Battery charge estimation method

Abstract

An embodiment of the present invention discloses a method for estimating the battery charge level, which first calculates the state of charge of the battery during the charging process using the Coulomb integration method until the battery enters the floating charge mode, and establishes a charging voltage table and a charging current table based on the state of charge and its corresponding charging voltage and charging current. After the battery is left at rest, the first current resting open-circuit voltage of the battery is measured. According to the current state of charge of the battery, the corresponding lookup charging voltage is found from the charging voltage table, and according to the current state of charge, the corresponding lookup charging current is found from the charging current table, and the voltage difference between the lookup charging voltage and the first current resting open-circuit voltage and the lookup charging current are recorded. Finally, the first resting state of charge of the battery is determined based on the current state of charge, the first current resting open-circuit voltage, the voltage difference, and the lookup charging current.

Description

Technical Field

[0001] The present invention relates to the field of estimation technology, and in particular to a method for estimating battery power. Background Art

[0002] Batteries (both non-rechargeable and rechargeable) have a wide range of applications. For example, they are used in electronic devices such as mobile phones, laptops, and portable medical devices. They are also used in automobiles, such as gasoline and diesel vehicles, and hybrid vehicles, such as hybrid electric vehicles and electric vehicles.

[0003] For some battery applications, providing accurate battery charge to users or technicians is crucial. A battery's charge represents how much energy remains in the battery (remaining charge), how much energy has been lost (battery aging charge), or how much energy has been consumed (battery discharge charge). Therefore, the term "charge" has three interpretations: battery discharge charge, battery aging charge, and battery remaining charge. It's understood that the remaining charge can be calculated from the discharged charge, and vice versa. For example, the remaining charge can be calculated by subtracting the discharged charge from the maximum charge, or vice versa. Currently, most battery charge estimation technologies on the market use the Coulomb integration method and the open-circuit voltage lookup table method. The Coulomb integration method integrates the battery's charge and discharge current over a period of time to estimate the battery's state of charge. The open-circuit voltage lookup table method estimates the state of charge (SOC) using the battery's open-circuit voltage when the battery is at rest. However, both methods have their own drawbacks. The Coulomb integration method is prone to cumulative errors due to long calculations, resulting in inaccurate remaining charge calculations and errors in estimating charge loss due to battery aging. The open-circuit voltage lookup table method requires pre-built tables and requires the battery to rest for a sufficient period of time, meaning that the battery has reached a stable state, to achieve high accuracy.

[0004] Therefore, the present invention aims at the above-mentioned problem and proposes a battery power estimation method to solve the problems arising from the conventional method. Summary of the Invention

[0005] In view of this, the present invention provides an operating method for a voltage converter, which avoids battery capacity loss and state of charge errors caused by battery aging, and implements an open-circuit voltage lookup method using a charging voltmeter and a charging ammeter without requiring the battery to remain stationary for a long time.

[0006] In one embodiment of the present invention, a method for estimating battery power is provided, comprising the following steps: charging a battery and collecting the charging voltage and charging current corresponding to the battery during the charging process; resetting the initial state of charge of the battery to zero, and calculating the residual state of charge of the battery during the charging process using the coulomb integration method, the preset battery capacity of the battery, and the charging current until the battery enters a floating charge mode, and establishing a charging voltage table and a charging current table based on the residual state of charge and its corresponding charging voltage and charging current, and calculating the current state of charge of the battery using the coulomb integration method; after the battery is left at rest, measuring the first current resting open circuit voltage of the battery; finding a corresponding lookup table charging voltage from the charging voltage table according to the current state of charge, and finding a corresponding lookup table charging current from the charging current table according to the current state of charge; The battery comprises a battery cell, a battery cell, and a battery cell. The battery cell comprises a battery cell, a battery cell, and a battery cell. The battery cell comprises a battery cell, a battery cell, and a battery cell. The battery cell comprises a battery cell, a battery cell, and a battery cell. The battery cell comprises a battery cell, a battery cell, and a battery cell. The battery cell comprises a battery cell, a battery cell, and a battery cell. The battery cell comprises a battery cell, a battery cell, and a battery cell. The battery cell comprises a battery cell, a battery cell, and a battery cell. The battery cell comprises a battery cell, a battery cell, and a battery cell. The battery cell comprises a battery cell, a battery cell, and a battery cell. The battery cell comprises a battery cell, a battery cell, and a battery cell. The battery cell comprises a battery cell, a battery cell, and a battery cell. The battery cell comprises a battery cell, a battery cell, and a battery cell.

