A charging-prohibited-discharging system in a lithium battery BMS

Abstract

The utility model relates to battery charge -discharge management technical field discloses a kind of charging prohibition discharging system in lithium battery BMS, including control module and with the charging control module, discharging control module and charging detection module of control module connection, charging detection module is connected with charging control module, discharging control module, control module is connected with battery, according to the data output control signal of received and give charging control module, discharging control module, charging control module, discharging control module are connected between battery and input-output interface, charging control module, the signal of discharging control module receiving control module realizes the on or cut-off of the charge-discharge loop of battery;Avoid discharging from charging port to outside, avoid the appearance of the phenomenon of igniting when charger is accessed;And automatically disconnect the discharging loop to outside when lithium battery charges, guarantee the safety of host computer in charging process, automatically disconnect charging loop when battery is fully charged, guarantee the safety of battery.

Description

Technical Field

[0001] This utility model relates to the field of battery charge and discharge management technology, specifically to a charging-prohibition-discharge system in a lithium battery BMS. Background Technology

[0002] In lithium battery applications, some devices have non-removable batteries that need to be charged together with the main unit. When the charger voltage is higher than the battery voltage, arcing may occur during the charging process due to the voltage inconsistency. During normal charging, if the main circuit is not shut down, the main unit's controller and other devices will not be powered off. If any operation is performed at this time, there is a risk of malfunction, which may endanger the main unit during the charging process. Utility Model Content

[0003] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a charging-prohibition-discharge system in a lithium battery BMS.

[0004] To achieve the above objectives, this utility model provides the following technical solution:

[0005] A charging-discharging-prohibition system in a lithium battery BMS includes a control module and a charging control module, a discharging control module, and a charging detection module connected to the control module. The charging detection module is connected to the charging control module and the discharging control module. The control module is connected to the battery and is used to receive and collect voltage, current, and temperature data of the battery, and output control signals to the charging control module and the discharging control module based on the received data. The charging control module and the discharging control module are connected between the battery and the input / output interface. The charging control module and the discharging control module receive signals from the control module to connect or disconnect the charging or discharging circuit of the battery. The charging detection module is located between the battery and the output interface and is used to detect whether the battery's input interface is connected to a charger, and disconnect the circuit between the battery and the output interface when no charger is connected, thereby ending the battery's external discharge.

[0006] In this utility model, preferably, the control module includes a main controller U1. Pins 1-14 of the main controller U1 are connected to the two ends of each cell of a multi-cell lithium battery through several sampling circuits and an interface P1 to collect the voltage and current signals of each cell. Pins 16-20 and 27-30 of the main controller U1 are respectively connected to the charging control module, the discharging control module, and the charging detection module.

[0007] In this invention, preferably, the charging control module includes switching transistors Q6 and Q7. The base and collector of switching transistor Q6 are connected in series with resistors R182 and R183 respectively and then connected to the VREG terminal. The emitter is connected to the CH- terminal of the charging MOSFET N6. The CH- terminal is used to connect to the charger. The source of switching transistor Q7 is connected to the VREG terminal, the gate is connected to the collector of switching transistor Q6, and the drain of switching transistor Q7 is connected to the DO signal terminal.

[0008] In this invention, preferably, the charging control module further includes a diode U2, the positive terminal of which is connected to the negative terminal of the battery, and the negative terminal is connected to the charging MOSFET N6 to form a charging circuit.

[0009] In this utility model, preferably, the charging detection module includes a diode D7 and a resistor R39. The main controller U1's pin 18 is connected in series with the diode D7 and the resistor R39 and then connected to the charging MOSFET N6. The two ends of the resistor R39 are also connected in series with the diode D6.

[0010] In this invention, preferably, the DO signal terminal is connected to the gate of the switching transistor Q4 after being connected in series with resistor R177. The drain of the switching transistor Q4 is connected to the DFETO signal terminal after being connected in series with resistor R179 and diode D5. The source of the switching transistor Q4 is grounded. The gate of the switching transistor Q4 is connected to the ground terminal after being connected in series with resistor R178. The DFETO signal terminal is also connected to the emitter of the switching transistor Q5. The collector of the switching transistor Q5 is connected to the ground terminal after being connected in series with resistor R181. The base of the switching transistor Q5 is also connected to the ground terminal after being connected in series with resistor R180.

