State of charge determination method

Abstract

The application discloses a state of charge determination method, which can adjust the pre-calibrated power retention point for a target battery according to the resistance and current of the target battery before the apparent power of the target battery reaches a calibrated state of charge, wherein the power retention point comprises the calibrated state of charge and a calibrated voltage; when the apparent power of the target battery reaches the calibrated state of charge, the corresponding maximum cell voltage is collected according to the current charge and discharge state of the target battery; and the current state of charge of the target battery is determined according to the maximum cell voltage and the calibrated voltage of the corresponding adjusted power retention point. The application continuously corrects the power retention point based on the actual resistance and current of the target battery, and then comprehensively determines the current state of charge of the target battery by combining the apparent power, the calibrated state of charge, the current charge and discharge state and the maximum cell voltage, which is more in line with the actual situation, has high accuracy and high efficiency.

Description

Technical Field

[0001] This invention relates to the field of energy storage, and in particular to a method for determining the state of charge. Background Technology

[0002] As a crucial component of energy storage systems, battery management systems (BMS) primarily function to acquire data, estimate state, control charge and discharge, and balance battery energy. Among these, battery parameter acquisition and state estimation provide vital parameters for the BMS. State of charge (SOC) is one of the core parameters of a battery, and timely and accurate acquisition of SOC is essential for improving battery life and safety. Therefore, how to obtain timely and accurate SOC information has become a pressing technical challenge for researchers in this field. Summary of the Invention

[0003] In view of the above problems, the present invention provides a method for determining the state of charge that overcomes or at least partially solves the above problems.

[0004] A method for determining the state of charge, comprising:

[0005] Before the displayed charge of the target battery reaches the calibrated state of charge, the charge holding point pre-calibrated for the target battery is adjusted according to the resistance and current of the target battery, wherein the charge holding point includes the calibrated state of charge and the calibrated voltage.

[0006] When the displayed charge of the target battery reaches the calibrated state of charge, the corresponding maximum cell voltage value is collected according to the current charge / discharge state of the target battery, wherein the current charge / discharge state corresponds to the maximum cell voltage value.

[0007] The current state of charge of the target battery is determined based on the maximum and minimum cell voltage and the corresponding adjusted charge retention point calibration voltage, wherein the maximum and minimum cell voltage corresponds to the corresponding adjusted charge retention point.

[0008] Optionally, in some optional embodiments, adjusting the pre-calibrated charge holding point for the target battery based on the resistance and current of the target battery before the displayed charge of the target battery reaches the calibrated state of charge includes:

[0009] Before the target battery's displayed charge reaches the calibrated state of charge, the charge holding point of the target battery is adjusted according to the formula Vnew=f(Vold,R,I), where Vold is the previously calibrated charge holding point, Vnew is the adjusted charge holding point, R is the resistance, and I is the current.

[0010] Optionally, in some optional embodiments, when the displayed charge level of the target battery reaches the calibrated state of charge, the corresponding maximum cell voltage value is collected according to the current charge / discharge state of the target battery, including:

[0011] When the displayed charge of the target battery reaches the calibrated state of charge, if the current charge / discharge state of the target battery is charging, then the maximum value of the corresponding cell voltage of the target battery is collected.

[0012] Optionally, in some optional embodiments, when the displayed charge level of the target battery reaches the calibrated state of charge, if the current charge / discharge state of the target battery is a charging state, then collecting the corresponding maximum cell voltage of the target battery includes:

[0013] When the displayed charge of the target battery reaches the calibrated state of charge, if the current charge / discharge state of the target battery is the charging state, then the actual voltage value of each cell of the target battery is collected.

[0014] The largest actual voltage value among the actual voltage values ​​of each cell is determined as the maximum cell voltage value of the target battery.

[0015] Optionally, in some optional embodiments, determining the current state of charge of the target battery based on the maximum cell voltage and the corresponding adjusted calibration voltage of the charge retention point includes:

[0016] The current state of charge of the target battery is determined based on the maximum cell voltage and the corresponding adjusted calibration voltage of the first charge retention point, wherein the first charge retention point is the charge retention point corresponding to the upper limit of the state of charge corresponding to the charging state.

