled low again, and MOSFET Q3 returns to the on state. Thus, the waterproof protection circuit is re-energized after the battery pack dries, and the battery pack is put back into use.

[0020] Specifically, MOSFET Q2 is of the same type as MOSFET Q1, while MOSFET Q3 is of the opposite type to MOSFET Q1. MOSFET Q3 is a P-channel MOSFET, while MOSFETs Q2 and Q1 are N-channel MOSFETs. When the gate G of MOSFET Q3 is low, its source S and drain D are connected; when the gate G is high, it is cut off. When the gate G of MOSFETs Q2 and Q1 is high, their source S and drain D are connected; when the gate G is low, they are cut off.

[0021] Furthermore, the waterproof protection circuit is equipped with a waterproof insulating layer, and the high-level VCC contact 3 and the water ingress detection contact 4 are exposed and conductive. The waterproof insulating layer can be applied by coating with waterproof paint or waterproof adhesive to provide waterproofing and insulation, preventing leakage and short circuits in the electronic components of the waterproof protection circuit when water enters the battery pack. At the same time, the high-level VCC contact 3 and the water ingress detection contact 4 are exposed and conductive because when water enters the battery pack, they need to be electrically connected through the water to realize the water ingress detection function and the on / off control function of the waterproof protection circuit.

[0022] Specifically, several conductive probes are electrically connected to the water ingress detection contact 4. The probes are respectively located inside the battery pack casing and around the positive terminal or the high-level VCC contact 3. The conductive probes can explore the water ingress situation in more spaces inside the battery pack, thereby timely and effectively conducting electrical connection with the high-level VCC contact 3 to quickly realize the waterproof protection function.

[0023] In addition, the high-level VCC contact 3 and the water ingress detection contact 4 are made of corrosion-resistant conductive metal or alloy, or the surfaces of the high-level VCC contact 3 and the water ingress detection contact 4 are coated with conductive adhesive to isolate air, so as to avoid corrosion due to prolonged contact with water and air.

[0024] Specifically, the waterproof protection circuit is installed on the existing PCB circuit board inside the battery pack and in the power supply circuit for charging and discharging the battery pack, or a separate circuit board is installed and electrically connected to the power supply circuit between the power source inside the battery pack and the existing PCB circuit board. Different application designs can be selected based on the shape, structure and volume requirements of the battery pack. The method of setting a separate circuit board can realize the modification of the existing battery pack, so as to facilitate the promotion and application of the waterproof protection circuit.

[0025] This utility model also discloses a battery pack employing the above-mentioned waterproof protection circuit, the overall circuit structure of which is as follows: Figure 1 and Figure 2 As shown, it includes: a battery pack casing 11, a PCB circuit board 12, and a battery power supply 13. The PCB circuit board 12 is provided with a charge and discharge management circuit 14 for controlling the charging and discharging of the battery power supply 13, and is also provided with a discharge positive terminal 15, a charging positive terminal 16, a negative terminal 17, and a ground terminal 18.

[0026] Specifically, waterproof paint or adhesive is applied to the PCB circuit board 12 at the locations excluding the discharge positive terminal 15, charging positive terminal 16, and negative terminal 17; waterproof paint or adhesive is applied to the waterproof protection circuit, while the high-level VCC contact 3 and the water ingress detection contact 4 are exposed and conductive; because it is necessary to avoid affecting the conductivity of the discharge positive terminal 15, charging positive terminal 16, negative terminal 17, high-level VCC contact 3, and water ingress detection contact 4, a direct sealing waterproof coating cannot be applied; however, through the function of the aforementioned waterproof protection circuit, the high-potential output between the positive terminal of the battery power supply 13 and the charge / discharge management circuit 14, discharge positive terminal 15, and charging positive terminal 16 can be cut off in time, so that the PCB circuit board 12 is in a low-potential state, effectively realizing the waterproof protection function; at the same time, the preliminary waterproof insulation treatment of the PCB circuit board by the waterproof paint or waterproof adhesive can prevent damage to electronic components due to leakage or short circuit at the moment of water ingress.