[0007] In one embodiment of the present invention, the battery capacity estimation method further includes an updating step. In the updating step, a new battery capacity of the battery is calculated based on the start time of the charging process, the time point corresponding to the floating charge mode, and the charging current, and the preset battery capacity is updated based on the new battery capacity.

[0008] In one embodiment of the present invention, before charging the battery, the following steps are performed: determining whether the battery voltage is within a warning voltage range; charging the battery if the battery voltage is within the warning voltage range; and ending the charging process if the battery voltage is not within the warning voltage range.

[0009] In one embodiment of the present invention, before the battery enters the float charge mode, the residual state of charge of the battery during the charging process is calculated using the coulomb integration method, the preset battery capacity, and the charging current in the constant current mode and the constant voltage mode.

[0010] In one embodiment of the present invention, the constant current mode includes the following steps: calculating the residual state of charge of the battery during the charging process using the Coulomb integration method, a preset battery capacity, and the charging current, and recording the cumulative number of times the charging current is less than a preset fixed current; and determining whether the cumulative number has reached a preset value: terminating the process when the cumulative number has reached the preset value; and returning to the step of calculating the residual state of charge of the battery during the charging process using the Coulomb integration method, the preset battery capacity, and the charging current, and recording the cumulative number of times when the cumulative number has not reached the preset value.

[0011] In one embodiment of the present invention, in the step of allowing the battery to rest, the battery is allowed to rest for a first predetermined period of time.

[0012] In one embodiment of the present invention, after determining the first resting state of charge, the following steps are performed: determining whether the battery has been rested again for a second predetermined period of time: ending the process if the battery has not been rested again for the second predetermined period of time; and performing the following steps when the battery has been rested again for the second predetermined period of time: measuring a second current resting open-circuit voltage of the battery, calculating a second charging voltage based on the latest resting state of charge, the latest second current resting open-circuit voltage, a voltage difference, and a look-up table charging current, and finding a corresponding second look-up table state of charge from a charging voltage table based on the latest second charging voltage; and determining whether the latest second look-up table state of charge is less than the latest resting state of charge to determine the second resting state of charge of the battery: if the latest second look-up table state of charge is less than the latest resting state of charge, subtracting the fixed state of charge from the latest resting state of charge to generate and output the second resting state of charge; and if the latest second look-up table state of charge is not less than the latest resting state of charge, outputting the latest resting state of charge as the second resting state of charge.

[0013] In one embodiment of the present invention, the second preset period is shorter than the first preset period.

[0014] In one embodiment of the present invention, the latest resting state of charge is the first resting state of charge.

[0015] In one embodiment of the present invention, the latest second charging voltage EST_V2 = BV2 + ΔV × Table.A[Snew] / ΔA, where BV2 represents the latest second current static open-circuit voltage, ΔV represents the voltage difference, ΔA represents the table-based charging current, Snew represents the latest static state of charge, and Table.A[Snew] represents the charging current corresponding to the latest static state of charge in the charging current table. ΔV, ΔA, and Table.A[Snew] are all absolute values.

[0016] In one embodiment of the present invention, the first charging voltage EST_V1 = BV1 + ΔV × Table.A[Snow] / ΔA, where BV1 represents the first current static open-circuit voltage, ΔV represents the voltage difference, ΔA represents the table-based charging current, Snow represents the current state of charge, and Table.A[Snow] represents the charging current corresponding to the current state of charge in the charging current table. ΔV, ΔA, and Table.A[Snow] are all absolute values.

