Charging-state detection method and apparatus for on-board low-voltage storage battery, and vehicle

Abstract

Provided in the present disclosure are a charging-state detection method and apparatus for an on-board low-voltage storage battery, and a vehicle. The method comprises: when a direct-current-to-direct-current converter is charging a low-voltage storage battery, acquiring a first parameter corresponding to the low-voltage storage battery and a second parameter corresponding to the direct-current-to-direct-current converter, wherein the first parameter is used for representing the charging status of the low-voltage storage battery, and the second parameter is used for representing the discharging status of the direct-current-to-direct-current converter; on the basis of the first parameter and the second parameter, determining whether a diagnosis enabling condition is met; and if the diagnosis enabling condition is met, accumulating requested charging currents for the low-voltage storage battery and the actual charging currents for same, and on the basis of an accumulated value of the requested charging currents and an accumulated value of the actual charging currents, determining whether the charging state of the low-voltage storage battery is normal. By means of using the charging-state detection method and apparatus for an on-board low-voltage storage battery, and the vehicle, the problems of delayed detection modes and low detection efficiency during the charging-state detection of a low-voltage storage battery are solved.

Description

A method, device, and vehicle for detecting the charging status of an on-board low-voltage battery.

[0001] Cross-reference to related applications

[0002] This disclosure claims priority to Chinese Patent Application No. 2024119175444, filed on December 24, 2024, entitled "A Method, Apparatus and Vehicle for Detecting the Charging Status of an Onboard Low-Voltage Battery", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of vehicle battery technology, and more specifically, to a method, device, and vehicle for detecting the state of charge of an on-board low-voltage battery. Background Technology

[0004] Currently, the 12V power supply system of new energy vehicles typically uses a combination of a high-voltage power battery, a DC-to-DC converter, and a 12V lithium (lead-acid) battery. With increasing intelligence, each module has its own fault detection logic; however, wiring faults between modules are easily overlooked. For example, when modifying a vehicle, a customer might add wiring between the DC-to-DC converter and the 12V lithium battery but fail to tighten the screws at the DC-to-DC converter's output end. This causes the DC-to-DC converter to only intermittently charge the 12V lithium battery. Since both the DC-to-DC converter and the 12V lithium battery can supply power to the vehicle's low-voltage load, the relevant vehicle fault may not be detected in time, ultimately leading to the 12V lithium battery being depleted.

[0005] Current technology typically involves manually checking the charging status of low-voltage batteries after a failure, leading to delays and low efficiency in detection. Summary of the Invention

[0006] The purpose of this disclosure is to provide a method, device, and vehicle for detecting the charging status of an on-board low-voltage battery, so as to solve the problems of detection lag and low detection efficiency in the process of detecting the charging status of low-voltage batteries.

[0007] In a first aspect, an optional embodiment of this disclosure provides a method for detecting the charging status of an on-board low-voltage battery, including:

[0008] When the DC-DC converter charges the low-voltage battery, the first parameter corresponding to the low-voltage battery and the second parameter corresponding to the DC-DC converter are obtained. The first parameter is used to characterize the charging status of the low-voltage battery, and the second parameter is used to characterize the discharging status of the DC-DC converter.

[0009] Based on the first and second parameters, determine whether the diagnostic enable conditions are met;

[0010] If the diagnostic enable condition is met, the charging request current and actual charging current of the low-voltage battery are accumulated. Based on the accumulated value of the requested charging current and the accumulated value of the actual charging current, it is determined whether the charging status of the low-voltage battery is normal.

[0011] In one optional implementation, the first parameter includes charging mode, remaining power, and actual charging voltage; the second parameter includes converter status, maximum allowable output current, output voltage, and output current; and the diagnostic enable conditions include: the charging mode is constant current charging mode, the remaining power is less than a set power threshold, the converter status is working, the output voltage is greater than the sum of the actual charging voltage and the voltage compensation value, and the maximum allowable output current is greater than the sum of the output current and the current compensation value.

[0012] In one optional implementation, determining whether the charging status of the low-voltage battery is normal based on the requested cumulative charging current value and the actual cumulative charging current value includes: comparing the requested cumulative charging current value with a first set current threshold; if it is greater than the first set current threshold, comparing the actual cumulative charging current value with a second set current threshold; if it is greater than the second set current threshold, determining that the charging status of the low-voltage battery is normal.

[0013] In one optional implementation, after comparing the cumulative value of the requested charging current with a first set current threshold, the method further includes: if the cumulative value of the requested charging current is less than or equal to the first set current threshold and the current cumulative duration is equal to the set duration threshold, then the charging status detection for the low-voltage battery is exited.

