An electric vehicle battery control circuit and method

Abstract

The application discloses a kind of electric vehicle battery control circuit and method, the first end of the air switch of this control circuit is electrically connected with battery output end, second end is respectively electrically connected with the input end of sampling module and the first end of driving switch tube;The second end of driving switch tube is electrically connected with system power supply end;The output end of sampling module is electrically connected with the voltage sampling end of controller, for output sampling voltage to controller;The first end of first start switch tube is electrically connected with the control end of driving switch tube, second end connects ground, for controlling driving switch tube to turn on or turn off;The control end of first start switch tube is electrically connected with the enable end of controller, for controlling first start switch tube to turn on or turn off;Controller is used to control first start switch tube to turn on when sampling voltage is greater than first voltage threshold and control first start switch tube to turn off when sampling voltage is less than second voltage threshold.The technical scheme provided by the application is to improve the endurance of battery.

Description

Technical Field

[0001] This invention relates to the field of battery control technology, and in particular to a battery control circuit and method for electric vehicles. Background Technology

[0002] With the development of two-wheeled vehicle technology and the increasing demands on the range and lifespan of two-wheeled electric vehicle batteries, it is required to disconnect the battery for discharge under low or undervoltage conditions.

[0003] Currently, most car batteries still have a certain static power consumption even when the vehicle is not used for a long time and the whole vehicle system is in a static state. This causes the battery to continue discharging even when it is undervoltage. If it is not charged in time, it may lead to the battery's range or permanent damage to the battery itself, thus reducing the battery's lifespan and causing economic losses to the user in severe cases. Summary of the Invention

[0004] This invention provides an electric vehicle battery control circuit and method to meet customer needs for extended battery range and lifespan.

[0005] In a first aspect, embodiments of the present invention provide an electric vehicle battery control circuit, including: an air switch, a first start-up switch transistor, a sampling module, a drive switch transistor, and a controller;

[0006] The first terminal of the air switch is electrically connected to the battery output terminal; the second terminal of the air switch is electrically connected to both the input terminal of the sampling module and the first terminal of the drive switch transistor; the second terminal of the drive switch transistor is electrically connected to the system power supply terminal for transmitting the battery voltage to the system power supply terminal; the output terminal of the sampling module is electrically connected to the voltage sampling terminal of the controller for outputting the sampled voltage to the controller; the first terminal of the first start switch transistor is electrically connected to the control terminal of the drive switch transistor, and the second terminal of the first start switch transistor is connected to ground for controlling the drive switch transistor to be turned on or off; the enable terminal of the controller is electrically connected to the control terminal of the first start switch transistor for controlling the first start switch transistor to be turned on or off.

[0007] The controller is used to control the first start-up switch to turn on when the sampled voltage is greater than a first voltage threshold; the controller is also used to control the first start-up switch to turn off when the sampled voltage is less than a second voltage threshold.

[0008] Secondly, embodiments of the present invention provide an electric vehicle battery control method, applicable to any electric vehicle battery control circuit provided in any embodiment of the present invention. The electric vehicle battery control circuit further includes: a second start module; the second start module includes a trigger unit and a second start switch tube; the second terminal of the air switch is electrically connected to the control terminal of the second start switch tube through the trigger unit; the first terminal of the second start switch tube is electrically connected to the first terminal of the first start switch tube; the second terminal of the second start switch tube is electrically connected to the ground terminal.

[0009] The electric vehicle battery control method includes:

[0010] When the air switch is momentarily closed, the second start-up module is turned on to turn on the drive switch tube, so that the drive switch tube outputs the battery voltage to the system power supply terminal;

[0011] If the air switch is turned off and then remains closed, and the controller detects that the sampled voltage is greater than the first voltage threshold, then it controls the first start-up switch to turn on so that the drive switch remains on; the second start-up switch is turned off.

[0012] The controller is also configured to control the first start-up switch to turn off when the sampled voltage is less than the second voltage threshold.

