Electric quantity determination method, energy storage equipment and storage medium

Abstract

The invention discloses an electric quantity determination method, energy storage equipment and a storage medium, and is applied to the technical field of battery management. The method comprises the steps that the current discharging stage of the battery is determined, the current discharging stage is any one of multiple preset discharging stages, and the preset discharging stages comprise at least one of the pre-discharging stage, the discharging stage and the discharging intermittent stage; based on the current discharge stage, a target electric quantity calculation strategy is determined in multiple preset electric quantity calculation strategies, and the preset electric quantity calculation strategies are in one-to-one correspondence with the preset discharge stages; and based on the target electric quantity calculation strategy, determining the current remaining electric quantity of the battery. According to different current discharge stages of the battery, the corresponding preset electric quantity calculation strategy is adopted to determine the current residual electric quantity of the battery, so that the calculation accuracy of the current residual electric quantity can be improved.

Description

Technical Field

[0001] The present application belongs to the field of battery management technology, and in particular relates to a method for determining power, an energy storage device, and a non-transitory computer-readable storage medium. Background Art

[0002] Batteries are a core energy carrier in modern society and are widely used in diverse scenarios, including portable electronic devices, new energy transportation, and energy storage systems. A battery's remaining charge indicates the amount of energy available for controllable use. Accurate remaining charge prevents overdischarge and even electrode damage, improving battery safety. Dynamically adjusting the battery's discharge strategy based on the accurate remaining charge facilitates battery recycling and improves energy efficiency.

[0003] Therefore, it is very important to accurately calculate the remaining capacity (SOC) of the battery. Summary of the Invention

[0004] This application aims to solve at least one of the technical problems existing in the prior art. To this end, this application proposes a method for determining the remaining power of a battery, an energy storage device, and a non-transitory computer-readable storage medium, which can improve the accuracy of calculating the remaining power of a battery, thereby improving the safety and stability of discharge management and extending the service life of the battery.

[0005] In a first aspect, the present application provides a method for determining power, comprising:

[0006] Determining a current discharge stage of the battery, where the current discharge stage is any one of a plurality of preset discharge stages, wherein the preset discharge stage includes at least one of a pre-discharge stage, a discharge stage, and a discharge intermittent stage;

[0007] Based on the current discharge stage, determining a target power calculation strategy from a plurality of preset power calculation strategies, wherein the preset power calculation strategies correspond to the discharge stages in a one-to-one manner;

[0008] Based on the target power calculation strategy, the current remaining power of the battery is determined.

[0009] In a second aspect, the present application provides an energy storage device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned method for determining power when executing the program.

[0010] In a third aspect, the present application provides a non-transitory computer-readable storage medium having a computer program stored thereon, which implements the above-mentioned method for determining power when executed by a processor.

[0011] The power determination method, energy storage device, and non-transitory computer-readable storage medium provided in the embodiments of the present application determine the current discharge stage of the battery, thereby adopting a corresponding preset power calculation strategy as the target power calculation strategy. By calculating the current remaining power in the current discharge stage according to the target power calculation strategy, the calculation accuracy of the current remaining power in each preset discharge stage can be improved, thereby improving the accuracy of the overall calculation of the current remaining power. In this way, based on the accurate current remaining power calculated, the safety and reliability of discharge management can be improved, and the service life of the battery can be extended.

[0012] Additional aspects and advantages of the embodiments of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the embodiments of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0014] Figure 1 This is an application scenario diagram of the method for determining power provided in an embodiment of the present application;

[0015] Figure 2 This is a schematic diagram of the first flow chart of the method for determining power provided in an embodiment of the present application;

[0016] Figure 3 This is a second flow chart of the method for determining power provided in an embodiment of the present application;

[0017] Figure 4 3 is a schematic diagram of a third flow chart of the method for determining power provided in an embodiment of the present application;

[0018] Figure 5 This is a fourth flow chart of the method for determining power provided in an embodiment of the present application;

[0019] Figure 6 This is a fifth flow chart of the method for determining power provided in an embodiment of the present application;

[0020] Figure 7 This is a sixth flow chart of the method for determining power provided in an embodiment of the present application;

[0021] Figure 8 This is a seventh flow chart of the method for determining power provided in an embodiment of the present application;

[0022] Figure 9 This is a module diagram of a device for determining power provided in an embodiment of the present application;

[0023] Figure 10It is a structural diagram of the energy storage device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0024] The following describes embodiments of the present application in detail. Examples of the embodiments of the present application are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and should not be understood as limiting the present application.

[0025] For ease of understanding, the following first introduces the technical background and application scenarios of this application:

[0026] Batteries provide essential energy for a wide range of devices and systems. From everyday mobile phones and laptops to new energy vehicles and energy storage power stations, battery performance directly determines the stability and sustainability of these devices. Batteries not only drive the portable revolution in electronic devices but also play a key role in the development of renewable energy and the construction of smart grids, contributing to the transition to a green and low-carbon energy structure.

[0027] Calculating the remaining battery charge is a crucial component of battery management. Accurate remaining charge calculation provides real-time information on the remaining battery charge, providing users with a reliable endurance reference and avoiding interruptions due to inaccurate charge estimates. For devices and systems, accurate remaining charge calculation facilitates charge and discharge control, effectively preventing overcharge and overdischarge, extending battery life, and reducing maintenance costs. Furthermore, remaining charge is a crucial factor in assessing battery health and formulating energy allocation strategies. In scenarios such as power control in new energy vehicles and energy scheduling in energy storage systems, remaining charge provides strong support for optimizing energy efficiency and ensuring safe and stable system operation.

[0028] Therefore, it is very important and meaningful to accurately calculate the remaining battery power.

[0029] The method for determining the power level provided in this application determines the current discharge stage of the battery and adopts a corresponding preset power level calculation strategy as the target power level calculation strategy. By calculating the current remaining power level in the current discharge stage according to the target power level calculation strategy, the accuracy of calculating the current remaining power level in each preset discharge stage can be improved, thereby improving the accuracy of calculating the overall current remaining power level. Thus, the accurate current remaining power level calculated can improve the safety and reliability of discharge management.