[0027] The embodiments described herein are merely preferred embodiments of the present invention and are not limited to the precise structures described above and shown in the accompanying drawings. Various modifications and changes can be made without departing from the scope of protection of the present invention. Any variations and improvements made by engineers in the art to the technical solutions of the present invention without departing from the design concept of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A waterproof protection circuit for a battery pack, which protects the components on the PCB circuit board inside the battery pack and the positive terminal pin electrically connected to them, and prevents the positive terminal pin from being electrolytically corroded by water, characterized in that: It includes a control circuit (1), an on / off switch (2), a high-level VCC contact (3), and a water ingress detection contact (4). The control circuit (1) is electrically connected to the on / off switch (2). The on / off switch (2) is electrically connected to the power supply circuit between the high-level VCC contact (3) and the positive terminal. The high-level VCC contact (3) is electrically connected to the positive terminal of the power supply in the battery pack. The water ingress detection contact (4) is electrically connected to the control circuit (1) and is used to connect the high-level VCC contact (3) through the water body when water enters, so that the control circuit (1) is triggered and controls the on / off switch (2) to switch from the on state to the off state, so as to cut off the power supply circuit between the highest potential of the power supply in the battery pack and the positive terminal, thereby so that all components on the PCB circuit board are in a low potential state.

2. The waterproof protection circuit for a battery pack according to claim 1, characterized in that: The control circuit (1) includes a first switching unit (5) and a second switching unit (6). The first switching unit (5) is a MOS transistor Q1, the second switching unit (6) is a MOS transistor Q2, and the on / off switch (2) is a MOS transistor Q3. The gate G of the MOS transistor Q1 is electrically connected to the water inlet detection contact (4) and one end of the resistor R1, and the other end of the resistor R1 is grounded. The drain D of the MOS transistor Q1 is electrically connected to the gate G of the MOS transistor Q2, and the source S of the MOS transistor Q1 is grounded. The gate G of the MOS transistor Q2 is connected to the high-level VCC contact (3) after being connected in series with the resistor R2. The drain D of the MOS transistor Q2 is connected to the gate G of the MOS transistor Q3, and the source S of the MOS transistor Q2 is grounded. The source S of the MOS transistor Q3 is connected to the high-level VCC contact (3). The gate G of the MOS transistor Q3 is connected to the high-level VCC contact (3) after being connected in series with the resistor R3. The drain D of the MOS transistor Q3 is connected to the positive terminal.

3. The waterproof protection circuit for a battery pack according to claim 2, characterized in that: MOSFET Q2 is of the same type as MOSFET Q1, while MOSFET Q3 is of the opposite type to MOSFET Q1. MOSFET Q3 is a P-channel MOSFET, while MOSFETs Q2 and Q1 are N-channel MOSFETs.

4. The waterproof protection circuit for a battery pack according to claim 1, characterized in that: The waterproof protection circuit is provided with a waterproof insulation layer, and the high-level VCC contact (3) and the water ingress detection contact (4) are exposed and conductive.

5. The waterproof protection circuit for a battery pack according to claim 1, characterized in that: Several conductive probes are electrically connected to the water inlet detection contact (4). The probes are respectively located inside the outer shell of the battery pack and around the positive terminal or the high-level VCC contact (3).

6. The waterproof protection circuit for a battery pack according to claim 1, characterized in that: The high-level VCC contact (3) and the water inlet detection contact (4) are made of corrosion-resistant conductive metal or alloy, or the surfaces of the high-level VCC contact (3) and the water inlet detection contact (4) are coated with conductive adhesive for isolating air.

7. The waterproof protection circuit for a battery pack according to any one of claims 1 to 6, characterized in that: The waterproof protection circuit is installed on the existing PCB circuit board inside the battery pack and is located in the power supply circuit for charging and discharging the battery pack, or a separate circuit board is installed and electrically connected to the power supply circuit between the power source inside the battery pack and the existing PCB circuit board.

8. A battery pack, characterized in that: The waterproof protection circuit according to any one of claims 1 to 7 includes a battery pack shell (11), a PCB circuit board (12), and a battery power supply (13). The PCB circuit board (12) is provided with a charge and discharge management circuit (14) for controlling the charging and discharging of the battery power supply (13). It is also provided with a discharge positive terminal (15), a charging positive terminal (16), a negative terminal (17), and a ground terminal (18).

9. The battery pack according to claim 8, characterized in that: Waterproof paint or waterproof glue is applied to the positions of the discharge positive terminal pin (15), the charging positive terminal pin (16) and the negative terminal pin (17) on the PCB circuit board (12); waterproof paint or waterproof glue is applied to the waterproof protection circuit and the high-level VCC contact (3) and the water ingress detection contact (4) are exposed and conductive.

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