[0013] In this invention, the electric vehicle battery control circuit includes an air switch, a first start-up switch transistor, a sampling module, a drive switch transistor, and a controller. The air switch connects the battery output terminal to the first terminal of the drive switch transistor, and the second terminal of the drive switch transistor is electrically connected to the system power supply terminal. A sampling module is positioned between the air switch and the first terminal of the drive switch transistor, and the first start-up switch transistor is electrically connected to the control terminal of the drive switch transistor. After the controller closes the air switch, the sampling module acquires the sampled voltage at the first terminal of the drive switch transistor and outputs it to the controller. When the controller detects that the sampled voltage is greater than a first voltage threshold, it controls the first start-up switch transistor to conduct, thus turning on the drive switch transistor and allowing the battery to continuously supply power to the system power supply terminal. Conversely, when the controller acquires a sampled voltage less than a second voltage threshold, it controls the first start-up switch transistor to turn off, disconnecting the battery's power supply to the system power supply terminal in a low-voltage or under-voltage state, thereby improving the battery's range and lifespan. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of an electric vehicle battery control circuit provided in an embodiment of the present invention;

[0015] Figure 2 This is a flowchart illustrating an electric vehicle battery control method provided in an embodiment of the present invention. Detailed Implementation

[0016] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0017] This invention provides an electric vehicle battery control circuit. Figure 1 This is a schematic diagram of the structure of an electric vehicle battery control circuit provided in an embodiment of the present invention. The electric vehicle battery control circuit includes: an air switch DZ1, a first start switch transistor Q3, a sampling module 11, a drive switch transistor Q1, and a controller 12.

[0018] The first terminal of the air switch DZ1 is electrically connected to the battery output terminal VBAT; the second terminal of the air switch DZ1 is electrically connected to the input terminal of the sampling module 11 and the first terminal of the drive switch Q1; the second terminal of the drive switch Q1 is electrically connected to the system power supply terminal VCC-OUT, used to transmit the battery voltage to the system power supply terminal VCC-OUT; the output terminal of the sampling module 11 is electrically connected to the voltage sampling terminal MCU-ADC of the controller 12, used to output the sampled voltage to the controller 12; the first terminal of the first start switch Q3 is electrically connected to the control terminal of the drive switch Q1, and the second terminal of the first start switch Q3 is connected to the ground terminal GND, used to control the drive switch Q1 to be turned on or off; the enable terminal MCU-EN of the controller 12 is electrically connected to the control terminal of the first start switch Q3, used to control the first start switch Q3 to be turned on or off.

[0019] The controller 12 is used to control the first start-up switch Q3 to turn on when the sampled voltage is greater than the first voltage threshold; the controller 12 is also used to control the first start-up switch Q3 to turn off when the sampled voltage is less than the second voltage threshold.

[0020] Air switch DZ1, also known as an air circuit breaker, is a switch that automatically disconnects when the current in the circuit exceeds the rated current. Controller 12 is electrically connected to air switch DZ1 and controls its on / off state. The first terminal of air switch DZ1 is electrically connected to the battery output terminal VBAT, and the second terminal is electrically connected to the first terminal of drive switch Q1. The second terminal of drive switch Q1 is electrically connected to the system power supply terminal VCC-OUT. Thus, the battery output terminal VBAT is transmitted sequentially through air switch DZ1 and drive switch Q1 to the system power supply terminal VCC-OUT, facilitating subsequent supply to motors and other electronic equipment.

[0021] The electric vehicle battery control circuit also includes a sampling module 11. The sampling module 11 is located between the second terminal of the air switch DZ1 and the first terminal of the drive switch Q1. It is used to collect the power supply voltage output from the battery output terminal VBAT and output a sampled voltage that identifies the power supply voltage to the voltage sampling terminal MCU-ADC of the controller 12. The controller 12 is used to activate the first start-up switch Q3 through the enable terminal MCU-EN of the controller 12 when the sampled voltage is greater than a first voltage threshold. The control terminal of the first start-up switch Q3 is electrically connected to the enable terminal MCU-EN of the controller 12, the first terminal of the first start-up switch Q3 is electrically connected to the control terminal of the drive switch Q1, and the second terminal of the first start-up switch Q3 is connected to ground GND. When the controller 12 controls the first start-up switch Q3 to conduct through the enable terminal MCU-EN, the drive switch Q1 is turned on, and the first start-up switch Q3 controls the drive switch Q1 to remain on to supply power to the system power supply terminal VCC-OUT.

[0022] Subsequently, the sampling module 11 continuously sends the sampling voltage to the controller 12. The controller 12 is also used to control the first startup switch Q3 to turn off via the enable terminal MCU-EN when the sampling voltage is less than the second voltage threshold, thereby turning off the drive switch Q1 to prevent the battery from continuing to discharge in a low-voltage or under-voltage state. The controller 12 promptly turns off the drive switch Q1 when the sampling voltage is too low, preventing the battery voltage from becoming too low, thus preventing permanent damage to the battery's later operating range or the battery itself, improving battery life, and reducing economic losses for the user.