[0030] See also Figure 1 , Figure 11 is an application scenario diagram of a method for determining power provided in an embodiment of the present application. The application scenario provided in the present application includes an energy storage device 100, which includes a battery 10 and a controller 20. The method for determining power provided in the present application can be executed by the controller 20.

[0031] The battery 10 is a device for storing and releasing electric energy. The battery 10 is connected to an electric load and can discharge electric energy to the electric load so that the electric load can operate normally.

[0032] Optionally, the battery 10 can be a battery pack (such as a lithium-ion battery, a lead-acid battery, etc.), a battery module (such as a nickel-hydrogen battery, a sodium-ion battery, etc.), a single cell (such as a lithium iron phosphate cell, etc.), etc., and the embodiments of the present application are not limited to this.

[0033] The controller 20 is a device with data processing capabilities. The controller 20 is connected to the battery 10 to obtain battery information (such as current, voltage, etc.) of the battery 10. Based on the battery information of the battery 10, the controller 20 can accurately calculate the current remaining power of the battery 10. Optionally, the controller 20 can also be a device with display capabilities. The controller 20 displays the calculated current remaining power to the user in real time to enhance the user experience.

[0034] Optionally, the controller 20 may be a battery management system (BMS), etc., which is not limited in the embodiment of the present application.

[0035] Based on the above technical background and the introduction of related scenarios, the embodiment of the present application provides a method for determining power. The method for determining power is described in detail below:

[0036] See also Figure 2 A method for determining power provided in an embodiment of the present application is implemented by steps 011, 012, and 013, which are described in detail below.

[0037] Step 011: Determine a current discharge stage of the battery, where the current discharge stage is any one of a plurality of preset discharge stages;

[0038] Step 012: Based on the current discharge stage, determine a target power calculation strategy from a plurality of preset power calculation strategies, where the preset power calculation strategies correspond to the preset discharge stages in a one-to-one manner;

[0039] Step 013: Determine the current remaining battery power based on the target power calculation strategy.

[0040] The preset discharge phase refers to a segment of the entire phase in which the battery releases stored energy into electrical energy. The preset discharge phase includes at least one of a pre-discharge phase, a discharge phase, and a discharge intermission phase.

[0041] The current discharge stage refers to the preset discharge stage that the battery is in at the current moment.

[0042] The current remaining capacity refers to the state of charge (SOC) of the battery at the current moment, and is usually expressed as the ratio of the electric energy stored in the battery to the total electric energy capacity (the maximum electric energy that the battery can store).

[0043] The preset power calculation strategy refers to a strategy for calculating the current remaining power using pre-set algorithmic logic rules. The preset power calculation strategies include a first preset power calculation strategy, a second preset power calculation strategy, and a third preset power calculation strategy, and the first preset power calculation strategy, the second preset power calculation strategy, and the third preset power calculation strategy are all different.

[0044] The target power calculation strategy refers to the preset power calculation strategy adopted in the current discharge phase.

[0045] Specifically, by determining the current discharge stage of the battery, a corresponding preset power calculation strategy is adopted as the target power calculation strategy. Calculating the current remaining power in the current discharge stage according to the target power calculation strategy can improve the calculation accuracy of the current remaining power in each preset discharge stage, thereby improving the overall accuracy of the current remaining power calculation.

[0046] In this way, the safety and reliability of battery discharge management can be improved based on the accurate current remaining power calculated.

[0047] In some embodiments, see Figure 3 Optionally, step 011 includes:

[0048] Step 0111: When the current current of the battery is zero and has lasted for a first preset time period, determining that the current discharge stage is a pre-discharge stage;

[0049] Step 0112: when the current current is greater than the first preset current threshold, determining that the current discharge stage is the discharge stage;

[0050] Step 0113: when the current is 0 and the current is greater than the first preset current threshold within a second preset time period before the current moment, determine that the current discharging stage is a discharging intermittent stage.

[0051] The current current refers to the current value of the battery at the current moment.

[0052] The first preset duration and the second preset duration are both time lengths set based on experience. The first preset duration is greater than (or equal to) the second preset duration, for example, the first preset duration is 30 minutes and the second preset duration is 15 minutes.

[0053] The first preset current threshold is a current value set based on experience. For example, the first preset current threshold is 10A.

[0054] Specifically, according to the current current value of the battery, it can be determined which preset discharge stage the current discharge stage is.

[0055] When the current current is greater than the first preset current threshold, it indicates that the discharge current of the battery is relatively large at the current moment, the battery is discharging to the power load, and the battery is in the discharge stage;

[0056] When the current current is 0 and the first preset duration is 0, it indicates that the battery has not been discharged for a long time. Even if the battery supplies power to the load again later, the battery is not in the discharging intermission stage at the current moment, but in the pre-discharging stage.

[0057] Compared with the pre-discharge stage, the discharge intermittent stage is when the current current is 0 and there is a large current (i.e., powering the electrical load) for the second preset time before. This indicates that the battery has been over-discharged in a short period of time and the battery is in the discharge intermittent stage (such as the user has suspended using the battery for power supply).

[0058] Optionally, when the current current is less than a second preset current threshold and has lasted for a first preset time, the current discharge stage is determined to be the pre-discharge stage, wherein the second preset current threshold is a current value set based on experience, for example, the second preset current threshold is 0.5A.

[0059] Optionally, when the current current is less than a third preset current threshold and the current was greater than the first preset current threshold within a second preset time period before the current moment, the current discharge phase is determined to be a discharge intermittent phase. The third preset current threshold is a current value set based on experience, for example, the third preset current threshold is 0.5A.

[0060] In this way, the current discharge stage is determined according to the numerical value of the current current of the battery, and then the corresponding preset power calculation strategy is adopted, which can improve the calculation accuracy of the current remaining power in each preset discharge stage, thereby improving the calculation accuracy and robustness of the current remaining power of the battery under different ambient temperatures, different service life stages, and different discharge behaviors.

[0061] In some embodiments, see Figure 3 Optionally, step 012 includes:

[0062] Step 0121: when the current discharging stage is the pre-discharging stage, the target power calculation strategy is the first preset power calculation strategy;

[0063] Step 0122: when the current discharging stage is the discharging stage, the target power calculation strategy is the second preset power calculation strategy;

[0064] Step 0123: When the current discharging stage is the discharging intermission stage, the target power calculation strategy is the third preset power calculation strategy.

