Charging current estimation method and vehicle

Abstract

The application discloses a charging current estimation method and a vehicle, and relates to the technical field of intelligent cockpits, wherein the charging current estimation method comprises the following steps: acquiring an ambient temperature, an initial battery temperature at a charging starting moment, and a state-of-charge difference value between a charging target state-of-charge and a current state-of-charge; in the case that the ambient temperature is greater than a preset temperature threshold, determining a temperature rise compensation value based on the initial battery temperature and the state-of-charge difference value; determining a target battery temperature based on the initial battery temperature and the temperature rise compensation value; and determining a target charging current based on the target battery temperature. The method of the application can effectively consider the battery temperature rise in the charging process, can take the real-time temperature influence into the current estimation, can improve the estimation accuracy of the terminal charging current, and can improve the accuracy of the remaining charging time estimation, and can improve the user experience.

Description

Technical Field

[0001] This application relates to the field of intelligent cockpit technology, and in particular to a charging current estimation method and a vehicle. Background Technology

[0002] During AC charging of electric vehicles, accurate estimation of remaining charging time is necessary to meet users' needs for reasonable trip planning. Since the state of charge is high and charging time is long at the end of the charging process, the accuracy of the final charging current estimation has a significant impact on the overall accuracy of the remaining charging time prediction.

[0003] Related technologies generally employ a fixed algorithm—multiplying the difference in State of Charge (SOC) by a preset charging current—to estimate charging time. This algorithm assumes that the charging current remains constant during charging, changing linearly with the SOC according to a preset curve. However, in actual charging, the magnitude of the AC charging current is closely related to the battery temperature, which is influenced by both the battery's own thermal management system and the ambient temperature. Especially towards the end of the charging process (high SOC range), the battery's internal electrochemical characteristics change significantly due to temperature variations, and the battery management system actively adjusts the actual charging current substantially to ensure safety. Traditional fixed algorithms fail to dynamically sense and correct the coupled effect of temperature on current, leading to a significant deviation between the estimated and actual current, which in turn affects the accuracy of estimating the charging time of the power battery. Summary of the Invention

[0004] This application aims to at least partially address one of the technical problems in related technologies. To this end, the first objective of this application is to propose a charging current estimation method. Firstly, it obtains the ambient temperature, the initial battery temperature, and the difference in state of charge (SOC). When the ambient temperature exceeds a preset threshold, it determines a temperature rise compensation value based on the initial battery temperature and the SOC difference, then calculates the target battery temperature, and dynamically selects the corresponding charging current mapping curve to predict the charging current. This effectively overcomes the interference of temperature changes on charging current estimation, significantly improves the accuracy and real-time performance of charging time prediction, thus providing users with a more reliable charging progress reference, while avoiding the risk of low charging efficiency or battery overheating due to estimation errors.

[0005] The second objective of this application is to propose a vehicle.

[0006] To achieve the above objectives, a first aspect of this application proposes a charging current estimation method, the method comprising: acquiring an ambient temperature, an initial battery temperature at the start of charging, and a state of charge difference between a target state of charge and the current state of charge; determining a temperature rise compensation value based on the initial battery temperature and the state of charge difference when the ambient temperature is greater than a preset temperature threshold; determining a target battery temperature based on the initial battery temperature and the temperature rise compensation value; and determining a target charging current based on the target battery temperature.

[0007] According to the charging current estimation method of this application embodiment, the ambient temperature, the initial battery temperature at the start of charging, and the state of charge difference between the target state of charge and the current state of charge are obtained. If the ambient temperature is greater than a preset temperature threshold, a temperature rise compensation value is determined based on the initial battery temperature and the state of charge difference. The target battery temperature is determined based on the initial battery temperature and the temperature rise compensation value. The target charging current is determined based on the target battery temperature. Therefore, this method can effectively offset the temperature change caused by the battery's own heat generation during charging. It no longer relies on a fixed charging current relationship and can match charging current parameters that are more realistically suited to the actual operating temperature the battery will reach. This improves the accuracy of charging time estimation, allowing users to obtain a more accurate charging progress reference, and avoids battery overheating problems caused by inaccurate current estimation in high-temperature environments, ensuring the safety of the charging process and optimizing charging efficiency.

[0008] According to one embodiment of this application, determining the target charging current based on the target battery temperature includes: determining the temperature range of the target battery, where different temperature ranges correspond to different preset current characteristic mapping sets; and determining the target charging current based on the temperature range and the preset current characteristic mapping sets.

[0009] According to one embodiment of this application, determining the temperature range in which the target battery temperature is located includes: determining the temperature range as a first temperature range when the target battery temperature is greater than or equal to a first preset temperature threshold; determining the temperature range as a second temperature range when the target battery temperature is greater than or equal to a second preset temperature threshold and less than the first preset temperature threshold; and determining the temperature range as a third temperature range when the target battery temperature is less than the second preset temperature threshold.

[0010] According to one embodiment of this application, the preset current characteristic mapping set includes a first charging current mapping curve, a second charging current mapping curve, and a third charging current mapping curve. Determining the target charging current based on the temperature range and the preset current characteristic mapping set includes: determining the target charging current based on the first charging current mapping curve and the current state of charge when the temperature range is the first temperature range; determining the target charging current based on the second charging current mapping curve and the current state of charge when the temperature range is the second temperature range; and determining the target charging current based on the third charging current mapping curve and the current state of charge when the temperature range is the third temperature range.

[0011] According to one embodiment of this application, the first charging current mapping curve, the second charging current mapping curve, and the third charging current mapping curve are all pre-calibrated mapping relationships between charging current and state of charge.

[0012] According to one embodiment of this application, the method further includes: when the ambient temperature is less than or equal to the preset temperature threshold, determining the target charging current based on a fourth charging current mapping curve and the current state of charge, wherein the fourth charging current mapping curve is a pre-calibrated mapping relationship between charging current and state of charge.

[0013] According to one embodiment of this application, before determining the temperature rise compensation value, the method further includes: obtaining the temperature difference between the ambient temperature and the initial battery temperature; and determining the temperature rise compensation value if the temperature difference is greater than a preset temperature difference threshold.