[0017] Based on the above, the battery capacity estimation method uses the Coulomb integration method to calculate the battery's state of charge during the charging process to establish a charging voltage meter and a charging current meter, and update the battery capacity. This avoids battery capacity loss and state of charge errors caused by battery aging. In addition, the charging voltage meter and charging current meter are used to implement the open circuit voltage lookup method when the battery does not need to be left idle for a long time. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0019] Figure 1 is a schematic diagram of a power estimation device according to an embodiment of the present invention;

[0020] FIG2( a ) and FIG2 ( b ) are flow charts of a method for estimating battery power according to an embodiment of the present invention;

[0021] Figure 3 FIG. 4 is a schematic diagram of a charging voltage meter according to an embodiment of the present invention.

[0022] Figure 4 is a schematic diagram of a charging current meter according to an embodiment of the present invention;

[0023] Figure 5 is a waveform diagram of charging current and charging voltage during a charging process according to one embodiment of the present invention;

[0024] Figure 6 is a flowchart of the operation of the constant current mode according to one embodiment of the present invention;

[0025] Figure 7 is a flowchart of a first power estimation process according to an embodiment of the present invention;

[0026] Figure 8 FIG. 4 is a flowchart of a second power estimation process according to an embodiment of the present invention.

[0027] Description of reference numerals:

[0028] 1-power estimation device; 10-charger; 100-electrical signal detector; 11-processor;

[0029] 2-Battery. DETAILED DESCRIPTION

[0030] The embodiments of the present invention are further explained below with reference to the accompanying drawings. Whenever possible, identical reference numerals will be used in the drawings and the specification to represent identical or similar components. In the drawings, shapes and thicknesses may be exaggerated for simplicity and convenience. It should be understood that components not specifically shown in the drawings or described in the specification are generally known to those skilled in the art. Those skilled in the art may make various changes and modifications based on the disclosure of the present invention.

[0031] Unless otherwise specified, conditional clauses or words such as "can," "could," "might," or "may" are generally intended to indicate that an embodiment of the present invention has features, components, or steps, but may also be interpreted as not being required. In other embodiments, these features, components, or steps may not be required.

[0032] The description below of "one embodiment" or "an embodiment" refers to a specific component, structure, or feature associated with at least one embodiment. Therefore, multiple references to "one embodiment" or "an embodiment" below do not necessarily refer to the same embodiment. Furthermore, specific components, structures, and features in one or more embodiments may be combined in any suitable manner.

[0033] Certain words are used in the specification and claims to refer to specific components. However, a person with ordinary knowledge in the technical field should understand that the same component may be referred to by different terms. The specification and claims do not use differences in name as a way to distinguish components, but use differences in the functions of the components as a basis for distinction. The term "including" mentioned in the specification and claims is an open-ended term and should be interpreted as "including but not limited to". In addition, "coupling" here includes any direct and indirect connection means. Therefore, if the text describes a first component coupled to a second component, it means that the first component can be directly connected to the second component through electrical connection or signal connection methods such as wireless transmission, optical transmission, etc., or can be indirectly electrically or signal-connected to the second component through other components or connection means.

[0034] The disclosure is described with particular reference to the following examples, which are intended to be illustrative only. Various modifications and variations will readily occur to those skilled in the art without departing from the spirit and scope of the disclosure, and the scope of protection of the disclosure is to be determined by the appended claims. Throughout the specification and claims, unless the context clearly dictates otherwise, "a," "an," and "the" include references to "one or at least one" of the element or component. Furthermore, as used in the disclosure, the singular article includes references to plural elements or components unless the context clearly dictates otherwise. Furthermore, as used in this description and throughout the claims that follow, "in which" includes "in which" and "on which," unless the context clearly dictates otherwise. Terms used throughout the specification and claims generally have their ordinary meanings as used in the art, within the disclosure, and in the specific context, unless otherwise noted. Certain terms used to describe the present disclosure are discussed below and elsewhere in this specification to provide practitioners with additional guidance regarding the present disclosure. The use of examples anywhere throughout this specification, including examples of any terms discussed herein, is intended to be illustrative only and does not limit the scope or meaning of the present disclosure or any exemplified terms. Similarly, the present disclosure is not limited to the various embodiments set forth in this specification.