[0065] In this way, according to the current discharge stage of the battery, the corresponding preset power calculation strategy is adopted to improve the accuracy of the calculation of the current remaining power, avoid the battery from being deeply over-discharged, and help extend the battery life in low temperature environments.

[0066] In some embodiments, see Figure 3 Optionally, step 013 includes:

[0067] Step 0131: Determine the current remaining capacity of the battery based on the target capacity calculation strategy and the preset mapping relationship between the open circuit voltage of the battery and the remaining capacity.

[0068] The open circuit voltage (OCV) refers to the stable voltage value between the positive and negative electrodes of the battery when the battery is in an open circuit state.

[0069] The preset mapping relationship between open circuit voltage and remaining capacity refers to a table of correspondence between the open circuit voltage and remaining capacity of a battery obtained through experimental calibration (such as static capacity testing or dynamic modeling). The preset mapping relationship includes multiple calibration points, each of which includes a one-to-one correspondence between a calibrated open circuit voltage and a calibrated remaining capacity.

[0070] Different ambient temperature ranges correspond to different preset mapping relationships. For example, when the ambient temperature ranges are [0°C, 10°C], [-10°C, 0°C), and [-20°C, -10°C], they correspond to different preset mapping relationships.

[0071] Specifically, according to the target power calculation strategy, the open circuit voltage of the battery is corrected, and then the preset mapping relationship between the open circuit voltage and the remaining power is used to query the calibrated open circuit voltage corresponding to (or adjacent to) the corrected open circuit voltage. Based on the calibrated remaining power corresponding to these calibrated open circuit voltages, the accurate value of the current remaining power of the battery is obtained.

[0072] In this way, the accuracy of the calculation of the current remaining power can be effectively improved, preventing users from mistakenly believing that there is remaining power but cannot use it, and avoiding the situation where the calculation of the current remaining power deviates significantly from the true value due to the failure of a single model.

[0073] In some embodiments, see Figure 4 Optionally, step 0131 includes:

[0074] Step 01311: When the target power calculation strategy is the first preset power calculation strategy, determine a target remaining power range from a plurality of preset remaining power ranges based on the current open circuit voltage of the battery, where the preset remaining power ranges include at least one of a first preset remaining power range, a second preset remaining power range, and a third preset remaining power range, and the first preset remaining power range, the second preset remaining power range, and the third preset remaining power range do not intersect.

[0075] The first, second, and third preset remaining power ranges are all numerical ranges set based on experience. In the corresponding preset mapping relationship within the second preset remaining power range, the open circuit voltage changes more slowly with the remaining power, and the curve is relatively flat, located in a flat region.

[0076] For example, the first preset remaining power range is [0%, 20%], the second preset remaining power range is (20%, 80%), and the third preset remaining power range is [80%, 100%].

[0077] Optionally, the first preset remaining power range is [0%, 30%), the second preset remaining power range is [30%, 70%], and the third preset remaining power range is (70%, 100%).

[0078] The target remaining power range refers to the range of the current remaining power of the battery.

[0079] Specifically, when the battery is in the pre-discharge stage, the preset remaining capacity range within which the current remaining capacity corresponds to the current open circuit voltage can be determined based on the magnitude relationship between the current open circuit voltage and the calibrated open circuit voltages at various calibration points in the preset mapping relationship. Depending on the preset remaining capacity range within which the current remaining capacity of the battery lies, the corresponding influencing factors and the situations requiring correction also vary.

[0080] In this way, the accuracy of calculating the current remaining power in each preset remaining power range can be improved.

[0081] Step 01312: When the target remaining power range is within the first preset remaining power range, determine the current remaining power based on calibration points corresponding to two calibrated open circuit voltages having the smallest absolute value of difference from the current open circuit voltage;

[0082] Specifically, the absolute value of the difference between the current open-circuit voltage and each calibrated open-circuit voltage is taken, and the calibration points corresponding to the two smallest calibrated open-circuit voltages are selected as the first calibration point (V1, SOC1) and the second calibration point (V2, SOC2), where V1 is less than V2. The current remaining power satisfies the relationship expressed by the following formula (1):

[0083]

[0084] Among them, SOC 插值 is the current remaining capacity, SOC1 is the calibrated remaining capacity at the first calibration point, V is the current open circuit voltage, V1 is the calibrated open circuit voltage at the first calibration point, SOC2 is the calibrated remaining capacity at the second calibration point, and V2 is the calibrated open circuit voltage at the second calibration point.

[0085] Optionally, when the current open circuit voltage is detected (the detection frequency can be 0.2 Hz, etc.) and the falling slope is greater than the preset voltage falling slope, it indicates that there is polarization or load interference. 插值 The empirical coefficient k is introduced for correction to obtain a more accurate current remaining power. The value of k is selected based on the battery type and the range is (0.05, 0.2). The corrected current remaining power satisfies the relationship expressed by formula (2):

[0086]

[0087] Among them, SOC 修正 The current remaining power after correction, SOC 插值 is the current remaining power before correction, k is the empirical coefficient, is the rate of change of open circuit voltage with time.

[0088] Step 01313: When the target remaining power range is the second preset remaining power range, the current remaining power is determined based on the calibration point corresponding to the larger of the two calibrated open circuit voltages having the smallest absolute value of the difference from the current open circuit voltage, and two calibration points adjacent to the calibration point corresponding to the larger value;

[0089] Specifically, the absolute value of the difference between the current open-circuit voltage and each calibrated open-circuit voltage is taken, and the calibration points corresponding to the two smallest calibrated open-circuit voltages are selected as the first calibration point (V1, SOC1) and the second calibration point (V2, SOC2), where V1 is smaller than V2, and the calibrated open-circuit voltage of the second calibration point is the larger value. The two calibration points adjacent to the second calibration point are the first calibration point and the third calibration point (V3, SOC3), where V1, V2, and V3 increase in sequence.

[0090] Then, the initial value of the current remaining power is obtained by the dynamic difference method, and the corrected current remaining power is obtained by curvature compensation, which can improve the accuracy of the calculation of the remaining power in this case.

