Lithium battery charging method and device and battery management system

Abstract

The invention provides a charging method and device for a lithium battery and a battery management system, and belongs to the technical field of new energy, and the method comprises the steps: obtaining the charge state of the lithium battery and the vehicle state information of a vehicle where the lithium battery is located; the vehicle state information comprises vehicle gears, vehicle working state information and DCDC converter state information; on the basis of the charge state and the vehicle state information, under the condition that it is determined that the electric quantity of the lithium battery is insufficient, the SOC of the lithium battery needs to be fully charged and calibrated, the vehicle can be charged, a switching tube in a battery management system corresponding to the lithium battery is in a closed state, or a DCDC converter is not in a working state, a charging request is sent to a vehicle control system, controlling the DCDC converter to start working through a vehicle control system; the input end of the DCDC converter is connected with a high-voltage battery of the vehicle, and the output end of the DCDC converter is connected with the lithium battery. The problems of low use efficiency and short service life of the lithium battery can be solved.

Description

Technical Field

[0001] The present invention relates to the field of new energy technologies, and in particular to a lithium battery charging method, device and battery management system. Background Art

[0002] With the popularity of electric vehicles and hybrid vehicles, the role of battery management systems (BMS) in vehicles is becoming increasingly important. Battery management systems generally manage the charging and discharging of batteries in electric vehicles. In existing technologies, battery charging and discharging management often lacks intelligence and automation, and cannot automatically determine when lithium batteries need to be recharged, so they cannot automatically recharge lithium batteries when they need to be recharged, resulting in low lithium battery efficiency and shortened lifespan. Summary of the invention

[0003] In view of this, it is necessary to provide a lithium battery charging method, device and battery management system to solve the technical problems of low efficiency and shortened life of lithium batteries.

[0004] In order to solve the above problems, in a first aspect, the present invention provides a method for replenishing power of a lithium battery, comprising: Acquire the state of charge of the lithium battery and the vehicle status information of the vehicle in which the lithium battery is located; the vehicle status information includes: vehicle gear position, vehicle working status information and DCDC converter status information; When it is determined based on the state of charge and the vehicle status information that the power of the lithium battery is insufficient, the SOC of the lithium battery needs to be fully charged and calibrated, the vehicle is chargeable, the switch tube inside the battery management system corresponding to the lithium battery is in a closed state, or the DCDC converter is not in a working state, a charging request is sent to the vehicle control system so as to control the DCDC converter to start working through the vehicle control system; The input end of the DCDC converter is connected to the high-voltage battery of the vehicle, and the output end is connected to the lithium battery.

[0005] In a possible implementation, determining that the power of the lithium battery is low includes: When it is determined that the state of charge is lower than a preset state of charge threshold, determining that the lithium battery is low on power; Determine that the SOC of the lithium battery needs to be fully charged and calibrated, including: In a case where it is determined based on the state of charge that the lithium battery is not fully charged within the target time, determining that the SOC of the lithium battery needs to be fully charged and calibrated; Verify that the vehicle is rechargeable, including: When it is determined based on the vehicle state information that the vehicle is in a working state and the vehicle is in a non-OFF gear position, it is determined that the vehicle can be charged.

[0006] In a possible implementation, after sending the power replenishment request to the vehicle control system, the method further includes: When it is determined based on the vehicle state information that the DCDC converter starts to operate within a set time, a requested power replenishment voltage is sent to the high-voltage battery to control the high-voltage battery to output a constant voltage according to the requested power replenishment voltage.

[0007] In a possible implementation, the initial value of the requested power replenishment voltage is greater than the voltage value of the total voltage of the lithium battery.

[0008] In a possible implementation, the process of controlling the high-voltage battery to output a constant voltage according to the requested supplementary voltage further includes: When the charging current output by the high-voltage battery is lower than the preset minimum continuous charging current and the difference between the requested charging voltage and the output voltage of the DCDC converter is less than the preset voltage difference threshold, the high-voltage battery is controlled to increase the requested charging voltage in a gradient increasing manner.