[0014] According to one embodiment of this application, determining the target battery temperature based on the initial battery temperature and the temperature rise compensation value includes: using the sum of the initial battery temperature and the temperature rise compensation value as the target battery temperature.

[0015] According to one embodiment of this application, determining the temperature rise compensation value based on the initial battery temperature and the state of charge difference includes: determining the temperature rise compensation value based on the initial battery temperature, the state of charge difference, and a preset mapping relationship, wherein the preset mapping relationship is used to indicate the correspondence between the initial battery temperature, the state of charge difference, and the temperature rise compensation value.

[0016] To achieve the above objectives, a vehicle is provided in a second aspect of this application, including a memory, a processor, and a program stored in the memory and executable on the processor. When the processor executes the program, it implements the above-described charging current estimation method.

[0017] The vehicle according to the embodiments of this application, by executing the above-described charging current estimation method, can effectively take into account the battery temperature rise during the charging process, incorporate the influence of real-time temperature into the current estimation, improve the estimation accuracy of the final charging current, thereby improving the accuracy of the remaining charging time prediction and enhancing the user experience.

[0018] 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

[0019] Figure 1 This is a flowchart of a charging current estimation method according to an embodiment of this application.

[0020] Figure 2 This is a flowchart illustrating a specific example of a charging current estimation method according to this application.

[0021] Figure 3 This is a block diagram of a vehicle according to an embodiment of this application. Detailed Implementation

[0022] 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.

[0023] To accurately calculate the remaining charging time and improve user experience, related technologies typically employ estimation based on a fixed charging current model. The core of this model lies in pre-setting a fixed mapping relationship between charging current and state of charge (SOC). Based on this mapping relationship, the system calculates the difference between the target SOC and the current SOC, and combines this with the fixed pre-set current value or mapping curve to linearly estimate the time required to complete charging.

[0024] However, this solution performs poorly when applied to AC charging in real-world driving scenarios. The single, fixed current estimation model used to optimize computational efficiency inevitably compromises the accuracy of the estimation results. Specifically, this solution ignores the dynamic impact of the battery's actual operating temperature on the charging current. For example, during AC charging in low-temperature winter or high-temperature summer environments, especially at the end of the charging process (when the State of Charge (SOC) is between 90% and 100%), the battery's internal electrochemical characteristics change significantly due to temperature. To ensure battery safety and extend its lifespan, the Battery Management System (BMS) typically actively and significantly limits or adjusts the charging current. This inherent contradiction leads to a significant deviation between the estimated and actual charging current under complex temperature conditions, resulting in severely distorted estimates of remaining charging time. For instance, the dashboard might display 30 minutes remaining, but the actual charging time could exceed one hour, greatly impacting the user's charging planning and overall experience.

[0025] In-depth analysis revealed that the root cause of the aforementioned problems lies in the fact that traditional charging time estimation models are temperature-independent, and their pre-defined charging current-State of Charge (SOC) mapping is calibrated under constant, ideal temperature conditions. This model fails to consider ambient temperature and the dynamic temperature rise caused by the battery's internal resistance during charging as key variables affecting the current. In other words, the core bottleneck in solving this problem lies in how to incorporate the battery's actual operating temperature (especially the final temperature resulting from the combined effects of ambient temperature and self-heating) into the estimation of the charging current.

[0026] To address the aforementioned issues, this invention proposes a charging current estimation method that introduces a compensation mechanism based on the coupling of ambient temperature and dynamic battery temperature rise to dynamically correct the core parameter upon which the estimated charging current is based—battery temperature. This scheme no longer uses a single, fixed charging current-SOC mapping curve, but instead pre-calibrates multiple sets of charging current-SOC mapping curves corresponding to different temperature ranges. During charging, the system acquires the ambient temperature and the initial battery temperature in real time, and calculates a temperature rise compensation value based on the difference between the initial battery temperature and SOC, thereby predicting the target battery temperature at the end of charging. Finally, based on this target temperature, the most suitable charging reference table is dynamically selected and used for current prediction, thus solving the technical problem of inaccurate estimation of remaining charging time caused by ignoring the dynamic influence of temperature on current in related technologies. This achieves a significant improvement in the accuracy of AC charging time prediction across the entire temperature range and the entire SOC range.

[0027] In one embodiment of this application, the battery charging system is integrated into the vehicle, including a Battery Management System (BMS). The BMS, as the core control unit, contains one or more processors and memory for storing data and programs. The BMS is responsible for real-time monitoring of battery status, such as temperature, voltage, current, and state of charge (SOC). Specifically, the BMS can collect real-time temperature data of the battery through multiple temperature sensors (e.g., thermistors) arranged within the battery pack, and monitor the charging current through current sensors (e.g., Hall effect sensors). The on-board charger (OBC) is connected to an external AC power source, responsible for converting AC power to DC power and charging the battery pack according to the current command issued by the BMS. That is, the temperature and current sensors convert the collected analog signals into digital signals and send them to the BMS; the BMS processor executes the control algorithm stored in the memory, calculates the target charging current command, and sends the command to the OBC; the OBC controls its internal power conversion circuit to output the corresponding charging current according to the command.

[0028] The charging current estimation method and vehicle proposed in this application are described below with reference to the accompanying drawings.

[0029] Figure 1 This is a flowchart of a charging current estimation method according to an embodiment of this application.

[0030] like Figure 1 As shown, the charging current estimation method in this application embodiment may include the following steps: S1, acquire the ambient temperature, the initial battery temperature at the start of charging, and the state of charge difference between the target state of charge and the current state of charge.

[0031] Specifically, when the user plugs in the charging gun and starts charging, the BMS first reads data from the ambient temperature sensor installed outside the vehicle to obtain the current ambient temperature (T_env). Simultaneously, the BMS reads the real-time battery temperature at the start of charging using the temperature sensor inside the battery pack, recording it as the initial battery temperature (T_bat_init). Furthermore, the BMS reads the battery's current SOC value (SOC_cur) and obtains the target SOC value (SOC_tar) from the charger or vehicle controller. Subsequently, the BMS calculates the state-of-charge difference ΔSOC = SOC_tar - SOC_cur. For example, if the current ambient temperature is 15°C, the initial battery temperature is 10°C, the current SOC is 50%, and the target SOC is 100%, then the state-of-charge difference is 50%.

