Methods, devices, and vehicles for charging low-voltage batteries

Abstract

This application relates to the field of vehicle technology, and in particular to a method, device, and vehicle for replenishing a vehicle's low-voltage battery. The method includes: in a vehicle's sleep state, acquiring relevant data about the low-voltage battery using a low-voltage battery management system, wherein the relevant data includes at least one of total voltage, total current, total temperature, and individual cell voltage; estimating the remaining charge of the low-voltage battery based on the relevant data, and determining whether the low-voltage battery meets preset replenishment conditions based on the relevant data and at least one of the remaining charge; if the preset replenishment conditions are met, waking up the vehicle and controlling the vehicle's power battery to replenish the low-voltage battery; if the preset replenishment conditions are not met, controlling the low-voltage battery management system to enter a sleep state, and waking up the low-voltage battery management system again after a preset interval. This solves the problems in related technologies where a low-voltage battery is depleted in a vehicle's sleep state, leading to the vehicle's inability to start normally and a poor user experience.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and in particular to a method, apparatus and vehicle for replenishing a low-voltage battery in a vehicle. Background Technology

[0002] With the development of intelligent trends in new energy vehicles, the number of electronic and electrical components in new energy vehicles is increasing, which gradually increases the consumption of low-voltage power supply. Due to the self-discharge of low-voltage batteries and the continuous power consumption of electronic components, the power of low-voltage batteries continues to decrease.

[0003] When a vehicle is left unused for an extended period, the low-voltage battery may become depleted, which can prevent the user from starting the vehicle and severely impact the user's driving experience. Summary of the Invention

[0004] This application provides a method, device, and vehicle for replenishing a vehicle's low-voltage battery, in order to solve the problems in the related art where the low-voltage battery is depleted during the vehicle's dormant state, resulting in the vehicle being unable to start normally and a poor user experience.

[0005] The first aspect of this application provides a method for replenishing a vehicle's low-voltage battery, comprising the following steps: in a vehicle sleep state, acquiring relevant data of the low-voltage battery using a low-voltage battery management system, wherein the relevant data includes at least one of total voltage, total current, total temperature, and cell voltage; estimating the remaining charge of the low-voltage battery based on the relevant data, and determining whether the low-voltage battery meets preset replenishment conditions based on the relevant data and at least one of the remaining charge; if the preset replenishment conditions are met, waking up the vehicle and controlling the vehicle's power battery to replenish the low-voltage battery; if the preset replenishment conditions are not met, controlling the low-voltage battery management system to enter a sleep state, and waking up the low-voltage battery management system again after a preset interval.

[0006] Optionally, the preset charging conditions include at least one of the following: the remaining power is less than a first preset threshold; the individual cell voltage is less than a second preset threshold; and the total voltage is less than a third preset threshold.

[0007] Optionally, controlling the vehicle's power battery to replenish the low-voltage battery includes: controlling the vehicle to activate the DC-DC converter, which converts the high-voltage DC power from the power battery into low-voltage DC power, and replenishing the low-voltage battery based on the low-voltage DC power.

[0008] Optionally, before controlling the vehicle's power battery to replenish the low-voltage battery, the method further includes: acquiring the vehicle's status and the power battery's status; determining whether the vehicle meets preset charging conditions based on the vehicle's status and the power battery's status; if the preset charging conditions are met, controlling the vehicle's power battery to replenish the low-voltage battery; otherwise, prohibiting the low-voltage battery management system from being woken up again.

[0009] Optionally, controlling the vehicle's power battery to replenish the low-voltage battery further includes: obtaining the current state of the vehicle and the current state of the power battery; determining whether the vehicle meets the preset charging exit conditions based on the current state of the vehicle and the current state of the power battery; if the preset charging exit conditions are met, controlling the vehicle's power battery to stop replenishing the low-voltage battery.

[0010] Optionally, the vehicle's status includes the vehicle's own status and the DC-DC converter's status. The power battery's status includes the remaining power battery charge and the individual cell voltages of the power battery. The preset charging conditions include the following: the vehicle's own status is that there is no high-voltage power-off fault and it is not under maintenance; the DC-DC converter's status is that it is not faulty; the remaining power battery charge is greater than a fourth preset threshold, and the individual cell voltages of the power battery are greater than a fifth preset threshold. The preset charging exit conditions include at least one of the following: the vehicle's own status is that there is no high-voltage power-off fault and it is not under maintenance; the DC-DC converter's status is that it is not faulty; the remaining power battery charge is less than a sixth preset threshold or the individual cell voltages of the power battery are less than a seventh preset threshold; the DC-DC converter's startup time is greater than a first preset time; the vehicle's own status is that it is under maintenance.

[0011] Optionally, after controlling the vehicle's power battery to replenish the low-voltage battery, the method further includes: obtaining the highest single-cell voltage, charging current, and charging time of the low-voltage battery; if at least one of the remaining power, highest single-cell voltage, charging current, and charging time meets a preset replenishment stop condition, then replenishing the low-voltage battery is stopped.

[0012] Optionally, the preset charging stop conditions include at least one of the following: the remaining charge of the low-voltage battery is equal to the ninth preset threshold; the highest single cell voltage is greater than the tenth preset threshold; the charging current is less than the eleventh preset threshold; and the charging time is greater than the second preset time.

[0013] A second aspect of this application provides a charging device for a vehicle low-voltage battery, comprising: an acquisition module, configured to acquire relevant data of the low-voltage battery using a low-voltage battery management system when the vehicle is in a dormant state, wherein the relevant data includes at least one of total voltage, total current, total temperature, and cell voltage; a judgment module, configured to estimate the remaining charge of the low-voltage battery based on the relevant data, and to determine whether the low-voltage battery meets preset charging conditions based on the relevant data and at least one of the remaining charge; a first control module, configured to wake up the vehicle and control the vehicle's power battery to charge the low-voltage battery if the preset charging conditions are met; and a second control module, configured to control the low-voltage battery management system to enter a dormant state and wake up the low-voltage battery management system again after a preset interval if the preset charging conditions are not met.

[0014] Optionally, the preset charging conditions include at least one of the following: the remaining power is less than a first preset threshold; the individual cell voltage is less than a second preset threshold; and the total voltage is less than a third preset threshold.

[0015] Optionally, the first control module is further configured to: control the vehicle to activate the DC-DC converter, which converts the high-voltage DC power from the power battery into low-voltage DC power, and replenishes the low-voltage battery based on the low-voltage DC power.

[0016] Optionally, it further includes: a first judgment module, used to obtain the status of the vehicle and the status of the power battery before controlling the vehicle's power battery to replenish the low-voltage battery; to determine whether the vehicle meets the preset charging conditions based on the status of the vehicle and the status of the power battery; if the preset charging conditions are met, to control the vehicle's power battery to replenish the low-voltage battery, otherwise to prohibit the low-voltage battery management system from being woken up again.

[0017] Optionally, the first control module is further configured to: acquire the current state of the vehicle and the current state of the power battery; determine whether the vehicle meets the preset charging exit conditions based on the current state of the vehicle and the current state of the power battery; if the preset charging exit conditions are met, control the vehicle's power battery to stop charging the low-voltage battery.