[0014] In one optional implementation, after determining whether the actual cumulative charging current value is greater than the second set current threshold, the method further includes: if it is less than or equal to the second set current threshold, then determining that the charging state of the low-voltage battery is abnormal.

[0015] In an optional implementation, the method further includes: comparing the current accumulated duration with a set duration threshold, so as to compare the accumulated value of the requested charging current with a first set current threshold based on the duration comparison result.

[0016] In one alternative implementation, different remaining battery power corresponds to different set duration thresholds, and the set duration thresholds are proportional to the remaining battery power.

[0017] Secondly, this disclosure also provides an on-board low-voltage battery charging status detection device, the device comprising:

[0018] The parameter acquisition module is used to acquire a first parameter corresponding to the low-voltage battery and a second parameter corresponding to the DC-DC converter when the DC-DC converter is charging the low-voltage battery. The first parameter is used to characterize the charging status of the low-voltage battery, and the second parameter is used to characterize the discharging status of the DC-DC converter.

[0019] The condition judgment module is used to determine whether the diagnostic enable condition is met based on the first parameter and the second parameter.

[0020] The charging status detection module is used to accumulate the charging request current and actual charging current of the low-voltage battery if the diagnostic enable conditions are met, and to determine whether the charging status of the low-voltage battery is normal based on the accumulated value of the requested charging current and the accumulated value of the actual charging current.

[0021] Thirdly, embodiments of this disclosure also provide a vehicle, including a vehicle controller, a low-voltage battery, and a DC-DC converter;

[0022] The vehicle controller is used to perform the steps of the above-described method for detecting the charging status of an on-board low-voltage battery.

[0023] The low-voltage battery is used to send the first parameter characterizing the charging status of the low-voltage battery to the vehicle controller.

[0024] A DC-DC converter is used to send a second parameter characterizing the discharge status of the DC-DC converter to the vehicle controller.

[0025] The embodiments disclosed herein bring the following beneficial effects:

[0026] This disclosure provides a method, apparatus, and vehicle for detecting the charging status of an on-board low-voltage battery. It can acquire the charging and discharging parameters of the low-voltage battery and the DC-DC converter in real time while the DC-DC converter is charging the low-voltage battery. Based on these parameters, it determines whether diagnostic enable conditions are met. If the conditions are met, it uses the requested cumulative charging current value and the actual cumulative charging current value to detect the charging status. These values ​​reflect the charging amount, and detecting the charging status based on the charging amount improves the timeliness and accuracy of the detection. It avoids the risk of the vehicle malfunctioning due to a depleted low-voltage battery. Compared with existing on-board low-voltage battery charging status detection methods, this method solves the problems of detection lag and low efficiency in the low-voltage battery charging status detection process.

[0027] To make the above-mentioned objects, features and advantages of this disclosure more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this disclosure and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 shows a flowchart of a method for detecting the charging status of an on-board low-voltage battery provided in an optional embodiment of the present disclosure;

[0030] Figure 2 shows a schematic diagram of a normally charged vehicle lithium battery according to an optional embodiment of the present disclosure;

[0031] Figure 3 shows a schematic diagram of an abnormal charging state of an on-board lithium battery provided in an optional embodiment of this disclosure;

[0032] Figure 4 shows a schematic diagram of the structure of an on-board low-voltage battery charging status detection device provided in an optional embodiment of the present disclosure;

[0033] Figure 5 shows a schematic diagram of the structure of a vehicle provided in an optional embodiment of this disclosure. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. The components of the embodiments of this disclosure described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this disclosure provided in the accompanying drawings is not intended to limit the scope of the claimed disclosure, but merely represents selected embodiments of this disclosure. Based on the embodiments of this disclosure, every other embodiment obtained by those skilled in the art without inventive effort falls within the scope of protection of this disclosure.

[0035] It is worth noting that prior to this disclosure, the 12V power supply system of new energy vehicles typically employs a combination of a high-voltage power battery, a DC-to-DC converter, and a 12V lithium (lead-acid) battery. With increasing intelligence, each module has its own fault detection logic; however, wiring faults between modules are easily overlooked. For example, when modifying a vehicle, a customer might add wiring between the DC-to-DC converter and the 12V lithium battery but fail to tighten the screws at the DC-to-DC converter's output end, causing the converter to only intermittently charge the 12V lithium battery. Since both the DC-to-DC converter and the 12V lithium battery can supply power to the vehicle's low-voltage load, related vehicle faults may not be detected in time, ultimately leading to the 12V lithium battery being depleted. Current technology typically involves manually checking the charging status of the low-voltage battery after a fault occurs, resulting in delayed detection and low efficiency.

