CN107783051B

CN107783051B - Full charge capacity calibration method

Info

Publication number: CN107783051B
Application number: CN201610799535.9A
Authority: CN
Inventors: 张峰铭
Original assignee: Taipu Power New Energy Changshu Co ltd
Current assignee: Taipu Power New Energy Changshu Co ltd
Priority date: 2016-08-30
Filing date: 2016-08-30
Publication date: 2020-08-21
Anticipated expiration: 2036-08-30
Also published as: CN107783051A; TW201809714A; TWI613454B

Abstract

The invention discloses a full charge capacity calibration method, which is characterized in that a first curve and a first adjustment table of a healthy battery (namely, a battery with low cycle number) and a second curve and a second adjustment table of an aged battery (namely, a battery with high cycle number) are established in advance. The first curve represents the OCV value versus the SOC value of a healthy battery. The second curve represents OCV values versus SOC values for an aged battery. The first adjustment table represents the relationship between the OCV value of the healthy battery and a first adjustment value. The second adjustment table represents a relationship between the OCV value of the aged battery and a second adjustment value. Then, the full charge capacity of the battery is adjusted according to the current OCV value, the current temperature and the charging cycle number of the battery, so as to obtain the accurate full charge capacity.

Description

Full charge capacity calibration method

Technical Field

The present invention relates to a full charge capacity calibration method, and more particularly, to a calibration method for calibrating a full charge capacity according to a degree of aging of a battery and a current operating temperature.

Background

Recently, rechargeable batteries are widely used as energy sources for mobile devices, auxiliary power devices, Electric Vehicles (EVs), Hybrid Electric Vehicles (HEVs), plug-in hybrid electric vehicles (plug-in HEVs), or similar electronic devices. The chargeable and dischargeable battery supplements the originally consumed electric energy back through a charging mode, and when the battery is fully charged relates to when the battery stops receiving charging power. Therefore, it is very important to determine accurate Full Charge Capacity (FCC) information of the battery.

However, the FCC information for a rechargeable battery can easily change as the battery ages and at the current operating temperature. Here, the battery aging indicates that the battery is repeatedly charged (i.e., the number of charge cycles) several hundred or more. The current operating temperature is the temperature at which the battery is actually operating. Therefore, it is important how to accurately measure the FCC of cells with different levels of aging and current operating temperatures.

Disclosure of Invention

In one embodiment, a Full Charge Capacity (FCC) calibration method for estimating a full charge capacity of a battery is disclosed. The full charge capacity calibration method comprises the following steps: detecting that the battery is in an Open Circuit Voltage (OCV) state; analyzing a current OCV value, a current temperature and a cycle count of the battery; adjusting a healthy battery electric quantity (SOC) value corresponding to the current OCV value in a first curve according to a first adjustment table; judging whether the number of charging cycles is greater than a preset number; if the charging cycle number is larger than a preset number, the execution steps comprise: adjusting an aging SOC value corresponding to the current OCV value in a second curve according to a second adjusting table; calculating a current SOC value corresponding to the charging cycle times between the adjusted healthy SOC value and the adjusted aging SOC value; and determining whether there is an initial value. If no initial value is determined, the current SOC value is taken as the initial value, an electric quantity of the battery for charging or discharging is accumulated, and whether the battery is in the OCV state is determined again. If the initial value is determined, the current SOC value is used as an end value, the full charge capacity of the battery is estimated according to the initial value, the end value and the accumulated electric quantity, and the initial value and the end value are cleared.

Preferably, in the full charge capacity calibration method, the battery is in the OCV state representing a state in which the battery stops being charged or discharged for a certain period of time.

Preferably, in the full-charge capacity calibration method, the first curve is a relationship between a current OCV value and a healthy SOC value of the healthy battery at a first temperature, the third curve is a relationship between a current OCV value and a healthy SOC value of the healthy battery at a third temperature, the first adjustment table is a relationship between a current OCV value and a first adjustment value, and the first adjustment value is a difference between a healthy SOC value corresponding to the current OCV value of the first curve and a healthy SOC value corresponding to the current OCV value of the third curve.

Preferably, in the step of adjusting the healthy SOC value, the method further includes: acquiring a first adjusting value corresponding to the current OCV value from a first adjusting table; and adjusting the healthy SOC value corresponding to the current OCV value in the first curve according to the first adjustment value.

Preferably, in the full charge capacity calibration method, the first temperature is higher than the third temperature.

Preferably, in the full charge capacity calibration method, the second curve is a relationship between a current OCV value and an aged SOC value of an aged battery at a second temperature. A fourth curve is the relationship between the current OCV value and the aged SOC value of the aged battery at a fourth temperature. The second adjustment table is a second adjustment value corresponding to the current OCV value, and the second adjustment value is a difference between an aged SOC value corresponding to the current OCV value of the second curve and an aged SOC value corresponding to the current OCV value of the fourth curve.

Preferably, in the step of adjusting the aging SOC value, the method further includes: obtaining a second adjusting value corresponding to the current OCV value in a second adjusting table; and adjusting the aging SOC value corresponding to the current OCV value in the second curve according to the second adjustment value.

Preferably, in the full charge capacity calibration method, the second temperature is higher than the fourth temperature.