[0032] It should be noted that, in this application, ambient temperature refers to any physical quantity that can characterize the thermodynamic state of the external air in which the battery is located. For example, this may include, but is not limited to: the external air temperature of the vehicle directly measured by a temperature sensor, or the ambient temperature indirectly obtained through meteorological data, or a combination thereof. The initial battery temperature at the start of charging refers to any physical quantity that can reflect the thermodynamic state of the battery at the instant the charging operation begins. For example, this may include, but is not limited to: the average temperature of the individual cells inside the battery pack monitored by the Battery Management System (BMS), or the lowest or highest temperature of the individual cells in the battery module. Specifically, this initial battery temperature is the battery temperature value first reported by the BMS after receiving the charging request command. The state of charge difference refers to the difference between the desired state of charge (target SOC) and the current state of charge (current SOC) of the battery at the start of charging. This difference represents the battery capacity that needs to be replenished during the charging process. For example, if the target SOC is 100% and the current SOC is 30%, then the state of charge difference is 70%. Specifically, this difference can be directly calculated by the BMS through subtraction.

[0033] S2, when the ambient temperature is higher than a preset temperature threshold, determines the temperature rise compensation value based on the difference between the initial battery temperature and the state of charge. The preset temperature threshold can be determined according to the actual situation.

[0034] Specifically, after obtaining the ambient temperature, the relationship between the ambient temperature and a preset temperature threshold can be determined. If the ambient temperature is greater than the preset temperature threshold, a temperature rise compensation value is determined based on the difference between the initial battery temperature and the state of charge. In this application, the preset temperature threshold refers to a boundary value used to determine whether complex dynamic temperature rise compensation calculation is needed. For example, the preset temperature threshold can be specifically -5℃. The temperature rise compensation value refers to any amount that can quantify the temperature rise caused by the self-heating effect of the battery during charging. For example, it may include, but is not limited to: the temperature increase value obtained by looking up a table based on the difference between the initial battery temperature and the state of charge, or the heat accumulation calculated by empirical formulas, or a combination thereof.

[0035] In other words, when the ambient temperature is above -5℃, compensation calculations are considered necessary to address the impact of complex ambient temperatures on battery temperature rise. This means that the higher the ambient temperature, the higher the initial battery temperature tends to be. When the required additional charging capacity is large, i.e., the state-of-charge difference is significant, the battery generates more heat during the entire charging process, and the temperature rise will be more pronounced. Therefore, a corresponding compensation value is needed to correct the subsequently estimated charging current, preventing excessive temperature rise during charging from affecting battery life and safety. Based on the initial battery temperature and the state-of-charge difference, a temperature rise compensation value adapted to the current charging scenario can be directly obtained through a pre-defined lookup table or a pre-defined calculation formula. This temperature rise compensation value reflects the correction range of the expected battery temperature rise under the current charging scenario to the charging current.

[0036] For example, the BMS compares the acquired ambient temperature (T_env) with -5℃. If T_env > -5℃, it enters the dynamic temperature rise prediction logic. Based on the initial battery temperature (T_bat_init) and state of charge difference (ΔSOC) obtained in step S1, the BMS determines the temperature rise compensation value (ΔT_comp) by querying a preset mapping relationship. As a specific implementation, the BMS stores a two-dimensional lookup table in its memory. The input of this table is the initial battery temperature and the state of charge difference, and the output is the temperature rise compensation value. For example, this table can divide ΔSOC from 0 to 100% into 10 intervals, each interval corresponding to a temperature rise compensation value. For example, interval 1 (0-10%) corresponds to a compensation value of 0℃, interval 2 (10-20%) corresponds to a compensation value of 1℃, and so on, with interval 10 (90-100%) corresponding to a compensation value of 9℃ or 10℃. At the same time, the initial battery temperature can also be divided into multiple intervals to further refine the compensation calculation. For example, if the initial battery temperature is 10℃ (in the medium-low temperature range) and ΔSOC is 50% (in the high range), the temperature rise compensation value obtained by looking up the table might be 5℃. This value represents the amount of battery temperature rise estimated by the BMS during this charging process due to heat generated by the battery's internal resistance (especially the heat generated by reduced efficiency during the final low-current charging). Using this method, very specific temperature rise predictions can be given based on different charging start conditions, thereby improving the accuracy of subsequent target temperatures.

[0037] More generally, the temperature rise compensation value can also be calculated in real time using a function model, such as ΔT_comp=f(T_bat_init,ΔSOC,T_env), which is fitted based on the battery's thermal model and a large amount of experimental data.

[0038] Therefore, the temperature rise prediction under different charging scenarios is more in line with the actual heat generation pattern in the charging process. It will not underestimate the battery temperature rise in high temperature and high charging capacity scenarios, nor will it make useless overcompensation in low temperature and low charging capacity scenarios. It takes into account the estimation accuracy and calculation cost, and provides a reliable correction basis for subsequent accurate estimation of charging current. It avoids unreasonable charging current setting due to temperature rise prediction deviation, thereby ensuring the safety and charging efficiency of the charging process.

[0039] S3 determines the target battery temperature based on the initial battery temperature and the temperature rise compensation value.

[0040] Specifically, after obtaining the temperature rise compensation value (ΔT_comp), the target battery temperature can be determined based on the initial battery temperature and the temperature rise compensation value. In this application, the target battery temperature refers to any predicted battery temperature that can be used as a basis for selecting charging parameters. For example, it may include, but is not limited to: the sum of the initial battery temperature and the temperature rise compensation value, or a composite temperature obtained through other temperature correction algorithms, or a combination thereof.

[0041] For example, the BMS adds it to the initial battery temperature (T_bat_init) obtained in step S1. In this embodiment, the target battery temperature (T_target) is defined as the sum of the initial battery temperature and the temperature rise compensation value, i.e., T_target = T_bat_init + ΔT_comp. Continuing the previous example, if the initial battery temperature is 10°C and the temperature rise compensation value is 5°C, then the target battery temperature is 15°C. This calculation process is very straightforward and easy to implement in engineering. That is, the target temperature is neither the ambient temperature nor the real-time battery temperature, but a predicted value that has been corrected by an algorithm to characterize the final operating temperature that the battery may reach during this charging process. For example, even in an environment of 15°C, the battery temperature may rise from 10°C to 15°C due to self-heating during charging.

