Method for estimating electric quantity of battery

Abstract

The embodiment of the invention discloses a method for estimating the electric quantity of a battery, which comprises the following steps of: calculating the charge state of the battery in a charging process by using a coulomb integral method until the battery enters a floating charge mode, and establishing a charging voltmeter and a charging ampere meter according to the charge state and the corresponding charging voltage and charging current; after the battery is stood, a first current stood open-circuit voltage of the battery is measured. Finding out a corresponding table look-up charging voltage from the charging voltmeter according to the current state of charge of the battery, finding out a corresponding table look-up charging current from the charging ammeter according to the current state of charge, and recording a voltage difference between the table look-up charging voltage and the first current standing open-circuit voltage and the table look-up charging current; and finally, determining a first standing charge state of the battery according to the current charge state, the first current standing open-circuit voltage, the voltage difference and the table look-up charging current.

Description

Technical Field

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

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

[0003] For some battery applications, it is important to provide accurate battery capacity to users or technicians. The battery capacity represents how much power can be left in the battery (battery residual capacity), how much power has been lost (battery aging capacity), or how much power has been discharged (battery discharge capacity). Therefore, the term "capacity" has three interpretations: battery discharge capacity, battery aging capacity, and battery residual capacity. It is understandable that the battery residual capacity can be calculated from the battery discharge capacity, and vice versa. For example, the battery residual capacity can be obtained by subtracting the battery discharge capacity from the maximum capacity, or the battery discharge capacity can be obtained by subtracting the battery residual capacity from the battery maximum capacity. Most of the battery capacity estimation technologies on the market today use the Coulomb integration method and the open circuit voltage lookup method. The Coulomb integration method integrates the charge and discharge current of the battery over a period of time to estimate the battery's state of charge. The open circuit voltage lookup method estimates the state of charge (SOC) through the open circuit voltage of the battery when the battery is in a static state. However, both methods have their own problems. The Coulomb integral method is prone to cumulative errors due to long-term calculations, resulting in inaccurate calculations of remaining power and estimation errors of power loss after battery aging. The open-circuit voltage lookup table method requires a table to be built in advance and requires the battery to be left to rest for a long enough time, that is, the battery reaches a stable state, to have a higher accuracy.

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

[0005] In view of this, the present invention provides an operating method of a voltage converter, which avoids the loss of battery capacity and the error of the state of charge 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 be 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 by 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 according to the residual state of charge and its corresponding charging voltage and charging current, and using the coulomb integration method to calculate the current state of charge of the battery; after the battery is 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 voltage from the charging current table according to the current state of charge; The method comprises the steps of: calculating a first charging voltage according to the current state of charge, the first current static open-circuit voltage, the voltage difference and the table-lookup charging current, finding a corresponding first table-lookup state of charge from a charging voltage table according to 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 static 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 a first static 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, outputting the current state of charge as the first static state of charge.

[0007] In one embodiment of the present invention, the battery capacity estimation method further includes an updating step. In the updating step, 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.

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

[0009] In one embodiment of the present invention, before the battery enters the floating charge mode, the residual state of charge of the battery during the charging process is calculated by 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 by 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 determining whether the cumulative number has reached a preset value: when the cumulative number has reached the preset value, ending; and when the cumulative number has not reached the preset value, returning to the step of calculating the residual state of charge of the battery during the charging process by the Coulomb integration method, the preset battery capacity and the charging current, and recording the cumulative number.

[0011] In one embodiment of the present invention, in the step of leaving the battery at rest, the battery is left at rest for a first preset period of time.

[0012] In one embodiment of the present invention, after the step of determining the first static state of charge, the following steps are performed: determining whether the battery is again static for a second preset period of time: ending when the battery is not again static for a second preset period of time; and performing the following steps when the battery is again static for a second preset period of time: measuring the second current static open circuit voltage of the battery, and calculating a second charging voltage according to the latest static state of charge, the latest second current static open circuit voltage, the voltage difference and the table lookup charging current, and finding the corresponding second table lookup state of charge from the charging voltage table according to the latest second charging voltage; and determining 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 static state of charge, subtracting the fixed state of charge from the latest static state of charge to generate and output the second static state of charge; and when the latest second table lookup state of charge is not less than the latest static state of charge, outputting the latest static state of charge as the second static state of charge.

