A method for calibrating the near-full charge of a terminal device, a chip, and a terminal.

Abstract

This invention discloses a method, chip, and terminal for calibrating the battery level of a terminal device near full charge. The calibration method addresses the problem of inaccurate battery level calculations in existing consumer electronics terminals near full charge. By using a pre-set battery percentage-temperature-current relationship table, it identifies two error directions—"under-calculated battery level" and "over-calculated battery level"—in real time during the constant voltage stage. For "under-calculated battery level," a weighted increase algorithm is used; for "over-calculated battery level," a time-limited incremental algorithm is used. Calibration can be completed near full charge without a complete charge-discharge cycle, achieving a seamless UI curve transition and improving user experience. Furthermore, the algorithm has low complexity, making it suitable for implementation in the phone's PMIC or SoC firmware.

Description

Technical Field

[0001] This invention relates to the field of battery management technology for consumer electronic terminals, and more particularly to a method and terminal device for online calibration of the state of charge (SOC) of a battery when the battery charge is close to 100%. Background Technology

[0002] The accuracy of battery level display is always a major concern for end users, especially mobile phone users. Affected by coulomb integration error, temperature drift, and battery aging, fuel gauges often exhibit phenomena such as "reporting full charge prematurely" or "failing to report full charge" towards the end of the charging process, making it difficult for users to accurately estimate the remaining usable time. At the moment of charging termination, the battery level may jump from non-100% to 100%, a sudden change that makes users perceive an abnormal charge level. Furthermore, if the device begins to discharge before it is truly fully charged, it may suddenly shut down without warning, causing considerable inconvenience in daily use.

[0003] Smartphones, tablets, and other terminal devices commonly use lithium batteries for power. These batteries generally follow a charging curve of constant current (CC) followed by constant voltage (CV). According to the charging characteristics of lithium batteries, during the constant voltage stage, the charging current gradually decreases until it drops to the charging cutoff current Iterm, during which the battery terminal voltage VBAT remains constant. At the same temperature, the current battery capacity and the current charging current exhibit an approximately linear relationship. Therefore, based on the cutoff current, the charging current at 99% capacity, 98% capacity, and 97% capacity can be calculated backwards, establishing a SOC-IBAT correspondence table.

[0004] Based on the aforementioned SOC-IBAT relationship, existing technologies have proposed corresponding calibration schemes. For example, invention patent CN120446775A discloses a method for calibrating the SOC of a vehicle power battery, including the following steps: conducting battery characteristic experiments at different temperatures; establishing a table showing the correspondence between battery model parameters and SOC at different temperatures; deriving a current recursive formula for the constant voltage stage; performing current simulation in the constant voltage stage based on the current recursive formula and CV stage charging data, establishing a temperature-current-SOC relationship table, which records the SOC calibration point when the current drops to a specific value in the constant voltage stage at different temperatures; writing the table into the battery management system (BMS), and calibrating the SOC in real time based on the current drop value in the constant voltage stage (paragraphs

[0048] -

[0052] of the specification). However, the above-mentioned power battery SOC calibration scheme has the following shortcomings:

[0005] 1. The current recursive formula derived based on the Thevenin model and genetic algorithm parameter identification involves a large amount of computation, requiring 10kB of RAM and BMS computing power, making it difficult to directly port to mobile phone PMICs with less than 512B of RAM and less than 1% CPU load. Therefore, this method is geared towards large-capacity battery packs, requires complex battery models and BMS-level computing power, and is difficult to apply directly to resource-constrained consumer terminals.

[0006] 2. The triggering calibration conditions are as follows (see paragraphs

[0048] -

[0052] of the instruction manual): When charging is prematurely terminated due to various unexpected factors or human intervention, the temperature-current-SOC calibration mechanism is triggered. The actual SOC is interpolated based on the temperature and current at the last moment before the termination, triggering SOC calibration. In addition, if the charging is fully charged normally, the current reaches the cutoff current, and the charging automatically ends (the end of charging is usually determined based on the current of the constant voltage section. Usually, a value is given, and when the current drops to this value, it is assumed that the battery is fully charged and the charging ends), then the full charge calibration is triggered, and the SOC calibration is 100%. Based on the above calibration scheme, when the battery capacity is too high, the calibration will cause the battery capacity to jump down from a high level (instantly decrease), and when the battery capacity is too low, the calibration will cause the battery capacity to jump up from a low level (instantly increase). That is, there are unreasonable situations where the charging capacity jumps down, such as the battery's calibration capacity jumping from 100% to 95% after being fully charged, which will cause inconvenience to users. Therefore, this solution performs power calibration at the moment of stopping charging, lacking a smooth UI transition mechanism, which will make users perceive the power level jump, and cannot be directly applied to resource-constrained consumer terminals.

[0007] Therefore, there is an urgent need for a lightweight, online, and smooth near-full charge calibration solution. Summary of the Invention

[0008] A brief overview of embodiments of the invention is provided below to provide a basic understanding of certain aspects of the invention. It should be understood that this overview is not an exhaustive summary of the invention. It is not intended to identify key or essential parts of the invention, nor is it intended to limit the scope of the invention. Its purpose is merely to present certain concepts in a simplified form as a prelude to the more detailed description that follows.