[0035] The following presents a battery capacity estimation method according to the present invention. It utilizes the Coulomb integration method to calculate the battery's state of charge during the charging process, thereby establishing a charging voltage meter and a charging current meter, and updating the battery capacity. This method avoids capacity loss and state of charge errors due to battery aging. Furthermore, the charging voltage meter and charging current meter can be used to implement an open-circuit voltage lookup table method without requiring the battery to remain stationary for extended periods of time.

[0036] Figure 1 FIG is a schematic diagram of a power estimation device according to an embodiment of the present invention. Figure 1 The battery capacity estimation device 1 includes a charger 10 and a processor 11. The charger 10 has an electrical signal detector 100. The electrical signal detector 100 can not only detect the voltage of the battery 2, but also detect the charging voltage and charging current provided by the charger 10 to the battery 2. The charger 10 is electrically connected between the processor 11 and the battery 2.

[0037] FIG2(a) and FIG2(b) are flow charts of a method for estimating battery power according to an embodiment of the present invention. Figure 1As shown in Figure 2(a), first, as shown in step S10, the charger 10 uses the electrical signal detector 100 to detect the voltage of the battery 2 and determine whether the voltage of the battery 2 is within a warning voltage range. For example, the warning voltage range is between a first warning voltage and a second warning voltage, where the second warning voltage can be equal to the first warning voltage multiplied by 1.02. If the voltage of the battery 2 is within the warning voltage range, the process proceeds to step S12. In step S12, the charger 10 charges the battery 2 and collects the corresponding charging voltage and charging current of the battery 2 during the charging process, and transmits these to the processor 11. If the voltage of the battery 2 is not within the warning voltage range, the process proceeds to step S14. In step S14, the entire process ends.

[0038] In step S16, processor 11 resets the initial state of charge of battery 2 to zero and calculates the residual state of charge (SOC) of battery 2 during the charging process using the Coulomb integration method, the preset battery capacity of battery 2, and the charging current until battery 2 enters the float charge mode. A charging voltage table and a charging current table are established based on the residual state of charge and its corresponding charging voltage and charging current, and the current state of charge of battery 2 is calculated using the Coulomb integration method. The residual state of charge of battery 2 is expressed as formula (1).

[0039]

[0040] SOC(t) represents the remaining state of charge of Battery 2 at time t. When Battery 2 enters float charge mode, SOC(t) represents the current state of charge of Battery 2. SOC(t0) represents the initial state of charge of Battery 2 at time t0, where I represents the charging current and CN represents the preset battery capacity of Battery 2. Figure 3 is a schematic diagram of a charging voltage meter according to an embodiment of the present invention, Figure 4 FIG. 1 is a schematic diagram of a charging current meter according to an embodiment of the present invention. The charging voltage meter and the charging current meter are respectively as follows: Figure 3 and Figure 4 shown. Figure 3 and Figure 4 Record the results of the quick test of battery 2 during the charging process. Figure 3 In the example, the charging voltage is equal to the voltage of battery 2.

[0041] Figure 5 FIG is a waveform diagram of the charging current and charging voltage during the charging process according to an embodiment of the present invention. Figure 1 and Figure 5, the charging process of battery 2 actually includes a constant current mode between time points t1 and t2, a constant voltage mode between time points t2 and t3, and a floating charge mode after time point t3. The constant current mode, constant voltage mode, and floating charge mode appear in sequence. In the constant current mode, the charging current is a fixed current, and the charging voltage is an increasing voltage. In the constant voltage mode, the charging current is a decreasing current, and the charging voltage is a fixed voltage. The charging current in the floating charge mode is smaller than the charging current in the constant voltage mode and the constant current mode. For example, the charging current in the floating charge mode may be less than the charging current in the constant current mode / 10. Before battery 2 enters the floating charge mode, in the constant current mode and the constant voltage mode, the residual state of charge of battery 2 during the charging process is calculated using the coulomb integration method, the preset battery capacity, and the charging current.