[0023] It is important to note that when the sampled voltage is greater than the first voltage threshold, the power supply voltage output from the air switch DZ1 to the first terminal of the drive switch Q1 is sufficient to meet the power supply requirements of the system power supply terminal VCC-OUT. Therefore, when the controller 12 obtains sufficient power supply voltage to meet the power supply requirements of the power supply terminal VCC-OUT, it controls the drive switch Q1 to turn on via the first start switch Q3. When the sampled voltage is less than the first voltage threshold, it indicates that the power supply voltage output from the air switch DZ1 to the first terminal of the drive switch Q1 is too low or the battery is already in an undervoltage state. To protect the battery, the controller 12 controls the drive switch Q1 to turn off via the first start switch Q3, avoiding disconnection of the system power supply and ensuring battery lifespan and performance.

[0024] Optionally, the first voltage threshold can be greater than the second voltage threshold. The first voltage threshold is the turn-on signal for driving switch Q1, and the second voltage threshold is the turn-off signal for driving switch Q1. Therefore, the first voltage threshold needs to be greater than the second voltage threshold. To further improve the reliability of the electric vehicle battery control circuit, the difference between the first and second voltage thresholds can be set to be significant for easy differentiation, thereby facilitating the controller 12 to control the first start-up switch Q3 to be turned on or off based on the first and second voltage thresholds.

[0025] In this embodiment of the invention, the electric vehicle battery control circuit includes an air switch, a first start-up switch transistor, a sampling module, a drive switch transistor, and a controller. The air switch connects the battery output terminal to the first terminal of the drive switch transistor, and the second terminal of the drive switch transistor is electrically connected to the system power supply terminal. A sampling module is positioned between the air switch and the first terminal of the drive switch transistor, and the first start-up switch transistor is electrically connected to the control terminal of the drive switch transistor. After the controller closes the air switch, the sampling module acquires the sampled voltage at the first terminal of the drive switch transistor and outputs it to the controller. When the controller detects that the sampled voltage is greater than a first voltage threshold, it controls the first start-up switch transistor to conduct, thus turning on the drive switch transistor and allowing the battery to continuously supply power to the system power supply terminal. Conversely, when the controller acquires a sampled voltage less than a second voltage threshold, it controls the first start-up switch transistor to turn off, disconnecting the battery's power supply to the system power supply terminal in a low-voltage or under-voltage state, thereby improving the battery's range and lifespan.

[0026] The above is the core idea of ​​this invention. The technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0027] Continue to refer to Figure 1 Optionally, the electric vehicle battery control circuit may further include: a second start module 13; the second start module 13 includes a trigger unit 131 and a second start switch tube Q2; the second terminal of the air switch DZ1 is electrically connected to the control terminal of the second start switch tube Q2 through the trigger unit 131; the first terminal of the second start switch tube Q2 is electrically connected to the first terminal of the first start switch tube Q3; the second terminal of the second start switch tube Q2 is electrically connected to the ground terminal GND; the first start switch tube Q3 and the second start module 13 are not turned on at the same time.

[0028] The second start-up module 13 includes a second start-up switch Q2 and a trigger unit 131 that drives the second start-up switch Q2. The trigger unit 131 is electrically connected to the second terminal of the air switch DZ1 and is used to turn on the second start-up switch Q2 the instant the air switch DZ1 is closed, so that the drive switch Q1 can quickly supply power to the system power supply terminal VCC-OUT. When the controller 12 detects that the sampled voltage is greater than a first voltage threshold, it controls the first start-up switch Q3 to turn on. At the same time, the second start-up switch Q2 is turned off, and the first start-up switch Q3 continuously controls the drive switch Q1 to turn on. In this embodiment, the first start-up switch Q3 and the second start-up module 13 achieve internal self-locking through the characteristics of an RC circuit, and the first start-up switch Q3 and the second start-up switch Q2 do not need to be turned on simultaneously.