[0018] Optionally, the vehicle's status includes the vehicle's own status and the DC-DC converter's status. The power battery's status includes the remaining power battery charge and the individual cell voltages of the power battery. The preset charging conditions include the following: the vehicle's own status is that there is no high-voltage power-off fault and it is not under maintenance; the DC-DC converter's status is that it is not faulty; the remaining power battery charge is greater than a fourth preset threshold, and the individual cell voltages of the power battery are greater than a fifth preset threshold. The preset charging exit conditions include at least one of the following: the vehicle's own status is that there is no high-voltage power-off fault and it is not under maintenance; the DC-DC converter's status is that it is not faulty; the remaining power battery charge is less than a sixth preset threshold or the individual cell voltages of the power battery are less than a seventh preset threshold; the DC-DC converter's startup time is greater than a first preset time; the vehicle's own status is that it is under maintenance.

[0019] Optionally, it also includes: a second judgment module, used to obtain the highest single cell voltage, charging current and charging time of the low-voltage battery after the power battery of the controlled vehicle is replenishing the low-voltage battery; if at least one of the remaining power, highest single cell voltage, charging current and charging time meets the preset replenishment stop condition, then the replenishment of the low-voltage battery is stopped.

[0020] Optionally, the preset charging stop conditions include at least one of the following: the remaining charge of the low-voltage battery is equal to the ninth preset threshold; the highest single cell voltage is greater than the tenth preset threshold; the charging current is less than the eleventh preset threshold; and the charging time is greater than the second preset time.

[0021] A third aspect of this application provides a vehicle, including: a memory, a processor, and a computer program stored in the memory and executable on the processor. The processor executes the program to perform a method for replenishing a low-voltage battery of a vehicle as described in the above embodiments.

[0022] A fourth aspect of this application provides a computer-readable storage medium having a computer program or instructions stored thereon, which are executed by a processor to perform a method for replenishing a vehicle low-voltage battery as described in the above embodiments.

[0023] The fifth aspect of this application provides a computer program product, including a computer program or instructions, which, when executed, implement the method for replenishing a vehicle low-voltage battery as described in the above embodiments.

[0024] Therefore, this application has at least the following beneficial effects:

[0025] This application embodiment can acquire relevant data of the low-voltage battery while the vehicle is in a dormant state. Based on the relevant data, it determines whether the low-voltage battery meets preset charging conditions. When the preset charging conditions are met, the power battery is automatically activated to charge the low-voltage battery, effectively reducing the risk of low-voltage battery depletion and improving user experience and vehicle reliability. This solves the technical problem in related technologies where low-voltage battery depletion during vehicle dormant state leads to vehicle failure to start normally and a poor user experience.

[0026] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0027] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a flowchart of a method for replenishing a vehicle low-voltage battery according to an embodiment of this application; Figure 2 This is a schematic diagram of a vehicle low-voltage battery charging system provided according to an embodiment of this application; Figure 3 This is a flowchart of the low-voltage lithium battery charging control in a dormant scenario according to an embodiment of this application; Figure 4 This is a flowchart of the low-voltage lithium battery charging control in a wake-up scenario according to an embodiment of this application; Figure 5 This is an example diagram of a vehicle low-voltage battery charging device provided according to an embodiment of this application; Figure 6This is a structural schematic diagram of a vehicle provided according to an embodiment of this application. Detailed Implementation

[0028] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0029] The following description, with reference to the accompanying drawings, outlines a method, apparatus, and vehicle for replenishing a vehicle's low-voltage battery according to embodiments of this application. Addressing the issue mentioned in the background art where prolonged inactivity of a vehicle can lead to a depleted low-voltage battery, resulting in the inability to start the vehicle and severely impacting the user experience, this application provides a method for replenishing a vehicle's low-voltage battery. In this method, while the vehicle is in a dormant state, relevant data about the low-voltage battery is acquired. Based on this data, it is determined whether the low-voltage battery meets preset replenishment conditions. If the preset conditions are met, the power battery is automatically activated to replenish the low-voltage battery. This solves the problem in related technologies where a depleted low-voltage battery during vehicle dormancy prevents the vehicle from starting normally, resulting in a poor user experience.

[0030] Specifically, Figure 1 This is a schematic flowchart illustrating a method for replenishing a vehicle's low-voltage battery, as provided in an embodiment of this application.

[0031] like Figure 1 As shown, the method for charging the low-voltage battery of this vehicle includes the following steps: In step S101, while the vehicle is in sleep mode, relevant data of the low-voltage battery are obtained using the low-voltage battery management system. The relevant data includes at least one of total voltage, total current, total temperature, and cell voltage.

[0032] The low-voltage battery can be a low-voltage lithium battery or a low-voltage storage battery.

[0033] It is understood that the embodiments of this application can utilize LBMS (Low-Voltage Battery Management System) to obtain relevant data of the low-voltage battery in order to determine whether the low-voltage battery needs to be recharged.

[0034] The LBMS in this embodiment of the application has a timed wake-up function, such as waking up once every 10 minutes. When the timed wake-up time arrives, the LBMS will automatically wake up, but will only remain in a wake-up state without sending network packets.

[0035] In step S102, the remaining power of the low-voltage battery is estimated based on relevant data, and it is determined whether the low-voltage battery meets the preset charging conditions based on at least one of the relevant data and the remaining power.

[0036] It is understood that the embodiments of this application can estimate the remaining power of the low-voltage battery based on relevant data, and can determine whether the low-voltage battery meets the preset charging conditions based on the remaining power and at least one of the total voltage and single cell voltage in the relevant data. By comprehensively judging whether the low-voltage battery is at risk of being depleted by multiple data, the accuracy of the judgment is improved, and the problem of inaccurate judgment caused by judging based on only a single data is avoided, thereby reducing the risk of low-voltage battery being depleted.

[0037] The embodiments of this application can estimate the remaining power using the coulomb method or the OCV method, and then correct it based on the total voltage and the individual cell voltage to obtain the final estimated remaining power.

[0038] In one embodiment of this application, the preset charging conditions include at least one of the following: the remaining power is less than a first preset threshold; the individual cell voltage is less than a second preset threshold; and the total voltage is less than a third preset threshold.

[0039] The first, second, and third preset thresholds can all be set according to specific circumstances, without any specific limitations. For example, the first preset threshold can be set to 10%, the second preset threshold can be set to 3V, and the third preset threshold can be set to 9V.

[0040] In step S103, if the preset charging conditions are met, the vehicle is woken up and the vehicle's power battery is controlled to charge the low-voltage battery.

[0041] It is understood that, in this embodiment of the application, when the low-voltage battery of the vehicle meets the preset charging conditions, the components of other controllers of the vehicle are activated to control the vehicle's power battery to charge the low-voltage battery, thereby preventing the vehicle from failing to start due to low-voltage battery depletion and improving the user experience.

[0042] In one embodiment of this application, controlling the vehicle's power battery to replenish the low-voltage battery includes: controlling the vehicle to turn on the DC-DC converter, the DC-DC converter converting the high-voltage DC power of the power battery into low-voltage DC power, and replenishing the low-voltage battery based on the low-voltage DC power.