[0017] Optionally, in some optional embodiments, determining the current state of charge of the target battery based on the maximum cell voltage and the corresponding adjusted calibration voltage of the first charge retention point includes:

[0018] If the maximum value of the cell voltage is greater than the calibrated voltage of the first charge holding point, then the ampere-hour integration calculation is continued for the target battery to obtain the current state of charge of the target battery.

[0019] If the maximum value of the cell voltage is not greater than the calibration voltage of the first charge retention point, then the current state of charge of the target battery is determined to be the calibration state of charge of the first charge retention point.

[0020] Optionally, in some optional embodiments, when the displayed charge level of the target battery reaches the calibrated state of charge, the corresponding maximum cell voltage value is collected according to the current charge / discharge state of the target battery, including:

[0021] When the displayed charge of the target battery reaches the calibrated state of charge, if the current charge / discharge state of the target battery is the discharge state, then the minimum value of the corresponding cell voltage of the target battery is collected.

[0022] Optionally, in some optional embodiments, when the displayed charge of the target battery reaches the calibrated state of charge, if the current charge / discharge state of the target battery is a discharge state, then the minimum value of the corresponding cell voltage of the target battery is collected, including:

[0023] When the displayed charge of the target battery reaches the calibrated state of charge, if the current charge / discharge state of the target battery is the discharge state, then the actual voltage value of each cell of the target battery is collected.

[0024] The minimum actual voltage value among the actual voltage values ​​of each cell is determined as the minimum cell voltage value of the target battery.

[0025] Optionally, in some optional embodiments, determining the current state of charge of the target battery based on the maximum cell voltage and the corresponding adjusted calibration voltage of the charge retention point includes:

[0026] The current state of charge of the target battery is determined based on the minimum cell voltage and the calibrated voltage of the corresponding adjusted second charge retention point, wherein the second charge retention point is the charge retention point corresponding to the state of charge limit of the discharge state.

[0027] Optionally, in some optional embodiments, determining the current state of charge of the target battery based on the maximum cell voltage and the corresponding adjusted calibration voltage of the second charge retention point includes:

[0028] If the minimum cell voltage is less than the calibrated voltage of the second charge retention point, then the ampere-hour integration calculation is continued for the target battery to obtain the current state of charge of the target battery.

[0029] If the minimum cell voltage is not less than the calibration voltage of the second charge retention point, then the current state of charge of the target battery is determined to be the calibration state of charge of the second charge retention point.

[0030] Optionally, in some alternative embodiments, after determining the current state of charge of the target battery based on the maximum cell voltage and the corresponding adjusted calibration voltage of the charge retention point, the method further includes:

[0031] The current state of charge of the target battery is displayed on the screen.

[0032] Optionally, in some optional embodiments, the calibration process for the pre-calibrated charge retention point of the target battery includes:

[0033] A first voltage curve is obtained through pre-calibration, wherein the rate of the target battery on which the first voltage curve is based is matched, and the temperature on which the first voltage curve is based is matched with the current temperature of the target battery;

[0034] Select at least one point of voltage and corresponding state of charge from the first voltage curve to calibrate the charge retention point of the target battery, wherein one point in the first voltage curve corresponds to one charge retention point.

[0035] By employing the above technical solution, the present invention provides a method for determining the state of charge (SOC). Before the displayed charge of a target battery reaches the calibrated SOC, a pre-calibrated charge holding point is adjusted based on the resistance and current of the target battery. This charge holding point includes the calibrated SOC and a calibrated voltage. When the displayed charge of the target battery reaches the calibrated SOC, the maximum and minimum cell voltage values ​​are collected based on the current charge / discharge state of the target battery. The current charge / discharge state corresponds to the maximum and minimum cell voltage values. The current SOC of the target battery is determined based on the maximum and minimum cell voltage values ​​and the calibrated voltage of the adjusted charge holding point. Thus, the present invention continuously corrects the charge holding point based on the actual resistance and current of the target battery, and then comprehensively determines the current SOC of the target battery by combining the displayed charge, calibrated SOC, current charge / discharge state, and maximum and minimum cell voltage values. This method is more consistent with actual conditions, and has high accuracy and efficiency.