[0009] In a possible implementation, the process of controlling the high-voltage battery to output a constant voltage according to the requested supplementary voltage further includes: When the charging current output by the high-voltage battery is greater than the preset maximum continuous charging current, and the difference between the requested charging voltage and the output voltage of the DCDC converter is less than the preset voltage difference threshold, the high-voltage battery is controlled to reduce the requested charging voltage in a gradient decreasing manner.

[0010] In a possible implementation, after sending the power replenishment request to the vehicle control system, the method further includes: When it is determined based on the vehicle status information that the DCDC converter starts to operate within a set time, the battery management system is controlled to update the charging state of the lithium battery.

[0011] In a second aspect, the present invention further provides a lithium battery charging device, comprising: An acquisition module, used to acquire the state of charge of the lithium battery and the vehicle status information of the vehicle in which the lithium battery is located; the vehicle status information includes: vehicle gear position, vehicle working status information and DCDC converter status information; A control module, configured to send a charging request to a vehicle control system to control the DCDC converter to start working through the vehicle control system when it is determined based on the state of charge and the vehicle state information that the power of the lithium battery is insufficient, the SOC of the lithium battery needs to be fully charged and calibrated, the vehicle is chargeable, the switch tube inside the battery management system corresponding to the lithium battery is in a closed state, or the DCDC converter is not in a working state; The input end of the DCDC converter is connected to the high-voltage battery of the vehicle, and the output end is connected to the lithium battery.

[0012] In a third aspect, the present invention further provides a battery management system, including a memory and a processor, wherein: The memory is used to store programs; The processor is coupled to the memory and is used to execute the program stored in the memory to implement the steps of the lithium battery charging method as described in any one of the above.

[0013] In a fourth aspect, the present invention further provides a non-transitory computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the steps of the lithium battery charging method as described in any one of the above items are implemented.

[0014] The beneficial effect of adopting the above-mentioned implementation mode is: the lithium battery charging method, device and battery management system provided by the present invention, when the lithium battery is insufficient in power, the SOC of the lithium battery needs to be fully charged and calibrated, the vehicle is rechargeable, the switch tube inside the battery management system corresponding to the lithium battery is in a closed state, and the DCDC converter is not in a working state, if the lithium battery is not recharged in time, the service life of the lithium battery will be shortened and the health state of the lithium battery will be reduced. The present invention uses the charge state of the lithium battery and the vehicle status information to identify these situations where recharging is required, so that the DCDC converter can be automatically controlled to start working. After the DCDC converter starts working, the electric energy of the high-voltage battery can be converted into electric energy that meets the requirements of the lithium battery, thereby recharging the lithium battery, thereby improving the health state and service life of the lithium battery, thereby solving the technical problems of low efficiency and shortened life of the lithium battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0016] Figure 1 A flow chart of an embodiment of a lithium battery charging method provided by the present invention; Figure 2 A flow chart of another embodiment of the lithium battery charging method provided by the present invention; Figure 3 A flow chart of another embodiment of the lithium battery charging method provided by the present invention; Figure 4A functional block diagram of an embodiment of a lithium battery charging device provided by the present invention; Figure 5 A schematic structural diagram of an embodiment of an electronic device provided by the present invention. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0018] In the description of the embodiments of the present application, unless otherwise specified, “plurality” means two or more than two.

[0019] The terms "including" and "having" and any variations thereof in the embodiments of the present invention are intended to cover non-exclusive inclusions. For example, a process, method, apparatus, product or equipment comprising a series of steps or modules is not necessarily limited to those steps or modules clearly listed, but may include other steps or modules not clearly listed or inherent to these processes, methods, products or equipment.

[0020] The naming or numbering of the steps in the embodiments of the present invention does not mean that the steps in the method flow must be executed in the time / logical sequence indicated by the naming or numbering. The execution order of the named or numbered process steps can be changed according to the technical purpose to be achieved, as long as the same or similar technical effects can be achieved.

[0021] Reference to an "embodiment" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0022] The present invention provides a lithium battery charging method, device and battery management system, which are described below respectively.

[0023] like Figure 1 As shown, the present invention provides a lithium battery charging method, comprising: S101, acquiring the state of charge of a lithium battery and vehicle status information of a vehicle in which the lithium battery is located; the vehicle status information includes: vehicle gear position, vehicle operating status information and DCDC converter status information.

