Lithium battery protection circuit with water inlet detection function
By designing a lithium battery protection circuit with water ingress detection function, the water ingress detection circuit and NMOS transistor are used to detect water ingress into the lithium battery, triggering the protection chip to protect the lithium battery. This solves the safety hazards of water ingress into lithium batteries and improves safety and stability.
Patent Information
- Application Number
- CN202423243785.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2025-12-12
- Estimated Expiration
- 2034-12-27
AI Technical Summary
Existing lithium battery protection boards lack water ingress detection circuits, which prevents timely detection of water ingress into the battery, increasing safety hazards such as short circuits, spontaneous combustion, and explosions.
Design a lithium battery protection circuit with water ingress detection function. Through the water ingress detection circuit and the lithium battery charge and discharge protection circuit, the water ingress detection components and NMOS transistors are used to detect water ingress into the battery and trigger the protection chip to perform protection actions.
It enables timely triggering of protection actions when lithium batteries are exposed to water, reducing the safety risks of battery pack use. It has a simple structure and sensitive operation.
Smart Images
Figure CN223666035U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to the field of lithium battery application, especially relates to a lithium battery protection circuit with water inlet detection function. BACKGROUND
[0002] The application of the lithium battery protection plate can improve the safety and stability of the battery, thereby protecting the equipment and the user from potential safety risks.
[0003] At present, most protection plates do not have a water inlet detection circuit. If the battery is waterlogged, the user may not be able to learn the status of the battery pack in time, and if the charging and discharging continues, it will increase the risk of safety hazards such as short circuit, spontaneous combustion and explosion of the battery pack. Therefore, it is necessary to design a water inlet detection protection circuit. UTILITY MODEL CONTENTS
[0004] The utility model aims at: provide a kind of lithium battery protection circuit with water inlet detection function, reduce the use safety risk of entire battery pack.
[0005] The technical scheme of the utility model is:
[0006] The lithium battery protection circuit with water inlet detection function includes water inlet detection circuit and lithium battery charging and discharging protection circuit;
[0007] The lithium battery charging and discharging protection circuit includes charging power supply and protection chip U1;The positive pole P+ of charging power supply is connected with the positive pole B+ of lithium battery pack by three-terminal fuse F1, and the negative pole P- of charging power supply is connected with the negative pole B- of lithium battery pack by charging and discharging MOS tube;Protection chip U1 collects the state information of each single body of lithium battery pack, and controls charging and discharging MOS tube;
[0008] The water inlet detection circuit includes water inlet detection component J2 and NMOS tube Q8, Q5;The water inlet detection component J2 includes two pads with certain spacing, one pad is connected with the positive pole B+ of lithium battery pack, and the other pad is connected with the gate of NMOS tube Q8 and Q5 respectively, the source of NMOS tube Q8 and Q5 is connected with ground respectively, the drain of NMOS tube Q8 is connected with the control end of three-terminal fuse F1, and the drain of NMOS tube Q5 is connected with temperature detection connection pin TS3 of protection chip U1.
[0009] Preferably, the spacing of the two pads of the water inlet detection component J2 is 1-3mm;The two pads of water inlet detection component J2 are not conducted when lithium battery pack is in normal operation, when lithium battery pack is waterlogged, the two pads are conducted through water, and trigger protection.
[0010] Preferably, the protection chip U1 uses SH3676X.
[0011] Preferably, the CHG pin and the DSG pin of the protection chip SH3676X are connected to the control charging MOS tube and the control discharging MOS tube respectively.
[0012] Preferably, the gate of the NMOS tube Q8 and the gate of the NMOS tube Q5 are connected with the resistor R33 and the resistor R32 respectively; the gate and the source of the NMOS tube Q8 are connected with the resistor R31 and the capacitor C23 in parallel; the gate and the source of the NMOS tube Q5 are connected with the resistor R34 and the capacitor C22 in parallel.
[0013] The utility model has the advantages of:
[0014] The lithium battery protection circuit with water inlet detection function of the utility model discloses a water inlet detection circuit, when the lithium battery group is waterlogged, the conductivity of water makes two pads of the water inlet detection component conductive to trigger the protection of the lithium battery charging and discharging protection circuit, reduces the use safety risk of the whole battery group, and the structure is simple and the action is sensitive. BRIEF DESCRIPTION OF DRAWINGS
[0015] The utility model will be further described in connection with the drawings and examples:
[0016] Figure 1 It is the principle drawing of lithium battery charging and discharging protection circuit;
[0017] Figure 2 It is the principle drawing of water inlet detection circuit. DETAILED DESCRIPTION
[0018] The lithium battery protection circuit with water inlet detection function of the utility model discloses a water inlet detection circuit and lithium battery charging and discharging protection circuit.
