Battery charging system and vehicle

Abstract

The utility model provides a battery charging system and a vehicle, and is applied to the technical field of vehicles, the battery charging system comprises a storage battery, a monitoring module, a vehicle control unit and a power battery system, the monitoring module sends a wake-up signal to the vehicle control unit when monitoring that the vehicle is in a power-off state and the storage battery is lack of power, and the power battery system sends the wake-up signal to the vehicle control unit; and the vehicle control unit controls the power battery system to charge the storage battery under the condition that the wake-up signal is received. According to the embodiment of the invention, the storage battery can be charged in time when the power shortage of the storage battery is monitored, and the long-time power shortage of the storage battery is prevented, so that the power shortage condition of the storage battery caused by the power-off of the vehicle can be reduced, and the condition that the vehicle cannot be normally started due to the power shortage of the storage battery can be reduced. And moreover, the damage to the storage battery caused by power shortage can be reduced, the service life of the storage battery is prolonged, and the scrapping probability of the storage battery is reduced, so that the economic loss of a user is reduced.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and more particularly, to a battery charging system and a vehicle in the field of vehicle technology. Background Art

[0002] With the continuous development of battery technology, electric vehicles (also called vehicles) are increasingly used in people's production and life. Electric vehicles include batteries, which are used to supply power to low-voltage loads in electric vehicles. Some low-voltage loads need to remain running when the electric vehicle is in a power-off state.

[0003] During the use of electric vehicles, electric vehicles may be in a power-off state for a long time. When electric vehicles are in a power-off state for a long time, the low-voltage loads that remain running may cause the battery to run low. When the battery runs low, it may not only cause the electric vehicle to fail to start, but may even damage the battery and shorten the battery life. Utility Model Content

[0004] The present application provides a battery charging system and a vehicle, which can reduce the situation where the battery is depleted due to the vehicle being powered off.

[0005] In a first aspect, an embodiment of the present application provides a battery charging system, including: a storage battery, a monitoring module, a vehicle controller and a power battery system;

[0006] The monitoring module is connected to the battery and the vehicle controller respectively, and is used to send a wake-up signal to the vehicle controller when the vehicle is in a power-off state and the battery is detected to be low on power;

[0007] The vehicle controller is connected to the power battery system, and the power battery system is connected to the storage battery. The vehicle controller is used to control the power battery system to charge the storage battery when receiving the wake-up signal.

[0008] In the embodiment of the present application, the monitoring module in the battery charging system sends a wake-up signal to the vehicle controller when it detects that the vehicle is in a power-off state and the battery is low on power. The vehicle controller controls the power battery system to charge the battery when receiving the wake-up signal. The battery can be monitored after the vehicle is powered off. Regardless of whether the vehicle is powered off for a short time or a long time, the battery can be charged in time when it is detected that the battery is low on power, to prevent the battery from being low on power for a long time, thereby reducing the situation where the battery is low on power due to the vehicle being powered off, and further reducing the situation where the vehicle cannot start normally due to the battery being low on power. In addition, the damage caused by low power to the battery can be reduced, the service life of the battery can be extended, and the probability of the battery being scrapped can be reduced, thereby reducing the economic loss of the user.

[0009] Moreover, since the monitoring module is connected to the vehicle controller, when the vehicle is powered off, the vehicle controller can monitor the battery status in real time through the monitoring module to determine whether the battery is low on power, and control the power battery system to charge the battery when the battery is low on power, which can facilitate the vehicle controller to effectively control the battery status. At the same time, when the vehicle is powered off and the battery is low on power, the vehicle controller controls the power battery system to charge the battery, which can facilitate the vehicle controller to uniformly control the power battery system and the battery, thereby improving the safety and reliability of the vehicle.

[0010] Optionally, the monitoring module includes a voltage stabilizing circuit, a voltage conversion circuit and a comparison circuit;

[0011] The voltage stabilizing circuit is connected to the battery and the comparison circuit respectively, and is used to output a first voltage to the comparison circuit based on the actual voltage of the battery; wherein the first voltage is used to represent the low-power voltage of the battery;

[0012] The voltage conversion circuit is connected to the storage battery and the comparison circuit respectively, and is used to convert the actual voltage into a second voltage, and output the second voltage to the comparison circuit; wherein the second voltage is used to match the first voltage, so as to indicate whether the storage battery is low on power through the voltage difference between the second voltage and the first voltage;

[0013] The comparison circuit is connected to the vehicle controller, and is used to send the wake-up signal to the vehicle controller when it is detected that the second voltage is less than the first voltage.