[0036] Based on this, the present disclosure provides a method for detecting the charging status of an on-board low-voltage battery, so as to improve the timeliness and efficiency of low-voltage battery charging status detection.

[0037] Please refer to Figure 1, which is a flowchart of a method for detecting the charging status of an on-board low-voltage battery according to an optional embodiment of this disclosure. As shown in Figure 1, the method for detecting the charging status of an on-board low-voltage battery provided in this embodiment of the disclosure includes:

[0038] Step S101: When the DC-DC converter is charging the low-voltage battery, obtain the first parameter corresponding to the low-voltage battery and the second parameter corresponding to the DC-DC converter.

[0039] Step S102: Determine whether the diagnostic enable condition is met based on the first parameter and the second parameter;

[0040] Step S103: If the diagnostic enable condition is met, the charging request current and actual charging current of the low-voltage battery are accumulated. Based on the accumulated value of the requested charging current and the accumulated value of the actual charging current, it is determined whether the charging status of the low-voltage battery is normal.

[0041] The vehicle-mounted low-voltage battery charging status detection method provided in this embodiment can acquire the charging and discharging parameters of the low-voltage battery and the DC-DC converter in real time when the DC-DC converter is charging the low-voltage battery. Based on the charging and discharging parameters, it determines whether the diagnostic enable conditions are met. When the diagnostic enable conditions are met, the charging status is detected using the requested cumulative charging current value and the actual cumulative charging current value. The requested cumulative charging current value and the actual cumulative charging current value can accurately reflect the charging amount. Detecting the charging status based on the charging amount improves the timeliness and accuracy of the detection, avoids the risk of the vehicle not being able to use normally due to the low-voltage battery being depleted, and solves the problems of detection lag and low detection efficiency in the low-voltage battery charging status detection process.

[0042] To facilitate understanding of this embodiment, the following description uses the application of the on-board low-voltage battery charging status detection method to a vehicle controller as an example to illustrate the exemplary steps provided in this disclosure embodiment. The vehicle controller may refer to a VCU (Vehicle Control Unit), and as an example, the VCU may be a Mobility Domain Control Unit (MDCU).

[0043] In step S101, when the DC-DC converter is charging the low-voltage battery, the first parameter corresponding to the low-voltage battery and the second parameter corresponding to the DC-DC converter are obtained.

[0044] In this step, the DC-DC converter can refer to a DC-DC converter, and the low-voltage battery can refer to the 12V lithium battery installed in the vehicle. Both the 12V lithium battery and the DC-DC converter can provide power to the vehicle under low-voltage load.

[0045] The first parameter characterizes the charging status of the low-voltage battery, and the second parameter characterizes the discharging status of the DC-DC converter.

[0046] In this embodiment of the disclosure, both the lithium battery and the DC-DC converter are connected to the VCU, which is capable of acquiring the operating status and related parameters of the lithium battery and the DC-DC converter. Here, the parameters of the lithium battery acquired by the VCU are referred to as the first parameters, and the parameters of the DC-DC converter acquired by the VCU are referred to as the second parameters.

[0047] The first parameter includes the charging mode, requested charging current, requested charging voltage, remaining power, actual charging voltage, and actual charging current.

[0048] Charging modes include constant current charging mode and constant voltage charging mode; requested charging current refers to the expected current when the lithium battery sends a charging request to the DC-DC converter; requested charging voltage refers to the voltage corresponding to the requested charging current; remaining capacity refers to SOC (State of Charge); actual charging current refers to the actual external current, which is the current sensed by the external sensor of the lithium battery; actual charging voltage refers to the actual external voltage, which is the voltage corresponding to the actual charging current.

[0049] The second parameter includes converter status, maximum allowable output current, output voltage, and output current.

[0050] The converter status includes operating status, holding status, initialization status, and fault status; the output voltage refers to the actual output voltage of the DC-DC converter; the output current refers to the actual output voltage of the DC-DC converter; the maximum allowable output current is calculated based on the input current of the DC-DC converter.

[0051] In this embodiment of the disclosure, the IBS (lithium battery controller) sends the parameter value of the first parameter to the VCU, and the DC-DC converter sends the parameter value of the second parameter to the VCU, so that the VCU can determine whether the diagnostic enable condition is met based on the parameter values ​​of the first parameter and the second parameter.