[0036] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0037] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0038] Figure 1 A flowchart of the first method for determining the state of charge provided by the present invention is shown;

[0039] Figure 2 A flowchart of the second method for determining the state of charge provided by the present invention is shown;

[0040] Figure 3 A flowchart of the third method for determining the state of charge provided by the present invention is shown;

[0041] Figure 4 A flowchart of the fourth method for determining the state of charge provided by the present invention is shown;

[0042] Figure 5 A flowchart of the fifth method for determining the state of charge provided by the present invention is shown;

[0043] Figure 6 A schematic diagram of the structure of a state of charge determination device provided by the present invention is shown;

[0044] Figure 7 A schematic diagram of the structure of an electronic device provided by the present invention is shown. Detailed Implementation

[0045] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0046] like Figure 1 As shown, the present invention provides a method for determining the state of charge, including: S100, S200 and S300;

[0047] S100. Before the displayed charge of the target battery reaches the calibrated state of charge, adjust the pre-calibrated charge holding point for the target battery according to the resistance and current of the target battery.

[0048] The charge holding point includes the calibrated state of charge and the calibrated voltage;

[0049] Optionally, the present invention can display the target battery's charge level (i.e., the displayed charge level) on a screen in real time. The displayed charge level can be a percentage or a decimal. For example, the displayed charge level of the present invention corresponds to the ratio of the current remaining charge level to the fully charged charge level (the present invention can also convert it to a percentage).

[0050] It should be noted that the calibrated state of charge (SOC) described in this invention can be understood as the calibrated value corresponding to the SOC. The SOC is the ratio of the current remaining charge to the fully charged charge. Therefore, this invention can determine whether the displayed charge is equal to the calibrated SOC. If not, this invention can continuously adjust the pre-calibrated charge holding point for the target battery multiple times based on the resistance and current of the target battery. This invention does not impose any limitations on this process.

[0051] For example, in some alternative implementations, S100 includes: step 1.1;

[0052] Step 1.1: Before the displayed charge of the target battery reaches the calibrated state of charge, adjust the charge holding point of the target battery according to the formula Vnew=f(Vold,R,I), where Vold is the previously calibrated charge holding point, Vnew is the adjusted charge holding point, R is the resistance, and I is the current.

[0053] Optionally, the charge retention point mentioned in this invention may include: calibrated state of charge, calibrated voltage, and calibrated current. It should be noted that since the pre-calibrated charge retention point may be inaccurate, this invention can adjust the charge retention point based on the actual resistance and current of the target battery. During the adjustment of the charge retention point, only the values ​​of the calibrated voltage and calibrated current are adjusted, while the calibrated state of charge remains unchanged. For example, if the pre-calibrated charge retention point for the target battery is initially (95%, 3.5V, 100A), after adjustment, the obtained charge retention point may be (95%, 3V, 50A), and this invention does not impose any limitation on this.

[0054] Optionally, the present invention does not specifically limit the calibration process for the charge retention point. For example, in some optional embodiments, the calibration process for the pre-calibrated charge retention point of the target battery includes:

[0055] A first voltage curve is obtained through pre-calibration, wherein the rate of the target battery on which the first voltage curve is based is matched, and the temperature on which the first voltage curve is based is matched with the current temperature of the target battery;

[0056] Select at least one point of voltage and corresponding state of charge from the first voltage curve to calibrate the charge retention point of the target battery, wherein one point in the first voltage curve corresponds to one charge retention point.

[0057] Optionally, since temperature affects the resistance of the target battery, and resistance affects the charge retention point, this invention can also incorporate temperature to pre-calibrate voltage curves corresponding to different rates and temperatures. When needed, this invention can select a corresponding first voltage curve based on the target battery's rate and current temperature, and then select a suitable point from the first voltage curve to calibrate the target battery's charge retention point; this invention does not impose any limitations on this.

[0058] It should be noted that the horizontal axis of the first voltage curve mentioned in this invention can be the calibrated state of charge, and the vertical axis can be the calibrated voltage. Of course, it can also be the other way around, with the vertical axis being the calibrated state of charge and the horizontal axis being the calibrated voltage; this invention does not impose any restrictions on this.