[0042] The synergistic effect of this step is that it directly reflects the temperature rise effect estimated based on the initial conditions in the previous step into the final temperature parameter used for decision-making, providing a quantitative basis for selecting the correct charging MAP in the next step.

[0043] S4, determine the target charging current based on the target battery temperature.

[0044] Specifically, after determining the target battery temperature, the target charging current can be determined based on the target battery temperature. The target charging current refers to any current value used to calculate the remaining charging time. For example, it may include, but is not limited to: current values ​​read from a preset charging current mapping curve based on the current state of charge, or segmented current values ​​obtained through interpolation algorithms.

[0045] For example, the BMS uses the target battery temperature (T_target) determined in step S3 as a criterion to select the best match from multiple preset charging current-MAPs (charging current mapping tables), and combines this with the current state of charge (SOC_cur) to find the corresponding charging current value. For example, the BMS stores three sets of pre-calibrated charging current mapping curves corresponding to different temperature ranges: low temperature MAP (suitable for low temperature environments), normal temperature MAP (suitable for normal temperature environments), and high temperature MAP (suitable for high temperature environments).

[0046] When the target battery temperature is calculated to be 15°C, the system determines that this temperature falls within the normal temperature range and therefore calls the normal temperature MAP. Then, the system queries the normal temperature MAP for the charging current value (e.g., 15 amps) corresponding to the current state of charge (e.g., 50%). This value is the final target charging current to be output.

[0047] Therefore, by taking into account the impact of self-heating temperature rise during the charging process on the charging current, the selected target charging current is more in line with the actual temperature tolerance of the battery during the charging process. It avoids blindly selecting a large current for charging just because the initial battery temperature is low, thus avoiding the safety risks caused by excessive battery temperature rise in the second half of the charging process. It also retains a higher charging current as much as possible while meeting the temperature requirements, thus balancing charging speed and battery safety.

[0048] According to one embodiment of this application, determining a target charging current based on a target battery temperature includes: determining the target battery temperature and the temperature range in which the target battery temperature is located, with different temperature ranges corresponding to different preset current characteristic mapping sets; and determining the target charging current based on the temperature range and the preset current characteristic mapping sets.

[0049] Specifically, to further optimize the accuracy of the mapping from the target battery temperature to the final charging current in the above embodiments, this application also provides the following preferred solution. In this preferred solution, the BMS first determines the temperature range of the target battery temperature. Different temperature ranges correspond to different preset current characteristic mapping sets. Then, the target charging current is determined based on the temperature range and the preset current characteristic mapping set. The preset current characteristic mapping set refers to any set of data pre-configured for different temperature ranges to describe the correspondence between charging current and state of charge. For example, it may include, but is not limited to, charging current mapping curves corresponding to each range, or current lookup tables corresponding to each range. This limitation aims to discretize continuous temperature values ​​into multiple temperature segments and assign a dedicated charging curve that best reflects the electrochemical characteristics of the battery in that segment to each temperature segment. Its advantage is that it avoids the deviation caused by using a single mapping curve at all temperatures.

[0050] For example, at high temperatures, the battery resistance decreases, but if the normal temperature curve is still used, the output current may be too large, causing the battery to age faster; while at low temperatures, if a special low-temperature curve is not used, the current may be frequently reduced due to low-temperature protection, resulting in low charging efficiency.

[0051] Those skilled in the art will understand that alternative methods to achieve the same purpose include: dividing the temperature range into four intervals (e.g., extremely low temperature, low temperature, normal temperature, and high temperature), each interval corresponding to a MAP, or using a continuous family of functions whose coefficients vary with temperature. For example, a model can be established through polynomial fitting, where the coefficients of the polynomial are functions of temperature T.

[0052] Therefore, compared to a single mapping curve, setting a preset current characteristic mapping set in intervals allows the output target charging current to better match the actual state of the battery at the current temperature. This avoids current matching deviations at extreme temperatures and balances charging speed and battery lifespan: in high-temperature scenarios, it limits the charging current to within the battery's tolerance range, preventing overheating and accelerated aging, and ensuring battery safety; in low-temperature scenarios, it matches the battery's charging acceptance capacity without excessively reducing the charging current, ensuring overall charging efficiency; and in the normal temperature range, it matches the battery's optimal charging characteristics, balancing charging speed and battery degradation. The resulting target charging current has stronger adaptability, maximizing charging efficiency while ensuring battery health, and solving the problem of poor adaptability caused by using a single mapping curve across the entire temperature range.

[0053] According to one embodiment of this application, determining the temperature range of the target battery temperature includes: determining the temperature range as a first temperature range when the target battery temperature is greater than or equal to a first preset temperature threshold; determining the temperature range as a second temperature range when the target battery temperature is greater than or equal to a second preset temperature threshold and less than the first preset temperature threshold; and determining the temperature range as a third temperature range when the target battery temperature is less than the second preset temperature threshold. The first and second preset temperature thresholds can be determined according to actual conditions.

[0054] Specifically, to ensure that the differences in battery characteristics under different temperature zones can be effectively distinguished, this solution defines the zone boundaries by setting a clear first preset temperature threshold and a second preset temperature threshold. For example, the first preset temperature threshold can be set to 24℃, and the second preset temperature threshold can be set to 10℃.

[0055] The BMS determines the temperature range based on the relationship between the target battery temperature and a first preset temperature threshold and a second preset temperature threshold. If the target battery temperature is greater than or equal to the first preset temperature threshold (e.g., 24°C), the BMS defines the temperature range as the first temperature range (high temperature range). If the target battery temperature is greater than or equal to the second preset temperature threshold (e.g., 10°C) but less than the first preset temperature threshold (24°C), the temperature range is defined as the second temperature range (normal temperature range). If the target battery temperature is less than the second preset temperature threshold (10°C), the temperature range is defined as the third temperature range (low temperature range).