Preferably, in the full charge capacity calibration method, if the number of charging cycles is determined to be less than or equal to the predetermined number, the executing step includes: judging whether an initial value exists or not; if no initial value is judged, the adjusted healthy SOC value is used as the initial value, the electric quantity of the battery for charging or discharging is accumulated, and whether the battery is in the OCV state is judged again; and if the initial value is judged, taking the adjusted healthy SOC value as an end value, estimating the full charge capacity of the battery according to the initial value, the end value and the accumulated electric quantity, and clearing the initial value and the end value.

Preferably, in the full charge capacity calibration method, the first curve is a relationship between a current OCV value and a healthy SOC value of a healthy battery at a first temperature with a first number of charge cycles. The second curve is a relationship between a current OCV value and an aged SOC value of an aged battery having a second number of charge cycles at a second temperature. And in the step of calculating the current SOC value corresponding to the number of charging cycles, the method further includes: and calculating the current SOC value corresponding to the charging cycle times by an interpolation method between the adjusted healthy SOC value and the adjusted aging SOC value according to the first charging cycle times and the second charging cycle times.

In another embodiment, a full charge capacity calibration method for estimating a full charge capacity of a battery is disclosed. The full charge capacity calibration method comprises the following steps: detecting that the battery is in an Open Circuit Voltage (OCV) state; analyzing a current OCV value, a current temperature and a charging cycle number of the battery; adjusting a healthy battery electric quantity (SOC) value corresponding to the current OCV value in a first curve according to a first adjusting table; judging whether the number of charging cycles is greater than a preset number; if the charging cycle number is larger than a preset number, the execution steps comprise: adjusting an aging SOC value corresponding to the current OCV value in a second curve according to a second adjusting table; calculating a current SOC value corresponding to the charging cycle times between the adjusted healthy SOC value and the adjusted aging SOC value; and using the current SOC value as a starting value and accumulating an electric quantity charged by the battery. When the battery reaches a fully charged state, a fully charged SOC value of the fully charged state is used as an end value, the full charge capacity of the battery is estimated according to the initial value, the end value and the accumulated electric quantity, and the initial value and the end value are cleared.

Preferably, in the full charge capacity calibration method, if the number of charging cycles is determined to be less than or equal to the predetermined number, the executing step includes: taking the adjusted health SOC value as an initial value, and accumulating the charged electric quantity of the battery; and when the battery reaches the full charge state, taking the full charge SOC value of the full charge state as an end value, estimating the full charge capacity of the battery according to the initial value, the end value and the accumulated electric quantity, and clearing the initial value and the end value.

In summary, the full charge capacity calibration method disclosed in the embodiments of the present invention pre-establishes the relationship between the OCV value and the SOC value at different temperatures between the aged battery (the battery with the high number of charge cycles) and the healthy battery (the battery with the low number of charge cycles). Then, the current full charge capacity of the battery is adjusted according to the established relationship, the aging degree of the battery and the current operating temperature, so as to obtain the accurate full charge capacity.

For a better understanding of the nature and technical content of the present invention, reference should be made to the following detailed description of the invention and the accompanying drawings, which are provided for illustration purposes only and are not intended to limit the scope of the invention.

Drawings

Fig. 1 is a schematic diagram of an electronic device to which a full charge capacity calibration method according to an embodiment of the invention is applied.

Fig. 2 is a flowchart of a full charge capacity calibration method according to an embodiment of the present invention.

Fig. 3A is a schematic diagram of a first curve and a second curve according to an embodiment of the invention.

FIG. 3B is a diagram of the first adjustment table of FIG. 3A.

Fig. 4A is a schematic diagram of a third curve and a fourth curve provided in the embodiment of the present invention.

FIG. 4B is a diagram of the second adjustment table of FIG. 4A.

Fig. 5 is a schematic diagram of an adjusted healthy SOC value and an adjusted aged SOC value according to an embodiment of the present invention.

Fig. 6 is a detailed flowchart of step S230 according to an embodiment of the present invention.

Fig. 7 is a detailed flowchart of step S250 according to an embodiment of the present invention.

Fig. 8 is a flowchart of a full charge capacity calibration method according to another embodiment of the invention.

Detailed Description

Hereinafter, the present invention will be described in detail by illustrating various exemplary embodiments thereof through the accompanying drawings. The inventive concept may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. Moreover, in the drawings, like reference numerals may be used to designate similar components.

The embodiment of the invention discloses a full charge capacity calibration method, which is characterized in that a first curve and a first adjustment table of a healthy battery and a second curve and a second adjustment table of an aged battery are established in advance. Wherein the first curve represents the OCV value versus the SOC value for a healthy battery having a low number of charge cycles (e.g., 0). The second curve represents OCV versus SOC values for an aged battery having a high number of charge cycles (e.g., 300). The first adjustment table represents the relationship between the OCV value of the healthy battery and a first adjustment value. The second adjustment table represents a relationship between the OCV value of the aged battery and a second adjustment value. The OCV value represents the voltage measured by the battery without any charge-discharge action. The SOC value represents the state of available electrical energy in the battery and is typically expressed in percentage. Then, the full charge capacity of the battery is adjusted according to the current OCV value, the current temperature and the charging cycle number of the battery, so as to obtain the accurate full charge capacity. The full charge capacity calibration method disclosed in the present invention will be further described below.