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

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

[0015] In one embodiment of the present invention, the latest second charging voltage EST_V2=BV2+ΔV×Table.A[Snew] / ΔA, 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, Table.A[Snew] represents the charging current corresponding to the latest static state of charge in the charging current table, and 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, 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, 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.

[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, thereby avoiding the loss of battery capacity and the error of the state of charge caused by battery aging, and without the need to keep the battery stationary for a long time, the open circuit voltage lookup method is realized using the charging voltage meter and the charging current meter. 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] 2(a) and 2(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 charging according to an embodiment of the present invention;

[0024] Figure 6 is an operation flow chart of a constant current mode according to an embodiment of the present invention;

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

[0026] Figure 8 FIG. 4 is a flow chart 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-electric signal detector; 11-processor;

[0029] 2-Battery. DETAILED DESCRIPTION

[0030] The embodiments of the present invention will be further explained below with reference to the relevant drawings. As far as possible, the same reference numerals represent the same or similar components in the drawings and the specification. In the drawings, shapes and thicknesses may be exaggerated for simplicity and convenience. It is understood that the components not specifically shown in the drawings or described in the specification are in the form known to those skilled in the art. Those skilled in the art may make various changes and modifications based on the contents of the present invention.

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

[0032] The description of "one embodiment" or "an embodiment" in the following text refers to a specific element, structure or feature associated with at least one embodiment. Therefore, multiple descriptions of "one embodiment" or "an embodiment" appearing in multiple places in the following text do not refer to the same embodiment. Furthermore, specific components, structures and features in one or more embodiments can be combined in an appropriate manner.

[0033] Certain words are used in the specification and claims to refer to specific components. However, those 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" 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 indirectly connected to the second component electrically or by signal through other components or connection means.

[0034] The disclosure is particularly described with the following examples, which are only used for illustration, because for those skilled in the art, various changes and modifications can be made without departing from the spirit and scope of the disclosure, so the protection scope of the disclosure should be determined by the scope of the attached claims. Throughout the specification and the claims, unless the content clearly specifies, the meaning of "one" and "the" includes such a description including "one or at least one" of the elements or components. In addition, as used in the disclosure, unless it is obvious from the specific context that the plurality is excluded, the singular article also includes the description of plural elements or components. Moreover, when applied in this description and the following claims, unless the content clearly specifies, the meaning of "in which" may include "in which" and "on which". The terms used in the specification and the claims, unless otherwise specified, generally have the ordinary meaning of each term used in this field, in the content of this disclosure and in the specific content. Certain terms used to describe the present disclosure will be discussed below or elsewhere in this specification to provide practitioners with additional guidance in describing the present disclosure. The use of examples anywhere throughout the specification, including examples of any term discussed herein, is intended to be illustrative only and certainly does not limit the scope and meaning of the present disclosure or any exemplified term. Likewise, the present disclosure is not limited to the various embodiments set forth in this specification.

[0035] A battery power estimation method of the present invention is proposed below. It uses the Coulomb integration method to calculate the state of charge of the battery during the charging process to establish a charging voltage meter and a charging current meter, and update the battery capacity, thereby avoiding the loss of battery capacity and the error of the state of charge due to battery aging. The open circuit voltage lookup method is implemented using the charging voltage meter and the charging current meter without the need to leave the battery stationary for a long time.

[0036] Figure 1 FIG. 1 is a schematic diagram of a power estimation device according to an embodiment of the present invention. Figure 1 The power 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] FIG. 2( a ) and FIG. 2( b ) are flow charts of a method for estimating battery power according to an embodiment of the present invention. Figure 1As shown in FIG. 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 determines whether the voltage of the battery 2 is within a warning voltage range. For example, the warning voltage range is between the first warning voltage and the second warning voltage, wherein the second warning voltage can be equal to the first warning voltage multiplied by 1.02. When the voltage of the battery 2 is within the warning voltage range, step S12 is performed. In step S12, the charger 10 charges the battery 2, and collects the charging voltage and charging current corresponding to the battery 2 during the charging process, and transmits this to the processor 11. When the voltage of the battery 2 is not within the warning voltage range, step S14 is performed. In step S14, the entire process ends.