[0019] As Figure 1 Shown, the lithium battery charging and discharging protection circuit includes charging power supply and protection chip U1;The positive pole P+ of charging power supply is connected with the positive pole B+ of lithium battery group through three-terminal fuse F1, and the negative pole P- of charging power supply is connected with the negative pole B- of lithium battery group through charging and discharging MOS tube;Protection chip U1 gathers the state information of each single body of lithium battery group, controls charging and discharging MOS tube;Protection chip U1 adopts SH3676X.The CHG pin and the DSG pin of protection chip SH3676X are connected to control charging MOS tube Q2, Q4 and discharging MOS tube Q1, Q3 respectively.
[0020] As Figure 2 Shown, the water inlet detection circuit includes water inlet detection component J2 and NMOS tube Q8, Q5;The interval of two pads of water inlet detection component J2 is 1-3mm;When lithium battery group is in normal operation, two pads of water inlet detection component J2 are not conductive, when lithium battery group is waterlogged, two pads are conductive through water, and trigger protection.
[0021] The water inlet detection component J2 includes two pads with a certain interval, one of which is connected with the positive pole B+ of the lithium battery, and the other is connected with the gate of the NMOS tube Q8 and Q5 respectively, the source of the NMOS tube Q8 and Q5 is connected with the ground respectively, the drain of the NMOS tube Q8 is connected with the control end of the three-terminal fuse F1, and the drain of the NMOS tube Q5 is connected with the temperature detection connecting pin TS3 of the protection chip SH3676X. The gate of the NMOS tube Q8 and Q5 is respectively connected with the resistor R33 and R32 in series; the resistor R31 and the capacitor C23 are connected in parallel between the gate and the source of the NMOS tube Q8; and the resistor R34 and the capacitor C22 are connected in parallel between the gate and the source of the NMOS tube Q5.
[0022] When the detection point J2 in the water inlet detection circuit detects water conduction, the Q8 MOS is turned on to melt the three-terminal fuse F1, and the Q5 MOS is also turned on, the temperature detection connecting end signal of the 18 pin of the U1 chip SH3676 is detected abnormally, the CHG pin and the DSG pin output low level, the charging MOS tube Q2 and Q4 and the discharging MOS tube Q1 and Q3 are closed, and the charging and discharging main circuit is completely disconnected to stop charging and discharging.
[0023] The above examples are only for illustrating the technical concept and characteristics of the utility model, and the purpose is to enable the person skilled in the art to understand the content of the utility model and to implement it, and it cannot limit the protection scope of the utility model. Any modification according to the spirit and essence of the main technical scheme of the utility model should be covered in the protection scope of the utility model.
Claims
1. A lithium battery protection circuit with water inlet detection function, characterized in that, The water inlet detection circuit and the lithium battery charging and discharging protection circuit are included. The lithium battery charging and discharging protection circuit includes a charging power supply and a protection chip U1; the positive pole P+ of the charging power supply is connected with the positive pole B+ of the lithium battery group through a three-terminal fuse F1, and the negative pole P- of the charging power supply is connected with the negative pole B- of the lithium battery group through a charging and discharging MOS tube; the protection chip U1 collects the state information of each single cell of the lithium battery group and controls the charging and discharging MOS tube. The water inlet detection circuit includes a water inlet detection component J2 and NMOS tubes Q8 and Q5; the water inlet detection component J2 includes two pads with a certain interval, one of which is connected with the positive pole B+ of the lithium battery group, and the other of which is connected with the gate of the NMOS tube Q8 and the gate of the NMOS tube Q5 respectively; the source of the NMOS tube Q8 and the source of the NMOS tube Q5 are connected with the ground respectively; the drain of the NMOS tube Q8 is connected with the control end of the three-terminal fuse F1; and the drain of the NMOS tube Q5 is connected with the temperature detection connection pin TS3 of the protection chip U1.
2. The lithium battery protection circuit with water inlet detection function according to claim 1, characterized in that, The interval of the two pads of the water inlet detection component J2 is 1-3 mm; the two pads of the water inlet detection component J2 are not conductive when the lithium battery group is in normal operation, and the two pads are conductive through water when the lithium battery group is in water, triggering protection.
3. The lithium battery protection circuit with water inlet detection function according to claim 2, characterized in that, The protection chip U1 adopts SH3676X.
4. The lithium battery protection circuit with water inlet detection function according to claim 3, characterized in that, The CHG pin and the DSG pin of the protection chip SH3676X are connected with the control charging MOS tube and the discharging MOS tube respectively.
5. The lithium battery protection circuit with water inlet detection function according to claim 1, characterized in that, The gate of the NMOS tube Q8 and the gate of the NMOS tube Q5 are respectively connected with resistors R33 and R32 in series; the gate and the source of the NMOS tube Q8 are connected with a parallel-connected resistor R31 and a capacitor C23; and the gate and the source of the NMOS tube Q5 are connected with a parallel-connected resistor R34 and a capacitor C22.