First, please refer to fig. 1, which shows a schematic diagram of an electronic device with a full charge capacity calibration method according to an embodiment of the present invention. As shown in fig. 1, the electronic device 100 is coupled to a battery 110 for estimating a full charge capacity of the battery 110. In the present embodiment, the electronic device 100 may be a mobile device, an auxiliary power device, an Electric Vehicle (EV), a Hybrid Electric Vehicle (HEV), a plug-in hybrid electric vehicle (plug-in HEV), or other electronic devices that can charge and discharge the battery 110, which is not limited by the present invention.

How the electronic device 100 estimates the full charge capacity of the battery 110 will be further described below. Please refer to fig. 2, which shows a flowchart of a full charge capacity calibration method according to an embodiment of the present invention. First, the electronic device 100 detects whether the battery 110 is in an Open Circuit Voltage (OCV) state (step S210). The OCV state indicates a state in which the battery 110 is not subjected to any charge and discharge operation. In the present embodiment, the OCV state of the battery 110 represents a state in which the battery 110 stops charging or discharging for a certain period of time (e.g., 1 hour).

If the electronic device 100 detects that the battery 110 is not in the OCV state, it will detect whether the battery 110 is in the OCV state again. The next step is not performed until the electronic device 100 detects that the battery 110 is in the OCV state. On the contrary, if the electronic device 100 detects that the battery 110 is in the OCV state, it will start to analyze a current OCV value, a current temperature and a number of charging cycles (i.e. the number of times the battery 110 is repeatedly charged) of the battery 110 (step S220).

Referring to fig. 2, fig. 3A and fig. 3B, next, the electronic device 100 adjusts the healthy SOC value corresponding to the current OCV value in the first curve Cv1 according to a first adjustment table Tb1 (step S230). In the present embodiment, as shown in fig. 3A, the first curve Cv1 is a relationship between a current OCV value and a healthy SOC value of a healthy battery (not shown in the drawing) at a first temperature T1. The third curve Cv3 is the relationship between the current OCV value and the healthy SOC value of the healthy battery at a third temperature T3. As shown in fig. 3B, the first adjustment table Tb1 is a relationship between the current OCV value and a first adjustment value, and the first adjustment value is a difference between the healthy SOC value corresponding to the current OCV value of the first curve Cv1 and the healthy SOC value corresponding to the current OCV value of the third curve Cv 3.

In the present embodiment, the first curve Cv1, the third curve Cv3 and the first adjustment table Tb1 are previously established by the user, and the first temperature T1 is higher than the third temperature T3, so as to take the current operating temperature of the healthy battery into account. The first curve Cv1 has a relationship between an OCV value and a healthy SOC value of the healthy battery with the first number of charging cycles N1 (e.g., N1 is 0) at the first temperature T1 (e.g., the first temperature T1 of fig. 3A is 25 ℃), that is, each OCV value corresponds to a healthy SOC value. For example, the current OCV value of FIG. 3A is 3.65(V), which corresponds to a healthy SOC value of 50%. The third curve Cv3 shows the relationship between the OCV value and the healthy SOC value of the healthy battery at the third temperature T3 (e.g., the third temperature T3 of fig. 3A is 40 ℃), i.e., each OCV value corresponds to a healthy SOC value. For example, the current OCV value of fig. 3A is 3.65(V), which corresponds to a healthy SOC value of 47%.

The first adjustment table Tb1 is a relationship between the current OCV value and a first adjustment value. The first adjustment value is a difference between the healthy SOC value corresponding to the current OCV value of the first curve Cv1 and the healthy SOC value corresponding to the current OCV value of the third curve Cv 3. For example, as shown in fig. 3A, the current OCV value of the first curve Cv1 is 3.65(V), which corresponds to a healthy SOC value of 50%. The current OCV value of the third curve Cv3 is 3.65(V), which corresponds to a healthy SOC value of 47%. Therefore, the difference is 50% to 47% to 3%, that is, the current OCV value (3.65V) corresponds to the first adjustment value of 3%. Therefore, the user can find the corresponding first adjustment value under different OCV values to form the first adjustment table Tb1 of fig. 3B accordingly.

In step S230, the following steps are further included to enable the electronic device 100 to adjust the healthy SOC value corresponding to the current OCV value in the first curve Cv1 according to the first adjustment table Tb 1. Please refer to fig. 6, which shows a detailed flowchart of step S230 according to the disclosure of the present invention. First, the electronic device 100 obtains a first adjustment value corresponding to the current OCV value from the first adjustment table Tb1 (step S610). Then, the electronic device 100 adjusts the healthy SOC value corresponding to the current OCV value in the first curve Cv1 according to the first adjustment value (step S620).

For example, the electronic device 100 detects that the current OCV value of the battery 110 is 3.65V, the current temperature is 30 ℃, and the number of charging cycles is 150 in step 220. At this time, the electronic device 100 obtains the first adjustment value corresponding to the current OCV value (i.e., 3.65V) in the first adjustment table Tb1 as 3%. Next, the electronic device 100 obtains the healthy SOC value corresponding to the current OCV value from the first curve Cv1 in fig. 3A as 50%, and subtracts the healthy SOC value by the first adjustment value, i.e., 50% -3% — 47%, to thereby complete the adjusted healthy SOC value. At this time, the first curve Cv1 of fig. 3A is obtained to obtain a healthy SOC value corresponding to the current OCV value, and the healthy SOC value is adjusted from 50% to 47% so that the first curve Cv1 of the healthy battery is adjusted to a healthy SOC value corresponding to the current temperature.