[0091] The current initial value of the remaining power satisfies the relationship expressed by formula (3):

[0092]

[0093] Among them, SOC linear is the initial value of the current remaining power, SOC1 is the remaining power at the first calibration point, V meas is the current open circuit voltage, V1 is the calibrated open circuit voltage at the first calibration point, SOC2 is the calibrated remaining capacity at the second calibration point, and V2 is the calibrated open circuit voltage at the second calibration point.

[0094] The corrected current remaining power satisfies the relationship expressed by formula (4):

[0095] SOC final =SOC linear +k·(SOC linear -SOC1)(SOC linear -SOC2) (4)

[0096]

[0097] Among them, SOC final The current remaining power after correction, SOC linear is the initial value of the current remaining power, k is the curvature coefficient and satisfies the relationship expressed by formula (5), SOC1 is the calibrated remaining power at the first calibration point, SOC2 is the calibrated remaining power at the second calibration point, V n is the second-order derivative within the window and satisfies the relationship expressed by formula (6), V1 is the calibrated open-circuit voltage at the first calibration point, V2 is the calibrated open-circuit voltage at the second calibration point, V3 is the calibrated open-circuit voltage at the third calibration point, and SOC3 is the calibrated remaining capacity at the third calibration point.

[0098] For example, when the battery is a lithium iron phosphate battery with a rated capacity of 2550mAh, a discharge current of 0.2C, and a current open circuit voltage of 3.203V, the first calibration point (20%, 3.200V), the second calibration point (25%, 3.205V), and the third calibration point (30%, 3.208V) are determined by the preset mapping relationship.

[0099] The current initial value of remaining power SOC can be calculated linear =23%, second-order derivative V within the window n is -0.2V, the curvature coefficient k is -20, and the corrected current remaining power SOC final =23%+1.2%=24.2%.

[0100] Step 01314: When the target remaining power range is the third preset remaining power range, determine the current remaining power based on the calibration points corresponding to the two calibrated open circuit voltages with the smallest absolute value of the difference from the current open circuit voltage, and the historical number of cycles and health status of the battery.

[0101] The historical cycle count refers to the cumulative number of complete charge and discharge cycles completed by the battery. The historical cycle count can be collected by the controller and is rounded to an integer. If the historical cycle count is not met, the historical cycle count is determined by rounding off, rounding down, or rounding up. The historical cycle count satisfies the relationship expressed by formula (7):

[0102]

[0103] Where "Cycle" is the battery's historical cycle count, "Total charge capacity" is the battery's total charge capacity (in Ah), and "Rated Capacity" is the rated capacity (in Ah). The total charge capacity can be determined through controller testing. The rated capacity is an inherent property of the battery and can be obtained by querying the battery's labeling.

[0104] The health state refers to the value that characterizes the degree of battery performance degradation and can be expressed as a percentage. The health state satisfies the relationship expressed by formula (8):

[0105]

[0106] Where SOH is the battery's state of health, N is the rated number of cycles, and Cycle is the battery's historical cycle count. The rated cycle count is an inherent property of the battery and can be obtained by querying the battery's label. The rated cycle count may vary for different battery types. For example, a lithium iron phosphate battery with a rated capacity of 2550mAh and a discharge current of 0.2C has a rated cycle count of 10,000 cycles.

[0107] Specifically, within the third preset remaining power range, the current remaining power is dynamically corrected through temperature compensation and health status, thereby improving the accuracy of calculating the current remaining power of the battery within the third preset remaining power range.

[0108] The corrected current remaining power satisfies the relationship expressed by formula (9):

[0109] f(T,SOC,SOC,Cycle)=f T (T)·f SOC (SOC)·f SOH (SOH) (9)

[0110] Among them, F(T,SOC,SOH,Cycle) is the corrected current remaining power, f T (T) is the temperature compensation value, f SOC (SOC) is the current remaining capacity before correction, f SOC (SOC) satisfies the relationship expressed by the above formula (1). The temperature compensation value is obtained based on the preset relationship between the ambient temperature and the remaining power of the battery, and the temperature compensation value corresponds to the ambient temperature one-to-one.

[0111] In some embodiments, the current remaining power before correction f SOC (SOC) For the case where the remaining power in the second preset remaining power range decays faster, when the remaining power is 50%, the remaining power loss rate is the largest.

[0112] In some embodiments, see Figure 5 Optionally, step 0131 includes:

[0113] Step 01315: When the target power calculation strategy is the second preset power calculation strategy, determine a target remaining power range from a plurality of preset remaining power ranges based on the current open circuit voltage of the battery, where the preset remaining power ranges include at least one of a first preset remaining power range, a second preset remaining power range, and a third preset remaining power range.

[0114] Specifically, when the current remaining power of the battery is within different preset remaining power ranges, the factors affecting the calculation accuracy of the current remaining power are different. Therefore, different calculation methods need to be adopted to correct the current remaining power and improve the calculation accuracy of the current remaining power.

[0115] Step 01316: When the target remaining power range is within the first preset remaining power range, determining the remaining power based on calibration points corresponding to two calibrated open circuit voltages having the smallest absolute difference from the first open circuit voltage, wherein the first open circuit voltage is determined based on the real-time voltage, real-time current, and real-time internal resistance of the battery;

[0116] The first open circuit voltage is a corrected current open circuit voltage when the target remaining power range is within the first preset remaining power range;

[0117] Among them, the real-time voltage is the real-time discharge voltage during the discharge process, which can be detected by the controller;

[0118] Among them, the real-time current is the real-time discharge current during the discharge process, which can be detected by the controller;

[0119] Among them, the real-time internal resistance is the real-time internal resistance of the battery during the discharge process, which can be calculated using the pulse current method; the pulse current method includes: during the discharge process, injecting a short pulse current (such as 1% of the rated current value, lasting 100ms) into the battery; sampling the steady-state voltage at a high speed (such as 1kHz) for a period of time before the injection of the pulse current (such as 10ms), continuing to sample the battery voltage during the injection of the pulse current, and obtaining the instantaneous voltage at the end of the injection of the pulse current, so as to calculate the real-time internal resistance.

[0120] The real-time internal resistance satisfies the relationship expressed by formula (10):

[0121]

[0122] Among them, R internal is the real-time internal resistance, V pre is the steady-state voltage before injecting the pulse current, V post is the instantaneous voltage at the end of the injected pulse current, I pulse is the value of the injected pulse current.