[0011] In this invention, preferably, the discharge control module includes a switching transistor N3, the gate of the switching transistor N3 is connected to the DFETO signal terminal, the source of the switching transistor N3 is connected to the DFETO signal terminal after a resistor R15 is connected in series, the drain of the switching transistor N3 is connected to the output terminal PACK- of the battery, and the source of the switching transistor N3 is also connected to the negative terminal of the battery after a resistor R18 is connected in series.

[0012] In this invention, preferably, the two ends of the switching transistor N3 are also connected in parallel to a series circuit consisting of capacitors C19 and C20, and a diode D2.

[0013] In this invention, preferably, the 19th pin of the main controller U1 is connected in series with resistor R32 and then connected to the drain of the switching transistor N3.

[0014] Compared with the prior art, the beneficial effects of this utility model are:

[0015] This system, through a simple circuit design, prevents the lithium battery from discharging externally from the charging port, ensuring the safety of the lithium battery and avoiding sparking when connected to the charger. It also automatically disconnects the external discharge circuit during lithium battery charging, ensuring the safety of the main unit during the charging process. Simultaneously, it collects battery voltage and other data, automatically disconnecting the charging circuit when the battery is fully charged, ensuring battery safety. Attached Figure Description

[0016] Figure 1 This is a structural block diagram of a charging-prohibited-discharge system in a lithium battery BMS according to the present invention.

[0017] Figure 2 This is a circuit diagram of a charging-prohibited-discharge system in a lithium battery BMS according to the present invention. Detailed Implementation

[0018] 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, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0019] It should be noted that when a component is described as "fixed to" another component, it can be directly on the other component or may have a component in between. When a component is described as "connected to" another component, it can be directly connected to the other component or may have a component in between. When a component is described as "set on" another component, it can be directly set on the other component or may have a component in between. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0021] Please also see Figure 1 and Figure 2This utility model provides a charging-to-discharge prevention system in a lithium battery BMS, including a control module and a charging control module, a discharging control module, and a charging detection module connected to the control module. The charging detection module is connected to the charging control module and the discharging control module. The control module is connected to the battery and is used to receive and collect voltage, current, and temperature data of the battery, and output control signals to the charging control module and the discharging control module based on the received data. The charging control module and the discharging control module are connected between the battery and the input / output interface. The charging control module and the discharging control module receive signals from the control module to connect or disconnect the charging and discharging circuit of the battery. The charging detection module is located between the battery and the output interface and is used to detect whether the battery's input interface is connected to a charger. When no charger is connected, the circuit between the battery and the output interface is disconnected to end the battery's external discharge, thereby protecting the battery. When the charging control module is activated, it cuts off the charging circuit to the lithium battery, preventing further charging. At the same time, through the built-in anti-reverse connection diode, it prevents discharge from the charging port, achieving the function of preventing arcing, thereby protecting the battery. When the discharging control module is activated, it cuts off the battery's external discharge circuit, preventing discharge and avoiding battery depletion. Meanwhile, the charging detection module is responsible for detecting whether the charger is connected and cutting off the discharge circuit when the charger is connected.

[0022] In this embodiment, the control module includes a main controller U1. Pins 1-14 of the main controller U1 are connected to the two ends of each cell in a multi-cell lithium battery array via several sampling circuits and an interface P1 to collect the voltage and current signals of each cell. Pins 16-20 and 27-30 of the main controller U1 are respectively connected to the charging control module, the discharging control module, and the charging detection module. Each sampling circuit includes a resistor connected in series and a capacitor connected in parallel across each cell to collect the voltage data of each cell and send it to the main controller U1.

[0023] In this embodiment, the charging control module includes switching transistors Q6 and Q7. The base and collector of switching transistor Q6 are connected in series with resistors R182 and R183 respectively and then connected to the VREG terminal. The emitter is connected to the CH- terminal of the charging MOSFET N6. The CH- terminal is used to connect to the charger. The source of switching transistor Q7 is connected to the VREG terminal, the gate is connected to the collector of switching transistor Q6, and the drain of switching transistor Q7 is connected to the DO signal terminal.