Next, the electronic device 100 determines whether the number of charging cycles is greater than a predetermined number (step S240). If the electronic device 100 determines that the number of charging cycles is equal to or less than the predetermined number, it indicates that the number of charging cycles of the battery 110 is close to the number of charging cycles of a healthy battery (i.e., a battery with a low number of charging cycles), and it is not necessary to consider the condition of an aged battery (i.e., a battery with a high number of charging cycles). At this time, the electronic device 100 executes steps S255, S257 and S259 to estimate the full charge capacity of the battery 110 according to the first curve Cv1 and the first adjustment table Tb 1.

More specifically, in steps S255-S259, the electronic device 100 first determines whether there is a starting value to determine whether the full charge capacity of the battery 110 can be calculated (step S255). If the electronic device 100 determines that there is no initial value, it indicates that sufficient information (i.e., the initial value, the end value, and the accumulated amount of power) to calculate the full charge capacity of the battery 110 has not been obtained. At this time, the electronic device 100 uses the adjusted healthy SOC value as a starting value, and then accumulates the amount of electricity charged or discharged by the battery 110 (step S257). In the present embodiment, the accumulated amount of electricity is an amount of electricity accumulated for a period of continuous charging or discharging, or an amount of electricity accumulated under a plurality of discontinuous charging or discontinuous discharging. The accumulated electric quantity may be accumulated in other ways, which is not limited in the present invention.

In response to the above example, if the predetermined number of times is set to 20, the number of charging cycles of the battery 110 is 10, and the electronic device 100 executes the steps S220-S240 for the first time, the electronic device 100 determines that there is no initial value. At this time, the electronic device 100 uses the adjusted healthy SOC value, i.e. 47%, as a starting value, and then accumulates the amount of electricity charged or discharged by the battery 110, for example, the amount of electricity accumulated for a period of time after charging or discharging is 4 ampere hours (Ah). After step S257 is completed, the electronic device 100 will re-determine whether the battery is in the OCV state (i.e., return to step S210) to perform the next steps S220-S240.

On the contrary, if the electronic device 100 determines that there is the initial value, it indicates that sufficient information for calculating the full charge capacity of the battery 110 has been obtained. At this time, the electronic device 100 uses the adjusted healthy SOC value as an end value, estimates the full charge capacity according to the start value, the end value and the accumulated electric quantity, and clears the start value and the end value (step S259). In the present embodiment, the full charge capacity is calculated by an FCC equation as follows: full Charge Capacity (FCC) — accumulated charge/(end value — start value).

In connection with the above example, the electronic device 100 first executes steps S220-S240 to obtain an initial value of 47% and an accumulated power of 4 Ah. When the electronic device 100 performs the steps S220-S240 for the second time, the electronic device 100 determines that there is a start value. At this time, the electronic device 100 sets the adjusted healthy SOC value generated by executing steps S220 to S240 for the second time as an end value, for example, 85%. The electronic device 100 obtains the full charge capacity through calculation by the FCC equation, that is, the Full Charge Capacity (FCC) is 4/(85% -47%) is 10.5 Ah. For another example, the initial value is 47%, the accumulated amount of power is 5.5Ah, and the end value is 100% (i.e., the full state), the electronic device 100 obtains the full charge capacity through the FCC equation, i.e., the Full Charge Capacity (FCC) is 5.5/(100% -47%) is 10.4 Ah. After calculating the full charge capacity, the electronic device 100 clears the start value and the end value to complete the estimation of the full charge capacity of the battery 110. Furthermore, the electronic device 100 may stop estimating the full charge capacity of the battery 110, estimate the full charge capacity of the battery 110 after a certain period of time, or immediately determine whether the battery is in the OCV state again (i.e. go back to step S210), which is not limited by the invention.

Accordingly, the electronic device 100 estimates the full charge capacity of the battery 110 at the current temperature (i.e., 30 ℃) and the cycle number (i.e., 10), so as to correct the full charge capacity to the full charge capacity more suitable for the current condition of the battery 110.

Referring to fig. 2, fig. 4A and fig. 4B, if the electronic device 100 determines that the number of charging cycles is greater than the predetermined number, it indicates that the number of charging cycles of the battery is close to the number of charging cycles of the aged battery (i.e., the battery with a high number of charging cycles), and the condition of the aged battery needs to be considered. At this time, the electronic device 100 adjusts the aging SOC value corresponding to the current OCV value in a second curve Cv2 according to a second adjustment table Tb2 (step S250). In the present embodiment, as shown in fig. 4A, the second curve Cv2 is a relationship between a current OCV value and an aged SOC value of an aged battery (not shown in the drawing) at a second temperature T2. The fourth curve Cv4 is the relationship between the current OCV value and the aged SOC value of the aged battery at a fourth temperature T4. As shown in fig. 4B, the second adjustment table Tb2 is a relationship between the current OCV value and a second adjustment value, and the second adjustment value is a difference between the aged SOC value corresponding to the current OCV value of the second curve Cv2 and the aged SOC value corresponding to the current OCV value of the fourth curve Cv 4.