[0059] Optionally, taking the first voltage curve at 0.5C rate and 30 degrees Celsius as an example, the charge retention point (95%, 3.5V, 100A) obtained based on the first voltage curve can be understood as follows: when the target battery is charged at 0.5C rate at 30 degrees Celsius to reach 95% charge, the voltage should be equal to 3.5V and the current should be equal to 100A. This invention does not impose any limitations on this.

[0060] S200. When the displayed charge of the target battery reaches the calibrated state of charge, the corresponding maximum cell voltage value is collected according to the current charge and discharge state of the target battery.

[0061] The current charge / discharge state corresponds to the maximum / minimum value of the cell voltage;

[0062] Optionally, the statement that the displayed charge of the target battery reaches the calibrated state of charge can be understood as: the displayed charge is equal to the calibrated state of charge. In this case, the present invention can combine the current charge / discharge state (charging state or discharging state) of the target battery to collect the corresponding maximum cell voltage value, so as to facilitate subsequent determination of the current state of charge of the target battery.

[0063] It should be noted that the target battery described in this invention may include multiple cells, each with a corresponding voltage. Therefore, this invention can determine the maximum or minimum cell voltage from the voltages of each cell, specifically considering the current charge / discharge state of the target battery. For example, in the charging state, this invention can determine the maximum cell voltage from the voltages of each cell; in the discharging state, this invention can determine the minimum cell voltage from the voltages of each cell. This invention does not impose any limitations on these determinations.

[0064] S300. Determine the current state of charge of the target battery based on the maximum value of the cell voltage and the calibration voltage of the corresponding adjusted charge retention point.

[0065] The maximum value of the cell voltage corresponds to the corresponding adjusted charge holding point.

[0066] Optionally, as mentioned above, the maximum cell voltage used in the charging state and the discharging state are different. Therefore, the charge holding point used in the charging state and the discharging state are also different (and thus the calibration voltage is different).

[0067] For example, regarding the charging status, taking the adjusted charge hold point (95%, 3V, 50A) as an example, there might be a situation where the display shows 95%, but the target battery's actual charge level has not yet reached 95%. In this case, it will result in the target battery not being charged to its maximum capacity. Therefore, this invention can further determine whether the target battery's actual charge level has truly reached 95% based on the cell's maximum voltage and the corresponding charge hold point's calibrated voltage. This invention does not impose any limitations on this determination.

[0068] For example, such as Figure 2 As shown, in some optional embodiments, S200 includes: S210;

[0069] S210. When the displayed charge of the target battery reaches the calibrated state of charge, if the current charge / discharge state of the target battery is the charging state, then the maximum value of the corresponding cell voltage of the target battery is collected.

[0070] Optionally, in some alternative implementations, step S210 includes: steps 2.1 and 2.2;

[0071] Step 2.1: When the displayed charge of the target battery reaches the calibrated state of charge, if the current charge / discharge state of the target battery is the charging state, then collect the actual voltage value of each cell of the target battery.

[0072] Step 2.2: Determine the largest actual voltage value from the actual voltage values ​​of each cell as the maximum cell voltage value of the target battery.

[0073] Optionally, in some alternative implementations, S300 includes: step 3.1;

[0074] Step 3.1: Determine the current state of charge of the target battery based on the maximum cell voltage and the calibration voltage of the first charge retention point after adjustment, wherein the first charge retention point is the charge retention point corresponding to the upper limit of the state of charge corresponding to the charging state.

[0075] like Figure 3As shown, in some optional embodiments, step 3.1 includes: S310 and S311;

[0076] S310. If the maximum value of the cell voltage is greater than the calibrated voltage of the first charge holding point, then continue to perform ampere-hour integration calculation on the target battery to calculate and obtain the current state of charge of the target battery.

[0077] S311. If the maximum value of the cell voltage is not greater than the calibration voltage of the first charge retention point, then the current state of charge of the target battery is determined to be the calibration state of charge of the first charge retention point.

[0078] Optionally, regarding the charging state, if the maximum cell voltage is greater than the calibrated voltage when the displayed charge level reaches the calibrated state of charge, it indicates that the displayed charge level is relatively accurate and close to the actual situation. Therefore, this invention can further maintain the ampere-hour integral calculation of the target battery, so that during subsequent charging processes, the current state of charge of the target battery can continue to be calculated based on the ampere-hour integral and displayed (the value continuously increases according to the calculation result).