[0009] This invention proposes a method for calibrating the near-full charge of a terminal device. By distinguishing between two error directions, namely "under-calculated power" and "over-calculated power", a weighted boosting algorithm and a time-limiting algorithm are used respectively to continuously calibrate the device at the end of the charging process and simultaneously display 100% at the physical full charge point. The UI display is smooth and without any jumps.

[0010] According to a first aspect of this application, a method for calibrating the near-full charge of a terminal device is provided. The terminal device is a consumer electronic terminal powered by a lithium battery. The method includes:

[0011] S10, Preset Stage: Perform constant current-constant voltage charging test on the lithium battery at at least two different temperatures, generate and store a table of charge percentage-temperature-current relationship, the table of relationship includes at least: the charging cutoff current Iterm corresponding to 100% SOC;

[0012] S20. Real-time judgment stage: When the terminal device is in the charging state and the output value of the fuel meter is BATT_SOC≥SOC_THD or the current charging current is IBAT_NOW<IBAT_THD, the near full charge calibration window is entered; SOC_THD is the first percentage of the battery capacity in the relation table, and IBAT_THD is the first current in the relation table.

[0013] S30, Error Direction Determination Stage:

[0014] If the preset condition of low battery is met, proceed to the "Low Battery Calculation" branch;

[0015] If the preset conditions for high battery consumption are met, proceed to the "High Battery Consumption Calculation" branch;

[0016] S40, Calibration Calculation Stage:

[0017] Under the "low power consumption calculation" branch, execute the weighted boosting algorithm:

[0018] S411. Record the current sampling value IBAT_E at the moment of entering the "low power calculation" calibration window;

[0019] S412. Read the current charging current IBAT_NOW in real time during each power calculation cycle;

[0020] S413. Based on the "Battery Percentage-Temperature-Current" relationship table, using the current battery temperature as the index, find the battery percentage IBAT_SOC corresponding to the current charging current IBAT_NOW;

[0021] S414. Calculate the weight:

[0022] weight = (IBAT_NOW – Iterm) / (IBAT_E – Iterm), 0 ≤ weight ≤ 1; Iterm is the charging cutoff current;

[0023] To prevent weight from exceeding the range, if IBAT_NOW ≥ IBAT_E, set weight = 0; if IBAT_NOW ≤ Iterm, set weight = 1.

[0024] S415, Calculate calibration charge CALI_SOC:

[0025] CALI_SOC = BATT_SOC × weight + IBAT_SOC × (1 – weight); BATT_SOC is the output value of the fuel meter;

[0026] S416, outputs the calibrated battery level CALI_SOC as the final battery percentage for that cycle, and drives a smooth update of the user interface;

[0027] S417. Repeat S412-S416 until the current charging current IBAT_NOW≤Iterm and the calibration capacity CALI_SOC reaches 100%, then end the calibration.

[0028] Under the "Battery Calculation" branch, execute the time-limited rate algorithm:

[0029] S421. Using the battery meter reading BATT_SOC_E when entering the "Battery Calculation Multi-calibration" window as the baseline value, determine the first target battery percentage, SOC_NEXT = BATT_SOC_E + 1%; SOC_NEXT is the next integer battery percentage to be achieved.

[0030] S422. Based on the temperature-current-SOC relationship table at the current temperature, obtain the theoretical charging current IBAT_TABLE corresponding to the charge percentage SOC = BATT_SOC_E;

[0031] S423. Calculate the theoretical time (Time_need) required to push the battery percentage SOC from the baseline value BATT_SOC_E to the target battery percentage SOC_NEXT:

[0032] Time_need=(SOC_NEXT–BATT_SOC_E)×FCC / IBAT_TABLE;

[0033] FCC stands for battery full charge capacity, measured in mAh.

[0034] S424. Within each power calculation cycle Δt, the accumulated actual time is summed to obtain acc_time:

[0035] acc_time = acc_time + Δt; Δt is in seconds (s).

[0036] S425, Real-time calculation of calibration power CALI_SOC:

[0037] CALI_SOC=BATT_SOC_E+(SOC_NEXT–BATT_SOC_E)×acc_time / Time_need;

[0038] S426. When CALI_SOC≥SOC_NEXT and SOC_NEXT<100%, increment SOC_NEXT by 1% and clear acc_time to zero, then return to step S23.

[0039] S427. Repeat steps S423-S426 until the physical charging current IBAT drops to the cutoff current Iterm and the calibration capacity CALI_SOC reaches 100%, then end the calibration.

[0040] S50, Display Synchronization Stage: The calibrated power CALI_SOC is used as the final output of the power meter, and the terminal user interface is driven to smoothly update the displayed power.

[0041] S60. Termination Phase: When the charging current IBAT ≤ Iterm and the calibration capacity CALI_SOC = 100%, the near-full charge calibration process ends.