In the present embodiment, the user previously establishes the second curve Cv2, the fourth curve Cv4 and the second adjustment table Tb2, and the second temperature T2 is higher than the fourth temperature T4 to take the current operating temperature of the aged battery into account. The second curve Cv2 shows the relationship between the OCV value and the aged SOC value of the aged battery with the second cycle number N2 (e.g., N2 is 300) at the second temperature T2 (e.g., the second temperature T2 in fig. 4A is 25 ℃), i.e., each OCV value corresponds to an aged SOC value. For example, the current OCV value of FIG. 4A is 3.65(V), which corresponds to an aged SOC value of 45%. The fourth curve Cv4 shows the relationship between the OCV value and the aged SOC value of the aged battery at the fourth temperature T4 (e.g., the fourth temperature T4 of fig. 4A is 40 ℃), i.e., each OCV value corresponds to an aged SOC value. For example, the current OCV value of FIG. 4A is 3.65(V), which corresponds to an aged SOC value of 42%.

The second adjustment table Tb2 is a relationship between the current OCV value and a second adjustment value. The second adjustment value is a difference between the aged SOC value corresponding to the current OCV value of the second curve Cv2 and the aged SOC value corresponding to the current OCV value of the fourth curve Cv 4. For example, as shown in fig. 4A, the current OCV value of the second curve Cv2 is 3.65(V), which corresponds to a healthy SOC value of 45%. The current OCV value of the fourth curve Cv4 is 3.65(V), which corresponds to a healthy SOC value of 42%. Therefore, the difference is 45% -42%, which is 3%, that is, the current OCV value (3.65V) corresponds to the second adjustment value of 3%. Therefore, the user can find the corresponding second adjustment value under different OCV values to form the second adjustment table Tb2 of fig. 4B accordingly.

In step S250, the following steps are further included to enable the electronic device 100 to adjust the aged SOC value corresponding to the current OCV value in the second curve Cv2 according to the second adjustment table Tb 2. Please refer to fig. 7, which shows a detailed flowchart of step S250 according to the disclosure of the present embodiment. First, the electronic device 100 obtains a second adjustment value corresponding to the current OCV value from the second adjustment table Tb2 (step S710). Then, the electronic device 100 adjusts the aging SOC value corresponding to the current OCV value in the second curve Cv2 according to the second adjustment value (step S720).

For example, the electronic device 100 detects that the current OCV value of the battery 110 is 3.65V, the current temperature is 30 ℃, and the number of charging cycles is 150 in step 220. At this time, the electronic device 100 obtains the second adjustment value corresponding to the current OCV value (i.e., 3.65V) in the second adjustment table Tb2 as 3%. Next, the electronic device 100 obtains the aged SOC value corresponding to the current OCV value from the second curve Cv2 in fig. 4A as 45%, and subtracts a second adjustment value, i.e., 45% -3%, from the aged SOC value as 42%, so as to complete the adjusted aged SOC value. At this time, the second curve Cv2 of fig. 4A takes the aged SOC value corresponding to the current OCV value, and adjusts the aged SOC value from 45% to 42% so as to adjust the second curve Cv2 of the aged battery to the aged SOC value corresponding to the current temperature.

As shown in fig. 5, a first curve Cv1 is a relationship between a current OCV value and a healthy SOC value of a healthy battery having a first number of charge cycles N1 (i.e., 0) at a first temperature T1 (i.e., 25 ℃). The second curve Cv2 is the current OCV value versus the aged SOC value for the aged battery having a second number of charge cycles N2 (i.e., 300) at a second temperature T2. Since the electronic device 100 takes the current operating temperatures of the healthy and aged batteries into account, the healthy SOC value (i.e., 50%) corresponding to the current OCV value (i.e., 3.65V) of the first curve Cv1 will shift left by the first adjustment value (i.e., 3%) to the adjusted healthy SOC value (i.e., 47%), and the aged SOC value (i.e., 45%) corresponding to the current OCV value (i.e., 3.65V) of the second curve Cv2 will shift left by the second adjustment value (i.e., 3%) to the adjusted aged SOC value (i.e., 42%).

After obtaining the adjusted healthy SOC value and the adjusted aged SOC value, the electronic device 100 calculates a current SOC value corresponding to the number of charging cycles between the adjusted healthy SOC value and the adjusted aged SOC value (step S260). More specifically, the electronic device 100 calculates the current SOC value corresponding to the number of charging cycles by an interpolation method between the adjusted healthy SOC value and the adjusted aged SOC value according to the first number of charging cycles N1 and the second number of charging cycles N2.

Taking the above example into account, the adjusted healthy SOC value is 47% (corresponding to the first charging cycle number N1 being 0), the adjusted aged SOC value is 42% (corresponding to the second charging cycle number N2 being 300), and the charging cycle number is 150. Therefore, the electronic device 100 will calculate the value of 150 times to 44.5% by interpolation between 47% (corresponding to 0 times) and 42% (corresponding to 300 times) according to the interpolation, and set 44.5% as the current SOC value corresponding to the number of charging cycles. At this time, the current SOC value corresponding to the number of charging cycles obtained from the adjusted healthy SOC value and the adjusted aged SOC value corresponds to the current temperature and the number of charging cycles of the battery 110.

After acquiring the current SOC value corresponding to the number of charging cycles of the battery 110 (i.e., step S260), the electronic device 100 then determines whether there is a starting value to determine whether the full charge capacity of the battery 110 can be calculated (step S270). If the electronic device 100 determines that there is no initial value, it indicates that sufficient information (i.e., the initial value, the end value, and the accumulated amount of power) to calculate the full charge capacity of the battery 110 has not been obtained. At this time, the electronic device 100 uses the current SOC value as the initial value, and then accumulates the amount of electricity charged or discharged by the battery 110 (step S280). In the present embodiment, the accumulated amount of electricity is an amount of electricity accumulated for a period of continuous charging or discharging, or an amount of electricity accumulated under a plurality of discontinuous charging or discontinuous discharging. The accumulated electric quantity may be accumulated in other ways, which is not limited in the present invention.