[0014] In an embodiment of the present application, a first voltage representing a low-battery voltage is provided by a voltage stabilizing circuit, a second voltage representing an actual voltage is provided by a voltage conversion circuit, and a comparison circuit determines whether the battery is charged based on the first voltage and the second voltage. This makes the circuit logic of the entire monitoring module relatively simple, and can simplify the circuit structure of the monitoring module, thereby reducing the cost of the battery charging system.

[0015] Optionally, the voltage stabilizing circuit includes a first current limiting resistor and a voltage stabilizing diode;

[0016] One end of the first current limiting resistor is connected to the positive electrode of the battery, and the other end is connected to the negative electrode of the voltage stabilizing diode;

[0017] The positive electrode of the voltage stabilizing diode is connected to the negative electrode of the battery, and the negative electrode of the voltage stabilizing diode is connected to the comparison circuit, so as to output the first voltage to the comparison circuit.

[0018] In the embodiment of the present application, the voltage stabilizing circuit is composed of a voltage stabilizing diode and a current limiting resistor connected in series, which not only enables the voltage stabilizing circuit to output a first voltage used to characterize the low-power voltage of the battery, but also the circuit structure of the voltage stabilizing circuit is simple and the cost is low, thereby reducing the hardware cost of the entire battery charging system.

[0019] Optionally, the voltage conversion circuit includes two voltage-dividing resistors connected in series between the positive electrode and the negative electrode of the battery, and a connection node between the two voltage-dividing resistors is connected to the comparison circuit.

[0020] In the embodiment of the present application, the voltage conversion circuit is composed of two voltage-dividing resistors connected in series, which not only has a simple circuit structure but also has low cost. Therefore, when the second voltage is output through the two voltage-dividing resistors connected in series, the circuit structure of the monitoring module can be greatly simplified, thereby reducing the hardware cost of the battery charging system.

[0021] Optionally, the connection node is connected to the vehicle controller and is used to output the second voltage to the vehicle controller, so that after the vehicle controller determines that the battery is fully charged according to the second voltage, it controls the power battery system to stop charging the battery.

[0022] In an embodiment of the present application, when the voltage conversion circuit is composed of two voltage-dividing resistors connected in series and the connection node between the two voltage-dividing resistors is connected to the vehicle controller, a second voltage representing the actual voltage of the battery can be output to the vehicle controller through the connection node, thereby facilitating the vehicle controller to determine whether the battery is fully charged based on the second voltage, and further facilitating the vehicle controller to accurately control the charging process of the battery.

[0023] Optionally, the comparison circuit includes an operational amplifier and a pull-up resistor;

[0024] The non-inverting input terminal of the operational amplifier is connected to the voltage stabilizing circuit, the inverting input terminal of the operational amplifier is connected to the voltage conversion circuit, and the output terminal of the operational amplifier is connected to the vehicle controller;

[0025] One end of the pull-up resistor is connected to the positive electrode of the battery, and the other end is connected to the output end of the operational amplifier.

[0026] In the embodiment of the present application, the comparison circuit is composed of an operational amplifier and a pull-up resistor, which can not only accurately determine whether the battery is low on power based on the first voltage output by the voltage stabilizing circuit and the second voltage output by the voltage conversion circuit, but also has a simple circuit structure and low cost, thereby simplifying the circuit structure of the monitoring module and reducing the hardware cost of the battery charging system.

[0027] Optionally, the monitoring module further includes a first filter capacitor, one end of which is connected to the in-phase input end, and the other end of which is connected to the negative electrode of the battery.

[0028] In an embodiment of the present application, the first filter capacitor can filter the voltage at the input common-phase input terminal to reduce the interference of possible interference signals to the operational amplifier, thereby improving the anti-interference capability of the monitoring module and further reducing the probability of false operation of the battery charging system.

[0029] Optionally, the monitoring module further includes a second filter capacitor, one end of the second filter capacitor is connected to the inverting input end, and the other end of the second filter capacitor is connected to the negative electrode of the battery.

[0030] In an embodiment of the present application, the second filter capacitor can filter the voltage at the input inverting input terminal to reduce the interference of possible interference signals to the operational amplifier, thereby improving the anti-interference capability of the monitoring module and further reducing the probability of false operation of the battery charging system.

[0031] Optionally, the monitoring module also includes a prompt circuit, which includes a second current limiting resistor and a light emitting diode, one end of the second current limiting resistor is connected to the positive electrode of the battery, the other end is connected to the positive electrode of the light emitting diode, and the negative electrode of the light emitting diode is connected to the negative electrode of the battery; wherein the prompt circuit is used to prompt the user that the monitoring module is in working condition.

[0032] In an embodiment of the present application, a prompt circuit composed of a light-emitting diode and a current-limiting resistor is provided in the monitoring module. The prompt circuit can not only prompt the user of the working status of the monitoring module, but also has a simple circuit structure, which can reduce the hardware cost of the monitoring module.