[0042] As one implementation scheme, the preset condition for low power consumption is: satisfying the following for N consecutive cycles:

[0043] IBAT_NOW < IBAT_THD and BATT_SOC < SOC_THD; or

[0044] IBAT_NOW<IBAT_SOC_THD and BATT_SOC≥SOC_THD;

[0045] Where IBAT_THD is the first current in the relation table, SOC_THD is the first charge percentage in the relation table; IBAT_SOC_THD is the charging current corresponding to SOC=BATT_SOC in the relation table; N is a natural number, N≥2;

[0046] And simultaneously satisfy VBAT_NOW≥VBAT_FULL (full charge voltage) for N consecutive cycles;

[0047] The preset condition for battery power is: satisfying the following for N consecutive cycles:

[0048] IBAT_NOW≥IBAT_THD and BATT_SOC≥SOC_THD; or

[0049] IBAT_NOW>IBAT_SOC_THD and BATT_SOC≥SOC_THD and VBAT_NOW≥VBAT_FULL.

[0050] As one implementation, step S415 further includes a fuel meter error correction process:

[0051] The cumulative error correction threshold SOC_ADJ_THD of the fuel gauge is dynamically set within a preset range (e.g., 0%–5%) based on different charging temperatures.

[0052] When the temperature TBAT ≥ 25 degrees, let SOC_ADJ_THD = 3%;

[0053] When 25 degrees > temperature TBAT ≥ 15 degrees, let SOC_ADJ_THD = 4%;

[0054] When 15 degrees > temperature TBAT ≥ 0 degrees, let SOC_ADJ_THD = 5%;

[0055] When BATT_SOC > IBAT_SOC + SOC_ADJ_THD, BATT_SOC is corrected to: BATT_SOC = IBAT_SOC + SOC_ADJ_THD;

[0056] When BATT_SOC < IBAT_SOC - SOC_ADJ_THD, BATT_SOC is corrected to: BATT_SOC = IBAT_SOC - SOC_ADJ_THD.

[0057] This scheme may experience a "jump" in battery level during the first fitting or correction of accumulated errors in the fuel gauge, resulting in a SOC_GAP difference between the battery level and the previous cycle. To overcome this issue, as one implementation, S416 further includes a process for smoothing the output calibrated battery level CALI_SOC: Based on the current charging current IBAT_NOW, the SOC_GAP is evenly distributed to the remaining future chargeable capacity SOC_TO_CHG = FULL_SOC – BATT_SOC, where FULL_SOC is the maximum usable capacity the battery can charge under current conditions; the specific calculation method is as follows:

[0058] S416-1 calculates the uncharged capacity SOC_TO_CHG:

[0059] SOC_TO_CHG=FULL_SOC-CALI_SOC;

[0060] S416-2 Calculate the remaining time TIME_TO_FULL

[0061] TIME_TO_FULL=SOC_TO_CHG×FCC / IBAT_NOW;

[0062] S416-3 Calculation Steps STEPS:

[0063] STEPS = TIME_TO_FULL / TSTEP;

[0064] Where STEPS is rounded up and is ≥1; TSTEP is the energy calculation cycle, which is the time interval between each update of SOC by the energy meter or calibration algorithm, in seconds (s).

[0065] S416-4 Calculates the compensation amount for each step:

[0066] com_soc=SOC_GAP / STEPS; SOC_GAP is the difference between the calibration charge CALI_SOC calculated at the moment of this calibration and the output of the fuel meter in the previous cycle;

[0067] S416-5 Periodic Compensation:

[0068] The calibration power is updated every power calculation cycle: CALI_SOC = CALI_SOC + com_soc;

[0069] Compensation stops when IBAT_NOW≤ITERM and CALI_SOC=FULL_SOC or com_soc=0.

[0070] To allow the "speed limiting rhythm" to automatically adjust with temperature and aging, ensuring a smooth UI without slowing down or prematurely reaching its limit, a feasible solution is to introduce a dynamic speed limiting factor k(T, SOH) into the Time_need function of the aforementioned time-limiting increment algorithm, satisfying:

[0071] k(T, SOH)=1.8–0.02×(T–25)–0.01×SOH_loss;

[0072] Then Time_need is corrected to: Time_need=k(T,SOH)×(SOC_NEXT–BATT_SOC_E)×FCC / IBAT_TABLE;

[0073] Where T is the real-time battery temperature, and SOH_loss is the percentage of battery capacity decay, obtained from the cycle count of the fuel gauge or OTA calibration.

[0074] To further ensure seamless switching, this invention also designs a transition zone (with customizable parameters), such as [94.5%, 95.5%] or [94%, 95%]. The seamless switching scheme in the transition zone is applied between steps S30 and S40. That is, after the positive and negative error directions are determined in S30 (error direction determination stage), but before actually entering the calibration calculation stage in S40, a transition zone smoothing process is first performed on the SOC. Specifically, this seamless switching scheme in the transition zone includes:

[0075] If 94.5% ≤ SOC ≤ 95.5%, then proceed according to...

[0076] CALI_SOC= ×CALI_weight+(1- )×CALI_speed,

[0077] =(SOC–94.5%) / (95.5%–94.5%), Update in 0.1% increments to achieve Continuous (derivative is continuous); Continuity means that the CALI_SOC curve is continuously differentiable over time;

[0078] When SOC < 94.5% or SOC > 95.5%, directly proceed to the "More Power Calculation" or "Less Power Calculation" branch.