In response to the above example, if the predetermined number of times is set to 20, the number of charging cycles of the battery 110 is 150, and the electronic device 100 executes the steps S250 to S260 for the first time, the electronic device 100 determines that there is no initial value. At this time, the electronic device 100 uses the current SOC value, i.e. 44.5%, as the initial value, and then accumulates the amount of electricity charged or discharged by the battery 110, for example, the accumulated amount of electricity after charging or discharging for a certain time is 6 Ah. After step S280 is completed, the electronic device 100 will determine whether the battery is in the OCV state again (i.e., return to step S210) to perform steps S220-S260 again.

On the contrary, if the electronic device 100 determines that there is the initial value, it indicates that sufficient information for calculating the full charge capacity of the battery 110 has been obtained. At this time, the electronic device 100 uses the current SOC value as the end value, estimates the full charge capacity according to the start value, the end value and the accumulated electric quantity, and clears the start value and the end value (step S290). In this embodiment, the full charge capacity is also calculated by an FCC equation as follows: full Charge Capacity (FCC) — accumulated charge/(end value — start value).

In connection with the above example, the electronic device 100 first executes steps S220-S260 to obtain an initial value of 44.5% and an accumulated power of 6 Ah. When the electronic device 100 performs steps S220-S260 for the second time, the electronic device 100 determines that there is a start value. At this time, the electronic device 100 sets the adjusted healthy SOC value generated by executing steps S220 to S260 for the second time as an end value, for example, 85%. The electronic device 100 obtains the full charge capacity through the calculation of the FCC equation, that is, the Full Charge Capacity (FCC) is 6/(85% -44.5%) -14.8 Ah. For another example, the initial value is 44.5%, the accumulated amount of electricity is 7.5Ah, and the end value is 100% (i.e., fully charged), the electronic device 100 obtains the full charge capacity through the calculation of the FCC equation, i.e., the Full Charge Capacity (FCC) is 7.5/(100% -44.5%) is 13.5 Ah. After calculating the full charge capacity, the electronic device 100 clears the start value and the end value to complete the estimation of the full charge capacity of the battery 110. Furthermore, the electronic device 100 may stop estimating the full charge capacity of the battery 110, estimate the full charge capacity of the battery 110 after a certain period of time, or immediately determine whether the battery is in the OCV state again (i.e. go back to step S210), which is not limited by the invention.

Accordingly, the electronic device 100 can estimate the full charge capacity of the battery 110 at the current temperature (i.e. 30 ℃) and the number of charging cycles (i.e. 150), so as to correct the full charge capacity to the full charge capacity more suitable for the current condition of the battery 110.

In other embodiments, the electronic device 100 estimates the full charge capacity of the battery 110 in another manner. Please refer to fig. 1 and fig. 8. Fig. 8 shows a flowchart of a full charge capacity calibration method according to another embodiment of the disclosure. Steps S310, S320, S330, S340, S350 and S360 are substantially the same as steps S210 to S260 in the previous embodiment of fig. 2, and thus are not described again.

The difference is that if the electronic device 100 determines that the number of charging cycles is equal to or less than the predetermined number, it indicates that the number of charging cycles of the battery 110 is close to the number of charging cycles of a healthy battery (i.e., a battery with a low number of charging cycles), and it is not necessary to consider the situation of an aged battery (i.e., a battery with a high number of charging cycles). At this time, the electronic device 100 executes steps S345 and S347, i.e., directly charges the battery 110 to a fully charged state (Full Charge), and estimates the Full Charge capacity of the battery 110 according to the first curve Cv1 and the first adjustment table Tb 1.

More specifically, in steps S345-S347, the electronic device 100 takes the adjusted healthy SOC value as a starting value and accumulates the amount of power charged by the battery 110 (step S345). In the present embodiment, the accumulated amount of electricity is an amount of electricity accumulated during a period of continuous charging. When the battery 110 reaches a full charge state, the electronic device 100 uses a full SOC value of the full charge state as an end value, estimates a full charge capacity of the battery according to the start value, the end value and the accumulated electric quantity, and clears the start value and the end value. In the present embodiment, the full SOC value is 100%. And the full charge capacity is calculated by an FCC equation, which is as follows: full Charge Capacity (FCC) — accumulated charge/(end value — start value).

In the example of the previous embodiment shown in fig. 2, if the predetermined number of times is set to 20 times and the number of charging cycles of the battery 110 is 10 times, the electronic device 100 determines that the number of charging cycles is equal to or less than the predetermined number of times. At this time, the electronic device 100 uses the adjusted healthy SOC value, i.e. 47%, as the initial value, and then accumulates the amount of electricity charged by the battery 110, for example, the amount of electricity accumulated by continuously charging to the fully charged state (i.e. the end value is 100%) is 5.5 Ah. The electronic device 100 obtains the full charge capacity through the calculation of the FCC equation, that is, the Full Charge Capacity (FCC) is 5.5/(100% -47%) -10.4 Ah. After calculating the full charge capacity, the electronic device 100 clears the start value and the end value to complete the estimation of the full charge capacity of the battery 110. Furthermore, the electronic device 100 may stop estimating the full charge capacity of the battery 110, estimate the full charge capacity of the battery 110 after a certain period of time, or immediately determine whether the battery is in the OCV state again (i.e. go back to step S310), which is not limited by the invention.