[0123] Specifically, in low-temperature (or extremely cold) environments, the real-time internal resistance of the battery increases, and due to the ohmic voltage drop, the current open-circuit voltage of the battery decreases. By estimating the internal resistance and dynamically compensating the current open-circuit voltage to approximate the actual current open-circuit voltage, and then calculating the current remaining capacity using the relationship in formula (1), the accuracy of the current remaining capacity calculation can be improved.

[0124] The current open circuit voltage after compensation satisfies the relationship expressed by formula (11):

[0125] V corrected =V mesured +I load ·(R internal )(11)

[0126] Among them, V corrected is the current open circuit voltage after compensation, V mesured is the discharge voltage obtained, I load is the load current, R internal is the real-time internal resistance.

[0127] Step 01317: When the target remaining power range is the second preset remaining power range, determine the current remaining power based on the discharge current and discharge time of the battery and the calibration points corresponding to the two calibrated open circuit voltages whose absolute differences from the first open circuit voltage are the smallest;

[0128] The discharge current refers to the total real-time discharge current of the battery from the start of discharge to the current moment.

[0129] The discharge time refers to the total set of real-time discharge voltages of the battery from the start of discharge to the current moment.

[0130] Specifically, within the second preset remaining power range, slight changes in the open-circuit voltage of the battery can easily lead to ambiguous estimation of the remaining power, which can easily cause inaccurate remaining power estimation, thereby leading to false triggering of the flat area (such as the actual remaining power is less than the calculated remaining power, and during the discharge stage of the battery, the remaining power suddenly jumps to 0, causing the device to lose power).

[0131] The ampere-hour integration method integrates the discharge current and discharge time to determine the consumed power. The current remaining power is calculated by subtracting the consumed power from the initial remaining power before discharge. The ampere-hour integration method relies on the initial remaining power before discharge. To prevent the subsequent calculation of the current remaining power from deviating excessively from the actual value, a weighted sum of the current remaining power calculated using the ampere-hour integration method and the preset mapping relationship is used to obtain the corrected current remaining power.

[0132] The current remaining power obtained by the preset mapping relationship satisfies the relationship expressed by formula (11).

[0133] In this way, the accuracy of calculating the current remaining power in the second preset remaining power range can be improved.

[0134] Optionally, the weight of the current remaining power obtained by the ampere-hour integration method is 1 / 3, and the weight of the current remaining power obtained by the preset mapping relationship is 2 / 3.

[0135] Step 01318: When the target remaining power range is the third preset remaining power range, determine the current remaining power based on the calibration points corresponding to the two open circuit voltages whose absolute value of the difference with the second open circuit voltage is the smallest, wherein the second open circuit voltage is determined based on the real-time voltage, real-time current, real-time internal resistance and polarization voltage of the battery.

[0136] The second open circuit voltage is a corrected current open circuit voltage when the target remaining power range is within the third preset remaining power range.

[0137] Among them, polarization voltage refers to the part of the voltage that the battery voltage deviates from the true open circuit voltage due to polarization reaction during the discharge process of the battery.

[0138] Specifically, during the battery discharge process, due to the non-equilibrium state of the electrochemical reaction or the hysteresis of material transfer, the discharge voltage of the battery will deviate from the open circuit voltage in the equilibrium state. Therefore, the polarization voltage is calculated in real time by combining the collected discharge voltage and discharge current through an equivalent circuit model, intermittent open circuit voltage measurement, or machine learning algorithm. The open circuit voltage is compensated by the polarization voltage to obtain the accurate current open circuit voltage, and then the current remaining capacity is calculated by the relationship of formula (1). In this way, the accuracy of the calculation of the current remaining capacity in the third preset remaining capacity range during the discharge process can be improved.

[0139] The current open circuit voltage after compensation satisfies the relationship expressed by formula (12):

[0140] V corrected =V mesured +I·R internal +V polarization (12)

[0141] Among them, V corrected is the current open circuit voltage after compensation, V mesured is the discharge voltage obtained, I is the load current, R internal is the real-time internal resistance, V polarization is the polarization voltage.

[0142] In some embodiments, see Figure 6 Optionally, step 0131 includes:

[0143] Step 01319: When the target power calculation strategy is the third preset power calculation strategy, determine the current remaining power of the battery based on the calibration points corresponding to the two calibrated open circuit voltages whose absolute values ​​of the differences with the third open circuit voltage are the smallest, wherein the third open circuit voltage is determined based on the open circuit voltage of the battery after it has been stationary for a third preset period of time.

[0144] The third open circuit voltage refers to the corrected current open circuit voltage when the battery is in a discharging intermittent stage (such as when the user suspends use).

[0145] The third preset duration is a time length set based on experience, for example, the third preset duration is any value between [1, 5] minutes.

[0146] Specifically, during the discharging interval, there is no discharge current in the battery. After standing for a third preset time, the polarization effects (such as ohmic polarization, electrochemical polarization, concentration polarization, etc.) in the battery are substantially attenuated to a negligible degree. The relaxation voltage thus obtained is used as the third open-circuit voltage, which is substantially equal to the actual current open-circuit voltage. Then, by combining the third open-circuit voltage and the preset mapping relationship, the accurate current remaining capacity can be calculated through the relationship of formula (1).

[0147] Optionally, when the absolute value of the difference between the third open-circuit voltage and the open-circuit voltage at the discharge cut-off moment is greater than a preset voltage threshold, correction is performed based on a preset mapping relationship between the open-circuit voltage and the remaining capacity. The preset voltage threshold is a voltage value set based on experience. For example, the preset voltage threshold is 10 mV.

[0148] The corrected current remaining power satisfies the relationship expressed by formula (13):

[0149]

[0150] Among them, SOC new The current remaining power after correction, SOC est is the remaining capacity at the end of discharge, V relax is the third open circuit voltage, V OCV (SOC est ) is the open circuit voltage at the discharge cut-off moment; β is the sensitivity coefficient.

[0151] The sensitivity coefficient refers to the slope of a curve formed by a preset mapping relationship between the open circuit voltage of the battery and the remaining capacity. Optionally, if the slopes of the curves formed by the preset mapping relationships are inconsistent, a representative slope value is selected.