[0079] Among them, CALI_SOC is the final calibrated battery percentage output to the UI. After smoothing through the "transition zone" or the "high / low battery dual path," it is the number actually used to drive the screen battery bar and system notification bar. CALI_weight is the instantaneous calibration result of the "low battery calculation" branch. Under the "low battery calculation" branch, it is the SOC value calculated according to the weighted formula (weighted increase) and used to quickly approach 100%. CALI_speed is the instantaneous calibration result of the "high battery calculation" branch. Under the "high battery calculation" branch, it is the SOC value calculated according to the time-limited incremental algorithm and used to slowly and uniformly approach 100% to prevent premature full battery reporting.

[0080] As a feasible solution, the "temperature-current-power percentage" relationship table is stored as a two-dimensional array in the non-volatile memory area of ​​the power management chip of the terminal device, and loaded into RAM each time the device is powered on. The size of the two-dimensional array is ≤256 bytes, and it is stored in the form of uint8_t table[T_idx][SOC_idx].

[0081] As a feasible solution, under the "Power Calculation" branch, if acc_time exceeds the preset maximum speed limit time and CALI_SOC=100% is still not met, then CALI_SOC will be forcibly set to 100% and the calibration will end. The preset maximum speed limit time can be set to 180s–300s, determined based on the terminal's heat dissipation capacity and user experience testing.

[0082] As a feasible solution, the error direction determination stage further includes:

[0083] The current charging current IBAT is averaged using a multi-point sliding method (e.g., 8-point sliding) and then filtered using a first-order IIR filter before being compared with the current threshold IBAT_THD to reduce the false positive rate caused by sampling noise. For example, the first-order IIR coefficients... =0.25, sliding window length N=3.

[0084] According to a second aspect of this application, a near-full charge calibration chip is provided, comprising:

[0085] The memory is used to store the power percentage-temperature-current relationship table from the above near-full charge calibration method;

[0086] Temperature sensor interface, used to obtain real-time battery temperature;

[0087] Current sampling interface, used to obtain the real-time charging current of the battery;

[0088] The arithmetic unit is used to perform the calibration calculation steps in the above-mentioned method for calibrating the near-full charge of the terminal device;

[0089] The output interface is used to output the calibration power CALI_SOC to the terminal main controller or display driver.

[0090] The computing unit is started when the terminal is in a constant voltage phase and SOC≥SOC_THD, and stopped when IBAT≤Iterm and CALI_SOC=100%.

[0091] As a feasible solution, the computing unit is a dedicated hardware microcode circuit. Generally, the hardware microcode circuit has ≤64 instructions, used to perform weight calculation, time limiting, and smooth output, with an execution cycle ≤1µs.

[0092] According to a third aspect of this application, a terminal device is provided, comprising:

[0093] Lithium-ion batteries;

[0094] Nearly full charge calibration chip;

[0095] The application processor is used to receive the calibration power CALI_SOC output by the near-fully charged calibration chip and drive the smooth display of the user interface;

[0096] Display used to update the battery percentage (UISOC) in real time.

[0097] As a possible solution, the terminal device can be any one of a smartphone, tablet, wearable device, or Bluetooth headset.

[0098] Existing technologies trigger power calibration and complete SOC correction in a single step the instant charging stops. This abrupt calibration lacks a transition mechanism, and the user interface may display noticeable jumps in power levels, easily leading users to mistakenly believe there is a system malfunction. The technical problem this application aims to solve is: based on the acquired power percentage-temperature-current relationship, to calibrate the power SOC in real-time throughout the near-full charge phase, ensuring that: 1. when the physical current drops to the Iterm, both voltage and power are at the physical full charge point, and the UI displays a synchronous 100% power level; 2. the calibration process is smooth and without abrupt changes, thus improving the user experience of consumer terminals.

[0099] The present invention provides a near-full battery calibration scheme for terminal devices through the above-described method, which has the following advantages:

[0100] 1. Calibration can be completed at near full charge (95%-100% range) without a full charge-discharge cycle, and the UI curve can be switched imperceptibly by the naked eye through the transition zone (width ≤1%), improving the user experience;

[0101] 2. The algorithm is divided into "less power calculation" and "more power calculation" branches based on error direction determination. It has low algorithm complexity, making it suitable for implementation in mobile phone PMIC or SoC firmware. Simultaneously, it exhibits excellent noise immunity, especially with a 12-bit ADC. Under a 0.25 IIR filter condition, the recognition accuracy is ≥99.7%, and the false positive rate is <0.3%.

[0102] 3. A dynamic speed limiting factor k(T, SOH) was introduced to compensate for temperature and aging, so that the aged battery can smoothly return to zero error within 2 minutes without "stuttering" phenomenon;

[0103] 4. Compatible with existing fuel gauge chips, it can be completed within the PMIC without additional hardware costs, and the power consumption increment is <1mW. Attached Figure Description

[0104] The present invention can be better understood by referring to the description given below in conjunction with the accompanying drawings, in which the same or similar reference numerals are used throughout the drawings to denote the same or similar parts. These drawings, together with the following detailed description, are incorporated in and form part of this specification, and are used to further illustrate preferred embodiments of the invention and explain the principles and advantages of the invention. In the drawings:

[0105] Figure 1 This is a schematic diagram of the charging curve of a lithium battery in the prior art;

[0106] Figure 2 This is a schematic diagram of the calibration method according to an embodiment of the present invention;

[0107] Figure 3This is a schematic diagram illustrating the effect of the "less power consumption calculation" branch in an embodiment of the present invention;

[0108] Figure 4 This is a schematic diagram illustrating the effect of the "multiple power calculation" branch in an embodiment of the present invention. Detailed Implementation

[0109] Embodiments of the present invention will now be described with reference to the accompanying drawings. Elements and features described in one drawing or embodiment of the invention may be combined with elements and features shown in one or more other drawings or embodiments. It should be noted that, for clarity, representations and descriptions of components and processes unrelated to the present invention and known to those skilled in the art have been omitted from the drawings and description.