[0042] Please continue reading Figure 1 2(a). In step S18, an update step is performed. In the update step, the processor 11 calculates the new battery capacity of the battery 2 based on the start time point of the charging process, the time point corresponding to the floating charge mode, and the charging current, and updates the preset battery capacity based on this, thereby avoiding the loss of battery capacity and the error in the state of charge due to battery aging. In step S20, the processor 11 determines whether the battery 2 has been at rest for a first preset period of time. Specifically, the processor 11 determines that the battery 2 is at rest when the charging current is zero. When the battery 2 has been at rest for the first preset period of time, step S22 is performed. When the battery 2 has not been at rest for the first preset period of time, step S14 is performed. In step S22, the charger 10 uses the electrical signal detector 100 to measure the first current static open circuit voltage of the battery 2 and transmits it to the processor 11. In step S24, the processor 11 finds a corresponding table-based charging voltage from the charging voltage table according to the current state of charge, and finds a corresponding table-based charging current from the charging current table according to the current state of charge, and records the voltage difference between the table-based charging voltage and the first current static open-circuit voltage and the table-based charging current. In step S26, the processor 11 calculates a first charging voltage based on the current state of charge, the first current static open-circuit voltage, the voltage difference, and the table-based charging current, and finds the corresponding first table-based state of charge from the charging voltage table according to the first charging voltage. In certain embodiments of the present invention, the first charging voltage EST_V1 = BV1 + ΔV × Table.A[Snow] / ΔA, where BV1 represents the first current static open-circuit voltage, ΔV represents the voltage difference, ΔA represents the table-based charging current, Snow represents the current state of charge, Table.A[Snow] represents the charging current corresponding to the current state of charge in the charging current table, and ΔV, ΔA, and Table.A[Snow] are all absolute values. Please continue to refer to Figure 12(b). After step S26, step S28 is performed. In step S28, the processor 11 determines whether the first table lookup state of charge is less than the current state of charge to determine the first static state of charge of the battery 2. When the first table lookup state of charge is less than the current state of charge, step S30 is performed. In step S30, the processor 11 subtracts the fixed state of charge from the current state of charge to generate and output a first static state of charge, wherein the fixed state of charge is greater than 0% and less than or equal to 1%. When the first table lookup state of charge is not less than the current state of charge, step S32 is performed. In step S32, the processor 11 outputs the current state of charge and uses it as the first static state of charge. In certain embodiments of the present invention, step S10, step S18, or both may be omitted. When step S18 is omitted and step S16 is executed, step S20 is performed directly.

[0043] In certain embodiments of the present invention, after determining the first resting state of charge, the processor 11 may perform the following steps. In step S34, the processor 11 determines whether the battery 2 has been rested again for a second predetermined period, where the second predetermined period is less than the first predetermined period. For example, the first predetermined period is 30 minutes and the second predetermined period is 10 minutes. If the battery 2 has not been rested again for the second predetermined period, the processor 11 proceeds to step S14. If the battery 2 has been rested again for the second predetermined period, the processor 11 proceeds to step S36. In step S36, the charger 10 uses the electrical signal detector 100 to measure the second current resting open-circuit voltage of the battery 2 and transmits this value to the processor 11. The processor 11 calculates a second charging voltage based on the latest resting state of charge, the latest second current resting open-circuit voltage, the voltage difference, and the lookup table charging current. The processor 11 then retrieves the corresponding second lookup table state of charge from the charging voltage table based on the latest second charging voltage. The latest second charging voltage EST_V2 = BV2 + ΔV × Table.A[Snew] / ΔA, where BV2 represents the latest second current static open-circuit voltage, ΔV represents the voltage difference, ΔA represents the table-based charging current, Snew represents the latest static state of charge, and Table.A[Snew] represents the charging current corresponding to the latest static state of charge in the charging current table. ΔV, ΔA, and Table.A[Snew] are all absolute values. In step S38, the processor 11 determines whether the latest second table-based state of charge is less than the latest static state of charge to determine the second static state of charge of the battery 2. If the latest second table-based state of charge is less than the latest static state of charge, the processor 11 proceeds to step S40. In step S40, the processor 11 subtracts the fixed state of charge from the latest static state of charge to generate and output the second static state of charge. If the latest second table-based state of charge is not less than the latest static state of charge, the processor 11 proceeds to step S42. In step S42, processor 11 outputs the latest resting state of charge (SOC) as the second resting state of charge. The first time step S38 is performed, the latest resting state of charge is the first resting state of charge. After steps S40 and S42, step S44 is performed. In step S44, processor 11 determines whether battery 2 is still at rest. If so, the process returns to step S36; if not, the process proceeds to step S14. These steps do not necessarily need to be executed in the same order as shown in Figures 2(a) and 2(b) to achieve substantially the same result.