[0043] Since the power battery is high voltage, it cannot directly replenish the low voltage battery. Therefore, the embodiments of this application can use the vehicle's DC / DC converter to convert the high voltage of the power battery into low voltage, and replenish the low voltage battery based on the low voltage.

[0044] In one embodiment of this application, before controlling the vehicle's power battery to replenish the low-voltage battery, the method further includes: acquiring the vehicle's state and the power battery's state; determining whether the vehicle meets preset charging conditions based on the vehicle's state and the power battery's state; if the preset charging conditions are met, controlling the vehicle's power battery to replenish the low-voltage battery; otherwise, prohibiting the low-voltage battery management system from being woken up again until the vehicle is powered on again.

[0045] The vehicle's status includes its own status and the status of the DC-DC converter; the power battery's status includes the remaining charge of the power battery and the voltage of each individual cell; preset charging conditions can also be called charging entry conditions.

[0046] It is understood that the embodiments of this application can determine whether the vehicle meets the preset charging conditions based on the vehicle's state and the state of the power battery. When the preset charging conditions are met, the power battery of the vehicle is controlled to replenish the low-voltage battery. When the preset charging conditions are not met, the low-voltage battery management system is prohibited from being woken up again. This avoids the vehicle being woken up frequently when the preset charging conditions are no longer met, which would cause additional low-voltage battery power consumption and further deplete the low-voltage battery's power.

[0047] In one embodiment of this application, the preset charging conditions include the following: the vehicle itself is in a state of no high-voltage power failure and is not under maintenance; the DC converter is in a non-fault state; the remaining power of the power battery is greater than a fourth preset threshold, and the voltage of a single cell of the power battery is greater than a fifth preset threshold.

[0048] The fourth and fifth preset thresholds can be set according to specific circumstances, without any specific limitations. For example, the fourth preset threshold can be set to 15%, and the fifth preset threshold can be set to 3.2V.

[0049] It is understood that the preset charging conditions in this application embodiment include multiple conditions, and all of them must be met before the power battery can be controlled to charge the low-voltage battery; otherwise, the power battery will not be controlled to charge the low-voltage battery, and the vehicle will re-enter the dormant state. Specifically, the preset charging conditions include: (1) The vehicle has no high-voltage power failure.

[0050] Only when there is no high-voltage power-off fault can the vehicle maintain a continuous high-voltage connection, providing a continuous high-voltage power supply to the DC / DC converter and supporting low-voltage battery charging. High-voltage power-off faults include those where the high-voltage components themselves cannot maintain operation. To avoid damaging the faulty components, high-voltage power-on must be prohibited or the high-voltage power-off must be performed when such faults occur. High-voltage safety faults also include those such as high-voltage interlock faults or insulation resistance faults. To avoid the risk of electric shock to users, the vehicle must not maintain a high-voltage state.

[0051] (2) The power battery has sufficient power.

[0052] As the energy source for charging low-voltage batteries, the power battery must have sufficient charge. Insufficient charge prevents the continuous supply of high-voltage energy to the low-voltage battery. Furthermore, considering the power battery's need for resting and storage, a low charge level poses a risk of over-discharge and prevents the vehicle from starting. Therefore, low-voltage charging is only permitted when the power battery has sufficient charge. Sufficient power battery charge is determined by two conditions: the power battery's State of Charge (SOC) must be higher than the intelligent charging threshold SOC1 (the fourth preset threshold), and the voltage of each individual battery cell must be higher than the intelligent charging threshold V1 (the fifth preset threshold). Otherwise, if the power battery's SOC is lower than SOC1 or the voltage of each individual battery cell is lower than V1, the power battery is considered insufficient.

[0053] (3) DC / DC non-fault state.

[0054] As an intermediary for high-voltage to low-voltage conversion, the DC / DC converter must be in normal working condition to maintain the continuous intelligent charging process of the low-voltage battery. Therefore, when the DC / DC converter is faulty, it is not allowed to enter the low-voltage battery charging control; low-voltage battery charging control is only allowed when the DC / DC converter is in a non-faulty state.

[0055] (4) The vehicle is not under maintenance.

[0056] Because intelligent charging of low-voltage lithium batteries requires the activation of high voltage, and this scenario is not a user-initiated high-voltage power-on, in order to avoid the risk of high-voltage exposure caused by vehicle maintenance at this time, which could lead to electric shock to personnel, intelligent charging of low-voltage batteries will not be initiated when the vehicle is under maintenance.

[0057] In one embodiment of this application, controlling the vehicle's power battery to replenish the low-voltage battery further includes: obtaining the current state of the vehicle and the current state of the power battery; determining whether the vehicle meets a preset charging exit condition based on the current state of the vehicle and the current state of the power battery; if the preset exit condition is met, controlling the vehicle's power battery to stop replenishing the low-voltage battery.

[0058] It is understood that the embodiments of this application can determine whether the vehicle meets the preset charging exit conditions based on the vehicle's state and the state of the power battery. If the preset exit conditions are met, the vehicle's power battery is controlled to stop charging the low-voltage battery.

[0059] In one embodiment of this application, the preset charging stop conditions include at least one of the following: the vehicle itself is in a state of no high-voltage power failure and is not in a maintenance state; the DC converter is in a non-fault state; the remaining power of the power battery is less than a sixth preset threshold or the single cell voltage of the power battery is lower than a seventh preset threshold; the start-up time of the DC converter is greater than a first preset time; and the vehicle itself is in a maintenance state.

[0060] The sixth preset threshold, the seventh preset threshold, and the first preset duration can all be set according to specific circumstances, without any specific limitations. For example, the sixth preset threshold can be set to 15%, the seventh preset threshold can be set to 3.1V, and the first preset duration can be set to 10min.

[0061] It is understood that, in the process of controlling the power battery to charge the low-voltage battery, this application embodiment still determines in real time whether the vehicle meets the preset charging stop conditions. If the preset charging stop exit conditions are met, the charging process is exited; otherwise, the power battery continues to charge the low-voltage battery. The charging process can be exited when any of the preset charging stop conditions are met. Specifically, the preset charging stop conditions include: (1) No high voltage power failure.

[0062] Only when there is no high-voltage power-off fault can the vehicle maintain a continuous high-voltage connection, providing a continuous high-voltage power supply to the DC / DC converter and supporting the charging of low-voltage lithium batteries. High-voltage power-off faults include those where the high-voltage components themselves cannot maintain operation. To avoid damaging the faulty components, high-voltage power-on must be prohibited or the high-voltage power-off must be performed when such faults occur. High-voltage safety faults also include those such as high-voltage interlock faults or insulation resistance faults. To avoid the risk of electric shock to users, the vehicle must not maintain a high-voltage state.

[0063] (2) Insufficient power of the power battery.