[0024] It is understandable that the lithium battery in the present invention can be a lithium battery with a rated voltage of 12V on an electric car.

[0025] The charge state of the lithium battery and the vehicle status information of the vehicle in which the lithium battery is located can be obtained through the CAN bus (Controller Area Network bus) on the vehicle.

[0026] The vehicle operating status information can represent the current operating status of the vehicle, whether the vehicle is stopped, driving, or accelerating, etc.

[0027] The DCDC converter status information may indicate whether the DCDC converter is in a working state or a non-working state.

[0028] S102, when it is determined based on the state of charge and the vehicle status information that the power of the lithium battery is insufficient, the SOC of the lithium battery needs to be fully charged and calibrated, the vehicle is chargeable, the switch tube inside the battery management system corresponding to the lithium battery is in a closed state, or the DCDC converter is not in a working state, sending a charging request to the vehicle control system to control the DCDC converter to start working through the vehicle control system; The input end of the DCDC converter is connected to the high-voltage battery of the vehicle, and the output end is connected to the lithium battery.

[0029] It is understandable that the state of charge can determine whether the lithium battery is insufficient, and whether the SOC needs to be fully charged and calibrated. The vehicle status information can determine whether the vehicle can provide charging, and whether the switch tube inside the battery management system corresponding to the lithium battery is in a closed state, or whether the DCDC converter is in a working state.

[0030] It should be noted that to determine whether the switch tube inside the battery management system corresponding to the lithium battery is in a closed state, or the DCDC converter is not in a working state, it is necessary to first determine that the DCDC converter is fault-free and that the switch tube inside the battery management system has no disconnection-related faults. The switch tube here can be a MOS tube. Since the structure inside the battery management system is conventional technology, it will not be described here.

[0031] The method provided by the present invention can be applied to a battery management system, and the method is executed by an application installed inside the battery management system. The battery management system is communicatively connected to the vehicle's CAN bus, and can obtain the charge state of the lithium battery and the vehicle status information of the vehicle in which the lithium battery is located.

[0032] The method provided by the present invention can automatically request charging when the battery power is low, and intelligently adjust the charging strategy according to the battery status and vehicle status. The charging system used in the method provided by the present invention includes a battery management system (BMS), a DC-DC converter (DCDC converter), a high-voltage battery and a vehicle control system. The method provided by the present invention can be used in a battery management system.

[0033] In some embodiments, determining that the power of the lithium battery is low includes: When it is determined that the state of charge is lower than a preset state of charge threshold, determining that the lithium battery is low on power; Determine that the SOC of the lithium battery needs to be fully charged and calibrated, including: In a case where it is determined based on the state of charge that the lithium battery is not fully charged within the target time, determining that the SOC of the lithium battery needs to be fully charged and calibrated; Verify that the vehicle is rechargeable, including: When it is determined based on the vehicle state information that the vehicle is in a working state and the vehicle is in a non-OFF gear position, it is determined that the vehicle can be charged.

[0034] It is understandable that the preset state of charge value may be 10%, 20% or 30%, and the target time may be 0.5 hours, 1 hour or 2 hours.

[0035] ‌Non-OFF gear‌ means that the car's ignition switch or power switch is not in the off state, which usually means that the vehicle may be in the starting state or ready to start.

[0036] In some embodiments, after sending the power replenishment request to the vehicle control system, the power replenishment method further includes: When it is determined based on the vehicle state information that the DCDC converter starts to operate within a set time, a requested power replenishment voltage is sent to the high-voltage battery to control the high-voltage battery to output a constant voltage according to the requested power replenishment voltage.

[0037] The initial value of the requested power replenishment voltage is greater than the total voltage of the lithium battery.

[0038] It can be understood that according to the current total voltage of the lithium battery, the initial value of the charging voltage is set to a voltage slightly higher than the total voltage of the lithium battery, and the request for charging voltage is sent through the CAN bus. The high-voltage battery is charged at a constant voltage through the DCDC converter according to the requested charging voltage sent by the BMS, so that the battery can enter low-current charging more smoothly.