[0110] The terms used in this invention are explained as follows: IBAT (Battery current): Battery charging current; BATT_SOC (Battery SOC): Battery percentage calculated by the battery power calculation method; MSOC (Measured SOC): Final battery percentage measured by the battery meter; UISOC (UI SOC): Battery percentage displayed on the phone screen; CCCV (Constant Current / Constant Voltage): Constant current / constant voltage conversion point voltage; VBAT (Voltage of Battery): Battery terminal voltage; Iterm (Termination current): Charging cut-off current; FCC (Full Charge Capacity): Full charge capacity.

[0111] Example 1

[0112] This invention provides a method for calibrating the near-full battery level of a terminal device. See [link to relevant documentation]. Figure 2 It includes the following steps:

[0113] Step 1: Preset Stage: Obtain the relationship between charging current and charge [IBAT, SOC] at different temperatures as a table of charge percentage (SOC) - temperature (TBAT) - current (IBAT) (hereinafter referred to as the IBAT-SOC relationship table or relationship table). In this embodiment, the relationship table is as follows:

[0114]

[0115] Step 2: Real-time judgment stage: When the terminal device is in charging state and the fuel meter output value BATT_SOC≥95% or the current charging current IBAT_NOW<IBAT_THD, enter the near full charge calibration window;

[0116] For example, at 25 degrees Celsius, if the calculated battery percentage (BATT_SOC) is greater than 95%, but the charging current (IBAT) is greater than 650mA, then the current BATT_SOC is too high and requires calibration. Similarly, if the BATT_SOC is less than 95%, but the charging current (IBAT) is less than 650mA, then the current BATT_SOC is too low and requires calibration.

[0117] Step 3: Error Direction Determination Stage

[0118] Calibration entry conditions for entering the "Low Power Calculation" branch: Conditions 1 and 2 must be met.

[0119] Condition 1: One of the following conditions must be met.

[0120] For several consecutive electricity statistics cycles (e.g., 4 cycles), IBAT_NOW < IBAT_THD, and BATT_SOC < SOC_THD.

[0121] Where IBAT_THD is the first current in the calibration IBAT-SOC relationship table, and SOC_THD is the first charge in the calibration IBAT-SOC relationship table, such as 700mA and 95% at 45 degrees in the table above;

[0122] Example: When the actual battery level is greater than batt_soc, IBAT < IBAT_95, but BATT_SOC < 95.

[0123] For several consecutive electricity statistics cycles (e.g., 4 cycles), IBAT_NOW < IBAT_SOC_THD and BATT_SOC ≥ SOC_THD.

[0124] Where IBAT_SOC_THD is the current obtained by looking up BATT_SOC in the IBAT-SOC relationship table, and SOC_THD is the first quantity of the IBAT-SOC relationship table for calibration, such as 700mA and 95% at 45 degrees in the figure above.

[0125] Condition 2: The charging voltage VBAT_NOW ≥ VBAT_FULL for several consecutive power consumption statistics cycles.

[0126] Calibration entry conditions for entering the "Power Calculation" branch:

[0127] For N consecutive periods, the following conditions must be met: IBAT_NOW≥IBAT_THD and BATT_SOC≥SOC_THD.

[0128] Step 4: "Underreported Power Consumption" Branch: The power consumption counted by the power meter is less than the actual power consumption.

[0129] Execute the weighted upward algorithm:

[0130] When the actual power consumption is greater than BATT_SOC, IBAT < IBAT_95, but BATT_SOC < 95. IBAT is used as the entry condition to calculate the weight.

[0131] weight=(IBAT_NOW–Iterm) / (IBAT_E–Iterm);

[0132] Where, weight is the weight, weight∈[0,1], IBAT_NOW is the current charging current; Iterm is the charging cutoff current on the battery datasheet, and IBAT_E is the current sampling value when entering the calibration window for the first time, which is the first current that triggers the prediction, i.e. the threshold point for entering the prediction calibration.

[0133] CALI_SOC = BATT_SOC × weight + IBAT_SOC × (1 – weight); BATT_SOC is the output value of the fuel meter;

[0134] Among them, CALI_SOC is the calibrated power level, IBAT_SOC is the power percentage obtained in real time according to the "Power Percentage-Temperature-Current" relationship table, and BATT_SOC is the power percentage output by the current fuel gauge (FGU).