[0056] Therefore, by setting two clear boundary values ​​of 24℃ and 10℃, the target temperature is divided into three continuous and mutually exclusive intervals. This allows the current mapping to accurately correspond to three typical scenarios: high temperature, room temperature, and low temperature, avoiding current jumps or mismatches caused by fuzzy interval boundaries. It should be noted that the aforementioned preset temperature thresholds (24℃, 10℃) are exemplary, and their specific values ​​can be adjusted according to the battery's chemical system, cell formulation, and actual test results. For example, the first threshold can be set between 22℃ and 26℃, and the second threshold can be set between 8℃ and 12℃.

[0057] Therefore, by matching the charging current in different zones, the charging acceptance capacity of the battery at different temperatures can be adapted. While ensuring the charging speed, it avoids the battery aging caused by excessively high charging rates in high-temperature environments. It can also improve the lithium plating problem caused by high-current charging in low-temperature environments, effectively extend the battery cycle life, and improve the safety and stability of the charging process in different ambient temperatures.

[0058] According to one embodiment of this application, a preset current characteristic mapping set includes a first charging current mapping curve, a second charging current mapping curve, and a third charging current mapping curve. Determining a target charging current based on a temperature range and the preset current characteristic mapping set includes: determining the target charging current based on the first charging current mapping curve and the current state of charge when the temperature range is a first temperature range; determining the target charging current based on the second charging current mapping curve and the current state of charge when the temperature range is a second temperature range; and determining the target charging current based on the third charging current mapping curve and the current state of charge when the temperature range is a third temperature range. The first, second, and third charging current mapping curves are all pre-calibrated mapping relationships between charging current and state of charge.

[0059] Specifically, after determining the temperature range, it is necessary to further correlate the range with specific current curves. This application provides three preset charging current mapping curves: a first charging current mapping curve, a second charging current mapping curve, and a third charging current mapping curve. Furthermore, the first, second, and third charging current mapping curves are all pre-calibrated mapping relationships between charging current and state of charge. In other words, to ensure the stability and repeatability of the estimation process, these curves are not dynamic models calculated in real time, but rather static data analyzed from a large amount of experimental data (e.g., testing the battery cell at different charge / discharge rates under different ambient temperatures) and stored in the BMS non-volatile memory, thus ensuring the determinism of the current estimation.

[0060] In essence, a charging current mapping curve refers to any dataset that can characterize the correspondence between charging current and state of charge (SOC). Specifically, this mapping curve can be a one-dimensional lookup table stored in the BMS memory, recording multiple discrete SOC points and their corresponding standard or corrected charging current values. For example, in the SOC range of 0%-90%, a current value is calibrated at 10% intervals; in the SOC range of 90%-100%, more refined calibration can be performed at 1% or even 0.5% intervals to capture drastic changes in the final current. By querying this table and combining it with a linear interpolation algorithm (e.g., linear interpolation between two points), the system can obtain the corresponding target charging current based on the real-time SOC. These mapping curves are obtained in advance through extensive experimental data analysis and calibration. For example, the battery is placed in an environmental chamber at multiple temperature points such as -10℃, 10℃, 25℃, and 45℃, and a complete constant current and constant voltage charging test is performed, recording the steady-state charging current corresponding to each SOC point, thus forming a dedicated MAP under that temperature condition.

[0061] When the BMS determines the target temperature range as the first temperature range (high temperature), it determines the target charging current based on the first charging current mapping curve (high temperature MAP) and the current SOC. Similarly, if the BMS determines the target temperature range as the second temperature range (normal temperature), it uses the second charging current mapping curve (normal temperature MAP); if the BMS determines the target temperature range as the third temperature range (low temperature), it uses the third charging current mapping curve (low temperature MAP). For example, if the target battery temperature is 15°C, which is within the normal temperature range, the BMS looks up the normal temperature MAP at the current SOC=60% and obtains a corresponding charging current of 18 amps. If the target battery temperature is 30°C, which is within the high temperature range, it looks up the high temperature MAP at the current SOC=60% and may obtain a reduced current of 12 amps due to high temperature current limiting. Therefore, this design ensures that current estimation across the entire SOC range accurately reflects the combined effects of temperature and SOC.

[0062] Therefore, in different temperature ranges, the appropriate charging current can be matched with the current state of charge of the battery. This ensures that sufficient charging current is maintained under suitable ambient temperature conditions to improve charging efficiency and shorten charging waiting time, while also reasonably limiting the charging current in high and low temperature environments to avoid damage to the battery cells caused by excessive current, effectively extending the battery's lifespan. At the same time, it also improves the safety of the battery charging process and avoids charging failures caused by abnormal temperatures.

[0063] According to one embodiment of this application, the charging current estimation method further includes: when the ambient temperature is less than or equal to a preset temperature threshold, determining the target charging current based on a fourth charging current mapping curve and the current state of charge, wherein the fourth charging current mapping curve is a pre-calibrated mapping relationship between the charging current and the state of charge.

[0064] Specifically, the relationship between the ambient temperature and the preset temperature threshold is judged. When the ambient temperature is less than or equal to the preset temperature threshold, it indicates that the ambient temperature is low and the chemical activity of the battery itself is reduced. If the battery is charged with the charging current under normal room temperature conditions, problems such as lithium plating may occur, damaging the battery cell. Therefore, a fourth charging current mapping curve specifically calibrated for low temperature environments can be used to directly match the corresponding charging current based on the current state of charge of the battery. There is no need to further subdivide the temperature range and perform additional table lookup calculations. This can not only protect the battery cell through reasonable current limiting, but also simplify the calculation process, improve the response efficiency of the BMS, and adapt to the charging control requirements in low temperature environments.

[0065] In scenarios where the ambient temperature is low (less than or equal to a preset temperature threshold), this application provides an alternative optimization scheme. For example, when the ambient temperature is less than or equal to the preset temperature threshold (e.g., -5℃), the BMS determines that the ambient temperature is the dominant factor in battery temperature, and the battery's self-heating has a relatively small impact on the temperature rise. In this case, to simplify the calculation process and reduce the consumption of computing resources, the BMS does not execute the dynamic temperature rise prediction and target temperature calculation steps in S2 and S3. Instead, it directly determines the target charging current based on the fourth charging current mapping curve and the current state of charge. This fourth charging current mapping curve is a pre-calibrated charging current mapping relationship specifically designed for environments with large temperature differences and extremely low temperatures. For example, in a -10℃ environment, even if the initial battery temperature is -8℃, the system directly calls this low-temperature dedicated MAP, which already includes current limiting logic to prevent lithium plating at low temperatures. This approach ensures the accuracy of estimation in low-temperature scenarios and improves the system's response speed by avoiding complex compensation calculations.

