A lithium battery management system charging and discharging port negative voltage detection circuit
By designing a negative electrode voltage detection circuit for the charging and discharging port of a lithium battery management system, and utilizing a switch control circuit and a voltage detection circuit, the problem of damage to electrical components caused by short circuits in the charging and discharging port or reverse connection of the charger is solved. This achieves real-time detection and improved reliability, and is also cost-effective.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- TAIZHOU DONGYUAN LNTELLIGENT TECH CO LTD
- Filing Date
- 2025-06-19
- Publication Date
- 2026-07-03
AI Technical Summary
Existing lithium battery management systems cannot effectively detect short circuits at the charging/discharging port or reverse connection of the charger, leading to damage to electrical components. They lack simple, stable, and reliable detection circuits.
Design a negative terminal voltage detection circuit for the charging/discharging port of a lithium battery management system. Utilize a switch control circuit and a voltage detection circuit, and control the conduction of the switch circuit through an MCU processor to detect the negative terminal voltage of the charging/discharging port. The circuit structure consists of transistors, resistors, and capacitors.
It enables real-time detection of the negative voltage at the charging/discharging port, timely identification of short circuits or reverse connection of the charger, improves circuit reliability, and is low in cost, simple in structure, and stable and reliable in function.
Smart Images
Figure CN224456884U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of lithium battery management systems, and in particular to a negative electrode voltage detection circuit for the charging and discharging port of a lithium battery management system. Background Technology
[0002] As lithium battery products are increasingly used in daily life, lithium battery management systems are also developing. If the battery's charging / discharging port is short-circuited, or if the charger is connected in reverse, a large loop current will be generated, potentially damaging electrical components. To protect the battery and its internal components, it is necessary to check the voltage state of the negative terminal of the charging / discharging port before opening the output. Therefore, a simple, stable, and reliable negative terminal voltage detection circuit for the charging / discharging port of a lithium battery management system was designed. Utility Model Content
[0003] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a lithium battery management system charging and discharging port negative electrode voltage detection circuit that is simple in structure, stable and reliable in function, and low in cost.
[0004] The objective of this utility model is achieved through the following technical solution:
[0005] A negative terminal voltage detection circuit for a charging / discharging port of a lithium battery management system includes: a switch control circuit and a voltage detection circuit. The control terminal of the switch control circuit is used to connect to an MCU processor, and the output terminal of the switch control circuit is electrically connected to the control terminal of the voltage detection circuit. The detection terminal of the voltage detection circuit is connected to the negative terminal of the charging / discharging port of the battery pack, and the output terminal of the voltage detection circuit is electrically connected to the MCU processor.
[0006] Preferably, the switch control circuit includes resistor R4, resistor R5, and transistor Q2. Resistor R4 is electrically connected to the output terminal of the MCU processor. The other end of resistor R4 is electrically connected to the base of transistor Q2, and the other end of resistor R5 is grounded. The emitter of transistor Q2 is grounded, and the collector of transistor Q2 is electrically connected to the voltage detection circuit.
[0007] Preferably, the voltage detection circuit includes a conduction module and a voltage divider module. The control terminal of the conduction module is electrically connected to the output terminal of the switch control circuit, the input terminal of the conduction module is electrically connected to the negative terminal of the charging / discharging port of the battery pack, the output terminal of the conduction module is electrically connected to the input terminal of the voltage divider module, and the output terminal of the voltage divider module is electrically connected to the MCU processor.
[0008] Preferably, the voltage detection circuit includes a conduction module and a voltage divider module. The control terminal of the conduction module is electrically connected to the output terminal of the switch control circuit, the input terminal of the conduction module is electrically connected to the negative terminal of the charging / discharging port of the battery pack, the output terminal of the conduction module is electrically connected to the input terminal of the voltage divider module, and the output terminal of the voltage divider module is electrically connected to the MCU processor.
[0009] Preferably, the conduction module includes resistor R1, resistor R2, diode D1, and transistor Q1. One end of resistor R2 is electrically connected to the switch control circuit, and the other end of resistor R2 is electrically connected to resistor R1 and the base of transistor Q1. The other end of resistor R1 is electrically connected to the cathode of diode D1 and the emitter of transistor Q1. The anode of diode D1 is electrically connected to the negative terminal of the battery pack's charging / discharging port. The collector of transistor Q1 is electrically connected to the input terminal of the voltage divider module.