[0135] The embodiments of the present invention further correct for the error of the fuel meter:

[0136] The cumulative error correction threshold SOC_ADJ_THD for the fuel gauge is set to different values ​​depending on the charging temperature:

[0137] When the temperature TBAT ≥ 25 degrees, SOC_ADJ_THD = 3%;

[0138] When 25 degrees > temperature TBAT ≥ 15 degrees, SOC_ADJ_THD = 4%;

[0139] When 15 degrees > temperature TBAT ≥ 0 degrees, SOC_ADJ_THD = 5%;

[0140] When BATT_SOC > IBAT_SOC + SOC_ADJ_THD, BATT_SOC is corrected to: BATT_SOC = IBAT_SOC + SOC_ADJ_THD;

[0141] When BATT_SOC < IBAT_SOC - SOC_ADJ_THD, BATT_SOC is corrected to: BATT_SOC = IBAT_SOC - SOC_ADJ_THD.

[0142] This scheme may experience a "jump" in battery level during the first fitting or correction of the accumulated error of the fuel gauge, resulting in a SOC_GAP between the battery level and the previous cycle. To overcome this problem, step S416 also includes a post-calibration battery level smoothing process: the SOC_GAP is evenly distributed to the remaining amount to be charged in the future, based on the current charging current IBAT_NOW, as SOC_TO_CHG = FULL_SOC – BATT_SOC. The specific calculation method is as follows:

[0143] Calculate how long it will take, TIME_TO_FULL, to fully charge the amount of charge, SOC_TO_CHG, based on the current charging current IBAT_NOW.

[0144] Based on the current power calculation interval TSTEP, calculate how many cycles are needed to fully charge STEPS = TIME_TO_FULL / TSTEP;

[0145] Distribute SOC_GAP equally into STEPS: com_soc = SOC_GAP / STEPS;

[0146] The power consumption of com_soc is compensated in each power consumption calculation cycle to ensure that the power consumption is continuous, smooth and does not jump.

[0147] The "Insufficient Power Calculation" branch applies the aforementioned weighted boosting algorithm to increase the power consumption counted by the power meter. The effect after the boost is as follows: Figure 3 As shown in the diagram, the horizontal axis represents time, and the vertical axis represents the battery percentage. BATT_SOC is the battery percentage output by the fuel gauge (introducing a 10% error, which is smaller than the actual battery level); BATT_SOC_R is the battery percentage calculated by the fuel gauge, without error, used for comparison; CALI_SOC is the battery percentage after calibration; MSOC is the final battery percentage output by the fuel gauge; IBAT is the real-time current; and IBAT_SOC is the SOC corresponding to the current charging current.

[0148] Depend on Figure 3 It can be seen that with this scheme, after artificially introducing a 10% error, the battery level begins to calibrate when the charging current IBAT is less than IBAT_E. The error gradually decreases from 10% until it reaches zero when the charging cutoff current Iterm is reached, at which point charging stops synchronously when the battery level is reported as 100%, resulting in a smooth battery level display. Without this calibration scheme, it can be seen that BATT_SOC still has a 10% error when charging to Iterm, and only calibrates directly from 90% to 100% at full charge.

[0149] Step 5: In the "Power Calculation" branch: The power meter reading is higher than the actual power consumption.

[0150] BATT_SOC must first meet the calibration conditions. BATT_SOC cannot use IBAT as a reference point to calibrate the battery level, but the battery level increase can be limited by time.

[0151] Under the "Battery Calculation" branch, execute the time-limited rate increment algorithm:

[0152] 1. Using the battery meter reading BATT_SOC_E when entering the "Battery Calculation Multi-calibration" window as the baseline value, determine the first target battery percentage, SOC_NEXT = BATT_SOC_E + 1%; SOC_NEXT is the next target battery percentage to be achieved (usually an integer).

[0153] 2. Based on the temperature-current-SOC relationship table at the current temperature, obtain the theoretical charging current IBAT_TABLE corresponding to the charge percentage SOC = BATT_SOC_E;

[0154] 3. Calculate the theoretical time (Time_need) required to push the battery percentage (SOC) from the baseline value (BATT_SOC_E) to the target battery percentage (SOC_NEXT):

[0155] Time_need=(SOC_NEXT–BATT_SOC_E)×FCC / IBAT_TABLE;

[0156] FCC stands for battery full charge capacity, measured in mAh.

[0157] 4. In each power calculation cycle Within t, the accumulated actual time is summed to obtain acc_time:

[0158] acc_time = acc_time + t; The unit of t is s;

[0159] 5. Calculate the increase in battery power:

[0160] batt_cali_delta=(SOC_NEXT–BATT_SOC_E)×acc_time / Time_need;

[0161] Calculate the output power: BATT_SOC_E + batt_cali_delta;

[0162] The calibration charge CALI_SOC is obtained as follows:

[0163] CALI_SOC=BATT_SOC_E+(SOC_NEXT–BATT_SOC_E)×acc_time / Time_need;

[0164] 6. When CALI_SOC≥SOC_NEXT and SOC_NEXT<100%, increment SOC_NEXT by 1% and clear acc_time to zero, then return to step 3;

[0165] 7. Repeat steps 3-6 until the physical charging current IBAT drops to the cutoff current Iterm and the calibration charge CALI_SOC reaches 100%, then end the calibration.

[0166] In this time-limited incremental algorithm, the theoretical time Time_need is used to break down 1% of the power into several small steps. After each "power calculation cycle", acc_time is accumulated and CALI_SOC is output proportionally. When CALI_SOC reaches SOC_NEXT, the target is increased by 1% and the timer is restarted. This cycle continues until the physical current reaches Iterm and reaches 100%.