[0033] In a second aspect, an embodiment of the present application provides a vehicle, comprising a battery charging system as described in the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A schematic diagram showing the principle of a battery charging system provided by an embodiment of the present application is shown;

[0035] Figure 2 A schematic diagram showing the principle of another battery charging system provided by an embodiment of the present application is shown;

[0036] Figure 3 A schematic diagram showing the principle of another battery charging system provided by an embodiment of the present application is shown;

[0037] Figure 4 A schematic diagram showing the principle of another battery charging system provided by an embodiment of the present application is shown;

[0038] Figure 5 A schematic diagram showing the principle of another battery charging system provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0039] The technical solution in the present application will be described clearly and in detail below in conjunction with the accompanying drawings. In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B: "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0040] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as suggesting or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0041] At present, the loads in electric vehicles are mainly divided into low-voltage loads and high-voltage loads. Low-voltage loads include body control systems, alarm systems, lighting systems, dashboards and display screens, and high-voltage loads include motors, air-conditioning compressors, high-voltage oil pumps, etc. Low-voltage loads are mainly powered by batteries in electric vehicles, and batteries provide low-voltage DC power for low-voltage loads. High-voltage loads are mainly powered by power batteries in power battery systems, and power batteries provide high-voltage DC power for high-voltage loads.

[0042] Among them, the power battery is charged by an external power supply, and the storage battery is powered by the power battery. When the vehicle is in a powered-on state, the power battery can charge the storage battery when the battery power is insufficient. When the vehicle is in a powered-off state, the power battery stops supplying power to the high-voltage load and the storage battery.

[0043] Some low-voltage loads need to remain running when the vehicle is powered off. For example, when the vehicle is parked and turned off, the vehicle is powered off. At this time, the alarm system needs to remain running to promptly alarm when the vehicle is stolen and / or a collision occurs. Low-voltage loads that remain running will continue to consume power in the battery when the vehicle is powered off. Therefore, when the vehicle is powered off for a long time, the battery may become depleted. When the battery is depleted, not only may the vehicle fail to start normally, but it may also damage the battery, shorten the battery's service life, or even cause the battery to be scrapped, causing economic losses to users.

[0044] In the related art, in order to solve the above problems, one way is to set a switch in the discharge circuit of the battery. When the vehicle is in a power-off state for a long time, the user manually cuts off the switch to prevent the battery from running out of power. This method not only requires manual operation by the user, but also causes the low-voltage load to be powered off, which may cause the electric vehicle to fail to alarm in time when it is stolen or collided, posing certain safety hazards. Another way is to control the power battery system to charge the battery regularly when the vehicle is in a power-off state. The disadvantages of this method are: the power battery system may charge the battery when the battery is seriously running out of power, at which time the battery may have been damaged, or the power battery system may charge the battery when the battery is fully charged, at which time unnecessary energy may be wasted.

[0045] An embodiment of the present application provides a battery charging system, which is installed in a vehicle and includes a battery, a monitoring module, a vehicle controller (Virtual Computational Unit, VCU) and a power battery system. The monitoring module is connected to the battery and the vehicle controller respectively, and is used to send a wake-up signal to the vehicle controller when the vehicle is in a power-off state and detects that the battery is low on power. The vehicle controller is connected to the power battery system, and the power battery system is connected to the battery. The vehicle controller is used to control the power battery system to charge the battery when the wake-up signal is received.

[0046] See also Figure 1 , Figure 1 FIG. 1 is a schematic diagram showing the principle of a battery charging system provided by an embodiment of the present application. Figure 1 As shown, the battery charging system includes a storage battery 10, a vehicle controller 20, a monitoring module 30 and a power battery system 40. The power battery system 40 includes a battery management system (BMS) 41, a direct-current to direct-current converter (DCDC) 42 and a power battery 43, but is not limited thereto.

[0047] For example, the vehicle controller can control the monitoring module to start when the vehicle is in a power-off state, and the monitoring module can monitor the actual voltage of the battery after starting. The monitoring module determines that the battery is low-powered when it detects that the actual voltage of the battery is lower than the low-power voltage of the battery, and then sends a wake-up signal to the vehicle controller to notify the vehicle controller of the low-powered battery through the wake-up signal.

[0048] Alternatively, the monitoring module can continuously monitor the actual voltage of the battery. When it is detected that the actual voltage of the battery is less than the power-down voltage, if it is determined that the vehicle is in a power-off state, a wake-up signal is sent to the vehicle controller to notify the vehicle controller that the battery is low. Alternatively, the monitoring module can continuously monitor the actual voltage of the battery. When it is detected that the actual voltage of the battery is less than the power-down voltage, a wake-up signal can be directly sent to the vehicle controller to notify the vehicle controller that the battery is low.