[0039] It should be noted that the "slightly higher" here is to control the current range of the small current pre-charge stage at the beginning of charging. The initial charging voltage is set to the lithium battery voltage plus a small voltage to make the voltage difference small, thereby controlling the current within the range allowed by the pre-charge current. The size of this small voltage can be confirmed by the lithium battery charging test.

[0040] In some embodiments, in the process of controlling the high-voltage battery to output a constant voltage according to the requested power replenishment voltage, the power replenishment method further includes: When the charging current output by the high-voltage battery is lower than the preset minimum continuous charging current and the difference between the requested charging voltage and the output voltage of the DCDC converter is less than the preset voltage difference threshold, the high-voltage battery is controlled to increase the requested charging voltage in a gradient increasing manner.

[0041] It can be understood that during the voltage regulation and charging process, if the current is lower than the minimum allowable continuous charging current Imin, and the difference between the BMS requested charging voltage and the DCDC converter voltage (generally refers to the output voltage of the DCDC converter) is very small, that is, less than the preset voltage threshold, the requested charging voltage will be increased with a small gradient to slowly adjust and increase the charging current to avoid too low charging efficiency.

[0042] In some embodiments, in the process of controlling the high-voltage battery to output a constant voltage according to the requested power replenishment voltage, the power replenishment method further includes: When the charging current output by the high-voltage battery is greater than the preset maximum continuous charging current, and the difference between the requested charging voltage and the output voltage of the DCDC converter is less than the preset voltage difference threshold, the high-voltage battery is controlled to reduce the requested charging voltage in a gradient decreasing manner.

[0043] It can be understood that during the voltage regulation and charging process, if the current exceeds the maximum allowed continuous charging current Imax, and the BMS requests the charging voltage and DCDC.

[0044] If the voltage difference between the BMS requested recharging voltage and the DCDC converter voltage is very small, the requested recharging voltage is reduced with a small gradient to slowly adjust and reduce the charging current to avoid overcharging or overheating of the battery.

[0045] In some embodiments, after sending the power replenishment request to the vehicle control system, the power replenishment method further includes: When it is determined based on the vehicle status information that the DCDC converter starts to operate within a set time, the battery management system is controlled to update the charging state of the lithium battery.

[0046] It is understandable that the charging status of the lithium battery can be obtained from the CAN bus, and the charging status includes the value of the current charging amount of the lithium battery.

[0047] In some embodiments, the process of the power replenishment method provided by the present invention is as follows Figure 2 As shown, it can be summarized into four steps: monitoring the battery and vehicle status, sending a request for charging, confirming that the request for charging is successful, and regulating the voltage for charging.

[0048] Furthermore, if Figure 3 As shown, the power replenishment method provided by the present invention comprises the following steps: Step 1: Monitor the battery state of charge (SOC) and vehicle status.

[0049] Through SOC-related algorithms, BMS monitors and updates the state of charge of the lithium battery in real time and records the changes in the power of the lithium battery; Through the CAN bus, the vehicle status sent by the vehicle control system is received, including the current gear position and working status of the vehicle, and the DCDC converter status and DCDC converter voltage are received from the vehicle control system.

[0050] Step 2: Send a request for recharging.

[0051] Determine whether the SOC is lower than the preset threshold, indicating that the lithium battery is low on power; Determine whether the lithium battery has not been fully charged for a period of time, indicating that the SOC may have a large error and needs to be recharged for SOC full charge calibration; If the vehicle is in working state and in a non-OFF gear (closed gear or parking gear), it means that the vehicle can provide charging; Determine that the BMS has no MOS (i.e. switch tube) related faults and the MOS is in a closed state; Determine that the DCDC converter is not in working condition and has no faults; When the above conditions are met, the BMS sends a 12V lithium battery recharging request to the vehicle control system via the CAN bus.

[0052] Step 3: Confirm that the power replenishment request is successful.

[0053] The working status of the DCDC converter is monitored through the CAN bus. If the DCDC converter starts working within the specified time, a feedback signal is sent to the BMS through the CAN bus, indicating that the 12V lithium battery recharging request is successful; The BMS updates the status information to charging and sends it via the CAN bus.

[0054] Step 4: Regulate the voltage and replenish power.