[0066] Therefore, by directly matching the charging current through a pre-calibrated dedicated mapping curve, there is no need for complex calculations such as dynamic temperature rise prediction and interval table lookup. Under the premise of meeting the charging safety restrictions in low-temperature environments and avoiding lithium plating damage to the cells, the computational load of the battery management system is effectively reduced, the computational resource occupation is reduced, and the response speed of charging current estimation is improved. It can output the charging current value adapted to the current operating conditions more quickly, thus balancing battery charging safety and system operating efficiency.

[0067] According to one embodiment of this application, before determining the temperature rise compensation value, the charging current estimation method further includes: obtaining the temperature difference between the ambient temperature and the initial battery temperature; and determining the temperature rise compensation value if the temperature difference is greater than a preset temperature difference threshold. The preset temperature difference threshold can be determined according to actual conditions.

[0068] Specifically, to further improve resource utilization efficiency, this application also specifies the conditions for entering the temperature rise compensation calculation process. Before determining the temperature rise compensation value, the BMS first obtains the temperature difference between the ambient temperature and the initial battery temperature. It then judges the relationship between this temperature difference and a preset temperature difference threshold. Only when the temperature difference is greater than the preset threshold, indicating a significant difference between the current ambient temperature and the initial battery temperature, and a large potential for natural temperature rise in the battery, will the temperature rise compensation calculation process begin. If the temperature difference is not greater than the preset threshold, indicating a small difference between the ambient temperature and the initial battery temperature, no additional temperature rise compensation is needed. The appropriate charging current can be directly estimated based on the current operating conditions, eliminating unnecessary compensation calculation steps, further reducing computational resource consumption, and improving system operating efficiency.

[0069] In other words, when the ambient temperature is very close to the initial battery temperature (e.g., the temperature difference is less than 5°C), the temperature rise caused by the battery's self-heating will be the dominant factor in temperature change, and the disturbance to the ambient temperature does not require much compensation. Performing complex table lookup calculations in this situation would be a meaningless waste of resources. By introducing this condition, compensation calculations can be cleverly limited to scenarios where the temperature difference is significant and compensation is crucial, such as when the ambient temperature is much higher or lower than the initial battery temperature.

[0070] It should be noted that, in this application, the preset temperature difference threshold refers to any critical difference used to determine whether the temperature difference between the ambient temperature and the initial battery temperature is significant enough to trigger temperature rise compensation calculation. For example, it may include, but is not limited to, 2℃, 5℃, or 10℃. In this solution, the preset temperature difference threshold is used to exclude invalid compensation calculations when the ambient temperature and the initial battery temperature are close; the temperature rise compensation value determination step will only be performed when the temperature difference is greater than the set value.

[0071] Therefore, on the one hand, it can accurately and reasonably correct the charging current in scenarios with large temperature differences, ensuring charging efficiency and battery safety, and avoiding overcharging or undercharging. On the other hand, it can skip complex calculations in scenarios with small temperature differences and limited compensation to improve the results, reducing the computational load on the BMS, allowing the battery management system to output estimation results faster, improving the response speed of charging control, balancing estimation accuracy and system operating efficiency, and achieving optimization of performance and resource consumption.

[0072] According to one embodiment of this application, determining a target battery temperature based on an initial battery temperature and a temperature rise compensation value includes: using the sum of the initial battery temperature and the temperature rise compensation value as the target battery temperature.

[0073] Specifically, the target battery temperature is determined based on the initial battery temperature and the temperature rise compensation value. The sum of the initial battery temperature and the temperature rise compensation value can be directly used as the target battery temperature. This calculation method is logically simple and direct, requiring no additional weighting coefficients. It reduces computational complexity while ensuring the accuracy of temperature estimation, adapts to the operational needs of most vehicle battery management systems, and facilitates subsequent parameter adjustments and optimizations based on actual application scenarios.

[0074] Alternatively, an adjustment factor can be set for the temperature rise compensation value based on the current aging level and number of usage cycles of the battery. The initial battery temperature is then added to the temperature rise compensation value corrected by the adjustment factor to obtain the final target battery temperature. This method can adapt to batteries in different aging states, making more realistic temperature estimates for batteries with different degrees of degradation, further improving the accuracy of battery charging current estimation at different usage stages, and extending the overall battery life.

[0075] Therefore, by using the target battery temperature, the maximum charging current that the battery can currently withstand can be matched more accurately. This ensures charging speed while avoiding the risk of battery overheating caused by unreasonable charging current settings due to excessive deviation in actual temperature estimation. At the same time, it also avoids unnecessarily prolonging charging time by setting the current too low, thus balancing charging efficiency and battery safety and effectively improving the user experience.

[0076] According to one embodiment of this application, determining a temperature rise compensation value based on the difference between the initial battery temperature and the state of charge includes: determining the temperature rise compensation value based on the initial battery temperature, the difference between the state of charge and a preset mapping relationship, wherein the preset mapping relationship is used to indicate the correspondence between the initial battery temperature and the difference between the state of charge and the temperature rise compensation value.

[0077] Specifically, when determining the temperature rise compensation value based on the difference between the initial battery temperature and the state of charge, the temperature rise compensation value can be determined based on the initial battery temperature, the difference between the state of charge, and a preset mapping relationship. The preset mapping relationship is used to indicate the correspondence between the initial battery temperature and the difference between the state of charge and the temperature rise compensation value.

[0078] This preset mapping relationship can be represented as a two-dimensional table stored in the BMS, where the row index is the initial battery temperature, the column index is the state-of-charge (SOC) difference, and the value in each cell is the corresponding temperature rise compensation value. For example, this table can be calibrated for SOC differences from 0 to 100% (each cell representing 10%) and initial battery temperatures from -20°C to 60°C (each cell representing 10°C). This method of obtaining compensation values ​​through table lookup allows temperature rise compensation to be dynamically obtained based on the actual charging start conditions, thereby accurately predicting the cumulative temperature rise throughout the charging process.