[0152] For example, a lithium iron phosphate battery with a rated capacity of 2550 mAh and a discharge current of 0.2C corresponds to a β of 0.5 mV / %.

[0153] In this way, the accuracy of calculating the current remaining power during the discharging interval can be improved.

[0154] In some embodiments, see Figure 7 The method for determining the power quantity also includes steps 014, 015, 016 and 017, which are described in detail below.

[0155] Step 014: When the ambient temperature is within the first preset temperature range, the initial discharge power of the battery is a first preset percentage of the rated power, and the battery is discharged at the initial discharge power for a fourth preset time period;

[0156] Step 015: When the battery voltage drop slope is less than the first preset change threshold within the fourth preset time period, the battery discharge power is increased by a second preset percentage of the rated power at intervals of a fifth preset time period, and the current maximum discharge power of the battery is a third preset percentage of the rated power;

[0157] The ambient temperature refers to the temperature of the environment in which the battery is located.

[0158] The first preset temperature range is a temperature range set based on experience, for example, it may be (-10° C., 0° C.).

[0159] The rated power refers to the power that the battery can continuously and stably output under standard test conditions (such as an ambient temperature of 25°C and a remaining power of 100%). This can be obtained by consulting the battery's specification sheet.

[0160] The initial discharge power refers to the power output by the battery at the beginning of discharge. For example, if the rated power of the battery is 1800W, the initial discharge power can be 30% of the rated power, that is, 540W.

[0161] The first preset percentage, the second preset percentage, and the third preset percentage are all values ​​set based on experience. For example, the first preset percentage is 30%, the second preset percentage is 10%, and the third preset percentage is 80%.

[0162] The fourth preset time length and the fifth preset time length are both time lengths set based on experience. For example, the fourth preset time length is 30 seconds, and the fifth preset time length is 10 seconds.

[0163] The first preset change threshold is a value set based on experience. For example, the first preset change threshold is 0.1 V / s.

[0164] The current maximum discharge power is the maximum power that the battery can output within the current temperature range, which is set based on experience.

[0165] Specifically, outside the low temperature range (such as not less than 0°C), the discharge capacity of the battery is basically unrestricted and can be

[0166] When the ambient temperature is within the first preset temperature range, the viscosity of the battery's electrolyte increases and the diffusion rate of the conductive ions decreases, resulting in limited discharge capacity of the battery. If discharged directly at high power (such as 80% of the rated power), the voltage may drop severely due to insufficient supply of conductive ions, triggering the battery's protection mechanism and seriously affecting the battery's service life.

[0167] Therefore, a flexible control strategy is adopted to first discharge the battery at the initial discharge power for the fourth preset time to alleviate the ion conduction bottleneck at low temperatures. When the battery voltage changes normally, the discharge power is increased in a step-by-step manner to release the polarization pressure in stages, reduce polarization damage, and improve discharge efficiency. By limiting the current maximum discharge power of the battery within the first preset temperature range, safety risks can be reduced and the battery service life can be extended.

[0168] To ensure that the battery's discharge power increases in stages, the battery's voltage drop slope is detected at regular intervals (e.g., 10 seconds or 5 seconds) during the fourth preset duration of the battery's discharge at the initial discharge power. The voltage drop slope is obtained by taking the negative value of the voltage conversion rate, and the voltage change rate can be calculated using linear regression or a lookup method. The battery's voltage change rate satisfies the relationship expressed in formula (14):

[0169]

[0170] in, Indicates the voltage change rate (unit: V / s), V i is the battery voltage obtained for the i-th time, V i-1 is the battery voltage obtained for the i-1th time, t i is the timestamp of the battery voltage obtained for the i-th time, t i-1 The timestamp of the battery voltage obtained for the i-1th time.

[0171] Step 016: When the ambient temperature is within the second preset temperature range, the initial discharge power of the battery is a fourth preset percentage of the rated power, and the battery is discharged at the initial discharge power for a sixth preset time period;

[0172] Step 017: When the voltage drop slope of the battery within the sixth preset time period is less than the second preset change threshold, the discharge power of the battery is increased by the fifth preset percentage of the rated power at every seventh preset time period, and the current maximum discharge power of the battery is the sixth preset percentage of the rated power.

[0173] The second preset temperature range is a temperature range based on experience. The second preset temperature range does not overlap with the first preset temperature range. For example, it can be less than or equal to -10°C.

[0174] The fourth preset percentage, the fifth preset percentage, and the sixth preset percentage are all values ​​set based on experience. For example, the fourth preset percentage is 30%, the fifth preset percentage is 10%, and the sixth preset percentage is 60%.

[0175] The sixth preset time length and the seventh preset time length are both time lengths set based on experience. For example, the sixth preset time length is 30 seconds, and the seventh preset time length is 10 seconds.

[0176] The second preset change threshold is a value set based on experience. For example, the first preset change threshold is 0.1 V / s.

[0177] Specifically, when the ambient temperature is within the second preset temperature range, the viscosity of the battery's electrolyte increases (for example, the viscosity of a lithium-ion battery's electrolyte at -20°C can increase to 5-10 times that of room temperature), and the diffusion rate of conductive ions is lower, resulting in a more severe limitation on the battery's discharge capacity. If discharged directly at high power (such as 60% of the rated power), a severe voltage drop may occur due to insufficient supply of conductive ions, triggering the battery's protection mechanism and seriously affecting the battery's service life.

[0178] Similarly, a flexible control strategy is used to control the discharge process of the battery when the ambient temperature is within the second preset temperature range. The specific situation is basically similar to the discharge process of the above-mentioned battery when the ambient temperature is within the first preset temperature range. To avoid repetition, it will not be repeated here.

[0179] In this way, limiting the initial discharge power and the current maximum discharge power and increasing the discharge power in a step-by-step manner can reduce polarization damage, improve discharge efficiency, reduce safety risks, and extend the battery life.

[0180] In some embodiments, see Figure 8 The method for determining the power quantity also includes step 018, which is described in detail below.

[0181] Step 018: Determine the battery's discharge cut-off voltage based on the ambient temperature and the initial remaining capacity of the battery.

[0182] The initial remaining capacity refers to the remaining capacity of the battery at the beginning of discharge.

[0183] The discharge cut-off voltage refers to a preset minimum allowable discharge voltage value. If the battery voltage drops to the discharge cut-off voltage, the battery will stop discharging.