[0167] The "Energy Calculation" branch applies the time-limited incremental algorithm described above to reduce the energy consumption counted by the energy meter, with the following effect: Figure 4 As shown in the diagram, BATT_SOC is the percentage of electricity charged by the fuel meter (introducing a 10% error, which is smaller than the actual electricity charge); CALI_SOC is the percentage of electricity charged after calibration; MSOC is the final percentage of electricity charged output by the fuel meter; and IBAT is the real-time current of the electricity charged.

[0168] Depend on Figure 4 It can be seen that after artificially introducing a 10% error, when charging reaches BATT_SOC greater than 95%, the battery level begins to calibrate, gradually decreasing from the 10% error. Without a calibration scheme, the battery level would prematurely report 100%; after calibration, the reporting of full charge is delayed, more closely resembling the actual battery level, resulting in a smoother battery display.

[0169] To ensure the "speed limit rhythm" automatically adjusts with temperature and aging, guaranteeing a smooth UI without slowing down or prematurely reaching its limit, this embodiment introduces a dynamic speed limit factor k(T, SOH) into the Time_need function of the time-limited incremental algorithm, satisfying:

[0170] k(T, SOH)=1.8–0.02×(T–25)–0.01×SOH_loss;

[0171] Then Time_need is corrected to: Time_need=k(T,SOH)×(SOC_NEXT–BATT_SOC_E)×FCC / IBAT_TABLE;

[0172] Where T is the real-time battery temperature, and SOH_loss is the percentage of battery capacity decay, obtained from the cycle count of the fuel gauge or OTA calibration.

[0173] The dynamic speed limiting factor k(T, SOH) has the following advantages:

[0174] 1. Temperature compensation: At low temperatures, the internal resistance is high, and the current drops rapidly during the constant voltage phase → k decreases (shortening the time for each 1% increment), preventing the battery level from "stuck" at 97%. At high temperatures, the internal resistance is low, and the current drops slowly → k increases (lengthening the time for each 1% increment), preventing the battery from charging to 100% too quickly when the actual battery level is not full.

[0175] 2. Aging Compensation: As the battery degrades, its capacity decreases, and the duration of the constant voltage phase shortens. → k increases linearly with SOH_loss, still ensuring that "physical full charge" and "UI 100%" are reached simultaneously. This avoids the phenomenon in existing technology where aged batteries "report full charge at 95% after 600 cycles."

[0176] 3. Zero resource consumption: The formula for k only involves two multiplications and two additions, which can be completed within the existing MCU without additional RAM or power consumption.

[0177] Step 6: Display Synchronization Phase: The calibrated power CALI_SOC is used as the final output of the power meter, and the terminal user interface is driven to smoothly update the displayed power.

[0178] Step 7: Termination phase: When the charging current IBAT≤Iterm and the calibration capacity CALI_SOC=100%, the near full charge calibration process ends.

[0179] As a specific application scenario, a near-full charge calibration is performed on a 4500mAh battery:

[0180] Preset stage: The 4500mAh battery was charged to 4.45V at 0.7C constant current at 25℃, 10℃ and 45℃ respectively, and then charged to 0.05C cutoff. The relationship between current and SOC during the constant voltage stage was recorded, and three sets of two-dimensional tables were generated and burned into the phone's EEPROM.

[0181] Real-time judgment phase: When the fuel meter reports a SOC of 96% and the system is in the constant voltage phase, the calibration window is entered.

[0182] Error direction determination: If IBAT=400mA < 95% of the table corresponds to 650mA, then enter the "low power calculation" branch, calculate CALI_SOC according to the corresponding formula, and smoothly update the UI at 0.5% / s within 30s.

[0183] If IBAT=700mA≥650mA and SOC=96%, then enter the "Power Calculation More" branch, and use the time-limited algorithm to linearly increase the UI power from 96% to 100% within 180s.

[0184] Termination phase: When IBAT drops to 225mA (0.05C, where C is the battery's rated capacity) and CALI_SOC=100%, the system will display "Fully charged" and the calibration process will end.

[0185] This invention discloses a method for calibrating the near-full charge level of a terminal device, comprising: presetting a temperature-current-SOC relationship table; entering a calibration window when the fuel gauge output is ≥95%; distinguishing between two error directions, "under-calculated power" and "over-calculated power," and calculating the calibration power CALI_SOC using either a weighted scaling or time-limited algorithm respectively; outputting CALI_SOC to the user interface for smooth display, and ending when the current drops to the cutoff value and CALI_SOC = 100%. This method significantly improves the accuracy of the terminal device's power display at the end of charging and enhances the user experience without increasing hardware costs.

[0186] In the above description of specific embodiments of the present invention, features described and / or shown for one embodiment may be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments.

[0187] It should be emphasized that the term "including / comprises" as used herein refers to the presence of a feature, element, step, or component, but does not exclude the presence or addition of one or more other features, elements, steps, or components.

[0188] In the above embodiments and examples, numerical reference numerals are used to denote various steps and / or units. Those skilled in the art will understand that these reference numerals are merely for ease of description and drawing, and do not indicate their order or any other limitation.