Referring to fig. 8 again and returning to step S340, if the electronic device 100 determines that the number of charging cycles is greater than the predetermined number, it indicates that the number of charging cycles of the battery 110 is close to the number of charging cycles of an aged battery (i.e., a battery with a high number of charging cycles), and the condition of the aged battery needs to be considered. At this time, the electronic device 100 performs steps S350-S360, S370 and S380. The related implementation of steps S350-S360 is substantially the same as steps S250-S260 of the previous embodiment in fig. 2, and therefore will not be described herein again.

Therefore, after the electronic device 100 obtains the current SOC value (i.e., step S360), the electronic device 100 then performs steps S370-S380, i.e., directly charges the battery 110 to a Full Charge state (Full Charge) to estimate the Full Charge capacity of the battery 110. More specifically, in steps S370-S380, the electronic device 100 uses the current SOC value as the initial value and accumulates the amount of power charged by the battery 110 (step S370). In the present embodiment, the accumulated amount of electricity is an amount of electricity accumulated during a period of continuous charging. When the battery 110 reaches a full charge state, the electronic device 100 uses a full SOC value of the full charge state as an end value, estimates a full charge capacity of the battery according to the start value, the end value and the accumulated electric quantity, and clears the start value and the end value. In the present embodiment, the full SOC value is 100%. And the full charge capacity is calculated by an FCC equation, which is as follows: full Charge Capacity (FCC) — accumulated charge/(end value — start value).

In connection with the previous embodiment of fig. 2, the electronic device 100 executes steps S320-S360 to obtain an initial value of 44.5%, and the accumulated charge amount after continuously charging to the fully charged state (i.e. ending value of 100%) is 7.5 Ah. The electronic device 100 obtains the full charge capacity through the calculation of the FCC equation, that is, the Full Charge Capacity (FCC) is 7.5/(100% -44.5%) -13.5 Ah. After calculating the full charge capacity, the electronic device 100 clears the start value and the end value to complete the estimation of the full charge capacity of the battery 110. Furthermore, the electronic device 100 may stop estimating the full charge capacity of the battery 110, estimate the full charge capacity of the battery 110 after a certain period of time, or immediately determine whether the battery is in the OCV state again (i.e. go back to step S310), which is not limited by the invention.

In summary, the embodiments of the present invention disclose a full charge capacity calibration method, which pre-establishes the relationship between the OCV value and the SOC value of the aged battery (the battery with high number of charge cycles) and the healthy battery (the battery with low number of charge cycles) at different temperatures. Then, the current full charge capacity of the battery is adjusted according to the established relationship, the aging degree of the battery and the current operating temperature, so as to obtain the accurate full charge capacity.

The above description is only for the best embodiment of the present invention, but the present invention is not limited thereto, and any changes or modifications that can be easily made by those skilled in the art within the field of the present invention can be covered by the following claims.

Claims

1. A full-charge capacity calibration method for estimating a full-charge capacity of a battery, the full-charge capacity calibration method comprising:

detecting that the battery is in an open circuit voltage state;

analyzing a current open-circuit voltage value, a current temperature and a charging cycle number of the battery;

adjusting the healthy battery electric quantity value corresponding to the current open-circuit voltage value in a first curve according to a first adjusting table;

judging whether the number of the charging period is greater than a preset number;

if the charging cycle number is larger than a preset number, the execution steps comprise:

adjusting the aged battery electric quantity value corresponding to the current open-circuit voltage value in a second curve according to a second adjusting table;

calculating a current battery electric quantity value corresponding to the charging cycle times between the adjusted healthy battery electric quantity value and the adjusted aged battery electric quantity value; and

judging whether an initial value exists;

if the initial value is not determined, the current battery electric quantity value is used as the initial value, an electric quantity of the battery for charging or discharging is accumulated, and whether the battery is in the open-circuit voltage state is determined again;

wherein if the initial value is determined, the current battery capacity value is used as an end value, the full charge capacity of the battery is estimated according to the initial value, the end value and the accumulated electric quantity, and the initial value and the end value are cleared,

the first curve is the relation between the current open-circuit voltage value and the corresponding healthy battery electric quantity value of a healthy battery at a first temperature, the third curve is the relation between the current open-circuit voltage value and the corresponding healthy battery electric quantity value of the healthy battery at a third temperature, and the first adjusting table is the relation between the current open-circuit voltage value and a first adjusting value

The first adjustment value is obtained by the healthy battery electric quantity value corresponding to the current open-circuit voltage value of the first curve and the healthy battery electric quantity value corresponding to the current open-circuit voltage value of the third curve;

the adjusting the aged battery electric quantity value corresponding to the current open-circuit voltage value in a second curve according to a second adjustment table includes:

adjusting the aged battery electric quantity value in the second curve according to the difference between the aged battery electric quantity values of the second curve and a fourth curve, wherein the fourth curve is the relation between the current open-circuit voltage value and the corresponding aged battery electric quantity value at a fourth temperature;

the first adjustment value is obtained from the healthy battery electric quantity value corresponding to the current open-circuit voltage value of the first curve and the healthy battery electric quantity value corresponding to the current open-circuit voltage value of the third curve, and includes:

taking the difference between the healthy battery electric quantity values of the first curve and the third curve as a first adjustment value;

calculating a current battery electric quantity value corresponding to the charging cycle times between the adjusted healthy battery electric quantity value and the adjusted aged battery electric quantity value, including:

and calculating a current battery electric quantity value corresponding to the charging cycle times by applying the adjusted healthy battery electric quantity value and the adjusted aged battery electric quantity value based on an interpolation method.