[0064] As the energy source for charging low-voltage batteries, the power battery must have sufficient charge. Insufficient charge prevents the continuous supply of high-voltage energy to the low-voltage battery. Furthermore, considering the power battery's need for resting and storage, a low charge level poses a risk of over-discharge and prevents the vehicle from starting. Therefore, continuous low-voltage lithium battery charging is only permitted when the power battery has sufficient charge; otherwise, intelligent low-voltage lithium battery charging is discontinued. Insufficient power battery charge is determined when either the remaining SOC (State of Charge) is below the intelligent charging exit threshold SOC2 (the sixth preset threshold) or the individual battery cell voltage is below the intelligent charging exit threshold V2 (the seventh preset threshold). Conversely, when both the remaining SOC and individual battery cell voltage are above the intelligent charging exit threshold V2, the power battery is considered sufficiently charged, and intelligent low-voltage battery charging continues.

[0065] (3) DC / DC non-fault state.

[0066] As an intermediary for high-voltage to low-voltage conversion, the DC / DC converter must be in normal working condition to maintain the continuous process of intelligent charging of the low-voltage battery. Therefore, when the DC / DC converter fails, it will exit the low-voltage battery charging control; only when the DC / DC converter is in a non-faulty state will it be allowed to continue the low-voltage battery charging control.

[0067] (4) The DC / DC converter has not been working for a long time.

[0068] After the high voltage is started, the DC / DC working time is judged. If the DC / DC fails to work for a certain time threshold (i.e., the first preset time), it is considered that the DC / DC cannot work normally, and the low-voltage lithium battery intelligent charging is stopped.

[0069] (5) The vehicle is under maintenance.

[0070] Because intelligent charging of low-voltage batteries requires the activation of high voltage, and this scenario is not an active high-voltage power-on by the user, in order to avoid the risk of high voltage exposure caused by vehicle maintenance at this time, which could lead to electric shock to personnel, intelligent charging of low-voltage batteries is deactivated when the vehicle is under maintenance.

[0071] In one embodiment of this application, after controlling the vehicle's power battery to replenish the low-voltage battery, the method further includes: obtaining the highest single-cell voltage, charging current, and charging time of the low-voltage battery; if at least one of the remaining power, highest single-cell voltage, charging current, and charging time meets a preset replenishment stop condition, then replenishing the low-voltage battery is stopped.

[0072] It is understood that, in the embodiments of this application, when at least one of the remaining charge, maximum single cell voltage, charging current and charging time of the low-voltage battery meets the preset charging stop condition, it indicates that the low-voltage battery is fully charged and the charging of the low-voltage battery is stopped.

[0073] In one embodiment of this application, the preset charging stop conditions include at least one of the following: the remaining charge of the low-voltage battery is equal to a ninth preset threshold; the highest single cell voltage is greater than a tenth preset threshold; the charging current is less than an eleventh preset threshold; and the charging time is greater than a second preset time.

[0074] The tenth preset threshold, eleventh preset threshold, and second preset duration can be set according to specific circumstances without any specific limitations. For example, the ninth preset threshold can be set to 100%, the tenth preset threshold can be set to 3.7V, the eleventh preset threshold can be set to 0.5A, and the second preset duration can be set to 60min.

[0075] Specifically, the preset power-on stop conditions in this application embodiment include: (1) Low-voltage battery remaining charge SOC = 100%. When the LBMS estimates the low-voltage battery remaining charge SOC to be 100%, the low-voltage battery is considered to be fully charged; otherwise, the following conditions are determined.

[0076] (2) The highest voltage of a low-voltage battery cell is greater than or equal to the set threshold for the voltage of a fully charged low-voltage battery cell (i.e., the tenth preset threshold). Considering the accuracy of the remaining power estimation of the low-voltage battery, there may be an overcharge risk when the highest voltage of a low-voltage battery cell is too high. To protect the low-voltage battery, when the highest voltage of a low-voltage battery cell is higher than the set threshold for the voltage of a fully charged low-voltage battery cell, the low-voltage battery is also considered to be fully charged.

[0077] (3) Low-voltage battery charging current ≤ Low-voltage battery full charge current setting threshold (i.e., the eleventh preset threshold). Considering that during the intelligent charging process of the low-voltage battery, all electrical appliances in the vehicle are awakened, and each appliance will also consume a large amount of low-voltage electricity, when the low-voltage battery charging current is too low, the current consumed by the low-voltage appliances is much greater than the charging current for the low-voltage battery, resulting in excessive extra power consumption. In addition, considering that the charging and discharging current characteristics of the low-voltage battery are different under different ambient temperatures, especially in low-temperature environments, the charging of the low-voltage battery is limited. Therefore, based on the above two factors, when the low-voltage battery charging current is too low, it is also considered that the low-voltage battery is fully charged.

[0078] (4) The low-voltage battery intelligent charging time (i.e., charging duration) is greater than or equal to the low-voltage lithium battery intelligent charging timeout threshold (i.e., the second preset duration). Considering that during the low-voltage battery intelligent charging process, all electrical appliances in the vehicle are awakened, and each appliance will consume a large amount of low-voltage electricity, resulting in additional power consumption for the user, the user will perceive a significant decrease in driving range. Therefore, when the low-voltage battery intelligent charging time is too long, low-voltage battery intelligent charging will no longer be performed.

[0079] In step S104, if the preset charging conditions are not met, the low-voltage management system is controlled to enter a sleep state and then woke up again after a preset period.

[0080] The preset period can be set according to specific circumstances, and there is no specific limitation on it, such as 10 minutes.

[0081] It is understood that in this embodiment of the application, if the preset charging conditions are not met, the low-voltage management system is controlled to enter a sleep state, and the low-voltage battery management system is woken up again after a preset period of time to perform the next round of judgment.

[0082] This application also provides a low-voltage battery charging system, such as... Figure 2 As shown, taking a low-voltage lithium battery as an example, the low-voltage battery includes a VCU (Vehicle Control Unit), a BMS (Battery Management System), a DC / DC converter, and a low-voltage lithium battery management system (LBMS), comprising the power battery and the low-voltage lithium battery. The VCU, BMS, DC / DC converter, and LBMS communicate via a CAN (Controller Area Network). The vehicle control unit and the LBMS have network wake-up functionality. The DC / DC converter is connected to the power battery and the low-voltage lithium battery via a wiring harness.

[0083] The LBMS can accurately measure signals such as voltage, current, and temperature of low-voltage lithium batteries and estimate the state of charge (SOC) based on these signals. The LBMS also features a timed self-wake-up function, calculating the SOC upon wake-up and waking the vehicle when the battery level is low.

[0084] The VCU identifies the vehicle's charging conditions and detects the low-voltage lithium battery's remaining power level. When it detects that the low-voltage lithium battery's remaining power level is low and the charging conditions are met, it actively guides the high-voltage power to be turned on and controls the DC / DC converter to enable the low-voltage lithium battery.

[0085] The DC / DC converter is responsible for converting the high-voltage electricity from the power battery into low-voltage DC electricity, which can be used to replenish the low-voltage lithium battery and supply power to low-voltage electrical devices.

[0086] The BMS is responsible for estimating the state of the power battery and controlling the power battery to supply power to the high-voltage system.

[0087] The following will combine Figure 2 The low-voltage battery charging system shown in the illustration is used to describe the vehicle low-voltage battery charging method of this application embodiment. Taking low-voltage lithium battery charging as an example, the low-voltage lithium battery charging control process in the dormant scenario is as follows: Figure 3 As shown, it includes: 1. Automatic wake-up control for low-voltage lithium batteries.