[0055] According to the current total voltage of the lithium battery, the initial value of the charging voltage is set to a voltage slightly higher than the total voltage of the lithium battery. The request for charging voltage is sent through the CAN bus. The high-voltage battery charges the battery at a constant voltage through the DCDC converter according to the requested charging voltage sent by the BMS, so that the battery can enter the low-current charging more smoothly. Among them, "low current" is the range of pre-charge current determined according to the charging characteristics of the lithium battery to prevent the lithium battery from being subjected to excessive current shock in the early stage of charging to avoid damage. For example, some batteries may recommend using a current of 0.1C (10% of the lithium battery capacity) to 0.2C in the early stage of charging. According to the battery characteristics, the maximum value Imax and the minimum value Imin of the continuous charging current allowed under different temperatures and different battery life SOH (State of Health) are obtained in the test; During the voltage regulation and charging process, if the current is lower than the minimum allowed continuous charging current Imin, and the difference between the BMS requested charging voltage and the DCDC converter voltage (generally refers to the output voltage of the DCDC converter) is very small, that is, less than the preset voltage threshold, the requested charging voltage is increased with a small gradient to slowly adjust and increase the charging current to avoid too low charging efficiency. "Very small difference": The difference between the BMS requested charging voltage and the DCDC voltage is, for example, 0.2V. It is considered that the voltage difference is too small, resulting in too low charging current. The size of the voltage difference can be confirmed by lithium battery charging test. "Small gradient": Considering the time for the vehicle control system to respond to the BMS request for charging voltage, and avoiding the risk of fast charging exceeding the safe range of the lithium battery charging current or causing the lithium battery temperature to overheat, set a suitable gradient, such as increasing by 0.1V every 10ms. "Slow": By setting a suitable voltage change gradient, the charging current changes slowly. Because constant voltage charging is considered, the speed of current change cannot be quantified. The purpose is to avoid the risk of fast charging exceeding the safe range of the lithium battery charging current or causing the battery temperature to overheat. It can be set according to the charging characteristics of the lithium battery.

[0056] During the voltage regulation and charging process, if the current exceeds the maximum allowed continuous charging current Imax, and the BMS requests the charging voltage and DCDC.

[0057] If the voltage difference between the BMS requested recharging voltage and the DCDC converter voltage is very small, the requested recharging voltage is reduced with a small gradient to slowly adjust and reduce the charging current to avoid overcharging or overheating of the battery.

[0058] The method provided by the present invention controls the charging current by adjusting the requested power replenishment voltage, which can ensure that the battery is charged at the most efficient working point, help reduce energy waste, and improve the energy efficiency of the overall system; and prevent the charging current from exceeding the allowable continuous charging current range, avoid battery overcharging or overheating, protect the battery, and extend the battery life.

[0059] In addition, the method provided by the present invention can adjust the charging strategy according to the characteristics of the battery under different temperatures and different SOH conditions, ensuring safe and effective charging in various environments, and requesting power replenishment to assist in increasing the probability of SOC full charge calibration and improving SOC accuracy.

[0060] Moreover, the method provided by the present invention can also obtain Imin and Imax according to the (temperature, SOH, maximum and minimum values ​​of the allowed continuous charging current) data table, multiply them by a certain coefficient, and output them to the vehicle control system through CAN as the requested charging current. The vehicle DCDC can choose constant current charging or constant voltage charging according to the situation.

[0061] like Figure 4 As shown, the present invention also provides a lithium battery charging device 400, comprising: The acquisition module 401 is used to acquire the state of charge of the lithium battery and the vehicle state information of the vehicle in which the lithium battery is located; the vehicle state information includes: vehicle gear position, vehicle working state information and DCDC converter state information; The control module 402 is used to send a charging request to the vehicle control system to control the DCDC converter to start working through the vehicle control system when it is determined based on the state of charge and the vehicle state information that the power of the lithium battery is insufficient, the SOC of the lithium battery needs to be fully charged and calibrated, the vehicle is chargeable, the switch tube inside the battery management system corresponding to the lithium battery is in a closed state, or the DCDC converter is not in a working state; The input end of the DCDC converter is connected to the high-voltage battery of the vehicle, and the output end is connected to the lithium battery.