[0079] Alternatively, the preset mapping relationship can be stored through a pre-trained neural network model, and the difference between the initial battery temperature and the state of charge can be directly used as the model input to output the corresponding temperature rise compensation value. In practical applications, an appropriate implementation method can be selected according to the device's storage capacity and calculation accuracy requirements to ensure a balance between the efficiency and accuracy of compensation value acquisition.

[0080] Therefore, by reasonably determining the temperature rise compensation value, the impact of battery heat generation on charging capacity under different initial operating conditions can be fully considered when estimating the charging current. This avoids the problem of the fixed current limiting scheme being too conservative when starting charging at low temperatures and too aggressive when starting charging at high temperatures. This makes the estimated charging current more closely match the actual acceptable charging capacity of the battery, which helps to improve the overall charging speed, avoids excessive battery temperature during charging, ensures charging safety and battery life, and provides an accurate basis for the dynamic adjustment of the subsequent charging current.

[0081] In summary, as a specific example, an electric vehicle user plugs in the AC charging gun on a winter morning, intending to fully charge the battery before setting off. At this time, the instrument panel displays a current remaining SOC of 30%, while the user's target SOC is 100%. The charging control unit obtains the ambient temperature as 2°C through the vehicle temperature sensor and reads the lowest temperature among multiple measuring points within the battery pack at the moment charging begins, using this as the initial battery temperature, which is 5°C.

[0082] At this point, the ambient temperature is determined to be 2°C higher than the preset temperature threshold of -5°C. Therefore, the charging control unit determines that dynamic temperature rise compensation needs to be activated. The unit looks up a value in a pre-calibrated two-dimensional mapping table based on the initial battery temperature of 5°C and the state of charge (SOC) difference of 70% (i.e., the difference between the target SOC of 100% and the current SOC of 30%). This mapping table is built based on extensive real-vehicle charging test data, using the initial battery temperature and SOC difference as inputs and the expected battery temperature rise during charging as the output. The table shows a temperature rise compensation value of 7°C corresponding to the current operating condition. Subsequently, the control unit directly adds this temperature rise compensation value to the initial battery temperature to obtain the target battery temperature of 12°C. This target battery temperature represents a predictive estimate of the battery's own heat generation during charging, more closely approximating the actual battery temperature level when charging is complete.

[0083] Next, the charging control unit compares the target battery temperature with preset temperature thresholds to adaptively select the best-matching charging current mapping curve. The first preset temperature threshold is 24℃, and the second preset temperature threshold is 10℃. The target battery temperature of 12℃ falls within the range of greater than or equal to 10℃ and less than 24℃, and is therefore determined to be a normal temperature operating condition. The system then calls the normal temperature charging current mapping curve (normal temperature MAP). This curve, along with the high temperature MAP and low temperature MAP, is a SOC-current mapping relationship obtained through analysis and calibration of a large amount of measured data, and it is stored in the control unit's memory in the form of a data table.

[0084] During charging, the BMS estimates and updates the current SOC in real time. The control unit looks up the target charging current in the ambient temperature MAP based on the current SOC and sends it to the on-board charger via the CAN bus. The on-board charger then outputs power according to this current. For example, when the SOC rises from 30% to 40%, the charging current value corresponding to 40% SOC in the ambient temperature MAP is selected and used to adjust the charging power. As the SOC continues to increase, the target charging current decreases smoothly according to this curve. Since the expected temperature rise of the battery has been incorporated into the temperature criterion through temperature rise compensation at the beginning of charging, the selected ambient temperature MAP can accurately reflect the battery's charging acceptance capability under this specific thermal state. Even at the end of charging (such as in the SOC range of 90% to 100%), it can still accurately map a smaller current value that matches the actual battery response.

[0085] In another specific application scenario, a user drives a vehicle described in this invention home in the evening of winter (ambient temperature 0°C) and connects to an AC charging station. At this time, the initial temperature of the vehicle battery is -5°C, and the current State of Charge (SOC) is 40%. The user sets the target SOC to 100%. The vehicle's Battery Management System (BMS) first obtains the ambient temperature (0°C) and the initial battery temperature (-5°C). Comparing the ambient temperature with a preset threshold (-5°C), it finds that 0°C > -5°C, thus entering the dynamic temperature rise prediction logic. The BMS then calculates the state of charge difference ΔSOC = 60%, and based on the initial temperature of -5°C and ΔSOC = 60%, it queries a preset mapping table to obtain a temperature rise compensation value of 5°C (this value reflects the expected temperature rise due to battery self-heating under conditions of low initial temperature and the need to charge a large amount of energy). The BMS calculates the target battery temperature as -5°C + 5°C = 0°C. Next, the BMS determines that 0°C falls within the third temperature range (<10°C), therefore calling the third charging current mapping curve (low-temperature MAP). The BMS retrieved the corresponding charging current of 10 amps from the low-temperature MAP based on the current SOC=40%.

[0086] After determining the target charging current, this current value is then used to calculate the remaining time for the entire charging process. For example, the remaining charging capacity is the battery's full charge capacity multiplied by ΔSOC, i.e., full charge capacity multiplied by 60%. Dividing the remaining charging capacity by the current charging current of 10 amps gives an estimate of the approximate remaining charging time. This estimate is displayed directly on the vehicle's central control screen or the user's mobile application, allowing the user to plan their trip. During subsequent charging, the BMS periodically updates the battery's current temperature and SOC, repeating the above estimation steps to dynamically adjust the charging current value and the estimated remaining charging time, ensuring that the estimated results match the actual charging process.

[0087] Therefore, in this scenario, this application allows users to see a very close estimate of the remaining charging time on the dashboard even under harsh winter low-temperature conditions, greatly improving their sense of control and satisfaction with the charging plan.

[0088] The following is combined with Figure 2 The method described in this application is used to describe the method.

[0089] As a specific example, the charging current estimation method of this application may include the following steps: S101, acquire the ambient temperature, the initial battery temperature at the start of charging, and the state of charge difference between the target state of charge and the current state of charge.