[0049] In this embodiment, the vehicle controller is connected to the BMS, the BMS is connected to the power battery and the DCDC respectively, and the DCDC is connected to the storage battery. After receiving the wake-up signal, the vehicle controller determines that the storage battery is low on power, and then sends a first notification signal to the BMS. Correspondingly, the BMS starts after receiving the first notification signal, and after starting, the BMS controls the power battery's discharge circuit to close, and controls the DCDC to start. After starting, the DCDC can convert the high-voltage direct current output by the power battery into low-voltage direct current, and output high-voltage direct current to the storage battery to charge the storage battery.

[0050] During the process of charging the battery, after determining that the battery is fully charged, the vehicle controller can send a second notification signal to the BMS, and after receiving the second notification signal, the BMS can control the DCDC to shut down to stop charging the battery. After that, the BMS can automatically enter the shutdown state.

[0051] In the embodiment of the present application, the monitoring module in the battery charging system sends a wake-up signal to the vehicle controller when it detects that the vehicle is in a power-off state and the battery is low on power. The vehicle controller controls the power battery system to charge the battery when receiving the wake-up signal. The battery can be monitored after the vehicle is powered off. Regardless of whether the vehicle is powered off for a short time or a long time, the battery can be charged in time when it is detected that the battery is low on power, to prevent the battery from being low on power for a long time, thereby reducing the situation where the battery is low on power due to the vehicle being powered off, and further reducing the situation where the vehicle cannot start normally due to the battery being low on power. In addition, the damage caused by low power to the battery can be reduced, the service life of the battery can be extended, and the probability of the battery being scrapped can be reduced, thereby reducing the economic loss of the user.

[0052] Moreover, since the monitoring module is connected to the vehicle controller, when the vehicle is powered off, the vehicle controller can monitor the battery status in real time through the monitoring module to determine whether the battery is low on power, and control the power battery system to charge the battery when the battery is low on power, which can facilitate the vehicle controller to effectively control the battery status. At the same time, when the vehicle is powered off and the battery is low on power, the vehicle controller controls the power battery system to charge the battery, which can facilitate the vehicle controller to uniformly control the power battery system and the battery, thereby improving the safety and reliability of the vehicle.

[0053] Moreover, compared with the method of setting a switch in the discharge circuit of the battery, it not only does not require manual operation by the user, but also can reduce the power failure of the low-voltage load. Compared with the timed charging method, it can reduce the serious power loss of the battery and reduce unnecessary energy waste.

[0054] Optionally, the monitoring module includes a voltage stabilizing circuit, a voltage conversion circuit and a comparison circuit; the voltage stabilizing circuit is respectively connected to the battery and the comparison circuit, and is used to output a first voltage to the comparison circuit based on the actual voltage of the battery; the voltage conversion circuit is respectively connected to the battery and the comparison circuit, and is used to convert the actual voltage into a second voltage and output the second voltage to the comparison circuit; the comparison circuit is connected to the vehicle controller, and is used to send a wake-up signal to the vehicle controller when it is detected that the second voltage is lower than the first voltage.

[0055] The first voltage is used to characterize the low-power voltage of the battery; the second voltage is used to match the first voltage, so as to characterize whether the battery is low-power by the voltage difference between the first voltage and the first voltage.

[0056] For example, the first voltage may be equal to the battery-deficient voltage, and the second voltage may be equal to the actual voltage of the battery. When the second voltage is less than the first voltage, it indicates that the battery is deficient. For another example, the first voltage may be lower than the battery-deficient voltage, and the second voltage may be lower than the actual voltage. The voltage difference between the first voltage and the battery-deficient voltage is equal to the voltage difference between the second voltage and the actual voltage. Therefore, the voltage difference between the first voltage and the second voltage is equal to the voltage difference between the actual voltage and the battery-deficient voltage. When the second voltage is less than the first voltage, it indicates that the battery is deficient. Similarly, the first voltage may be greater than the battery-deficient voltage, and the second voltage may be greater than the actual voltage. The voltage difference between the first voltage and the battery-deficient voltage is equal to the voltage difference between the second voltage and the actual voltage. When the second voltage is less than the first voltage, it indicates that the battery is deficient.

[0057] See also Figure 2 , Figure 2 FIG. 2 shows a schematic diagram of another battery charging system provided by an embodiment of the present application. Figure 2As shown, the monitoring module 30 includes a voltage stabilizing circuit 31, a voltage conversion circuit 32 and a comparison circuit 33. The voltage stabilizing circuit 31 is connected to the battery 10 and is located in the discharge circuit of the battery 10. The battery 10 can supply power to the voltage stabilizing circuit 31, so that the voltage stabilizing circuit 31 can output a first voltage based on the actual voltage of the battery 10. The output end of the voltage stabilizing circuit is connected to an input end of the comparison circuit, and can output the first voltage to the comparison circuit.