[0038] In step S16, 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 by using the coulomb integration method, the preset battery capacity of the battery 2, and the charging current until the battery 2 enters the floating charge mode, and establishes a charging voltage table and a charging current table according to the residual state of charge and its corresponding charging voltage and charging current, and calculates the current state of charge of the battery 2 by using the coulomb integration method. The residual state of charge of the battery 2 is expressed by formula (1).

[0039]

[0040] SOC(t) represents the remaining 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 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 shown in FIG. 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. 1 is a waveform diagram of charging current and charging voltage during charging 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 a rising voltage. In the constant voltage mode, the charging current is a falling 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 / 10 in the constant current mode. Before the battery 2 enters the floating charge mode, in the constant current mode and the constant voltage mode, the residual state of charge of the 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 and Figure 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 according to 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 of the state of charge due to battery aging. In step S20, the processor 11 determines whether the battery 2 has been stationary for a first preset period of time. Specifically, the processor 11 determines that the battery 2 is in a stationary state when the charging current is zero. When the battery 2 has been stationary for the first preset period of time, step S22 is performed. When the battery 2 has not been stationary 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 stationary 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 according to 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 charging state 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 1and Figure 2(b). After step S26, proceed to step S28. 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, proceed to step S30. 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, proceed to step S32. 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 after step S16 is executed, proceed directly to step S20.

[0043] In certain embodiments of the present invention, the processor 11 may perform the following steps after the step of determining the first static state of charge. In step S34, the processor 11 determines whether the battery 2 is again at rest for a second preset period of time, wherein the second preset period of time is less than the first preset period of time. For example, the first preset period of time is 30 minutes and the second preset period of time is 10 minutes. When the battery 2 is not again at rest for the second preset period of time, step S14 is performed. When the battery 2 is again at rest for the second preset period of time, step S36 is performed. In step S36, the charger 10 uses the electrical signal detector 100 to measure the second current static open circuit voltage of the battery 2 and transmits it to the processor 11. The processor 11 calculates 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 lookup table charging current, and finds 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, BV2 represents the latest second current static open circuit voltage, ΔV represents the voltage difference, ΔA represents the table charging current, Snew represents the latest static state of charge, Table.A[Snew] represents the charging current corresponding to the latest static state of charge in the charging current table, and ΔV, ΔA and Table.A[Snew] are all absolute values. In step S38, the processor 11 determines 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 2. When the latest second table lookup state of charge is less than the latest static state of charge, step S40 is performed. 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. When the latest second table lookup state of charge is not less than the latest static state of charge, step S42 is performed. In step S42, the processor 11 outputs the latest static state of charge and uses it as the second static state of charge. When step S38 is performed for the first time, the latest static state of charge is the first static state of charge. After steps S40 and S42, step S44 is performed. In step S44, the processor 11 determines whether the battery 2 continues to be static. If so, it returns to step S36. If not, it performs step S14. If substantially the same result can be obtained, these steps do not necessarily have to be performed in the order shown in Figures 2(a) and 2(b).

[0044] Figure 6 For a flowchart of the operation of the constant current mode 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] The processor 11 continuously receives the charging voltage and the charging current. When the charging current is equal to zero, the processor 11 determines that the battery 2 is in a static state. When the charging current is greater than zero, the processor 11 determines that the battery 2 is in a charging state. After step S14 in FIG. 2( b), the processor 11 determines whether the battery 2 is in a charging state or a static state. When the battery 2 is in a charging state, the first power estimation process is performed at least once. When the battery 2 is in a static state, the second power estimation process is performed at least once.

[0046] Figure 7 FIG. 1 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 introduced 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 by 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 by 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 according to 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 of the state of charge due to battery aging.