[0024] In this embodiment, the charging control module also includes a diode U2. The positive terminal of the diode U2 is connected to the negative terminal of the battery, and the negative terminal is connected to the charging MOSFET N6. The diode U2 and the charging MOSFET N6 form a charging circuit. The CH- terminal is connected to the charger. The diode U2 is used to prevent reverse connection and avoid the battery from discharging through the charging port due to incorrect connection.

[0025] In this embodiment, the charging detection module includes a diode D7 and a resistor R39. The main controller U1's pin 18 is connected in series with the diode D7 and the resistor R39, and then connected to the charging MOSFET N6. The resistor R39 is also connected in series with the diode D6.

[0026] In this embodiment, the DO signal terminal is connected to the gate of the switching transistor Q4 via a series resistor R177. The drain of the switching transistor Q4 is connected to the DFETO signal terminal via a series resistor R179 and a diode D5. The source of the switching transistor Q4 is grounded. The gate of the switching transistor Q4 is connected to the ground via a series resistor R178. The DFETO signal terminal is also connected to the emitter of the switching transistor Q5. The collector of the switching transistor Q5 is connected to the ground via a series resistor R181. The base of the switching transistor Q5 is also connected to the ground via a series resistor R180.

[0027] The discharge control module includes a switching transistor N3. The gate of the switching transistor N3 is connected to the DFET0 signal terminal. The source of the switching transistor N3 is connected to the DFET0 signal terminal after a series resistor R15. The drain of the switching transistor N3 is connected to the output terminal PACK- of the battery. The source of the switching transistor N3 is also connected to the negative terminal of the battery after a series resistor R18. Pin 19 of the main controller U1 is connected to the drain of the switching transistor N3 after a series resistor R32.

[0028] The two ends of the switching transistor N3 are also connected in parallel by a series circuit consisting of capacitors C19 and C20, and diode D2.

[0029] Working principle:

[0030] In normal operation, the positive terminal of diode U2 is connected to the negative terminal of the battery, and the negative terminal is connected to the charging MOSFET N6, forming a charging circuit. Due to the unidirectional conductivity of the diode, diode U2 cannot carry reverse current, thus blocking the discharge circuit through the CH- terminal. CH- cannot output current, thereby ensuring that the lithium battery cannot discharge from the CH- terminal connected to the charger, ensuring battery safety.

[0031] The drive voltage output from pin 18 of the main controller U1 reaches the gate of the charging MOSFET N6 via resistor R24 ​​and diode D7. Due to the presence of diode D7, the CH- terminal has no output capability at this time, and charging stops. By controlling the conduction or cutoff of the charging MOSFET N6, the charging circuit can be controlled.

[0032] The CFET drive signal voltage output from pin 18 of the main controller U1 is approximately 14V. After passing through the body diode of the charging MOSFET N6, the voltage will be greater than 13V. The base of the switching transistor Q6 is connected to the VREG terminal with a 4.3V reference voltage, and the emitter is connected between the main controller U1 and the charging MOSFET N6. Due to the presence of the body diode between the drain and source of the charging MOSFET N6, there will be a 13V voltage at the emitter of the switching transistor Q6, and the switching transistor Q6 will not conduct. The switching transistor Q7 will also not conduct due to the presence of resistor R183, with a GS voltage of 0V. This results in no signal output at the DO signal terminal. Switches Q4 and Q5, connected through resistor R117, will not conduct, resulting in no signal output at the DFETO signal terminal. At this time, the switching transistor N3 will be cut off, thus preventing simultaneous discharge during lithium battery charging.

[0033] The drive voltage of the DFET is output to the DFETO network through resistor R179 and diode D5, which turns on the switching transistor N3. At this time, there is an output on the battery discharge port PACK-.

[0034] When the CH- terminal is connected to the charger, current flows through diode U2 and charging MOSFET N6, pulling the emitter of switch Q6 low and turning on switch Q6. Then switch Q7 turns on, and the DO signal outputs a high level through resistor R177 to switch Q4. Switch Q4 turns on, pulling the level of the DFET terminal low. Resistor R179 is grounded, and switch Q5 turns on, forming a new circuit with resistor R181 on the CE terminal, causing switch N3 to turn off quickly. There is no output on PACK-, thus achieving the purpose of preventing discharge during charging.