[0079] Optionally, regarding the charging state, if the maximum cell voltage is not greater than the rated voltage when the displayed charge level reaches the calibrated state of charge, it indicates that the displayed charge level is inaccurate, and the actual charge received is less than the displayed charge level. Therefore, this invention can maintain the displayed charge level unchanged and continue charging until the maximum cell voltage exceeds the rated voltage. Subsequent operations will then follow the aforementioned scheme where the maximum cell voltage exceeds the rated voltage.

[0080] Optionally, the calculation of ampere-hour integration is a well-known technique in the field, and this invention will not describe it in detail. Please refer to the relevant descriptions in the field for details.

[0081] For example, regarding the discharge state, taking the adjusted charge retention point (5%, 3V, 50A) as an example, there might be a situation where the display shows 5%, but the actual charge of the target battery after discharge has not reached 5%. In this case, it will result in the inability to discharge the target battery to its maximum extent. Therefore, this invention can further determine whether the actual charge of the target battery after discharge has truly reached 5% based on the maximum cell voltage and the corresponding charge retention point calibration voltage. This invention does not impose any limitations on this.

[0082] For example, such as Figure 4 As shown, in some optional embodiments, S200 includes: S220;

[0083] S220. When the displayed charge of the target battery reaches the calibrated state of charge, if the current charge / discharge state of the target battery is the discharge state, then the minimum value of the corresponding cell voltage of the target battery is collected.

[0084] Optionally, in some alternative implementations, step S220 includes: steps 4.1 and 4.2;

[0085] Step 4.1: When the displayed charge of the target battery reaches the calibrated state of charge, if the current charge / discharge state of the target battery is the discharge state, then collect the actual voltage value of each cell of the target battery.

[0086] Step 4.2: Determine the minimum actual voltage value from the actual voltage values ​​of each cell as the minimum cell voltage value of the target battery.

[0087] Optionally, in some alternative implementations, S300 includes: step 5.1;

[0088] Step 5.1: Determine the current state of charge of the target battery based on the minimum cell voltage and the corresponding adjusted calibration voltage of the second charge retention point, wherein the second charge retention point is the charge retention point corresponding to the charge limit of the discharge state.

[0089] like Figure 5 As shown, in some optional embodiments, step 5.1 includes: S320 and S321;

[0090] S320. If the minimum value of the cell voltage is less than the calibrated voltage of the second charge holding point, then continue to perform ampere-hour integration calculation on the target battery to calculate and obtain the current state of charge of the target battery.

[0091] S321. If the minimum value of the cell voltage is not less than the calibration voltage of the second charge retention point, then the current state of charge of the target battery is determined to be the calibration state of charge of the second charge retention point.

[0092] Optionally, regarding the charging state, if the minimum cell voltage is less than the calibrated voltage when the displayed charge level reaches the calibrated state of charge, it indicates that the displayed charge level is relatively accurate and close to the actual situation. Therefore, this invention can further maintain the ampere-hour integration calculation for the target battery, so that during subsequent discharge, the current state of charge of the target battery can be obtained and displayed based on the ampere-hour integration calculation (the value continuously decreases according to the calculation result).

[0093] Optionally, regarding the discharge state, if the minimum cell voltage is not less than the rated voltage when the displayed charge reaches the rated state of charge, it indicates that the displayed charge is inaccurate, and the actual discharged charge has not yet reached the displayed charge (there is still a portion of charge remaining). Therefore, this invention can maintain the displayed charge unchanged and continue discharging until the minimum cell voltage is less than the rated voltage, after which the process continues according to the aforementioned scheme where the minimum cell voltage is less than the rated voltage.

[0094] Optionally, the calculation of ampere-hour integration is a well-known technique in the field, and this invention will not describe it in detail. Please refer to the relevant descriptions in the field for details.

[0095] Optionally, in some alternative embodiments, after S300, the method further includes: step 6.1;

[0096] Step 6.1: Display the current state of charge of the target battery on the display screen.

[0097] Optionally, the display screen can simultaneously display the current state of charge determined by the present invention, so that users can know the current power status of the target battery in a timely and accurate manner.