2. The method of claim 1, wherein the open circuit voltage state of the battery represents a state in which the battery stops charging or discharging for a period of time.

3. The method of claim 1, wherein the first adjustment value is a difference between the healthy battery value corresponding to the current open circuit voltage value of the first curve and the healthy battery value corresponding to the current open circuit voltage value of the third curve.

4. The method of claim 3, wherein the step of adjusting the healthy battery value further comprises:

obtaining the first adjustment value corresponding to the current open-circuit voltage value in the first adjustment table; and

and adjusting the healthy battery electric quantity value corresponding to the current open-circuit voltage value in the first curve according to the first adjustment value.

5. The method of claim 3, wherein the first temperature is higher than the third temperature.

6. A full-charge capacity calibration method for estimating a full-charge capacity of a battery, the full-charge capacity calibration method comprising:

detecting that the battery is in an open circuit voltage state;

judging whether an initial value exists;

the second curve is the relation between the current open-circuit voltage value of an aged battery at a second temperature and the corresponding aged battery electric quantity value, a fourth curve is the relation between the current open-circuit voltage value of the aged battery at a fourth temperature and the corresponding aged battery electric quantity value, the second adjusting table is a second adjusting value corresponding to the current open-circuit voltage value, and the second adjusting value is a difference value between the aged battery electric quantity value corresponding to the current open-circuit voltage value of the second curve and the aged battery electric quantity value corresponding to the current open-circuit voltage value of the fourth curve;

based on interpolation method, calculating a current battery electric quantity value corresponding to the charging cycle times by applying the adjusted electric quantity value of the healthy battery and the adjusted electric quantity value of the aged battery;

the adjusting the healthy battery electric quantity value corresponding to the current open-circuit voltage value in a first curve according to a first adjustment table includes:

and adjusting the healthy battery electric quantity in the first curve according to the difference between the healthy battery electric quantity values of the first curve and the third curve.

7. The method of claim 6, wherein the step of adjusting the aged battery charge value further comprises:

obtaining the second adjustment value corresponding to the current open-circuit voltage value in the second adjustment table; and

and adjusting the aged battery electric quantity value corresponding to the current open-circuit voltage value in the second curve according to the second adjustment value.

8. The method of claim 6 or 7, wherein the second temperature is higher than the fourth temperature.

9. The method as claimed in claim 1 or 6, wherein if the number of charging cycles is determined to be less than or equal to the predetermined number, the step of performing includes:

judging whether the initial value exists or not;

if the initial value is not determined, the adjusted electric quantity value of the healthy battery is used as the initial value, the electric quantity of the battery for charging or discharging is accumulated, and whether the battery is in the open-circuit voltage state is judged again; and

if the initial value is determined, the adjusted electric quantity value of the healthy battery is used as the end value, the full charge capacity of the battery is estimated according to the initial value, the end value and the accumulated electric quantity, and the initial value and the end value are eliminated.

10. The method of claim 6, wherein the first curve is a relationship between the current open circuit voltage value and the healthy battery power value of the healthy battery at a first temperature for a first number of charging cycles, the second curve is a relationship between the current open circuit voltage value and the corresponding aged battery power value of the aged battery at a second temperature for a second number of charging cycles, and the step of calculating the current battery power value for the number of charging cycles further comprises:

and calculating the current battery electric quantity value corresponding to the charging cycle times by an interpolation method between the adjusted healthy battery electric quantity value and the adjusted aged battery electric quantity value according to the first charging cycle times and the second charging cycle times.

11. A full-charge capacity calibration method for estimating a full-charge capacity of a battery, the full-charge capacity calibration method comprising:

detecting that the battery is in an open circuit voltage state;

analyzing a current open-circuit voltage value, a current temperature and a charging cycle number of the battery; adjusting the healthy battery electric quantity value corresponding to the current open-circuit voltage value in a first curve according to a first adjusting table;

adjusting the aged battery electric quantity value corresponding to the current open-circuit voltage value in a second curve according to a second adjusting table; calculating a current battery electric quantity value corresponding to the charging cycle times between the adjusted healthy battery electric quantity value and the adjusted aged battery electric quantity value; and

using the current battery electric quantity value as an initial value, and accumulating an electric quantity charged by the battery;

wherein, when the battery reaches a fully charged state, a fully charged battery electric quantity value of the fully charged state is used as an end value, the full charge capacity of the battery is estimated according to the initial value, the end value and the accumulated electric quantity, and the initial value and the end value are cleared,

12. The method of claim 11, wherein if the number of charging cycles is determined to be less than or equal to the predetermined number, performing steps comprising:

taking the adjusted electric quantity value of the healthy battery as the initial value, and accumulating the electric quantity charged by the battery; and

when the battery reaches the fully charged state, the fully charged battery electric quantity value of the fully charged state is taken as the end value, the full charge capacity of the battery is estimated according to the initial value, the end value and the accumulated electric quantity, and the initial value and the end value are eliminated.