[0062] The lithium battery charging device provided in the above embodiment can implement the technical solution described in the above lithium battery charging method embodiment. The specific implementation principles of the above modules or units can refer to the corresponding contents in the above lithium battery charging method embodiment, which will not be repeated here.

[0063] like Figure 5 As shown, the present invention also provides an electronic device 500 , which may be a battery management system. The electronic device 500 includes a processor 501 and a memory 502 . Figure 5 Only some components of the electronic device 500 are shown, but it should be understood that it is not required to implement all of the components shown, and more or fewer components may be implemented instead.

[0064] In some embodiments, the memory 502 may be an internal storage unit of the electronic device 500, such as a hard disk or memory of the electronic device 500. In other embodiments, the memory 502 may also be an external storage device of the electronic device 500, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the electronic device 500.

[0065] Furthermore, the memory 502 may include both an internal storage unit of the electronic device 500 and an external storage device. The memory 502 is used to store application software installed in the electronic device 500 and various data.

[0066] In some embodiments, the processor 501 may be a central processing unit (CPU), a microprocessor or other data processing chip, used to run program codes or process data stored in the memory 502, such as the lithium battery charging method of the present invention.

[0067] In some embodiments of the present invention, when the processor 501 executes the lithium battery charging program in the memory 502, the following steps may be implemented: Acquire the state of charge of the lithium battery and the vehicle status information of the vehicle in which the lithium battery is located; the vehicle status information includes: vehicle gear position, vehicle working status information and DCDC converter status information; When it is determined based on the state of charge and the vehicle status information that the power of the lithium battery is insufficient, the SOC of the lithium battery needs to be fully charged and calibrated, the vehicle is chargeable, the switch tube inside the battery management system corresponding to the lithium battery is in a closed state, or the DCDC converter is not in a working state, a charging request is sent to the vehicle control system so as to control the DCDC converter to start working through the vehicle control system; The input end of the DCDC converter is connected to the high-voltage battery of the vehicle, and the output end is connected to the lithium battery.

[0068] It should be understood that: when the processor 501 executes the lithium battery charging program in the memory 502, in addition to the above functions, other functions can also be implemented. For details, please refer to the description of the corresponding method embodiment above.

[0069] Furthermore, the embodiment of the present invention does not specifically limit the type of the electronic device 500 mentioned, and the electronic device 500 may be a portable electronic device such as a mobile phone, a tablet computer, a personal digital assistant (PDA), a wearable device, a laptop computer, etc. Exemplary embodiments of portable electronic devices include but are not limited to portable electronic devices equipped with IOS, Android, Microsoft or other operating systems. The above-mentioned portable electronic device may also be other portable electronic devices, such as a laptop computer with a touch-sensitive surface (e.g., a touch panel). It should also be understood that in some other embodiments of the present invention, the electronic device 500 may not be a portable electronic device, but a desktop computer with a touch-sensitive surface (e.g., a touch panel).

[0070] In another aspect, the present invention further provides a non-transitory computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the method for recharging a lithium battery provided by the above methods is implemented, and the method comprises: Acquire the state of charge of the lithium battery and the vehicle status information of the vehicle in which the lithium battery is located; the vehicle status information includes: vehicle gear position, vehicle working status information and DCDC converter status information; When it is determined based on the state of charge and the vehicle status information that the power of the lithium battery is insufficient, the SOC of the lithium battery needs to be fully charged and calibrated, the vehicle is chargeable, the switch tube inside the battery management system corresponding to the lithium battery is in a closed state, or the DCDC converter is not in a working state, a charging request is sent to the vehicle control system so as to control the DCDC converter to start working through the vehicle control system; The input end of the DCDC converter is connected to the high-voltage battery of the vehicle, and the output end is connected to the lithium battery.

[0071] Those skilled in the art will appreciate that all or part of the processes of the above-mentioned embodiments can be implemented by instructing related hardware through a computer program, and the program can be stored in a computer-readable storage medium, wherein the computer-readable storage medium is a disk, an optical disk, a read-only storage memory, or a random access memory, etc.