[0088] When the vehicle is stationary, all vehicle controllers are in sleep mode. The LBMS has a timed wake-up function, for example, waking up every 10 minutes. When the timed wake-up time arrives, the LBMS automatically wakes up, but remains in a wake-up state without sending network messages. The LBMS begins periodically collecting low-voltage lithium battery signals such as voltage, current, and temperature, and estimates the remaining state of charge (SOC) of the low-voltage lithium battery based on these signals. The LBMS's wake-up time without sending messages is to prevent the entire vehicle from being woken up, causing additional vehicle components to wake up, thus avoiding interference with other vehicle functions and abnormal exit from sleep mode.

[0089] II. Determining low battery level in low-voltage lithium batteries.

[0090] Modern new energy vehicles are increasingly equipped with intelligent features and electronic components, leading to a rise in low-voltage power consumption. This consumption continues even when the user is away from the vehicle, draining the low-voltage lithium battery. Furthermore, considering the self-discharge characteristics of low-voltage lithium batteries, they will continue to deplete their own power when the vehicle is idle for extended periods. All these factors contribute to the continuous depletion of the low-voltage lithium battery. When the battery level drops below a certain threshold after prolonged inactivity, there is a risk of over-discharge, potentially causing losses for the user. In case of emergency, the vehicle may be unable to operate due to a dead battery, leading to user complaints.

[0091] Once the vehicle is activated and the remaining SOC (State of Charge) of the low-voltage lithium battery is estimated, the charging demand of the low-voltage lithium battery is assessed. If the remaining charge of the low-voltage lithium battery is below a predetermined low charge threshold, it is considered low, posing a potential risk of depletion, and requiring recharging. However, considering the characteristics of low-voltage lithium batteries and the accuracy of remaining charge estimation, to avoid depletion due to significant estimation errors, in addition to considering the remaining charge, the individual cell voltage and overall voltage of the low-voltage lithium battery should also be considered as criteria for determining whether recharging is needed. When the voltage of a single low-voltage lithium battery cell is too low, there is a risk of over-discharge, preventing the battery from providing sufficient energy to the vehicle's electrical systems. Therefore, when the voltage of a single low-voltage lithium battery cell is below a predetermined low cell voltage threshold, it is also considered that the low-voltage lithium battery requires recharging. Apart from situations where the remaining charge of the low-voltage lithium battery is not low and the voltage of the individual cells of the low-voltage lithium battery is not low, when the overall voltage of the low-voltage lithium battery is low, it may not be able to provide sufficient starting energy for the whole vehicle. Therefore, when the overall voltage of the low-voltage lithium battery is lower than the set threshold for the overall voltage of the low-voltage lithium battery, it is also considered that the low-voltage lithium battery has a need for recharging.

[0092] Therefore, when any one of the following three conditions is met—that the remaining charge of the low-voltage lithium battery is lower than the low-voltage lithium battery charge threshold (first preset threshold), that the voltage of a single low-voltage lithium battery cell is lower than the low-voltage lithium battery cell voltage threshold (second preset threshold), or that the overall voltage of the low-voltage lithium battery is lower than the overall voltage threshold (third preset threshold)—these conditions can be called preset charging conditions, indicating that the low-voltage lithium battery has a charging requirement. Then, the LBMS wakes up other vehicle controllers via the network to determine whether the vehicle's intelligent charging conditions for the low-voltage lithium battery are met. If none of the three conditions are met—that the remaining charge of the low-voltage lithium battery is lower than the low-voltage lithium battery charge threshold, that the voltage of a single low-voltage lithium battery cell is lower than the low-voltage lithium battery cell voltage threshold, or that the overall voltage of the low-voltage lithium battery is lower than the overall voltage threshold—the low-voltage lithium battery is considered to have sufficient charge, with no risk of depletion, and no charging requirement. If the low-voltage lithium battery charge condition is not met, the LBMS enters a sleep state and begins the next timed wake-up cycle.

[0093] III. Intelligent charging control for low-voltage lithium batteries.

[0094] 1. Determine whether the low-voltage lithium battery charging entry conditions (preset charging conditions) are met.

[0095] When the LBMS detects low remaining battery power, it wakes up the vehicle, and the vehicle controller (VCU) determines whether the vehicle meets the charging conditions. The basic principle of low-voltage lithium battery charging is that, under high-voltage connection, a DC / DC converter transforms the high-voltage power from the battery into low-voltage power to charge the low-voltage lithium battery. Therefore, it is necessary to ensure that the conditions of this link meet the continuous operating requirements.

[0096] The low-voltage lithium battery charging condition is deemed met when all of the following conditions are satisfied, and the low-voltage lithium battery charging control process is initiated. Otherwise, the low-voltage lithium battery intelligent charging control is not initiated, the vehicle re-enters sleep mode, and charging is no longer permitted.

[0097] (1) No high-voltage power-off fault. Only when there is no high-voltage power-off fault can the vehicle maintain a continuous high-voltage connection, providing continuous high-voltage energy to the DC / DC converter and supporting low-voltage lithium battery charging. High-voltage power-off faults include faults in which the high-voltage components themselves cannot maintain operation. In order to avoid damage to the faulty components, high-voltage power-on must be prohibited or high-voltage power-off must be performed when such faults occur. High-voltage safety faults also include high-voltage interlock faults or insulation resistance ground faults. In order to avoid the risk of electric shock to users, the vehicle must not maintain a high-voltage state.

[0098] (2) Sufficient power battery charge. As the energy source for charging low-voltage lithium batteries, the power battery must have sufficient power. Insufficient power cannot continuously provide high-voltage energy for charging low-voltage lithium batteries. In addition, considering that power batteries also have certain requirements for static storage, there is a risk of over-discharge and vehicle failure when the power battery is too low. Therefore, charging of low-voltage lithium batteries is only allowed when the power battery has sufficient power. Whether the power battery has sufficient power includes the following conditions being met simultaneously: the remaining power battery SOC is higher than the power battery remaining power entering the intelligent charging setting threshold SOC1 (fourth preset threshold), and the voltage of the power battery individual cell is higher than the power battery individual cell voltage entering the intelligent charging setting threshold V1 (fifth preset threshold). When the remaining power battery SOC is lower than the power battery remaining power entering the intelligent charging setting threshold SOC1 or the voltage of the power battery individual cell is lower than the power battery individual cell voltage entering the intelligent charging setting threshold V1, the power battery is considered to have insufficient power.

[0099] (3) DC / DC non-fault state. As an intermediary for high-voltage to low-voltage conversion, the DC / DC must be in normal working condition to maintain the continuous process of intelligent charging of low-voltage lithium battery. Therefore, when the DC / DC is faulty, it is not allowed to enter the low-voltage lithium battery charging control; low-voltage lithium battery charging control is allowed only when the DC / DC is in a non-faulty state.

[0100] (4) The vehicle is not under maintenance. Because low-voltage lithium battery smart charging requires starting high voltage, and this scenario is not a user-initiated high voltage power-on, in order to avoid the risk of high voltage exposure caused by vehicle maintenance at this time, which could lead to electric shock to personnel, low-voltage lithium battery smart charging will not be initiated when the vehicle is under maintenance.