[0052] In step S102, it is determined whether the diagnostic enable condition is met based on the first parameter and the second parameter.

[0053] In this step, the diagnostic enable condition can refer to the trigger condition used to start charging status detection.

[0054] In one example, diagnostic enable conditions include: the charging mode is constant current charging mode, the remaining battery level is less than a set battery level threshold, the DC-DC converter is active, the output voltage is greater than the sum of the actual charging voltage and the voltage compensation value, and the maximum allowable output current is greater than the sum of the output current and the current compensation value. For example: a 12V lithium battery requests a constant current charging mode, the 12V lithium battery's SOC is less than 90%, the DC-DC converter is active, the DC-DC converter's output voltage is greater than the sum of the 12V lithium battery's actual charging voltage and the voltage compensation value, and the DC-DC converter's maximum allowable output current is greater than the sum of the DC-DC converter's output current and the current compensation value.

[0055] When the 12V lithium battery requests charging and all five conditions mentioned above are met simultaneously, the diagnostic enable condition is determined to be met.

[0056] In step S103, if the diagnostic enable condition is met, the charging request current and actual charging current of the low-voltage battery are accumulated. Based on the accumulated value of the requested charging current and the accumulated value of the actual charging current, it is determined whether the charging status of the low-voltage battery is normal.

[0057] In this step, if the diagnostic enable conditions are met, the charging request current and actual charging current of the lithium battery are accumulated, and the accumulation time is recorded.

[0058] In one example, to determine whether the lithium battery's charging status is normal, the cumulative value of the requested charging current and the cumulative value of the actual charging current from the start of the accumulation to the current time can be continuously calculated. The cumulative value of the requested charging current is called the requested charging current cumulative value, and the cumulative value of the actual charging current is called the actual charging current cumulative value. The duration from the start of the accumulation to the current time is called the current accumulation duration. Simultaneously, a new accumulation process restarts every 3000 seconds, continuously cycling to uninterruptedly detect the lithium battery's charging status.

[0059] During a certain round of accumulation, the current accumulated time is first compared with the set time threshold. If the current accumulated time is less than or equal to the set time threshold, the accumulated value of the requested charging current is further compared with the first set current threshold. If the current accumulated time is greater than the set time threshold, it means that the accumulated time range of this round has been exceeded, and the next round of detection needs to be started. At this time, the accumulated value of the requested charging current, the accumulated value of the actual charging current, and the current accumulated time are cleared, and the accumulation starts again.

[0060] Taking a specific round of lithium battery state detection as an example, if the current cumulative duration is less than or equal to a set duration threshold, the cumulative value of the requested charging current is compared with a first set current threshold every 100ms within 3000s to determine whether the cumulative value of the requested charging current is greater than the first set current threshold. Here, 3000s is the set duration threshold, and 100ms is the comparison period.

[0061] If the cumulative value of the requested charging current is greater than the first set current threshold, it means that the cumulative value of the requested charging current meets the requested charging amount requirement. It is necessary to further compare the actual cumulative value of the charging current with the second set current threshold to determine whether the charging status of the lithium battery is normal based on the comparison result.

[0062] If the cumulative value of the requested charging current is less than or equal to the first set current threshold, it indicates that the cumulative value of the requested charging current does not meet the requested charging amount requirement. In this case, it is necessary to determine how to proceed based on the specific comparison result between the current cumulative duration and the set duration threshold. One scenario is that if the current cumulative duration is less than the set duration threshold and the cumulative value of the requested charging current is less than or equal to the first set current threshold, then the current cumulative duration, actual charging current, and requested charging current continue to be accumulated. Another scenario is that if the current cumulative duration is equal to the set duration threshold and the cumulative value of the requested charging current is less than or equal to the first set current threshold, it indicates that the cumulative value of the requested charging current is too small and does not meet the diagnostic reliability requirements; therefore, the charging status detection for the lithium battery is terminated.

[0063] When comparing the actual cumulative charging current with the second set current threshold, if the actual cumulative charging current is greater than the second set current threshold, it indicates that the actual charging amount of the lithium battery meets the requirements, and the charging state of the lithium battery is determined to be normal. The following refers to Figure 2 to illustrate the data curves corresponding to the actual cumulative charging current and the requested cumulative charging current when the lithium battery is in a normal charging state.