[0098] It can be seen that the present invention continuously corrects the charge holding point based on the actual resistance and current of the target battery, and then combines the displayed charge, calibrated state of charge, current charge and discharge state and cell voltage maximum and minimum values ​​to comprehensively determine the current state of charge of the target battery, which is more in line with the actual situation and has high accuracy and efficiency.

[0099] like Figure 6 As shown, the present invention provides a state of charge determination device, including: a holding point adjustment unit 100, a voltage maximum / minimum value acquisition unit 200, and a state of charge determination unit 300;

[0100] The holding point adjustment unit 100 is used to adjust the pre-calibrated holding point of the target battery according to the resistance and current of the target battery before the displayed charge of the target battery reaches the calibrated state of charge. The holding point includes the calibrated state of charge and the calibrated voltage.

[0101] The voltage maximum / minimum value acquisition unit 200 is used to acquire the corresponding cell voltage maximum / minimum value according to the current charge / discharge state of the target battery when the displayed charge of the target battery reaches the calibrated state of charge. The current charge / discharge state corresponds to the cell voltage maximum / minimum value.

[0102] The state of charge determination unit 300 is used to determine the current state of charge of the target battery based on the maximum and minimum cell voltage and the corresponding adjusted charge retention point calibration voltage, wherein the maximum and minimum cell voltage corresponds to the corresponding adjusted charge retention point.

[0103] Optionally, in some alternative embodiments, the holding point adjustment unit 100 includes: a holding point adjustment subunit;

[0104] The holding point adjustment subunit is used to adjust the holding point of the target battery according to the formula Vnew=f(Vold,R,I) before the displayed charge of the target battery reaches the calibrated state of charge, where Vold is the previously calibrated holding point, Vnew is the adjusted holding point, R is the resistance, and I is the electrical resistance.

[0105] Optionally, in some alternative embodiments, the voltage maximum / minimum value acquisition unit 200 includes: a maximum value acquisition subunit;

[0106] The maximum value acquisition subunit is used to acquire the corresponding maximum cell voltage of the target battery when the displayed charge of the target battery reaches the calibrated state of charge, and if the current charge / discharge state of the target battery is the charging state.

[0107] Optionally, in some alternative implementations, the maximum value acquisition subunit includes: a first voltage acquisition subunit and a maximum value determination subunit;

[0108] The first voltage acquisition subunit is used to acquire the actual voltage value of each cell of the target battery when the displayed charge of the target battery reaches the calibrated state of charge, if the current charge / discharge state of the target battery is the charging state.

[0109] The maximum value determination subunit is used to determine the largest actual voltage value from the actual voltage values ​​of each cell as the corresponding maximum cell voltage value of the target battery.

[0110] Optionally, in some alternative embodiments, the state of charge determination unit 300 includes: a first state determination subunit;

[0111] The first state determination subunit is used to determine the current state of charge of the target battery based on the maximum cell voltage and the calibration voltage of the corresponding adjusted first charge retention point, wherein the first charge retention point is the charge retention point corresponding to the upper limit of the state of charge of the charging state.

[0112] Optionally, in some alternative implementations, the first state determination subunit includes: a first calculation subunit and a first determination subunit;

[0113] The first calculation subunit is used to maintain the ampere-hour integration calculation of the target battery if the maximum value of the cell voltage is greater than the calibration voltage of the first charge holding point, thereby calculating the current state of charge of the target battery.

[0114] The first determining subunit is used to determine the current state of charge of the target battery as the calibrated state of charge of the first charge holding point if the maximum value of the cell voltage is not greater than the calibration voltage of the first charge holding point.

[0115] Optionally, in some alternative embodiments, the voltage maximum / minimum value acquisition unit 200 includes: a minimum value acquisition subunit;

[0116] The minimum value acquisition subunit is used to acquire the minimum cell voltage of the target battery when the displayed charge of the target battery reaches the calibrated state of charge, and if the current charge / discharge state of the target battery is the discharge state.

[0117] Optionally, in some alternative implementations, the minimum value acquisition subunit includes: a second voltage acquisition subunit and a minimum value determination subunit;

[0118] The second voltage acquisition subunit is used to acquire the actual voltage value of each cell of the target battery when the displayed charge of the target battery reaches the calibrated state of charge, if the current charge / discharge state of the target battery is the discharge state.