[0029] In this embodiment, after the drive switch Q1 is turned off in a low-voltage battery state, if the system needs to be powered on again, the controller 12 controls the air switch DZ1 to open from the closed state and then close again to re-trigger the self-locking circuit of this embodiment. Based on the above embodiment, refer to... Figure 1 The controller 12 can also be used to control the air switch DZ1 to change from a closed state to an open state and then back to a closed state when the system power supply terminal VCC-OUT is powered on. The electric vehicle battery control circuit does not automatically control the drive switch Q1 to turn on directly when the battery output voltage VBAT rises (through charging). Instead, when the controller 12 receives the vehicle's request to power on the system power supply terminal VCC-OUT, it controls the air switch DZ1 to change from a closed state to an open state and then back to a closed state, thereby controlling the drive switch Q1 to turn on or off again based on the sampling voltage of the sampling module 11. In this embodiment, the drive switch Q1 is not automatically turned on after the battery output voltage VBAT rises, preventing static power consumption in the vehicle system due to long-term vehicle idling, preventing undervoltage of the battery due to long-term idling, and avoiding damage to the battery itself. In this embodiment, when the system power supply VCC-OUT is powered on, the air switch DZ1 is controlled to close again, and the second start switch Q2 momentarily starts the drive switch Q1 to conduct. After the air switch DZ1 is opened and closed again, the first start switch Q3 continuously controls the drive switch Q1 to conduct, thereby further enhancing the reliability of the electric vehicle battery control circuit and improving the battery's lifespan and range.

[0030] Continue to refer to Figure 1 Optionally, the sampling module 11 may include: a first resistor R1, a second resistor R2, and a first capacitor C1; the first end of the first resistor R1 is electrically connected to the second end of the air switch DZ1; the second end of the first resistor R1 is electrically connected to the first end of the second resistor R2 and the voltage sampling terminal MCU-ADC of the controller 12; the second end of the second resistor R2 is electrically connected to ground GND; and the first capacitor C1 is connected in parallel with the second resistor R2. The first resistor R1, the second resistor R2, and the first capacitor C1 form a filter sampling circuit, and the first resistor R1 and the second resistor R2 form a voltage divider, thereby generating a sampling voltage output to the controller. Furthermore, the first capacitor C1 is connected in parallel with the second resistor R2 to further stabilize the sampling voltage, increase the accuracy of the sampling voltage, and facilitate the controller 12 to obtain the battery power supply voltage value based on the sampling voltage, thereby improving the control accuracy of the controller 12 and increasing the reliability of the electric vehicle battery control circuit.

[0031] Continue to refer to Figure 1Optionally, the electric vehicle battery control circuit may further include: a voltage protection module 15; the voltage protection module 15 includes a third resistor R3, a Zener diode DZ2, and a second capacitor C2; the negative terminal of the Zener diode DZ2 is electrically connected to the first terminal of the drive switch Q1; the positive terminal of the Zener diode DZ2 is electrically connected to the control terminal of the drive switch Q1; the third resistor R3 and the second capacitor C2 are both connected in parallel with the Zener diode DZ2. The third resistor R3, the Zener diode DZ2, and the second capacitor C2 constitute a protection against the voltage difference between the control terminal and the first terminal of the drive switch Q1, preventing the drive switch Q1 from being damaged due to excessive voltage difference. The third resistor R3 acts as a voltage divider and current limiter, and the Zener diode DZ2 acts as a voltage stabilizer. This embodiment further improves the reliability of the electric vehicle battery control circuit.

[0032] Continue to refer to Figure 1 Optionally, the trigger unit 131 may include: a fifth resistor R5, a first electrolytic capacitor C3, a first diode D1, a second electrolytic capacitor C4, a sixth resistor R6, and a seventh resistor R7; the first terminal of the fifth resistor R5 is electrically connected to the second terminal of the air switch DZ1; the second terminal of the fifth resistor R5 is connected to ground GND; the positive terminal of the first electrolytic capacitor C3 is electrically connected to the first terminal of the fifth resistor R5; the negative terminal of the first electrolytic capacitor C3 is electrically connected to the negative terminal of the first diode D1; the positive terminal of the first diode D1 is connected to ground GND; the positive terminal of the second electrolytic capacitor C4 is electrically connected to the negative terminal of the first diode D1; the negative terminal of the second electrolytic capacitor C4 is connected to ground GND; the first terminal of the sixth resistor R6 is electrically connected to the positive terminal of the second electrolytic capacitor C4; the second terminal of the sixth resistor R6 is electrically connected to the control terminal of the second start switch Q2; the control terminal of the second start switch Q2 is connected to ground GND via the seventh resistor R7. The fifth resistor R5, the first electrolytic capacitor C3, the first diode D1, the second electrolytic capacitor C4, the sixth resistor R6, and the seventh resistor R7 constitute an instantaneous start-up structure to instantaneously turn on the second start-up switch Q2. When the system power supply is powered on, the controller 12 controls the air switch DZ1 to change from the closed state to the open state, and the trigger unit 131 instantaneously turns on the second start-up switch Q2 to provide instantaneous power to the system power supply VCC-OUT. When the controller 12 controls the air switch DZ1 to change from the open state to the closed state again, the controller 12 continuously drives the switch Q1 through the first start-up switch Q3.