[0010] Preferably, the voltage divider module includes resistor R3, resistor R6, and capacitor C1. One end of resistor R3 is electrically connected to the conduction module, and the other end of resistor R3 is electrically connected to resistor R6 and capacitor C1 and is also electrically connected to the input terminal of the MCU processor. The other end of resistor R6 is grounded, and the other end of capacitor C1 is grounded.
[0011] The advantages and beneficial effects of this utility model compared to the prior art are as follows:
[0012] This utility model discloses a negative terminal voltage detection circuit for the charging / discharging port of a lithium battery management system. By controlling a switch circuit and a voltage detection circuit, when the MCU processor outputs a control signal, the switch circuit and voltage detection circuit are activated to ensure normal operation. This allows for the detection of the negative terminal voltage at the charging / discharging port of the battery pack, enabling timely detection of external short circuits or reverse charger connections, thus improving circuit reliability. Furthermore, the circuit primarily consists of transistors, resistors, and capacitors, resulting in low cost. Its simple structure, stable and reliable function, and ease of widespread adoption make it suitable for practical use. Attached Figure Description
[0013] Figure 1 This is a functional module diagram of a negative electrode voltage detection circuit for a lithium battery management system according to an embodiment of the present invention.
[0014] Figure 2 This is a circuit diagram of a negative electrode voltage detection circuit for a lithium battery management system according to an embodiment of the present invention. Detailed Implementation
[0015] To facilitate understanding of this invention, a more comprehensive description will be provided below with reference to the accompanying drawings. This invention can be implemented in many different forms and is not limited to the embodiments described herein.
[0016] Please see Figure 1 , Figure 2 A negative terminal voltage detection circuit for a charging / discharging port of a lithium battery management system includes: a switch control circuit and a voltage detection circuit. The control terminal of the switch control circuit is used to connect to an MCU processor. The output terminal of the switch control circuit is electrically connected to the control terminal of the voltage detection circuit. The detection terminal of the voltage detection circuit is connected to the negative terminal of the charging / discharging port of the battery pack, and the output terminal of the voltage detection circuit is electrically connected to the MCU processor.
[0017] Thus, a lithium battery management system charging / discharging port negative electrode voltage detection circuit, through a control switch circuit and a voltage detection circuit, can control the conduction of the switch circuit and voltage detection circuit to ensure normal operation when the MCU processor outputs a control signal. This enables the detection of the negative electrode voltage at the battery pack's charging / discharging port, allowing for timely identification of external short circuits or reverse charger connections, thereby improving circuit reliability. Furthermore, the circuit of this invention mainly consists of transistors, resistors, and capacitors, resulting in low cost. Its simple structure, stable and reliable function, and ease of widespread application make it suitable for widespread use.
[0018] In this embodiment, the switch control circuit includes resistors R4 and R5 and transistor Q2. Resistor R4 is electrically connected to the output terminal of the MCU processor. The other end of resistor R4 is electrically connected to the base of transistor Q2, and the other end of resistor R5 is grounded. The emitter of transistor Q2 is grounded, and the collector of transistor Q2 is electrically connected to the voltage detection circuit.
[0019] The voltage detection circuit includes a conduction module and a voltage divider module. The control terminal of the conduction module is electrically connected to the output terminal of the switch control circuit. The input terminal of the conduction module is electrically connected to the negative terminal of the charging / discharging port of the battery pack. The output terminal of the conduction module is electrically connected to the input terminal of the voltage divider module. The output terminal of the voltage divider module is electrically connected to the MCU processor.
[0020] The voltage detection circuit includes a conduction module and a voltage divider module. The control terminal of the conduction module is electrically connected to the output terminal of the switch control circuit. The input terminal of the conduction module is electrically connected to the negative terminal of the charging / discharging port of the battery pack. The output terminal of the conduction module is electrically connected to the input terminal of the voltage divider module. The output terminal of the voltage divider module is electrically connected to the MCU processor.