[0058] Similarly, the voltage conversion circuit 32 is connected to the battery 10 and is located in the discharge circuit of the battery 10. It can monitor the actual voltage of the battery 10 and convert the actual voltage to obtain a second voltage. The voltage conversion circuit 32 is connected to another input terminal of the comparison circuit and can output the second voltage to the comparison circuit.

[0059] The output end of the comparison circuit 33 is connected to an input end of the vehicle controller 20. After receiving the first voltage and the second voltage, the comparison circuit 33 can compare the first voltage and the second voltage, and when it is determined that the second voltage is less than the first voltage, it is determined that the battery 10 is low on power, and then a wake-up signal can be sent to the vehicle controller 20 to trigger the vehicle controller 20 to control the power battery system 40 to charge the battery 10 through the wake-up signal.

[0060] In an embodiment of the present application, a first voltage representing a low-battery voltage is provided by a voltage stabilizing circuit, a second voltage representing an actual voltage is provided by a voltage conversion circuit, and a comparison circuit determines whether the battery is charged based on the first voltage and the second voltage. This makes the circuit logic of the entire monitoring module relatively simple, and can simplify the circuit structure of the monitoring module, thereby reducing the cost of the battery charging system.

[0061] Optionally, the voltage stabilizing circuit includes a first current limiting resistor and a voltage stabilizing diode; one end of the first current limiting resistor is connected to the positive electrode of the battery, and the other end is connected to the negative electrode of the voltage stabilizing diode; the positive electrode of the voltage stabilizing diode is connected to the negative electrode of the battery, and the negative electrode of the voltage stabilizing diode is connected to the comparison circuit, for outputting a first voltage to the comparison circuit.

[0062] See also Figure 3 , Figure 3 FIG. 2 shows a schematic diagram of another battery charging system provided by an embodiment of the present application. Figure 3As shown, the voltage stabilizing circuit 31 in the monitoring module 30 includes a first current limiting resistor 311 and a voltage stabilizing diode 312 connected in series, one end of the first current limiting resistor 311 is connected to the positive electrode of the battery 10, the other end of the first current limiting resistor 311 is connected to the negative electrode of the voltage stabilizing diode 312, and the positive electrode of the voltage stabilizing diode 312 is connected to the negative electrode of the battery 10. A connection node A is formed between the first current limiting resistor 311 and the voltage stabilizing diode 312, and the connection node A includes a short-circuit connection portion between the first current limiting resistor 311 and the voltage stabilizing diode 312, and also includes other circuit portions short-circuited to the connection node A.

[0063] like Figure 3 As shown, the first current limiting resistor 311 and the voltage stabilizing diode 312 are connected in series between the positive electrode and the negative electrode of the storage battery 10, so that the storage battery 10 can supply power to the voltage stabilizing circuit. The first current limiting resistor 311 is used to control the current in the voltage stabilizing circuit to prevent the voltage stabilizing diode 312 from being damaged by excessive current in the voltage stabilizing circuit. The voltage stabilizing diode 312 can stabilize the voltage of the connection node A at a preset first voltage. The connection node A constitutes the output end of the voltage stabilizing circuit, and the output end is connected to an input end of the comparison circuit to output the first voltage to the comparison circuit.

[0064] In practical applications, the specifications of the first current limiting resistor 311 and the voltage zener diode 312 can be selected according to requirements so that the voltage of the connection node A can reach the preset first voltage. Alternatively, a first current limiting resistor 311 and a voltage zener diode 312 of a certain specification can be directly selected, and then the voltage of the connection node A is used as the first voltage.

[0065] In the embodiment of the present application, the voltage stabilizing circuit is composed of a voltage stabilizing diode and a current limiting resistor connected in series, which not only enables the voltage stabilizing circuit to output a first voltage used to characterize the low-power voltage of the battery, but also the circuit structure of the voltage stabilizing circuit is simple and the cost is low, thereby reducing the hardware cost of the entire battery charging system.

[0066] Optionally, the voltage conversion circuit includes two voltage-dividing resistors connected in series between the positive electrode and the negative electrode of the battery, and a connection node between the two voltage-dividing resistors is connected to the comparison circuit.