[0044] Figure 6 For a flowchart of the constant current mode operation according to an embodiment of the present invention, please refer to Figure 1 and Figure 6. The constant current mode may include steps S160 and S161. In step S160, the processor 11 calculates the residual state of charge of the battery 2 during the charging process using the Coulomb integration method, the preset battery capacity and the charging current, and records the cumulative number of times the charging current is less than a preset fixed current. For example, the preset fixed current may be 20% of the maximum charging current in the constant current mode, but the present invention is not limited to this. In step S161, the processor 11 determines whether the cumulative number has reached a preset value. For example, the preset value is 60. When the cumulative number reaches the preset value, step S14 is performed. When the cumulative number does not reach the preset value, return to step S160.

[0045] Processor 11 continuously receives charging voltage and charging current. When the charging current is zero, processor 11 determines that battery 2 is in a rest state. When the charging current is greater than zero, processor 11 determines that battery 2 is in a charging state. After step S14 in Figure 2(b), processor 11 determines whether battery 2 is in a charging state or a rest state. When battery 2 is in a charging state, the first charge estimation process is performed at least once. When battery 2 is in a rest state, the second charge estimation process is performed at least once.

[0046] Figure 7 FIG is a flow chart of a first power estimation process according to an embodiment of the present invention. Figure 1 and Figure 7 The first power estimation process is described below. First, as shown in step S46, the charger 10 uses the electrical signal detector 100 to detect the voltage of the battery 2 and determines whether the voltage of the battery 2 is within a warning voltage range. When the voltage of the battery 2 is within the warning voltage range, step S48 is performed. In step S48, the processor 11 resets the initial state of charge of the battery 2 to zero, and calculates the residual state of charge (SOC) of the battery 2 during the charging process using the Coulomb integration method, the first battery capacity of the battery 2 as the new battery capacity, and the charging current until the battery 2 enters the floating charge mode, and calculates the current state of charge of the battery 2 using the Coulomb integration method and outputs it. The residual state of charge of the battery 2 is expressed by formula (2).

[0047]

[0048] SOC(t) represents the residual state of charge of battery 2 at time point t. When battery 2 enters the floating charge mode, SOC(t) represents the current state of charge of battery 2. SOC(t0') represents the initial state of charge of battery 2 at time point t0, I represents the charging current, and CN' represents the first battery capacity of battery 2. When the voltage of battery 2 is not within the warning voltage range, step S50 is performed. In step S50, the first power estimation process is ended. After step S48, step S52 is performed. In step S52, the processor 11 calculates the second battery capacity of battery 2 based on the start time point of the charging process, the time point corresponding to the floating charge mode and the charging current, and updates the first battery capacity based on this, thereby avoiding the loss of battery capacity and the error in the state of charge due to battery aging.