[0119] The minimum value determination subunit is used to determine the minimum actual voltage value from the actual voltage values ​​of each of the cells as the minimum cell voltage value of the target battery.

[0120] Optionally, in some alternative embodiments, the state of charge determination unit 300 includes: a second state determination subunit;

[0121] The second state determination subunit is used to determine the current state of charge of the target battery based on the minimum cell voltage and the calibration voltage of the corresponding adjusted second charge retention point, wherein the second charge retention point is the charge retention point corresponding to the state of charge limit of the discharge state.

[0122] Optionally, in some alternative embodiments, the second state determination subunit includes: a second calculation subunit and a second determination subunit;

[0123] The second calculation subunit is used to maintain the ampere-hour integration calculation on the target battery if the minimum value of the cell voltage is less than the calibration voltage of the second charge holding point, thereby calculating the current state of charge of the target battery.

[0124] The second determining subunit is used to determine the current state of charge of the target battery as the calibrated state of charge of the second charge retention point if the minimum value of the cell voltage is not less than the calibration voltage of the second charge retention point.

[0125] Optionally, in some alternative embodiments, the device further includes: a display unit;

[0126] The method is used to display the current state of charge of the target battery on a display screen after determining the current state of charge of the target battery based on the maximum value of the cell voltage and the calibration voltage of the corresponding adjusted charge retention point.

[0127] Optionally, in some alternative embodiments, the device further includes a point calibration unit;

[0128] The hold point calibration unit includes: a voltage curve acquisition subunit and a hold point calibration subunit;

[0129] The holding point calibration unit is used for the calibration process of the pre-calibrated charge holding point of the target battery;

[0130] The voltage curve acquisition subunit is used to obtain a pre-calibrated first voltage curve, wherein the calibration of the first voltage curve is based on the rate matching of the target battery, and the calibration of the first voltage curve is based on the temperature matching the current temperature of the target battery.

[0131] The holding point calibration subunit is used to select the voltage and corresponding state of charge of at least one point from the first voltage curve to calibrate the charge holding point of the target battery, wherein one point in the first voltage curve corresponds to one charge holding point.

[0132] The present invention provides a computer-readable storage medium having a program stored thereon, which, when executed by a processor, implements the state of charge determination method described in any of the preceding claims.

[0133] like Figure 7 As shown, the present invention provides an electronic device 70, which includes at least one processor 701, at least one memory 702 and a bus 703 connected to the processor 701; wherein the processor 701 and the memory 702 communicate with each other through the bus 703; the processor 701 is used to call program instructions in the memory 702 to execute the state of charge determination method described above.

[0134] In this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, without necessarily requiring or implying any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0135] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0136] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined in this invention may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0137] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A method for determining the state of charge, characterized in that, include: Before the displayed charge of the target battery reaches the calibrated state of charge, the charge holding point pre-calibrated for the target battery is adjusted according to the resistance and current of the target battery, wherein the charge holding point includes the calibrated state of charge, calibrated voltage and calibrated current; When the displayed charge of the target battery reaches the calibrated state of charge, the corresponding maximum cell voltage value is collected according to the current charge / discharge state of the target battery, wherein the current charge / discharge state corresponds to the maximum cell voltage value. The current state of charge of the target battery is determined based on the maximum and minimum cell voltage and the corresponding adjusted charge retention point calibration voltage, wherein the maximum and minimum cell voltage corresponds to the corresponding adjusted charge retention point. The adjustment is aimed at the pre-calibrated charge retention point of the target battery, including: adjusting the calibration voltage and calibration current in the charge retention point to keep the calibration state of charge unchanged.

2. The method according to claim 1, characterized in that, Before the displayed charge level of the target battery reaches the calibrated state of charge, adjusting the pre-calibrated charge holding point for the target battery based on the resistance and current of the target battery includes: Before the target battery's displayed charge reaches the calibrated state of charge, the charge holding point of the target battery is adjusted according to the formula Vnew = f(Vold,R,I), where Vold is the previously calibrated charge holding point, Vnew is the adjusted charge holding point, R is the resistance, and I is the current.