[0033] Optionally, the first terminal of the first starter switch Q3 can be electrically connected to the control terminal of the drive switch Q1 via the eighth resistor R8. The eighth resistor R8 is a voltage divider resistor. In this embodiment, internal self-locking is achieved through the characteristics of the RC circuit, and the two starter switches do not need to be turned on simultaneously. Furthermore, the electric vehicle battery control circuit monitors the battery voltage in real time and can cut off the circuit. If the battery voltage fails to recover automatically after rising, the air switch DZ1 needs to be turned on and off again to re-trigger the self-locking circuit. This embodiment can effectively protect the battery, prevent the battery from being in an undervoltage state, and improve battery life.

[0034] Based on the same concept, embodiments of the present invention also provide an electric vehicle battery control method, applicable to the electric vehicle battery control circuit provided in any embodiment of the present invention. The electric vehicle battery control circuit may further include: a second start module; the second start module includes a trigger unit and a second start switch tube; the second terminal of the air switch is electrically connected to the control terminal of the second start switch tube through the trigger unit; the first terminal of the second start switch tube is electrically connected to the first terminal of the first start switch tube; the second terminal of the second start switch tube is electrically connected to the ground terminal. Figure 2 This is a flowchart illustrating an electric vehicle battery control method according to an embodiment of the present invention, as shown below. Figure 2 As shown, the method in this embodiment includes the following steps:

[0035] Step S110: When the air switch is momentarily closed, the second start module is turned on to turn on the drive switch tube so that the drive switch tube outputs the battery voltage to the system power supply terminal.

[0036] Step S120: After the air switch is turned off and then remains closed, the controller detects that the sampled voltage is greater than the first voltage threshold, and then controls the first start-up switch to turn on so that the drive switch remains on; the second start-up switch is turned off.

[0037] Step S130: The controller is also used to control the first start-up switch to turn off when the sampled voltage is less than the second voltage threshold.

[0038] In this embodiment of the invention, the electric vehicle battery control circuit includes an air switch, a first start-up switch transistor, a sampling module, a drive switch transistor, and a controller. The air switch connects the battery output terminal to the first terminal of the drive switch transistor, and the second terminal of the drive switch transistor is electrically connected to the system power supply terminal. A sampling module is positioned between the air switch and the first terminal of the drive switch transistor, and the first start-up switch transistor is electrically connected to the control terminal of the drive switch transistor. After the controller closes the air switch, the sampling module acquires the sampled voltage at the first terminal of the drive switch transistor and outputs it to the controller. When the controller detects that the sampled voltage is greater than a first voltage threshold, it controls the first start-up switch transistor to conduct, thus turning on the drive switch transistor and allowing the battery to continuously supply power to the system power supply terminal. Conversely, when the controller acquires a sampled voltage less than a second voltage threshold, it controls the first start-up switch transistor to turn off, disconnecting the battery's power supply to the system power supply terminal in a low-voltage or under-voltage state, thereby improving the battery's range and lifespan.

[0039] Based on the above embodiments, the electric vehicle battery control method may further include a controller that controls the air switch to change from a closed state to an open state and then back to a closed state when the system power supply is powered on. In this embodiment, power supply cannot be automatically restored after the battery voltage recovers; instead, the air switch needs to be turned on and off again to re-trigger the self-locking circuit. This embodiment can effectively protect the battery, prevent it from being in an undervoltage state, and improve battery life.

[0040] The electric vehicle battery control method in this embodiment includes the technical features of the electric vehicle battery control circuit provided in any embodiment of the present invention, and has the beneficial effects of the corresponding technical features, which will not be elaborated here.