[0049] Figure 8 FIG is a flow chart of a second power estimation process according to an embodiment of the present invention. Figure 1 and Figure 8The second charge estimation process is described below. First, as shown in step S54, the processor 11 determines whether the battery 2 has been at rest for the first predetermined period of time. If the battery 2 has been at rest for the first predetermined period of time, the process proceeds to step S56. If the battery 2 has not been at rest for the first predetermined period of time, the process proceeds to step S58. In step S56, the charger 10 uses the electrical signal detector 100 to measure the third current static open-circuit voltage of the battery 2 and transmits this value to the processor 11. The processor 11 calculates a third charging voltage based on the latest static state of charge, the latest third current static open-circuit voltage, the voltage difference, and the lookup table charging current. The processor 11 then retrieves the corresponding third lookup table state of charge from the charging voltage table based on the third charging voltage. In certain embodiments of the present invention, the third charging voltage EST_V3 = BV3 + ΔV × Table.A[Snew] / ΔA, where BV3 represents the latest third current static open-circuit voltage, ΔV represents the voltage difference, ΔA represents the table-based charging current, Snew represents the latest static state of charge, and Table.A[Snew] represents the charging current corresponding to the latest static state of charge in the charging current table. In step S58, the second charge estimation process ends. After step S56, the process proceeds to step S60. In step S60, the processor 11 determines whether the latest third table-based state of charge is less than the latest static state of charge to determine the third static state of charge of the battery 2. If the latest third table-based state of charge is less than the latest static state of charge, the process proceeds to step S62. In step S62, the processor 11 subtracts the fixed state of charge from the latest static state of charge to generate and output the third static state of charge. If the latest third table-based state of charge is not less than the latest static state of charge, the process proceeds to step S64. In step S64, the processor 11 outputs the latest resting state of charge and uses it as the third resting state of charge. When the first power estimation process is performed for the first time, the latest resting state of charge is the latest second resting state of charge. After step S62 or S64, step S66 is performed. In step S66, the processor 11 determines whether the battery 2 has been rested again for the second preset period of time. When the battery 2 has not been rested again for the second preset period of time, step S68 is performed. When the battery 2 has been rested again for the second preset period of time, the process returns to step S56. In step S68, the processor 11 determines whether the battery 2 continues to be rested. If so, the process returns to step S66. If not, the process proceeds to step S58. If substantially the same result can be obtained, these steps do not necessarily have to be followed. Figure 8 Execute in the order shown.

[0050] According to the above embodiment, the battery capacity estimation method uses the Coulomb integration method to calculate the battery's state of charge during the charging process, thereby establishing a charging voltage meter and a charging current meter, and updating the battery capacity. This avoids battery capacity loss and state of charge errors caused by battery aging. The charging voltage meter and charging current meter are used to implement an open circuit voltage lookup table method without requiring the battery to be left idle for a long time.

[0051] The above is only a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Therefore, all equivalent changes and modifications in the shape, structure, characteristics and spirit described in the scope of the claims of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A method for estimating battery power, characterized in that: The battery capacity estimation method includes: charging a battery and collecting the charging voltage and charging current corresponding to the battery during the charging process; Resetting the initial state of charge of the battery to zero, and calculating the residual state of charge of the battery during the charging process using a Coulomb integration method, a preset battery capacity of the battery, and the charging current until the battery enters a float charge mode, establishing a charging voltage table and a charging current table based on the residual state of charge and its corresponding charging voltage and charging current, and calculating the current state of charge of the battery using the Coulomb integration method; After the battery is at rest, measuring a first current resting open circuit voltage of the battery; Finding a corresponding lookup table charging voltage from the charging voltage table according to the current state of charge, and finding a corresponding lookup table charging current from the charging current table according to the current state of charge, and recording a voltage difference between the lookup table charging voltage and the first current static open-circuit voltage and the lookup table charging current; Calculating a first charging voltage based on the current state of charge, the first current static open-circuit voltage, the voltage difference, and the table-lookup charging current, and finding a corresponding first table-lookup state of charge from the charging voltage table based on the first charging voltage; and Determining whether the first table-lookup state of charge is less than the current state of charge to determine a first resting state of charge of the battery: When the first table-lookup state of charge is less than the current state of charge, subtracting a fixed state of charge from the current state of charge to generate and output the first resting state of charge, wherein the fixed state of charge is greater than 0% and less than or equal to 1%; and When the first table-lookup state of charge is not less than the current state of charge, the current state of charge is output as the first static state of charge.