[0101] If any of the above conditions are not met, the vehicle will not enter the low-voltage lithium battery intelligent charging control mode, will re-enter the sleep state, and will no longer allow the low-voltage lithium battery to wake up automatically.

[0102] 2. Intelligent charging control for low-voltage lithium batteries.

[0103] When the conditions for intelligent charging of low-voltage lithium batteries are met, the VCU starts controlling the vehicle to start high voltage, and the BMS performs high voltage power-on. After the high voltage start is successful, the VCU controls the DC / DC to enable, and the DC / DC starts to convert high voltage to low voltage to charge the low-voltage lithium battery.

[0104] During the intelligent charging process of the low-voltage lithium battery, it still judges in real time whether the charging exit condition of the low-voltage lithium battery is met. If it is not met, it continues to charge and further judges whether the low-voltage lithium battery is fully charged. If the intelligent charging exit condition of the low-voltage lithium battery (preset charging exit condition) is met, it exits the intelligent charging of the low-voltage lithium battery.

[0105] (1) No high-voltage power-off fault. Only when there is no high-voltage power-off fault can the vehicle maintain a continuous high-voltage connection, providing continuous high-voltage energy to the DC / DC converter and supporting low-voltage lithium battery charging. High-voltage power-off faults include faults in which the high-voltage components themselves cannot maintain operation. In order to avoid damage to the faulty components, high-voltage power-on must be prohibited or high-voltage power-off must be performed when such faults occur. High-voltage safety faults also include high-voltage interlock faults or insulation resistance ground faults. In order to avoid the risk of electric shock to users, the vehicle must not maintain a high-voltage state.

[0106] (2) Insufficient power battery charge. As the energy source for charging low-voltage lithium batteries, the power battery charge must be sufficient. Because insufficient charge cannot continuously provide high-voltage energy for charging low-voltage lithium batteries, and considering that power batteries also have certain static storage requirements, when the power battery charge is too low, there is also a risk of over-discharge of the power battery and the risk of the vehicle not being able to start. Therefore, low-voltage lithium battery charging is only allowed when the power battery charge is sufficient; otherwise, low-voltage lithium battery intelligent charging will be stopped. Whether the power battery charge is insufficient includes whether the remaining power battery charge SOC is lower than the power battery charge exit intelligent charging setting threshold SOC2 (sixth preset threshold), or whether the voltage of a single power battery cell is lower than the power battery cell voltage exit intelligent charging setting threshold V2 (seventh preset threshold). If these conditions are met, the power battery charge is considered insufficient. When the remaining power battery charge SOC is higher than the power battery charge exit intelligent charging setting threshold SOC2 and the voltage of a single power battery cell is higher than the power battery cell voltage exit intelligent charging setting threshold V2, the power battery charge is considered sufficient, and low-voltage lithium battery intelligent charging will continue.

[0107] (3) DC / DC non-fault state. As an intermediary for high-voltage to low-voltage conversion, the DC / DC must be in normal working condition to maintain the continuous process of intelligent charging of low-voltage lithium battery. Therefore, when the DC / DC fails, the low-voltage lithium battery charging control is terminated; the low-voltage lithium battery charging control is allowed to continue only when the DC / DC is in a non-fault state.

[0108] (4) If the DC / DC has not worked for a long time, the DC / DC working time will be judged after the high voltage is started. If the DC / DC fails to work for a certain time threshold (first preset time), it is considered that the DC / DC cannot work normally, and the low voltage lithium battery smart charging will be stopped.

[0109] (5) The vehicle is under maintenance. Because intelligent charging of low-voltage lithium batteries requires the activation of high voltage, and this scenario is not a user-initiated high-voltage power-on, in order to avoid the risk of high voltage exposure caused by vehicle maintenance at this time, which could lead to electric shock to personnel, intelligent charging of low-voltage lithium batteries is deactivated when the vehicle is under maintenance.

[0110] 3. Low-voltage lithium battery fully charged control.

[0111] During the intelligent charging control of the low-voltage lithium battery, the conditions for the low-voltage lithium battery to be fully charged (preset charging stop conditions) are continuously judged. The low-voltage lithium battery is considered to be fully charged when any of the following conditions are met; otherwise, the low-voltage lithium battery is considered not fully charged.

[0112] (1) The remaining capacity of the low-voltage lithium battery is 100%. When the remaining capacity of the low-voltage lithium battery estimated by the LBMS is 100%, the low-voltage lithium battery is considered to be fully charged. Otherwise, the following conditions shall be determined.

[0113] (2) The highest voltage of a low-voltage lithium battery cell is greater than or equal to the set threshold for the voltage of a fully charged low-voltage lithium battery cell (tenth preset threshold). Considering the accuracy of the remaining capacity estimation of low-voltage lithium batteries, there may be an overcharge risk when the highest voltage of a low-voltage lithium battery cell is too high. To protect the low-voltage lithium battery, when the highest voltage of a low-voltage lithium battery cell is higher than the set threshold for the voltage of a fully charged low-voltage lithium battery cell, the low-voltage lithium battery is also considered to be fully charged.

[0114] (3) Low-voltage lithium battery charging current ≤ Low-voltage lithium battery full charge current setting threshold (eleventh preset threshold). Considering that during the intelligent charging process of the low-voltage lithium battery, all electrical appliances in the vehicle are awakened, and each appliance will also consume a large amount of low-voltage electricity, when the low-voltage lithium battery charging current is too low, the current consumed by the low-voltage appliances is much greater than the charging current for the low-voltage lithium battery, resulting in excessive extra power consumption. In addition, considering that the charging and discharging current characteristics of the low-voltage lithium battery are different under different ambient temperatures, especially in low-temperature environments, the charging of the low-voltage lithium battery is limited. Therefore, based on the above two factors, when the low-voltage lithium battery charging current is too low, it is also considered that the low-voltage lithium battery is fully charged.

[0115] (4) The intelligent charging time of the low-voltage lithium battery is greater than or equal to the intelligent charging timeout threshold of the low-voltage lithium battery (second preset duration). Considering that during the intelligent charging process of the low-voltage lithium battery, all electrical appliances in the vehicle are awakened, and each electrical appliance will also consume a large amount of low-voltage electricity, resulting in additional power consumption for the user, and the user will perceive a significant decrease in driving range. Therefore, when the intelligent charging time of the low-voltage lithium battery is too long, intelligent charging of the low-voltage lithium battery will no longer be performed.

[0116] IV. Intelligent charging termination control for low-voltage lithium batteries.

[0117] When the following conditions are met: 1. Low-voltage lithium battery smart charging entry condition is not met, 2. Low-voltage lithium battery smart charging exit condition is met, or 3. Low-voltage lithium battery smart charging is fully charged, the low-voltage lithium battery smart charging will end, and the low-voltage lithium battery smart charging wake-up enable control will be performed simultaneously.