[0035] The above description is a detailed description of the preferred embodiments of the present utility model. However, the embodiments are not intended to limit the scope of the patent application of the present utility model. All equivalent changes or modifications made under the technical spirit of the present utility model should fall within the patent scope covered by the present utility model.

Claims

1. A charging-prohibition-discharge system in a lithium battery BMS, characterized in that, The system includes a control module and a charging control module, a discharging control module, and a charging detection module connected to the control module. The charging detection module is connected to the charging control module and the discharging control module. The control module is connected to the battery and is used to receive and collect voltage, current, and temperature data from the battery. Based on the received data, it outputs control signals to the charging control module and the discharging control module. The charging control module and the discharging control module are connected between the battery and the input / output interface. The charging control module and the discharging control module receive signals from the control module to connect or disconnect the charging and discharging circuit of the battery. The charging detection module is located between the battery and the output interface and is used to detect whether the battery's input interface is connected to a charger. When no charger is connected, it disconnects the circuit between the battery and the output interface to end the battery's external discharge.

2. The charging-prohibited-discharge system in a lithium battery BMS according to claim 1, characterized in that, The control module includes a main controller U1. Pins 1-14 of the main controller U1 are connected to the two ends of each cell of a multi-cell lithium battery through several sampling circuits and an interface P1 to collect the voltage and current signals of each cell. Pins 16-20 and 27-30 of the main controller U1 are respectively connected to the charging control module, the discharging control module, and the charging detection module.

3. The charging-prohibited-discharge system in a lithium battery BMS according to claim 2, characterized in that, The charging control module includes switching transistors Q6 and Q7. The base and collector of switching transistor Q6 are connected in series with resistors R182 and R183 respectively and then connected to the VREG terminal. The emitter is connected to the CH- terminal of the charging MOSFET N6. The CH- terminal is used to connect to the charger. The source of switching transistor Q7 is connected to the VREG terminal, the gate is connected to the collector of switching transistor Q6, and the drain of switching transistor Q7 is connected to the DO signal terminal.

4. The charging-prohibited-discharge system in a lithium battery BMS according to claim 3, characterized in that, The charging control module also includes a diode U2, the positive terminal of which is connected to the negative terminal of the battery, and the negative terminal is connected to the charging MOSFET N6.

5. A charging-prohibited-discharge system in a lithium battery BMS according to claim 4, characterized in that, The charging detection module includes a diode D7 and a resistor R39. The main controller U1 has a charging MOSFET N6 connected in series with the diode D7 and the resistor R39 at pin 18. The diode D6 is also connected in series across the resistor R39.

6. The charging-prohibited-discharge system in a lithium battery BMS according to claim 5, characterized in that, The DO signal terminal is connected to the gate of the switching transistor Q4 via a series resistor R177. The drain of the switching transistor Q4 is connected to the DFETO signal terminal via a series resistor R179 and a diode D5. The source of the switching transistor Q4 is grounded. The gate of the switching transistor Q4 is connected to the ground via a series resistor R178. The DFETO signal terminal is also connected to the emitter of the switching transistor Q5. The collector of the switching transistor Q5 is connected to the ground via a series resistor R181. The base of the switching transistor Q5 is also connected to the ground via a series resistor R180.

7. A charging-prohibited-discharge system in a lithium battery BMS according to claim 6, characterized in that, The discharge control module includes a switching transistor N3. The gate of the switching transistor N3 is connected to the DFETO signal terminal. The source of the switching transistor N3 is connected to the DFETO signal terminal after a resistor R15 in series. The drain of the switching transistor N3 is connected to the output terminal PACK- of the battery. The source of the switching transistor N3 is also connected to the negative terminal of the battery after a resistor R18 in series.

8. A charging-prohibited-discharge system in a lithium battery BMS according to claim 7, characterized in that, The two ends of the switching transistor N3 are also connected in parallel by a series circuit consisting of capacitors C19 and C20, and diode D2.

9. A charging-prohibited-discharge system in a lithium battery BMS according to claim 7, characterized in that, The main controller U1 has its pin 19 connected in series with resistor R32 and then connected to the drain of the switching transistor N3.

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