2. The method for estimating battery power according to claim 1, wherein: The battery charge estimation method further includes: The new battery capacity of the battery is calculated according to the starting time point of the charging process, the time point corresponding to the floating charge mode and the charging current, and the preset battery capacity is updated accordingly.

3. The method for estimating battery power according to claim 1, wherein: Before the step of charging a battery, the method further includes: Determine whether the battery voltage is within a warning voltage range: When the voltage of the battery is within the warning voltage range, charging the battery; and When the voltage of the battery is not within the warning voltage range, the process ends.

4. The method for estimating battery power according to claim 1, wherein: Before the step of the battery entering the float charge mode, the method further includes: In a constant current mode and a constant voltage mode, the residual state of charge of the battery during the charging process is calculated using the Coulomb integration method, the preset battery capacity, and the charging current.

5. The method for estimating battery power according to claim 4, wherein: The constant current mode specifically includes: Calculating the residual state of charge of the battery during the charging process using the Coulomb integration method, the preset battery capacity, and the charging current, and recording the cumulative number of times the charging current is less than a preset fixed current; and Determine whether the cumulative number reaches a preset value: When the accumulated number reaches the preset value, the process ends; and When the cumulative number does not reach the preset value, the process returns to the step of calculating the residual state of charge of the battery during the charging process using the Coulomb integration method, the preset battery capacity, and the charging current, and recording the cumulative number.

6. The method for estimating battery power according to claim 1, wherein: The step of allowing the battery to stand still specifically includes: The battery is left to stand for a first predetermined period of time.

7. The method for estimating battery power according to claim 6, wherein: After the step of determining the first resting state of charge of the battery, the method further includes: Determine whether the battery has been left idle for a second preset period of time again: When the battery is not left at rest for the second preset period of time again, the process ends; and When the battery is left to rest for the second preset period of time again, the following steps are performed: measuring a second current static open-circuit voltage of the battery, calculating a second charging voltage based on the latest static state of charge, the latest second current static open-circuit voltage, the voltage difference, and the look-up table charging current, and finding a corresponding second look-up table state of charge from the charging voltage table based on the latest second charging voltage; and Determine whether the latest second table-lookup state of charge is less than the latest static state of charge to determine the second static state of charge of the battery: When the latest second table-lookup state of charge is less than the latest resting state of charge, subtracting the fixed state of charge from the latest resting state of charge to generate and output the second resting state of charge; and When the latest second table-lookup state of charge is not less than the latest static state of charge, the latest static state of charge is output as the second static state of charge.

8. The method for estimating battery power according to claim 7, wherein: The second preset period is shorter than the first preset period.

9. The method for estimating battery power according to claim 7, wherein: The latest resting state of charge is the first resting state of charge.

10. The method for estimating battery power according to claim 7, wherein: The latest second charging voltage EST_V2 = BV2 + ΔV × Table.A[Snew] / ΔA, where BV2 represents the latest second current static open-circuit voltage, ΔV represents the voltage difference, ΔA represents the table-lookup charging current, Snew represents the latest static state of charge, and Table.A[Snew] represents the charging current corresponding to the latest static state of charge in the charging current table. ΔV, ΔA, and Table.A[Snew] are all absolute values.

11. The method for estimating battery power according to claim 1, wherein: The first charging voltage EST_V1 = BV1 + ΔV × Table.A[Snow] / ΔA, where BV1 represents the first current static open-circuit voltage, ΔV represents the voltage difference, ΔA represents the table-lookup charging current, Snow represents the current state of charge, and Table.A[Snow] represents the charging current corresponding to the current state of charge in the charging current table. ΔV, ΔA, and Table.A[Snow] are all absolute values.

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