[0118] If the conditions for entering intelligent charging of the low-voltage lithium battery (1) in Part 3 above are not met, or the conditions for exiting intelligent charging of the low-voltage lithium battery (2) are met, it is considered that the conditions for intelligent charging of the entire vehicle are not met. Therefore, waking up the low-voltage lithium battery intelligent charging system is prohibited to avoid frequent vehicle wake-ups due to unmet conditions, which would cause additional low-voltage power consumption and further deplete the low-voltage lithium battery's capacity. Conversely, if the conditions for entering intelligent charging of the low-voltage lithium battery (1) are met, but the conditions for exiting intelligent charging of the low-voltage lithium battery (2) are not met, it is considered that the conditions for intelligent charging of the entire vehicle are met. In this case, waking up the low-voltage lithium battery intelligent charging system is permitted.

[0119] When low-voltage lithium battery intelligent charging wake-up is enabled, the LBMS can be periodically woken up to estimate the low-voltage lithium battery status and perform logic checks (I and II). Otherwise, the LBMS only performs periodic wake-up and low-voltage lithium battery status estimation, without checking for low low-voltage lithium battery charge. Then, the vehicle enters sleep mode, waiting for the next wake-up.

[0120] Execution processes two to four in this embodiment can also be low-voltage lithium battery charging control processes in a wake-up scenario, such as... Figure 4 As shown.

[0121] The vehicle low-voltage battery charging method described in this application can automatically activate high voltage to charge the low-voltage lithium battery. Simultaneously, considering factors such as battery charging characteristics, vehicle energy consumption optimization, and high-voltage safety, corresponding safeguards are formulated. Specifically: (1) This application can automatically start the high voltage to replenish the low voltage battery when the vehicle is stationary for a long time or in a low voltage state, if the low voltage lithium battery is at risk of being depleted, so as to avoid the low voltage battery being depleted and the vehicle being unable to start, thereby improving the user experience. (2) The low-voltage battery intelligent charging entry conditions of this application not only determine the remaining power of the low-voltage battery and consider the accuracy of the remaining power estimation, but also increase the determination of the voltage of the individual cells and the total voltage of the low-voltage battery, thereby increasing the probability of identifying insufficient power of the low-voltage battery and reducing the risk of low-voltage battery depletion. (3) The low-voltage battery intelligent charging exit condition of this application not only judges the remaining power of the low-voltage battery, but also considers the battery charging characteristics, ambient temperature, and vehicle energy consumption optimization. It takes into account the individual cell voltage, charging and discharging current and charging time to ensure battery safety, reduce intelligent charging time to ensure vehicle energy consumption optimization, and avoid user complaints. (4) The low-voltage battery intelligent charging control of this application takes into account the DC / DC foolproof design, which can effectively prevent the DC / DC from failing to start or not working properly for a long time, which further aggravates the low-voltage battery depletion. (5) This application also considers the high voltage exposure risk that may be caused by high voltage safety or maintenance. When there is a high voltage exposure risk, it will not enter or exit the low voltage lithium battery smart charging.

[0122] According to the vehicle low-voltage battery charging method proposed in the embodiments of this application, relevant data of the low-voltage battery can be obtained when the vehicle is in a dormant state. Based on the relevant data, it is determined whether the low-voltage battery meets the preset charging conditions. When the preset charging conditions are met, the power battery is automatically started to charge the low-voltage battery, which effectively reduces the risk of low-voltage battery depletion and improves user experience and vehicle reliability.

[0123] Next, referring to the accompanying drawings, a charging device for a vehicle low-voltage battery according to an embodiment of this application is described.

[0124] Figure 5 This is a block diagram of a vehicle low-voltage battery charging device according to an embodiment of this application.

[0125] like Figure 5 As shown, the low-voltage battery charging device 10 of the vehicle includes: an acquisition module 100, a judgment module 200, a first control module 300, and a second control module 400.

[0126] The acquisition module 100 is used to acquire relevant data of the low-voltage battery using the low-voltage battery management system when the vehicle is in sleep mode. The relevant data includes at least one of total voltage, total current, total temperature, and cell voltage. The judgment module 200 is used to estimate the remaining power of the low-voltage battery based on the relevant data and to determine whether the low-voltage battery meets the preset charging conditions based on the relevant data and at least one of the remaining power. The first control module 300 is used to wake up the vehicle and control the vehicle's power battery to charge the low-voltage battery if the preset charging conditions are met. The second control module 400 is used to control the low-voltage battery management system to enter sleep mode if the preset charging conditions are not met, and wake up the low-voltage battery management system again after a preset interval.

[0127] In one embodiment of this application, the preset charging conditions include at least one of the following: the remaining power is less than a first preset threshold; the individual cell voltage is less than a second preset threshold; and the total voltage is less than a third preset threshold.

[0128] In one embodiment of this application, the first control module 300 is further configured to: control the vehicle to turn on the DC converter, the DC converter converts the high-voltage DC power of the power battery into low-voltage DC power, and replenish the low-voltage battery based on the low-voltage DC power.

[0129] In one embodiment of this application, the first control module 300 is further configured to: control the vehicle to turn on the DC converter, the DC converter converts the high-voltage DC power of the power battery into low-voltage DC power, and replenish the low-voltage battery based on the low-voltage DC power.

[0130] In one embodiment of this application, the apparatus 10 of this application embodiment further includes: a first determination module.

[0131] The first judgment module is used to obtain the status of the vehicle and the status of the power battery before controlling the vehicle's power battery to replenish the low-voltage battery; based on the status of the vehicle and the status of the power battery, it determines whether the vehicle meets the preset charging conditions; if the preset charging conditions are met, it controls the vehicle's power battery to replenish the low-voltage battery, otherwise it prohibits the low-voltage battery management system from being woken up again.

[0132] In one embodiment of this application, the first control module 300 is further configured to: acquire the current state of the vehicle and the current state of the power battery; determine whether the vehicle meets the preset charging exit conditions based on the current state of the vehicle and the current state of the power battery; if the preset charging exit conditions are met, control the vehicle's power battery to stop charging the low-voltage battery.

[0133] In one embodiment of this application, the vehicle's state includes the vehicle's own state and the state of the DC-DC converter. The power battery's state includes the remaining power battery charge and the individual cell voltage of the power battery. The preset charging conditions include the following: the vehicle's own state is free from high-voltage power failure and not under maintenance; the DC-DC converter's state is non-faulty; the remaining power battery charge is greater than a fourth preset threshold, and the individual cell voltage of the power battery is greater than a fifth preset threshold. The preset charging exit conditions include at least one of the following: the vehicle's own state is free from high-voltage power failure and not under maintenance; the DC-DC converter's state is non-faulty; the remaining power battery charge is less than a sixth preset threshold or the individual cell voltage of the power battery is less than a seventh preset threshold; the DC-DC converter's startup time is greater than a first preset time; the vehicle's own state is under maintenance.

[0134] In one embodiment of this application, the apparatus 10 of this application embodiment further includes: a second determination module.

[0135] The second judgment module is used to obtain the highest single cell voltage, charging current and charging time of the low-voltage battery after the power battery of the vehicle is used to replenish the low-voltage battery; if at least one of the remaining power, highest single cell voltage, charging current and charging time meets the preset replenishment stop condition, the replenishment of the low-voltage battery is stopped.