[0067] like Figure 3 As shown, the voltage conversion circuit 32 includes a first voltage-dividing resistor 321 and a second voltage-dividing resistor 322 connected in series, one end of the first voltage-dividing resistor 321 is connected to the positive electrode of the battery 10, and the other end is connected to one end of the second voltage-dividing resistor 322, and the other end of the second voltage-dividing resistor 322 is connected to the negative electrode of the battery 10. A connection node B is formed between the first voltage-dividing resistor 321 and the second voltage-dividing resistor 322, and the connection node B includes a short-circuit connection portion between the first voltage-dividing resistor 321 and the second voltage-dividing resistor 322, and also includes other circuit portions short-circuited to the connection node B.

[0068] The first voltage-dividing resistor 321 and the second voltage-dividing resistor 322 form a voltage-dividing circuit, and the voltage at the connection node B is:

[0069]

[0070] Among them, V b is the voltage at the connection node B, that is, the second voltage; V bat is the actual voltage of the battery, R1 is the resistance of the first voltage-dividing resistor 321 , and R2 is the resistance of the second voltage-dividing resistor 322 .

[0071] like Figure 3 As shown, the connection node B constitutes the output end of the voltage conversion circuit, and the output end is connected to an input end of the comparison circuit, and can output a second voltage to the comparison circuit. It can be seen from formula (1) that the second voltage V b The actual voltage V of the battery 10 bat Positive correlation, reasonably setting the resistance value of the first voltage-dividing resistor 321 and the resistance value of the second voltage-dividing resistor 322 can make the second voltage match the first voltage, that is, the voltage difference between the second voltage and the first voltage can represent the voltage difference between the actual voltage of the battery 10 and the low-power voltage.

[0072] In practical applications, the resistance of the first voltage-dividing resistor 321 can be set to be smaller than the resistance of the second voltage-dividing resistor 322, and there can be a large difference between the resistance of the first voltage-dividing resistor 321 and the resistance of the second voltage-dividing resistor 322, so that the second voltage outputted by the connection node B can be close to the actual voltage of the battery.

[0073] In the embodiment of the present application, the voltage conversion circuit is composed of two voltage-dividing resistors connected in series, which not only has a simple circuit structure but also has low cost. Therefore, when the second voltage is output through the two voltage-dividing resistors connected in series, the circuit structure of the monitoring module can be greatly simplified, thereby reducing the hardware cost of the battery charging system.

[0074] Optionally, the connection node B is connected to the vehicle controller and is used to output a second voltage to the vehicle controller so that the vehicle controller controls the power battery system to stop charging the battery after determining that the battery is fully charged according to the second voltage.

[0075] In some embodiments, the connection node B can be connected to an input terminal of the vehicle controller, so that the second voltage output by the connection node B can be input into the vehicle controller. In the process of controlling the power battery system to charge the battery, the vehicle controller can determine whether the battery is fully charged by the second voltage. A fully charged battery means that the voltage of the battery reaches a preset upper limit of a safe voltage, or the actual voltage of the battery reaches a preset voltage threshold, which is the maximum voltage of the battery during the charging process and is less than the upper limit of the safe voltage.

[0076] For example, the voltage of the connection node B after the battery is fully charged can be pre-determined through experiments, and the voltage can be used as a reference voltage. When the vehicle controller controls the power battery system to charge the battery, it can determine that the battery is fully charged when the second voltage output by the connection node B is greater than or equal to the reference voltage, and then send a stop signal to the BMS. After receiving the stop signal, the BMS can control the DCDC to shut down to stop charging the battery.

[0077] For another example, when the vehicle controller controls the power battery system to charge the battery, the charging current in the charging circuit of the battery can be obtained through the BMS. When the charging current is less than the preset current value and the second voltage output by the connection node B reaches the reference voltage, it is determined that the battery is fully charged. The above is only an illustrative example, and the specific method of judging whether the battery is fully charged according to the second voltage may include but is not limited to the above example.

[0078] In an embodiment of the present application, when the voltage conversion circuit is composed of two voltage-dividing resistors connected in series and the connection node between the two voltage-dividing resistors is connected to the vehicle controller, a second voltage representing the actual voltage of the battery can be output to the vehicle controller through the connection node, thereby facilitating the vehicle controller to determine whether the battery is fully charged based on the second voltage, and further facilitating the vehicle controller to accurately control the charging process of the battery.

[0079] Optionally, the comparison circuit includes an operational amplifier and a pull-up resistor; the non-inverting input terminal of the operational amplifier is connected to the voltage stabilizing circuit, the inverting input terminal of the operational amplifier is connected to the voltage conversion circuit, and the output terminal of the operational amplifier is connected to the vehicle controller; one end of the pull-up resistor is connected to the positive pole of the battery, and the other end is connected to the output terminal of the operational amplifier.