[0184] Specifically, different ambient temperatures affect the battery's electrolyte viscosity, ion conductivity, and chemical reaction activity. Therefore, setting the discharge cutoff voltage based on ambient temperature can protect the battery's discharge performance, mitigate electrode material aging, and extend the battery's service life.

[0185] Similarly, the initial remaining capacity of the battery is different (such as greater than 50% or less than 50%), the discharge characteristics of the battery are different, and the over-discharge risk is different. Therefore, different discharge cut-off voltages are set corresponding to higher and lower initial remaining capacity, respectively, which can reduce polarization damage, protect batteries with low initial remaining capacity, optimize energy utilization, and extend battery life.

[0186] For example, when the battery is a lithium iron phosphate cell with a rated capacity of 2550 mAh and a discharge current of 0.2C, the set discharge cut-off voltage satisfies the relationship expressed by formula (14):

[0187]

[0188] Among them, V cutoff is the discharge cut-off voltage, SOC is the initial remaining capacity, and T is the ambient temperature.

[0189] In this way, the battery can be prevented from over-discharging and irreversible damage to the battery (such as lithium dendrites piercing the diaphragm or electrolyte decomposition for lithium batteries), thereby improving the maintainability and reliability of the battery and extending the battery life.

[0190] In some embodiments, by integrating the main path (maintaining the ampere-hour integration method to calculate and output the current remaining power to ensure smooth changes in the displayed remaining power) and the secondary path (compensating for the current open-circuit voltage or the current remaining power to obtain the accurate current remaining power), a smoother remaining power change curve is displayed to the user, avoiding jumps in the remaining power display, avoiding frequent power outages of the power load, and improving the user experience.

[0191] According to the method described in the above embodiment, the present application also provides a device for determining power, which is used to perform the steps in the above power determination method. Figure 9 , Figure 9 : is a module diagram of a power determination device 200 provided in an embodiment of the present application. The power determination device 200 includes:

[0192] A first determining module 201 is configured to determine a current discharge stage of the battery, where the current discharge stage is any one of a plurality of preset discharge stages, wherein the preset discharge stages include at least one of a pre-discharge stage, a discharge stage, and a discharge intermittent stage;

[0193] A second determining module 202 is configured to determine a target power calculation strategy from a plurality of preset power calculation strategies based on the current discharge stage, wherein the preset power calculation strategies correspond to the discharge stages in a one-to-one manner;

[0194] The third determining module 203 is configured to determine the current remaining power of the battery based on the target power calculation strategy.

[0195] It should be noted that the specific details of each module unit in the above-mentioned power determination device have been described in detail in the embodiment of the above-mentioned power determination method, and will not be repeated here.

[0196] In the embodiments of the present application, the term "module" or "unit" refers to a computer program or a part of a computer program that has a predetermined function and works together with other related parts to achieve a predetermined goal, and can be implemented in whole or in part by using software, hardware (such as processing circuits or memories) or a combination thereof. Similarly, a processor (or multiple processors or memories) can be used to implement one or more modules or units. In addition, each module or unit can be part of an overall module or unit that includes the function of the module or unit.

[0197] In some embodiments, the power determination device in the embodiments of the present application can be implemented in hardware, such as an energy storage device, or a component in the energy storage device, such as an integrated circuit or chip; the power determination device can also be implemented in software, such as as an application installed in the energy storage device.

[0198] In some embodiments, see Figure 10 , Figure 10 3 is a schematic diagram of the structure of an energy storage device provided in an embodiment of the present application. Energy storage device 300 includes a processor 301 and a memory 302. Memory 302 stores a computer program 303 executable on processor 301. When executed by processor 301, program 303 implements the various processes of the aforementioned embodiment of the method for determining power, achieving the same technical effects. To avoid repetition, these are not described here.

[0199] An embodiment of the present application also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the various processes of the embodiment of the above-mentioned method for determining the power amount are implemented, and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0200] The processor may be the processor in the energy storage device in the above embodiment. The computer readable storage medium may be a computer read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0201] Computer-readable media may include computer storage media and communication media. Computer storage media include volatile and non-volatile, removable and non-removable media implemented by any method or technology for storing information such as computer-readable instructions, data structures, program modules or other data. Computer storage media include RAM, ROM, Erasable Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM), flash memory or other solid-state memory technology, CD-ROM, Digital Versatile Disc (DVD) or other optical storage, tape cassettes, magnetic tape, disk storage or other magnetic storage devices. Of course, those skilled in the art will appreciate that computer storage media are not limited to the above.

[0202] The present application also provides a computer program product, including a computer program, which, when executed by a processor, implements the aforementioned method for determining power. The processor may be the processor in the energy storage device described in the aforementioned embodiment. When executed by the processor, the computer program implements the various processes of the aforementioned embodiment of the method for determining power, achieving the same technical effects. To avoid repetition, these processes are not described here.

[0203] It is understandable that in the specific implementation of this application, data related to user identity or characteristics is involved. When the above embodiments of this application are applied to specific products or technologies, user permission or consent is required, and the collection, use and processing of relevant data must comply with relevant laws, regulations and standards of relevant countries and regions.

[0204] In the description of this specification, the reference terms "certain embodiments", "in an example", "exemplarily", etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are mutually inconsistent.

[0205] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code comprising one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may be performed out of the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present application belong.

[0206] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and intent of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A method for determining electric quantity, characterized in that: include: Determining a current discharge stage of the battery, where the current discharge stage is any one of a plurality of preset discharge stages, wherein the preset discharge stage includes at least one of a pre-discharge stage, a discharge stage, and a discharge intermittent stage; Based on the current discharge stage, determining a target power calculation strategy from a plurality of preset power calculation strategies, wherein the preset power calculation strategies correspond to the preset discharge stages in a one-to-one manner; Based on the target power calculation strategy, the current remaining power of the battery is determined.

2. The method for determining electric quantity according to claim 1, wherein: The determining of the current discharge stage of the battery includes: When the current current of the battery is zero and has lasted for a first preset time period, determining that the current discharge stage is the pre-discharge stage; When the current current is greater than a first preset current threshold, determining that the current discharging stage is the discharging stage; When the current is zero and a current greater than the first preset current threshold exists within a second preset time period before the current moment, the current discharging stage is determined to be the discharging intermittent stage.