[0136] In one embodiment of this application, the preset charging stop conditions include at least one of the following: the remaining charge of the low-voltage battery is equal to a ninth preset threshold; the highest single cell voltage is greater than a tenth preset threshold; the charging current is less than an eleventh preset threshold; and the charging time is greater than a second preset time.

[0137] It should be noted that the explanation of the above-described embodiment of the method for replenishing the low-voltage battery of a vehicle also applies to the replenishing device for the low-voltage battery of the vehicle in this embodiment, and will not be repeated here.

[0138] The vehicle low-voltage battery charging device proposed in the embodiments of this application can acquire relevant data of the low-voltage battery when the vehicle is in a dormant state, determine whether the low-voltage battery meets the preset charging conditions based on the relevant data, and automatically start the power battery to charge the low-voltage battery when the preset charging conditions are met, effectively reducing the risk of low-voltage battery depletion and improving user experience and vehicle reliability.

[0139] Figure 6 A schematic diagram of the structure of a vehicle provided in an embodiment of this application. The vehicle may include: The memory 601, the processor 602, and the computer program stored on the memory 601 and capable of running on the processor 602.

[0140] When the processor 602 executes the program, it implements the method for replenishing the low-voltage battery of the vehicle provided in the above embodiments.

[0141] Furthermore, the vehicle also includes: Communication interface 603 is used for communication between memory 601 and processor 602.

[0142] The memory 601 is used to store computer programs that can run on the processor 602.

[0143] The memory 601 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0144] If the memory 601, processor 602, and communication interface 603 are implemented independently, then the communication interface 603, memory 601, and processor 602 can be interconnected via a bus to complete communication between them. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. The bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 6 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0145] Optionally, in a specific implementation, if the memory 601, processor 602, and communication interface 603 are integrated on a single chip, then the memory 601, processor 602, and communication interface 603 can communicate with each other through an internal interface.

[0146] The processor 602 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of this application.

[0147] This application also provides a computer-readable storage medium storing a computer program or instructions thereon, which, when executed by a processor, implements the above-described method for replenishing a vehicle's low-voltage battery.

[0148] This application also provides a computer program product, including a computer program or instructions, which, when executed, implement the above-described method for replenishing a vehicle's low-voltage battery.

[0149] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0150] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0151] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or N executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0152] It should be understood that the various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or more of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (FPGAs), field-programmable gate arrays (FPGAs), etc.

[0153] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

Claims

1. A method for replenishing a vehicle's low-voltage battery, characterized in that, Includes the following steps: In the vehicle's sleep state, the low-voltage battery management system is used to obtain relevant data of the low-voltage battery, wherein the relevant data includes at least one of total voltage, total current, total temperature, and cell voltage. The remaining power of the low-voltage battery is estimated based on the relevant data, and the low-voltage battery is judged to meet the preset charging conditions based on at least one of the relevant data and the remaining power. If the preset charging conditions are met, the vehicle is woken up, and the vehicle's power battery is controlled to charge the low-voltage battery. If the preset charging conditions are not met, the low-voltage management system is controlled to enter a sleep state and then woke up again after a preset interval.

2. The method for replenishing a vehicle's low-voltage battery according to claim 1, characterized in that, The preset power replenishment conditions include at least one of the following: The remaining battery power is less than a first preset threshold; The voltage of the individual cell is less than the second preset threshold. The total voltage is less than a third preset threshold.

3. The method for replenishing a vehicle's low-voltage battery according to claim 1, characterized in that, The control of the vehicle's power battery to replenish the low-voltage battery includes: The vehicle is controlled to activate the DC-DC converter, which converts the high-voltage DC power from the power battery into low-voltage DC power, and then replenishes the low-voltage battery with the low-voltage DC power.

4. The method for replenishing a vehicle's low-voltage battery according to claim 1, characterized in that, Before controlling the vehicle's power battery to replenish the low-voltage battery, the method further includes: Obtain the status of the vehicle and the status of the power battery; Based on the state of the vehicle and the state of the power battery, determine whether the vehicle meets the preset charging conditions; If the preset charging conditions are met, the vehicle's power battery is controlled to charge the low-voltage battery; otherwise, the low-voltage battery management system is prohibited from being woken up again.

5. The method for replenishing a vehicle's low-voltage battery according to claim 4, characterized in that, The method of controlling the vehicle's power battery to replenish the low-voltage battery also includes: Obtain the current vehicle status and the current power battery status; Based on the current state of the vehicle and the current state of the power battery, determine whether the vehicle meets the preset charging exit conditions; If the preset charging exit condition is met, the vehicle's power battery is controlled to stop charging the low-voltage battery.

6. The method for replenishing a vehicle's low-voltage battery according to claim 5, characterized in that, The vehicle's status includes the vehicle's own status and the status of the DC-DC converter; the power battery's status includes the remaining charge of the power battery and the voltage of each individual cell in the power battery; and the preset charging conditions include the following: The vehicle itself is in a state of no high-voltage power failure and is not under maintenance. The DC-DC converter is in a non-fault state; The remaining power of the power battery is greater than the fourth preset threshold, and the voltage of a single cell of the power battery is greater than the fifth preset threshold. The preset charging exit condition includes at least one of the following: The vehicle itself is in a state of no high-voltage power failure and is not under maintenance. The DC-DC converter is in a non-fault state; The remaining charge of the power battery is less than the sixth preset threshold or the voltage of a single cell of the power battery is less than the seventh preset threshold. The startup time of the DC-DC converter is longer than a first preset time. The vehicle is currently under maintenance.

7. The method for replenishing a vehicle's low-voltage battery according to claim 1, characterized in that, After controlling the vehicle's power battery to replenish the low-voltage battery, the method further includes: Obtain the highest single-cell voltage, charging current, and charging time of the low-voltage battery; If at least one of the remaining power, the highest single-cell voltage, the charging current, and the charging duration meets the preset charging stop condition, then charging the low-voltage battery will stop.

8. The method for replenishing a vehicle low-voltage battery according to claim 7, characterized in that, The preset power-off condition includes at least one of the following: The remaining power of the low-voltage battery is equal to the ninth preset threshold. The highest single-cell voltage is greater than the tenth preset threshold. The charging current is less than the eleventh preset threshold; The charging time is greater than the second preset time.

9. A charging device for a vehicle's low-voltage battery, characterized in that, include: The acquisition module is used to acquire relevant data of the low-voltage battery using the low-voltage battery management system when the vehicle is in a dormant state. The relevant data includes at least one of total voltage, total current, total temperature, and cell voltage. The judgment module is used to estimate the remaining power of the low-voltage battery based on the relevant data, and to determine whether the low-voltage battery meets the preset charging conditions based on at least one of the relevant data and the remaining power. The first control module is used to wake up the vehicle and control the vehicle's power battery to charge the low-voltage battery if the preset charging conditions are met. The second control module is used to control the low-voltage management system to enter a sleep state if the preset charging conditions are not met, and to wake up the low-voltage battery management system again after a preset period.

10. A vehicle, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executing the program to implement the method for replenishing a vehicle low-voltage battery as described in any one of claims 1-8.

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