3. The method according to any one of claims 1-2, characterized in that, When the displayed charge level of the target battery reaches the calibrated state of charge, the corresponding maximum cell voltage value is collected based on the current charge / discharge state of the target battery, including: When the displayed charge of the target battery reaches the calibrated state of charge, if the current charge / discharge state of the target battery is charging, then the maximum value of the corresponding cell voltage of the target battery is collected.

4. The method according to claim 3, characterized in that, When the displayed charge level of the target battery reaches the calibrated state of charge, if the current charge / discharge state of the target battery is charging, then the maximum value of the corresponding cell voltage of the target battery is collected, including: When the displayed charge of the target battery reaches the calibrated state of charge, if the current charge / discharge state of the target battery is the charging state, then the actual voltage value of each cell of the target battery is collected. The largest actual voltage value among the actual voltage values ​​of each cell is determined as the maximum cell voltage value of the target battery.

5. The method according to claim 4, characterized in that, Determining the current state of charge of the target battery based on the maximum and minimum cell voltage and the corresponding adjusted calibration voltage of the charge retention point includes: The current state of charge of the target battery is determined based on the maximum cell voltage and the corresponding adjusted calibration voltage of the first charge retention point, wherein the first charge retention point is the charge retention point corresponding to the upper limit of the state of charge corresponding to the charging state.

6. The method according to claim 5, characterized in that, Determining the current state of charge of the target battery based on the maximum cell voltage and the corresponding adjusted calibration voltage of the first charge retention point includes: If the maximum value of the cell voltage is greater than the calibrated voltage of the first charge holding point, then the ampere-hour integration calculation is continued for the target battery to obtain the current state of charge of the target battery. If the maximum value of the cell voltage is not greater than the calibration voltage of the first charge retention point, then the current state of charge of the target battery is determined to be the calibration state of charge of the first charge retention point.

7. The method according to any one of claims 1-2, characterized in that, When the displayed charge level of the target battery reaches the calibrated state of charge, the corresponding maximum cell voltage value is collected based on the current charge / discharge state of the target battery, including: When the displayed charge of the target battery reaches the calibrated state of charge, if the current charge / discharge state of the target battery is the discharge state, then the minimum value of the corresponding cell voltage of the target battery is collected.

8. The method according to claim 7, characterized in that, When the displayed charge of the target battery reaches the calibrated state of charge, if the current charge / discharge state of the target battery is a discharge state, then the minimum value of the corresponding cell voltage of the target battery is collected, including: When the displayed charge of the target battery reaches the calibrated state of charge, if the current charge / discharge state of the target battery is the discharge state, the actual voltage value of each cell of the target battery is collected. The minimum actual voltage value among the actual voltage values ​​of each cell is determined as the minimum cell voltage value of the target battery.

9. The method according to claim 8, characterized in that, Determining the current state of charge of the target battery based on the maximum and minimum cell voltage and the corresponding adjusted calibration voltage of the charge retention point includes: The current state of charge of the target battery is determined based on the minimum cell voltage and the calibrated voltage of the corresponding adjusted second charge retention point, wherein the second charge retention point is the charge retention point corresponding to the state of charge limit of the discharge state.

10. The method according to claim 9, characterized in that, Determining the current state of charge of the target battery based on the minimum cell voltage and the corresponding adjusted calibration voltage of the second charge retention point includes: If the minimum cell voltage is less than the calibrated voltage of the second charge retention point, then the ampere-hour integration calculation is continued for the target battery to obtain the current state of charge of the target battery. If the minimum cell voltage is not less than the calibration voltage of the second charge retention point, then the current state of charge of the target battery is determined to be the calibration state of charge of the second charge retention point.

11. The method according to any one of claims 1-2, characterized in that, After determining the current state of charge of the target battery based on the maximum cell voltage and the corresponding adjusted calibration voltage of the charge retention point, the method further includes: The current state of charge of the target battery is displayed on the screen.

12. The method according to any one of claims 1-2, characterized in that, The calibration process for the pre-calibrated charge retention point of the target battery includes: A first voltage curve is obtained through pre-calibration, wherein the rate on which the first voltage curve is calibrated matches the rate of the target battery, and the temperature on which the first voltage curve is calibrated matches the current temperature of the target battery. Select at least one point of voltage and corresponding state of charge from the first voltage curve to calibrate the charge retention point of the target battery, wherein one point in the first voltage curve corresponds to one charge retention point.

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