3. The method for determining electric quantity according to claim 1 or 2, characterized in that: The preset power calculation strategy includes a first preset power calculation strategy, a second preset power calculation strategy and a third preset power calculation strategy, wherein the first preset power calculation strategy, the second preset power calculation strategy and the third preset power calculation strategy are all different; The determining of a target power calculation strategy from a plurality of preset power calculation strategies based on the current discharge stage includes: When the current discharging stage is the pre-discharging stage, the target power calculation strategy is the first preset power calculation strategy; In a case where the current discharging stage is the discharging stage, the target power calculation strategy is the second preset power calculation strategy; In a case where the current discharging stage is the discharging intermittent stage, the target power calculation strategy is the third preset power calculation strategy.

4. The method for determining electric quantity according to claim 3, characterized in that: The determining the current remaining power of the battery based on the target power calculation strategy includes: Based on the target power calculation strategy and a preset mapping relationship between the open circuit voltage of the battery and the remaining power, the current remaining power of the battery is determined.

5. The method for determining electric quantity according to claim 4, characterized in that: The preset mapping relationship between the open circuit voltage and the remaining power includes a plurality of calibration points, wherein the calibration points include a calibrated open circuit voltage and a calibrated remaining power; When the target power calculation strategy is the first preset power calculation strategy, determining the current remaining power of the battery based on the target power calculation strategy and a preset mapping relationship between the open circuit voltage and the remaining power of the battery includes: determining, based on the current open-circuit voltage of the battery, a target remaining power range within a plurality of preset remaining power ranges, the preset remaining power ranges comprising at least one of a first preset remaining power range, a second preset remaining power range, and a third preset remaining power range, wherein the first preset remaining power range, the second preset remaining power range, and the third preset remaining power range do not intersect; When the target remaining power range is the first preset remaining power range, determining the current remaining power based on calibration points corresponding to two calibrated open circuit voltages having the smallest absolute value of difference from the current open circuit voltage; When the target remaining power range is the second preset remaining power range, determining the current remaining power based on a calibration point corresponding to a larger value of the two calibrated open-circuit voltages having the smallest absolute value of the difference with the current open-circuit voltage, and two calibration points adjacent to the calibration point corresponding to the larger value; When the target remaining power range is the third preset remaining power range, the current remaining power is determined based on the calibration points corresponding to the two calibrated open circuit voltages whose absolute value of the difference with the current open circuit voltage is the smallest, and the historical number of cycles and health status of the battery.

6. The method for determining electric quantity according to claim 4, characterized in that: The preset mapping relationship between the open circuit voltage and the remaining power includes a plurality of calibration points, wherein the calibration points include a calibrated open circuit voltage and a calibrated remaining power; When the target power calculation strategy is the second preset power calculation strategy, determining the current remaining power of the battery based on the target power calculation strategy and a preset mapping relationship between the open circuit voltage and the remaining power of the battery includes: determining, based on the current open-circuit voltage of the battery, a target remaining power range within a plurality of preset remaining power ranges, the preset remaining power ranges comprising at least one of a first preset remaining power range, a second preset remaining power range, and a third preset remaining power range, wherein the first preset remaining power range, the second preset remaining power range, and the third preset remaining power range do not intersect; When the target remaining power range is the first preset remaining power range, determining the remaining power based on calibration points corresponding to two calibrated open circuit voltages having the smallest absolute value of difference from a first open circuit voltage, wherein the first open circuit voltage is determined based on the real-time voltage, real-time current, and real-time internal resistance of the battery; When the target remaining power range is the second preset remaining power range, determining the current remaining power based on the discharge current and discharge time of the battery, and calibration points corresponding to two calibrated open circuit voltages whose absolute differences from the first open circuit voltage are the smallest; When the target remaining power range is the third preset remaining power range, the current remaining power is determined based on the calibration points corresponding to the two open circuit voltages whose absolute value of the difference with the second open circuit voltage is the smallest, wherein the second open circuit voltage is determined based on the real-time voltage, real-time current, real-time internal resistance and polarization voltage of the battery.

7. The method for determining electric quantity according to claim 4, characterized in that: The preset mapping relationship between the open circuit voltage and the remaining power includes a plurality of calibration points, wherein the calibration points include a calibrated open circuit voltage and a calibrated remaining power; When the target power calculation strategy is the third preset power calculation strategy, determining the current remaining power of the battery based on the target power calculation strategy and a preset mapping relationship between the open circuit voltage and the remaining power of the battery includes: The current remaining power of the battery is determined based on the calibration points corresponding to the two calibrated open-circuit voltages whose absolute value of the difference with the third open-circuit voltage is the smallest, wherein the third open-circuit voltage is determined based on the open-circuit voltage of the battery after it has been stationary for a third preset time.

8. The method for determining electric quantity according to claim 1, wherein: Also includes: When the ambient temperature is within a first preset temperature range, the initial discharge power of the battery is a first preset percentage of the rated power, and the battery is discharged at the initial discharge power for a fourth preset time period; When the voltage drop slope of the battery is less than the first preset change threshold within the fourth preset time period, the discharge power of the battery is increased by a second preset percentage of the rated power at intervals of a fifth preset time period, and the current maximum discharge power of the battery is a third preset percentage of the rated power; When the ambient temperature is within a second preset temperature range, the initial discharge power of the battery is a fourth preset percentage of the rated power, and the battery is discharged at the initial discharge power for a sixth preset time period; When the voltage drop slope of the battery within the sixth preset time period is less than the second preset change threshold, the discharge power of the battery is increased by the fifth preset percentage of the rated power at every seventh preset time period, and the current maximum discharge power of the battery is the sixth preset percentage of the rated power, wherein the second preset temperature range and the first preset temperature range do not overlap.

9. The method for determining electric quantity according to claim 1, characterized in that: Also includes: A discharge cut-off voltage of the battery is determined based on the ambient temperature and the initial remaining capacity of the battery.

10. An energy storage device, characterized in that: The energy storage device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the method for determining the power quantity according to any one of claims 1 to 9 is implemented.

11. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for determining the power quantity according to any one of claims 1 to 9 is implemented.

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