[0072] The above is a detailed introduction to the lithium battery charging method, device and battery management system provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for technical personnel in this field, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A lithium battery charging method, characterized in that: include: Obtaining the state of charge of the lithium battery and vehicle status information of the vehicle in which the lithium battery is located; The vehicle status information includes: vehicle gear position, vehicle working status information and DCDC converter status information; When it is determined based on the state of charge and the vehicle status information that the power of the lithium battery is insufficient, the SOC of the lithium battery needs to be fully charged and calibrated, the vehicle is chargeable, the switch tube inside the battery management system corresponding to the lithium battery is in a closed state, or the DCDC converter is not in a working state, a charging request is sent to the vehicle control system so as to control the DCDC converter to start working through the vehicle control system; The input end of the DCDC converter is connected to the high-voltage battery of the vehicle, and the output end is connected to the lithium battery.

2. The lithium battery charging method according to claim 1, characterized in that: Determining that the lithium battery is low on power includes: When it is determined that the state of charge is lower than a preset state of charge threshold, determining that the lithium battery is low on power; Determine that the SOC of the lithium battery needs to be fully charged and calibrated, including: In a case where it is determined based on the state of charge that the lithium battery is not fully charged within the target time, determining that the SOC of the lithium battery needs to be fully charged and calibrated; Verify that the vehicle is rechargeable, including: When it is determined based on the vehicle state information that the vehicle is in a working state and the vehicle is in a non-OFF gear position, it is determined that the vehicle can be charged.

3. The lithium battery charging method according to claim 1, characterized in that: After sending the power replenishment request to the vehicle control system, the method further includes: When it is determined based on the vehicle state information that the DCDC converter starts to operate within a set time, a requested power replenishment voltage is sent to the high-voltage battery to control the high-voltage battery to output a constant voltage according to the requested power replenishment voltage.

4. The lithium battery charging method according to claim 3, characterized in that: The initial value of the requested power replenishment voltage is greater than the total voltage of the lithium battery.

5. The lithium battery charging method according to claim 3, characterized in that: In the process of controlling the high-voltage battery to output a constant voltage according to the requested supplementary voltage, the method further includes: When the charging current output by the high-voltage battery is lower than the preset minimum continuous charging current and the difference between the requested charging voltage and the output voltage of the DCDC converter is less than the preset voltage difference threshold, the high-voltage battery is controlled to increase the requested charging voltage in a gradient increasing manner.

6. The lithium battery charging method according to claim 5, characterized in that: In the process of controlling the high-voltage battery to output a constant voltage according to the requested supplementary voltage, the method further includes: When the charging current output by the high-voltage battery is greater than the preset maximum continuous charging current, and the difference between the requested charging voltage and the output voltage of the DCDC converter is less than the preset voltage difference threshold, the high-voltage battery is controlled to reduce the requested charging voltage in a gradient decreasing manner.

7. The lithium battery charging method according to any one of claims 1 to 6, characterized in that: After sending the power replenishment request to the vehicle control system, the method further includes: When it is determined based on the vehicle status information that the DCDC converter starts to operate within a set time, the battery management system is controlled to update the charging state of the lithium battery.

8. A lithium battery charging device, characterized in that: include: An acquisition module, used to acquire the state of charge of the lithium battery and vehicle status information of the vehicle in which the lithium battery is located; The vehicle status information includes: vehicle gear position, vehicle working status information and DCDC converter status information; A control module, configured to send a charging request to a vehicle control system to control the DCDC converter to start working through the vehicle control system when it is determined based on the state of charge and the vehicle state information that the power of the lithium battery is insufficient, the SOC of the lithium battery needs to be fully charged and calibrated, the vehicle is chargeable, the switch tube inside the battery management system corresponding to the lithium battery is in a closed state, or the DCDC converter is not in a working state; The input end of the DCDC converter is connected to the high-voltage battery of the vehicle, and the output end is connected to the lithium battery.

9. A battery management system, characterized in that: comprising a memory and a processor, wherein: The memory is used to store programs; The processor is coupled to the memory and is used to execute the program stored in the memory to implement the steps of the lithium battery charging method as described in any one of claims 1 to 7.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the lithium battery charging method as described in any one of claims 1 to 7 are implemented.

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