[0090] S102, determine whether the ambient temperature is greater than the preset temperature threshold. If yes, proceed to step S103; if no, proceed to step S109.

[0091] S103, obtain the temperature difference between the ambient temperature and the initial battery temperature.

[0092] S104. Determine whether the temperature difference is greater than the preset temperature difference threshold. If yes, proceed to step S105; if no, proceed to step S101.

[0093] S105, determine the temperature rise compensation value based on the initial battery temperature, the difference in state of charge, and a preset mapping relationship, wherein the preset mapping relationship is used to indicate the correspondence between the initial battery temperature and the difference in state of charge and the temperature rise compensation value.

[0094] S106, the sum of the initial battery temperature and the temperature rise compensation value is used as the target battery temperature.

[0095] S107, Determine the target battery temperature. The target battery temperature is located in a temperature range. Different temperature ranges correspond to different preset current characteristic mapping sets.

[0096] S108 determines the target charging current based on the temperature range and a preset current characteristic mapping set.

[0097] S109, determine the target charging current based on the fourth charging current mapping curve and the current state of charge. The fourth charging current mapping curve is a pre-calibrated mapping relationship between the charging current and the state of charge.

[0098] In summary, the charging current estimation method according to the embodiments of this application obtains the ambient temperature, the initial battery temperature at the start of charging, and the state of charge difference between the target state of charge and the current state of charge. When the ambient temperature is greater than a preset temperature threshold, a temperature rise compensation value is determined based on the initial battery temperature and the state of charge difference. The target battery temperature is determined based on the initial battery temperature and the temperature rise compensation value. The target charging current is then determined based on the target battery temperature. Therefore, this method can effectively offset the temperature changes caused by the battery's own heat generation during charging. It no longer relies on a fixed charging current relationship and can match charging current parameters that are more realistically suited to the actual operating temperature the battery will reach. This improves the accuracy of charging time estimation, providing users with a more accurate charging progress reference, and avoids battery overheating problems caused by inaccurate current estimation in high-temperature environments, ensuring the safety of the charging process and optimizing charging efficiency.

[0099] Corresponding to the above embodiments, this application also proposes a vehicle.

[0100] like Figure 3As shown, the vehicle 200 in this embodiment may include: a memory 210, a processor 220, and a program stored in the memory 210 and executable on the processor 220. When the processor 220 executes the program, it implements the above-described charging current estimation method.

[0101] The vehicle according to the embodiments of this application, by executing the above-described charging current estimation method, can effectively take into account the battery temperature rise during the charging process, incorporate the influence of real-time temperature into the current estimation, improve the estimation accuracy of the final charging current, thereby improving the accuracy of the remaining charging time prediction and enhancing the user experience.

[0102] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0103] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple 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 a combination 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 (PGAs), field-programmable gate arrays (FPGAs), etc.

[0104] 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.

[0105] 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, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0106] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0107] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for estimating charging current, characterized in that, The method includes: Acquire ambient temperature, initial battery temperature at the start of charging, and the state of charge difference between the target state of charge and the current state of charge; When the ambient temperature is greater than a preset temperature threshold, a temperature rise compensation value is determined based on the difference between the initial battery temperature and the state of charge. The target battery temperature is determined based on the initial battery temperature and the temperature rise compensation value; The target charging current is determined based on the target battery temperature.

2. The charging current estimation method according to claim 1, characterized in that, Determining the target charging current based on the target battery temperature includes: Determine the temperature range of the target battery temperature; different temperature ranges correspond to different preset current characteristic mapping sets. The target charging current is determined based on the temperature range and the preset current characteristic mapping set.

3. The charging current estimation method according to claim 2, characterized in that, Determining the temperature range within which the target battery temperature falls includes: If the target battery temperature is greater than or equal to a first preset temperature threshold, the temperature range is determined to be the first temperature range; If the target battery temperature is greater than or equal to the second preset temperature threshold and less than the first preset temperature threshold, the temperature range is determined to be the second temperature range. If the target battery temperature is lower than the second preset temperature threshold, the temperature range is determined to be the third temperature range.

4. The charging current estimation method according to claim 3, characterized in that, The preset current characteristic mapping set includes a first charging current mapping curve, a second charging current mapping curve, and a third charging current mapping curve. Determining the target charging current based on the temperature range and the preset current characteristic mapping set includes: When the temperature range is the first temperature range, the target charging current is determined based on the first charging current mapping curve and the current state of charge. When the temperature range is the second temperature range, the target charging current is determined based on the second charging current mapping curve and the current state of charge; When the temperature range is the third temperature range, the target charging current is determined based on the third charging current mapping curve and the current state of charge.

5. The charging current estimation method according to claim 4, characterized in that, The first charging current mapping curve, the second charging current mapping curve, and the third charging current mapping curve are all pre-calibrated mapping relationships between charging current and state of charge.

6. The charging current estimation method according to claim 1, characterized in that, The method further includes: When the ambient temperature is less than or equal to the preset temperature threshold, the target charging current is determined based on the fourth charging current mapping curve and the current state of charge. The fourth charging current mapping curve is a pre-calibrated mapping relationship between the charging current and the state of charge.

7. The charging current estimation method according to claim 1, characterized in that, Before determining the temperature rise compensation value, the method further includes: Obtain the temperature difference between the ambient temperature and the initial battery temperature; If the temperature difference is greater than a preset temperature difference threshold, the temperature rise compensation value is determined.

8. The charging current estimation method according to claim 1, characterized in that, Determining the target battery temperature based on the initial battery temperature and the temperature rise compensation value includes: The sum of the initial battery temperature and the temperature rise compensation value is taken as the target battery temperature.

9. The charging current estimation method according to claim 1, characterized in that, The step of determining the temperature rise compensation value based on the difference between the initial battery temperature and the state of charge includes: The temperature rise compensation value is determined based on the initial battery temperature, the state of charge difference, and a preset mapping relationship, wherein the preset mapping relationship is used to indicate the correspondence between the initial battery temperature, the state of charge difference, and the temperature rise compensation value.

10. A vehicle, characterized in that, include: A memory, a processor, and a program stored in the memory and executable on the processor, wherein when the processor executes the program, it implements the charging current estimation method according to any one of claims 1-9.

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