[0080] like Figure 3 As shown, the comparison circuit 33 includes an operational amplifier 331 and a pull-up resistor 332. The non-inverting input terminal of the operational amplifier 331 is connected to the connection node A, and can receive the first voltage output by the voltage stabilizing circuit. The inverting input terminal of the operational amplifier 331 is connected to the connection node B, and can receive the second voltage output by the voltage conversion circuit. The output terminal of the operational amplifier 331 is connected to the vehicle controller 20, and a wake-up signal can be sent to the vehicle controller 20. At the same time, the positive power supply terminal of the operational amplifier 331 is connected to the positive pole of the battery 10, and the negative power supply terminal of the operational amplifier 331 is connected to the negative pole of the battery 10, so as to power the operational amplifier 331 through the battery 10.

[0081] During the operation of the monitoring module 30, after receiving the first voltage and the second voltage, the operational amplifier 331 can determine that the battery 10 is low on power when the first voltage is less than the second voltage, and then output a high-level signal to the vehicle controller 20, which is a wake-up signal. One end of the pull-up resistor 332 is connected to the output end of the operational amplifier 331, and the other end is connected to the positive electrode of the battery 10, so that the operational amplifier 331 can output a stable and reliable wake-up signal.

[0082] Correspondingly, the input end of the vehicle controller 20 is provided with an analog to digital converter (ADC). The vehicle controller 20 can detect whether the voltage output by the operational amplifier 331 is a high-level signal through the ADC. After detecting that the operational amplifier 331 outputs a high-level signal, it is determined that the battery 10 is low on power, and the power battery system 40 can be controlled to charge the battery 10.

[0083] Among them, after the vehicle controller 20 receives the wake-up signal (high-level signal) and controls the power battery system 40 to charge the battery 10, before the battery 10 is fully charged, the signal output by the operational amplifier is always a high-level signal. The vehicle controller 20 can shield the high-level signal output by the operational amplifier to continue charging the battery 10 until the battery 10 is fully charged and the high-level signal output by the operational amplifier disappears.

[0084] In the embodiment of the present application, the comparison circuit is composed of an operational amplifier and a pull-up resistor, which can not only accurately determine whether the battery is low on power based on the first voltage output by the voltage stabilizing circuit and the second voltage output by the voltage conversion circuit, but also has a simple circuit structure and low cost, thereby simplifying the circuit structure of the monitoring module and reducing the hardware cost of the battery charging system.

[0085] Optionally, the monitoring module further includes a first filter capacitor, one end of which is connected to the in-phase input terminal, and the other end of which is connected to the negative electrode of the battery.

[0086] See also Figure 4 , Figure 4 FIG. 2 shows a schematic diagram of another battery charging system provided by an embodiment of the present application. Figure 4 As shown, the monitoring module 30 also includes a first filter capacitor 34, one end of which is connected to the connection node A, that is, connected to the non-inverting input terminal of the operational amplifier 331, and the other end is connected to the negative electrode of the battery 10. The first filter capacitor 34 can filter the voltage input to the non-inverting input terminal to reduce the interference of possible interference signals to the operational amplifier 331, thereby improving the anti-interference ability of the monitoring module 30, and further reducing the probability of malfunction of the battery charging system.

[0087] The specification of the first filter capacitor may be set according to the interference signal that may exist in the monitoring module 30 , and this embodiment does not impose any limitation on this.

[0088] Optionally, the monitoring module 30 further includes a second filter capacitor, one end of which is connected to the inverting input end, and the other end of which is connected to the negative electrode of the battery 10 .

[0089] like Figure 4 As shown, the monitoring module 30 also includes a second filter capacitor 35, one end of which is connected to the connection node B, that is, connected to the inverting input terminal of the operational amplifier 331, and the other end is connected to the negative electrode of the battery 10. The second filter capacitor 35 can filter the voltage input to the inverting input terminal to reduce the interference of possible interference signals to the operational amplifier 331, thereby improving the anti-interference ability of the monitoring module 30, and further reducing the probability of malfunction of the battery charging system.

[0090] The specification of the second filter capacitor may be set according to the interference signal that may exist in the monitoring module 30 , and this embodiment does not impose any limitation on this.

[0091] Optionally, the monitoring module also includes a prompt circuit, which includes a second current limiting resistor and a light emitting diode, one end of the second current limiting resistor is connected to the positive pole of the battery, the other end is connected to the positive pole of the light emitting diode, and the negative pole of the light emitting diode is connected to the negative pole of the battery; wherein the prompt circuit is used to prompt the user that the monitoring module is in working condition.