[0041] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A battery control circuit for an electric vehicle, characterized in that, include: Air switch, first start-up switch transistor, sampling module, drive switch transistor, controller, and second start-up module; The first terminal of the air switch is electrically connected to the battery output terminal; the second terminal of the air switch is electrically connected to both the input terminal of the sampling module and the first terminal of the drive switch transistor; the second terminal of the drive switch transistor is electrically connected to the system power supply terminal for transmitting the battery voltage to the system power supply terminal; the output terminal of the sampling module is electrically connected to the voltage sampling terminal of the controller for outputting the sampled voltage to the controller; the first terminal of the first start switch transistor is electrically connected to the control terminal of the drive switch transistor, and the second terminal of the first start switch transistor is connected to ground for controlling the drive switch transistor to be turned on or off; the enable terminal of the controller is electrically connected to the control terminal of the first start switch transistor for controlling the first start switch transistor to be turned on or off. The controller is configured to turn on the first start-up switch when the sampled voltage is greater than a first voltage threshold; the controller is also configured to turn off the first start-up switch when the sampled voltage is less than a second voltage threshold. The second startup module includes a trigger unit and a second startup switch transistor; The second terminal of the air switch is electrically connected to the control terminal of the second start switch tube via a triggering unit; the first terminal of the second start switch tube is electrically connected to the first terminal of the first start switch tube; the second terminal of the second start switch tube is electrically connected to the ground terminal. The first start switch and the second start module are not turned on at the same time.

2. The electric vehicle battery control circuit according to claim 1, characterized in that, The controller is also used to control the air switch to change from a closed state to an open state and then from the open state to a closed state when the system power supply is powered on.

3. The electric vehicle battery control circuit according to claim 1, characterized in that, The sampling module includes: a first resistor, a second resistor, and a first capacitor; The first end of the first resistor is electrically connected to the second end of the air switch; the second end of the first resistor is electrically connected to the first end of the second resistor and the voltage sampling terminal of the controller; the second end of the second resistor is electrically connected to ground; the first capacitor is connected in parallel with the second resistor.

4. The electric vehicle battery control circuit according to claim 1, characterized in that, Also includes: Extreme voltage protection module; The polarity protection module includes a third resistor, a Zener diode, and a second capacitor. The negative terminal of the Zener diode is electrically connected to the first terminal of the driving switch; the positive terminal of the Zener diode is electrically connected to the control terminal of the driving switch; the third resistor and the second capacitor are both connected in parallel with the Zener diode.

5. The electric vehicle battery control circuit according to claim 1, characterized in that, The triggering unit includes: a fifth resistor, a first electrolytic capacitor, a first diode, a second electrolytic capacitor, a sixth resistor, and a seventh resistor; The first terminal of the fifth resistor is electrically connected to the second terminal of the air switch; the second terminal of the fifth resistor is connected to ground; the positive terminal of the first electrolytic capacitor is electrically connected to the first terminal of the fifth resistor; the negative terminal of the first electrolytic capacitor is electrically connected to the negative terminal of the first diode; the positive terminal of the first diode is connected to ground; the positive terminal of the second electrolytic capacitor is electrically connected to the negative terminal of the first diode; the negative terminal of the second electrolytic capacitor is connected to ground. The first end of the sixth resistor is electrically connected to the positive terminal of the second electrolytic capacitor; the second end of the sixth resistor is electrically connected to the control terminal of the second start-up switch; the control terminal of the second start-up switch is connected to ground via the seventh resistor.

6. The electric vehicle battery control circuit according to claim 1, characterized in that, The first terminal of the first start-up switch is electrically connected to the control terminal of the drive switch through the eighth resistor.

7. The electric vehicle battery control circuit according to claim 1, characterized in that, The first voltage threshold is greater than the second voltage threshold.

8. A method for controlling an electric vehicle battery, characterized in that, Applicable to the electric vehicle battery control circuit according to any one of claims 1-7; The electric vehicle battery control method includes: When the air switch is momentarily closed, the second start-up module is turned on to turn on the drive switch tube, so that the drive switch tube outputs the battery voltage to the system power supply terminal; If the air switch is turned off and then remains closed, and the controller detects that the sampled voltage is greater than the first voltage threshold, then it controls the first start-up switch to turn on so that the drive switch remains on; the second start-up switch is turned off. The controller is also configured to control the first start-up switch to turn off when the sampled voltage is less than the second voltage threshold.

9. The electric vehicle battery control method according to claim 8, characterized in that, Also includes: The controller is also used to control the air switch to change from a closed state to an open state and then from the open state to a closed state when the system power supply is powered on.

Images