[0064] Figure 2 illustrates a schematic diagram of a normal charging state of an on-board lithium battery according to an optional embodiment of this disclosure. As shown in Figure 2, this figure represents normal charging data for a 12V battery. With the continuous increase of the current accumulated charging time, the State of Charge (SOC) continuously increases, indicating that the lithium battery is in a normal charging state. At this time, the requested charging current remains essentially constant, while the accumulated requested charging capacity increases linearly. The accumulated requested charging capacity is the accumulated value of the requested charging current. The actual charging current continuously changes around the requested charging current, and the accumulated actual charging capacity also increases linearly. The accumulated actual charging capacity is the actual charging current.

[0065] Conversely, if the current is less than or equal to the second set current threshold, it indicates that the actual charging amount of the lithium battery does not meet the requirements, and the charging state of the lithium battery is determined to be abnormal. The following refers to Figure 3 to illustrate the data curves corresponding to the actual cumulative charging current and the requested cumulative charging current when the lithium battery charging state is abnormal.

[0066] Figure 3 illustrates an abnormal charging state of an on-board lithium battery according to an optional embodiment of this disclosure. As shown in Figure 3, this figure represents abnormal charging data for a 12V battery. With the continuous increase of the current accumulated charging time, the State of Charge (SOC) remains unchanged, indicating that the lithium battery is in an abnormal charging state. At this time, the requested charging current and the actual charging current remain essentially constant, and the accumulated requested charging capacity increases linearly; the accumulated requested charging capacity is the accumulated value of the requested charging current. However, the accumulated actual charging capacity does not increase linearly; the accumulated actual charging capacity is the actual charging current.

[0067] In one example, the current requested by the lithium battery controller from the DC-DC converter varies depending on the state of charge (SOC). A higher charging current is requested at low SOC, and a lower charging current is requested at high SOC. Therefore, different remaining charge levels correspond to different setpoint duration thresholds, and these thresholds are directly proportional to the remaining charge level: the higher the remaining charge, the higher the setpoint duration threshold; the lower the remaining charge, the lower the setpoint duration threshold. This allows the 12V lithium battery to detect faults more quickly at low SOC and has a longer detection time at high SOC, improving diagnostic reliability.

[0068] Based on the same inventive concept, this disclosure also provides an on-board low-voltage battery charging status detection device corresponding to the on-board low-voltage battery charging status detection method. Since the principle of the device in this disclosure for solving the problem is similar to the on-board low-voltage battery charging status detection method described above in this disclosure, the implementation of the device can refer to the implementation of the method, and the repeated parts will not be described again.

[0069] Please refer to Figure 4, which is a structural schematic diagram of an on-board low-voltage battery charging status detection device provided in an optional embodiment of this disclosure. As shown in Figure 4, the on-board low-voltage battery charging status detection device 200 includes:

[0070] The parameter acquisition module 201 is used to acquire a first parameter corresponding to the low-voltage battery and a second parameter corresponding to the DC-DC converter when the DC-DC converter is charging the low-voltage battery. The first parameter is used to characterize the charging status of the low-voltage battery and the second parameter is used to characterize the discharging status of the DC-DC converter.

[0071] The condition judgment module 202 is used to determine whether the diagnostic enable condition is met based on the first parameter and the second parameter.

[0072] The charging status detection module 203 is used to accumulate the charging request current and actual charging current of the low-voltage battery if the diagnostic enable conditions are met, and to determine whether the charging status of the low-voltage battery is normal based on the accumulated value of the requested charging current and the accumulated value of the actual charging current.

[0073] Please refer to Figure 5, which is a schematic diagram of the structure of a vehicle provided in an optional embodiment of this disclosure. As shown in Figure 5, the vehicle 300 includes a vehicle controller 310, a low-voltage battery 320, and a DC-DC converter 330.

[0074] The vehicle controller 310 is used to execute the steps of the on-board low-voltage battery charging state detection method in the method embodiment shown in Figure 1 above.

[0075] The low-voltage battery 320 is used to send a first parameter characterizing the charging status of the low-voltage battery to the vehicle controller.

[0076] The DC-DC converter 330 is used to send a second parameter characterizing the discharge status of the DC-DC converter to the vehicle controller.

[0077] This disclosure also provides a computer-readable storage medium storing a computer program. When the computer program is run by a processor, it can execute the steps of the vehicle low-voltage battery charging status detection method in the method embodiment shown in FIG1 above. For specific implementation, please refer to the method embodiment, which will not be repeated here.