[0092] See also Figure 5 , Figure 5 FIG. 2 shows a schematic diagram of another battery charging system provided by an embodiment of the present application. Figure 5 As shown, the prompt circuit 36 ​​is composed of a second current limiting resistor 361 and a light emitting diode 362 connected in series. One end of the second current limiting resistor 361 is connected to the positive electrode of the battery 10, and the other end is connected to the positive electrode of the light emitting diode 362. The negative electrode of the light emitting diode 362 is connected to the negative electrode of the battery 10. The second current limiting resistor 361 is used to prevent a large current from appearing in the prompt circuit and burning the light emitting diode 362. The battery 10 supplies power to the prompt circuit. When the discharge circuit of the battery 10 is turned on, the light emitting diode emits light to prompt the user that the monitoring module 30 is in working condition. When the battery 10 stops running and the discharge circuit is disconnected, the light emitting diode goes out, indicating that the monitoring module 30 stops running.

[0093] In an embodiment of the present application, a prompt circuit composed of a light-emitting diode and a current-limiting resistor is provided in the monitoring module. The prompt circuit can not only prompt the user of the working status of the monitoring module, but also has a simple circuit structure, which can reduce the hardware cost of the monitoring module.

[0094] The embodiment of the present application also provides a vehicle, which includes the battery charging system in the above example. It should be understood that the vehicle also includes other components besides the battery charging system, and this embodiment does not limit this.

[0095] The above contents are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A battery charging system, characterized in that: include: Batteries, monitoring modules, vehicle controllers and power battery systems; The monitoring module is connected to the battery and the vehicle controller respectively, and is used to send a wake-up signal to the vehicle controller when the vehicle is in a power-off state and the battery is detected to be low on power; The vehicle controller is connected to the power battery system, and the power battery system is connected to the storage battery. The vehicle controller is used to control the power battery system to charge the storage battery when receiving the wake-up signal.

2. The battery charging system according to claim 1, wherein: The monitoring module includes a voltage stabilizing circuit, a voltage conversion circuit and a comparison circuit; The voltage stabilizing circuit is connected to the battery and the comparison circuit respectively, and is used to output a first voltage to the comparison circuit based on the actual voltage of the battery; wherein the first voltage is used to represent the low-power voltage of the battery; The voltage conversion circuit is connected to the storage battery and the comparison circuit respectively, and is used to convert the actual voltage into a second voltage, and output the second voltage to the comparison circuit; wherein the second voltage is used to match the first voltage, so as to indicate whether the storage battery is low on power through the voltage difference between the second voltage and the first voltage; The comparison circuit is connected to the vehicle controller, and is used to send the wake-up signal to the vehicle controller when it is detected that the second voltage is less than the first voltage.

3. The battery charging system according to claim 2, wherein: The voltage stabilizing circuit comprises a first current limiting resistor and a voltage stabilizing diode; One end of the first current limiting resistor is connected to the positive electrode of the battery, and the other end is connected to the negative electrode of the voltage stabilizing diode; The positive electrode of the voltage stabilizing diode is connected to the negative electrode of the battery, and the negative electrode of the voltage stabilizing diode is connected to the comparison circuit, so as to output the first voltage to the comparison circuit.

4. The battery charging system according to claim 2, wherein: The voltage conversion circuit includes two voltage-dividing resistors connected in series between the positive electrode and the negative electrode of the battery, and a connection node between the two voltage-dividing resistors is connected to the comparison circuit.

5. The battery charging system according to claim 4, characterized in that: The connection node is connected to the vehicle controller and is used to output the second voltage to the vehicle controller, so that after the vehicle controller determines that the battery is fully charged according to the second voltage, the power battery system is controlled to stop charging the battery.

6. The battery charging system according to claim 2, wherein: The comparison circuit includes an operational amplifier and a pull-up resistor; The non-inverting input terminal of the operational amplifier is connected to the voltage stabilizing circuit, the inverting input terminal of the operational amplifier is connected to the voltage conversion circuit, and the output terminal of the operational amplifier is connected to the vehicle controller; One end of the pull-up resistor is connected to the positive electrode of the battery, and the other end is connected to the output end of the operational amplifier.

7. The battery charging system according to claim 6, characterized in that: The monitoring module further includes a first filter capacitor, one end of which is connected to the in-phase input end, and the other end of which is connected to the negative electrode of the battery.

8. The battery charging system according to claim 6, wherein: The monitoring module further includes a second filter capacitor, one end of which is connected to the inverting input end, and the other end of which is connected to the negative electrode of the battery.

9. The battery charging system according to any one of claims 2 to 8, characterized in that: The monitoring module also includes a prompt circuit, which includes a second current limiting resistor and a light-emitting diode, one end of the second current limiting resistor is connected to the positive electrode of the battery, the other end is connected to the positive electrode of the light-emitting diode, and the negative electrode of the light-emitting diode is connected to the negative electrode of the battery; wherein the prompt circuit is used to prompt the user that the monitoring module is in a working state.

10. A vehicle, characterized in that: The vehicle comprises a battery charging system as claimed in any one of claims 1-9.

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