[0049] Figure 8 FIG. 1 is a flow chart of a second power estimation process according to an embodiment of the present invention. Figure 1 and Figure 8, the second power estimation process is introduced below. First, as shown in step S54, the processor 11 determines whether the battery 2 has been stationary for a first preset period of time. When the battery 2 has been stationary for a first preset period of time, step S56 is performed. When the battery 2 has not been stationary for a first preset period of time, step S58 is performed. In step S56, the charger 10 uses the electrical signal detector 100 to measure the third current stationary open circuit voltage of the battery 2, and transmits it to the processor 11. The processor 11 calculates a third charging voltage based on the latest stationary state of charge, the latest third current stationary open circuit voltage, the voltage difference and the lookup table charging current, and finds 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, BV3 represents the latest third current static open circuit voltage, ΔV represents the voltage difference, ΔA represents the table 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 power estimation process ends. After step S56, step S60 is performed. In step S60, the processor 11 determines whether the latest third table-lookup state of charge is less than the latest static state of charge to determine the third static state of charge of the battery 2. When the latest third table-lookup state of charge is less than the latest static state of charge, step S62 is performed. 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. When the latest third table-lookup state of charge is not less than the latest static state of charge, step S64 is performed. In step S64, the processor 11 outputs the latest static state of charge and uses it as the third static state of charge. When the first power estimation process is performed for the first time, the latest static state of charge is the latest second static state of charge. After step S62 or S64, proceed to step S66. In step S66, the processor 11 determines whether the battery 2 has been stationary again for the second preset period of time. When the battery 2 has not been stationary again for the second preset period of time, proceed to step S68. When the battery 2 has been stationary again for the second preset period of time, return to step S56. In step S68, the processor 11 determines whether the battery 2 continues to be stationary. If so, return to step S66. If not, proceed to step S58. If substantially the same result can be obtained, these steps do not have to be followed. Figure 8 Execute in the order shown.

[0050] According to the above embodiment, the battery power estimation method adopts the Coulomb integration method to calculate the charge state of the battery during the charging process, so as to establish a charging voltage meter and a charging current meter, and update the battery capacity, thereby avoiding the loss of battery capacity and the error of charge state caused by battery aging, and realizing the open circuit voltage lookup method by using the charging voltage meter and the charging current meter without the need to keep the battery stationary 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 to 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 power estimation method includes: Charging a battery, and collecting the charging voltage and charging current corresponding to the battery during the charging process; The initial state of charge of the battery is reset to zero, and the residual state of charge of the battery during the charging process is calculated by the Coulomb integration method, the preset battery capacity of the battery and the charging current until the battery enters a floating charge mode, and a charging voltage table and a charging current table are established according to the residual state of charge and the corresponding charging voltage and charging current, and the current state of charge of the battery is calculated by the Coulomb integration method; After the battery is at rest, measuring a first current resting open circuit voltage of the battery; Finding a corresponding table lookup charging voltage from the charging voltage table according to the current state of charge, and finding a corresponding table lookup charging current from the charging current table according to the current state of charge, and recording a voltage difference between the table lookup charging voltage and the first current static open circuit voltage and the table lookup charging current; Calculating a first charging voltage according to 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 according to the first charging voltage; and Determine whether the first table-lookup state of charge is less than the current state of charge to determine a first static 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 static 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 and used as the first static state of charge.

2. The method for estimating battery power according to claim 1, characterized in that: The battery power 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, characterized in that: Before the step of charging a battery, the method further comprises: Determine whether the voltage of the battery is within a warning voltage range: When the voltage of the battery is within the warning voltage interval, 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, characterized in that: Before the step of the battery entering the floating charge mode, the method further comprises: In constant current mode and 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, characterized in that: 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 method returns to the step of calculating the residual state of charge of the battery during the charging process by 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, characterized in that: The step of leaving the battery at rest 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, characterized in that: After the step of determining the first static state of charge of the battery, the method further comprises: Determine whether the battery is left to stand for a second preset period of time again: When the battery is not left to stand for the second preset period of time again, the process ends; and When the battery is left to stand for the second preset period of time again, the following steps are performed: Measuring a second current static open circuit voltage of the battery, and calculating a second charging voltage according to the latest static state of charge, the latest second current static open circuit voltage, the voltage difference and the table lookup charging current, and finding a corresponding second table lookup state of charge from the charging voltage table according to 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 static state of charge, subtracting the fixed state of charge from the latest static state of charge to generate and output the second static 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, characterized in that: The second preset period of time is shorter than the first preset period of time.

9. The method for estimating battery power according to claim 7, characterized in that: The latest static state of charge is the first static state of charge.

10. The method for estimating battery power according to claim 7, characterized in that: The latest second charging voltage EST_V2=BV2+ΔV×Table.A[Snew] / ΔA, 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, 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, characterized in that: The first charging voltage EST_V1=BV1+ΔV×Table.A[Snow] / ΔA, 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, 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.

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