[0021] The conduction module includes resistor R1, resistor R2, diode D1, and transistor Q1. One end of resistor R2 is electrically connected to the switch control circuit, and the other end of resistor R2 is electrically connected to resistor R1 and the base of transistor Q1. The other end of resistor R1 is electrically connected to the cathode of diode D1 and the emitter of transistor Q1. The anode of diode D1 is electrically connected to the negative terminal of the battery pack's charging / discharging port. The collector of transistor Q1 is electrically connected to the input terminal of the voltage divider module.
[0022] The voltage divider module includes resistor R3, resistor R6, and capacitor C1. One end of resistor R3 is electrically connected to the conduction module, and the other end of resistor R3 is electrically connected to resistor R6 and capacitor C1 and is also electrically connected to the input terminal of the MCU processor. The other end of resistor R6 is grounded, and the other end of capacitor C1 is grounded.
[0023] Working principle:
[0024] In the circuit, P- is the negative terminal of the battery pack's charging / discharging port, EN_VM is the output control I / O port of the MCU processor, and V_VM is the input detection I / O port of the MCU processor. When EN_VM is high, transistor Q2 turns on, which in turn turns on transistor Q1. When there is a voltage input to P-, the current flows through diode D1 and transistor Q1, then through resistors R3 and R6. This causes the input voltage of P- to be divided across resistors R3 and R6, filtered by capacitor C1, and then input to the input detection I / O port V_VM of the MCU processor. In this way, the MCU processor can detect the negative terminal voltage of the battery pack's charging / discharging port in real time, thereby determining the status of the external load.
[0025] Resistors R1 and R2 should be selected with appropriate resistance values to ensure that transistor Q1 can conduct normally even when the P- voltage is low. Resistors R3 and R6 should be selected with appropriate resistance values to ensure the detection accuracy when the P- voltage is low.
[0026] The above-described embodiments are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.
Claims
1. A lithium battery management system charge-discharge port negative voltage detection circuit, characterized in that, include: The circuit includes a switch control circuit and a voltage detection circuit. The control terminal of the switch control circuit is used to connect to the MCU processor. The output terminal of the switch control circuit is electrically connected to the control terminal of the voltage detection circuit. The detection terminal of the voltage detection circuit is connected to the negative terminal of the battery pack's charging / discharging port, and the output terminal of the voltage detection circuit is electrically connected to the MCU processor.
2. The lithium battery management system charge-discharge port negative voltage detection circuit of claim 1, wherein, The switch control circuit includes resistors R4 and R5 and transistor Q2. Resistor R4 is electrically connected to the output terminal of the MCU processor. The other end of resistor R4 is electrically connected to the base of transistor Q2, and the other end of resistor R5 is grounded. The emitter of transistor Q2 is grounded, and the collector of transistor Q2 is electrically connected to the voltage detection circuit.
3. The lithium battery management system charge-discharge port negative voltage detection circuit of claim 1, wherein, The voltage detection circuit includes a conduction module and a voltage divider module. The control terminal of the conduction module is electrically connected to the output terminal of the switch control circuit. The input terminal of the conduction module is electrically connected to the negative terminal of the charging / discharging port of the battery pack. The output terminal of the conduction module is electrically connected to the input terminal of the voltage divider module. The output terminal of the voltage divider module is electrically connected to the MCU processor.
4. The lithium battery management system charge-discharge port negative voltage detection circuit of claim 3, wherein, The conduction module includes resistor R1, resistor R2, diode D1, and transistor Q1. One end of resistor R2 is electrically connected to the switch control circuit, and the other end of resistor R2 is electrically connected to resistor R1 and the base of transistor Q1. The other end of resistor R1 is electrically connected to the cathode of diode D1 and the emitter of transistor Q1. The anode of diode D1 is electrically connected to the negative terminal of the battery pack's charging / discharging port. The collector of transistor Q1 is electrically connected to the input terminal of the voltage divider module.
5. The lithium battery management system charge-discharge port negative voltage detection circuit of claim 3, wherein, The voltage divider module includes resistor R3, resistor R6, and capacitor C1. One end of resistor R3 is electrically connected to the conduction module, and the other end of resistor R3 is electrically connected to resistor R6 and capacitor C1 and is also electrically connected to the input terminal of the MCU processor. The other end of resistor R6 is grounded, and the other end of capacitor C1 is grounded.