[0078] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0079] In the several embodiments provided in this disclosure, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the shown or discussed mutual couplings, direct couplings, or communication connections may be through some communication interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0080] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0081] In addition, the functional units in the various embodiments of this disclosure can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0082] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a processor-executable, non-volatile, computer-readable storage medium. Based on this understanding, the technical solution of this disclosure, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this disclosure. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0083] Finally, it should be noted that the above-described embodiments are merely specific implementations of this disclosure, used to illustrate the technical solutions of this disclosure, and not to limit it. The protection scope of this disclosure is not limited thereto. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the scope of the technology disclosed in this disclosure; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this disclosure, and should all be covered within the protection scope of this disclosure. Therefore, the protection scope of this disclosure should be determined by the protection scope of the claims.

Claims

1. A method for detecting the charging status of an on-board low-voltage battery, comprising: When the DC-DC converter charges the low-voltage battery, a first parameter corresponding to the low-voltage battery and a second parameter corresponding to the DC-DC converter are obtained. The first parameter is used to characterize the charging status of the low-voltage battery, and the second parameter is used to characterize the discharging status of the DC-DC converter. Based on the first parameter and the second parameter, determine whether the diagnostic enable condition is met; If the diagnostic enable condition is met, the charging request current and actual charging current of the low-voltage battery are accumulated. Based on the accumulated value of the requested charging current and the accumulated value of the actual charging current, it is determined whether the charging status of the low-voltage battery is normal.

2. The method according to claim 1, wherein the first parameter includes charging mode, remaining power, and actual charging voltage; the second parameter includes converter status, maximum allowable output current, output voltage, and output current; and the diagnostic enable condition includes: The charging mode is constant current charging mode, the remaining power is less than a set power threshold, the converter is in working state, the output voltage is greater than the sum of the actual charging voltage and the voltage compensation value, and the maximum allowable output current is greater than the sum of the output current and the current compensation value.

3. The method according to claim 1, wherein determining whether the charging state of the low-voltage battery is normal based on the requested cumulative charging current value and the actual cumulative charging current value includes: Compare the cumulative value of the requested charging current with a first set current threshold. If the current exceeds the first set current threshold, the cumulative value of the actual charging current is compared with the second set current threshold. If the current exceeds the second set current threshold, then the low-voltage battery is determined to be in a normal charging state.

4. The method according to claim 3, further comprising, after comparing the cumulative value of the requested charging current with the first set current threshold: If the cumulative value of the requested charging current is less than or equal to the first set current threshold and the current cumulative duration is less than the set duration threshold, then the current cumulative duration, the actual charging current, and the requested charging current continue to be accumulated.

5. The method according to claim 3, further comprising, after comparing the cumulative value of the requested charging current with the first set current threshold: If the cumulative value of the requested charging current is less than or equal to the first set current threshold and the current cumulative duration is equal to the set duration threshold, then the charging status detection for the low-voltage battery is exited.

6. The method according to claim 3, further comprising, after determining whether the cumulative value of the actual charging current is greater than the second set current threshold: If the current is less than or equal to the second set current threshold, then the charging state of the low-voltage battery is determined to be abnormal.

7. The method according to claim 3, further comprising: The current cumulative duration is compared with a set duration threshold, and the cumulative value of the requested charging current is compared with the first set current threshold based on the duration comparison result.

8. The method according to claim 4 or 5, wherein different remaining battery power corresponds to different set duration thresholds, and the set duration thresholds are proportional to the remaining battery power.

9. A vehicle-mounted low-voltage battery charging status detection device, comprising: Parameter acquisition module, used for DC - When the DC-DC converter charges the low-voltage battery, it acquires a first parameter corresponding to the low-voltage battery and a second parameter corresponding to the DC-DC converter. The first parameter is used to characterize the charging status of the low-voltage battery, and the second parameter is used to characterize the discharging status of the DC-DC converter. The condition judgment module is used to determine whether the diagnostic enable condition is met based on the first parameter and the second parameter. The charging status detection module is used to accumulate the charging request current and actual charging current of the low-voltage battery if the diagnostic enable conditions are met, and to determine whether the charging status of the low-voltage battery is normal based on the accumulated value of the requested charging current and the accumulated value of the actual charging current.

10. A vehicle, comprising a vehicle controller, a low-voltage battery, and a DC-DC converter; The vehicle controller is used to perform the steps of the on-board low-voltage battery charging status detection method as described in any one of claims 1 to 8; The low-voltage battery is used to send a first parameter characterizing the charging status of the low-voltage battery to the vehicle controller. The DC-DC converter is used to send a second parameter characterizing the discharge status of the DC-DC converter to the vehicle controller.

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