[0189] Furthermore, the method of the present invention is not limited to being executed in the chronological order described in the specification, but may also be executed in other chronological orders, in parallel, or independently. Therefore, the execution order of the method described in this specification does not constitute a limitation on the technical scope of the present invention.

[0190] Although the invention has been disclosed above through the description of specific embodiments, it should be understood that all the embodiments and examples described above are exemplary and not restrictive. Those skilled in the art can design various modifications, improvements, or equivalents to the invention within the spirit and scope of the appended claims. These modifications, improvements, or equivalents should also be considered to be included within the protection scope of the invention.

Claims

1. A method for calibrating the near-full charge level of a terminal device, characterized in that, The terminal device is a lithium battery-powered consumer electronic terminal, and the method includes: S10, Pre-setting stage: Perform constant current-constant voltage charging test on the lithium battery, generate and store a table of charge percentage-temperature-current relationship, the table of relationship includes at least the charging cut-off current Iterm corresponding to 100% SOC; S20. Real-time judgment stage: When the terminal device is in charging state and the output value of the fuel meter is BATT_SOC≥SOC_THD, or the current charging current IBAT_NOW<IBAT_THD, the near full charge calibration window is entered; SOC_THD is the first percentage of the battery capacity in the relation table, and IBAT_THD is the first current in the relation table. S30, Error Direction Determination Stage: If the preset condition of low battery is met, proceed to the "Low Battery Calculation" branch; If the preset conditions for high battery consumption are met, proceed to the "High Battery Calculation" branch; S40, Calibration Calculation Stage: Under the "low power calculation" branch, the power meter output value BATT_SOC is weighted and increased to obtain the calibrated power CALI_SOC; Under the "Energy Calculation" branch, the output value BATT_SOC of the energy meter is adjusted based on the time-limited incremental algorithm to obtain the calibrated energy CALI_SOC; S50, Display Synchronization Stage: The calibrated power CALI_SOC is used as the final output of the power meter, and the terminal user interface is driven to smoothly update the displayed power. S60. Termination Phase: When the charging current IBAT≤Iterm and the calibration capacity CALI_SOC=100%, the near-full charge calibration process ends. Under the "Insufficient Power Calculation" branch, the power meter output value BATT_SOC is weighted and increased, specifically including: S411. Record the current sampling value IBAT_E at the moment of entering the "low power calculation" calibration window; S412. Read the current charging current IBAT_NOW in real time during each power calculation cycle; S413. Based on the "Battery Percentage - Temperature - Current" relationship table, find the battery percentage IBAT_SOC of the current charging current IBAT_NOW at the same temperature; S414. Calculate the weight: weight = (IBAT_NOW – Iterm) / (IBAT_E – Iterm), 0 ≤ weight ≤ 1; Iterm is the charging cutoff current; S415, Calculate calibration charge CALI_SOC: CALI_SOC = BATT_SOC × weight + IBAT_SOC × (1 – weight); BATT_SOC is the output value of the fuel meter; S416, outputs the calibrated battery level CALI_SOC as the final battery percentage for that cycle, and drives a smooth update of the user interface; S417. Repeat S412-S416 until the current charging current IBAT_NOW≤Iterm and the calibration capacity CALI_SOC reaches 100%, then end the calibration.

2. The terminal device near full charge calibration method according to claim 1, characterized in that, Under the "Power Calculation" branch, the output value BATT_SOC of the power meter is adjusted based on the time-limited incremental algorithm, specifically including: S421. Using the battery meter reading BATT_SOC_E when entering the "Battery Calculation Multi" calibration window as the baseline value, determine the first target battery percentage, SOC_NEXT=BATT_SOC_E+1%; SOC_NEXT is the next integer battery percentage to be achieved. S422. Based on the temperature-current-SOC relationship table at the current temperature, obtain the theoretical charging current IBAT_TABLE corresponding to the charge percentage SOC = BATT_SOC_E; S423. Calculate the theoretical time (Time_need) required to push the battery percentage SOC from the baseline value BATT_SOC_E to the target battery percentage SOC_NEXT: Time_need=(SOC_NEXT–BATT_SOC_E)×FCC / IBAT_TABLE; Where FCC stands for battery full charge capacity, in mAh; S424. Within each power calculation cycle Δt, the accumulated actual time is summed to obtain acc_time: acc_time = acc_time + Δt; Δt is in seconds (s). S425, Real-time calculation of calibration power CALI_SOC: CALI_SOC=BATT_SOC_E+(SOC_NEXT–BATT_SOC_E)×acc_time / Time_need; S426. When CALI_SOC≥SOC_NEXT and SOC_NEXT<100%, increment SOC_NEXT by 1% and clear acc_time to zero, then return to step S23. S427. Repeat steps S423-S426 until the physical charging current IBAT drops to the cutoff current Iterm and the calibration capacity CALI_SOC reaches 100%, then end the calibration.

3. The terminal device near full charge calibration method according to claim 1, characterized in that, In S30, the low battery preset condition is: it must be satisfied for N consecutive cycles. IBAT_NOW < IBAT_THD and BATT_SOC < SOC_THD; or IBAT_NOW<IBAT_SOC_THD and BATT_SOC≥SOC_THD; Where IBAT_THD is the first current in the relation table, SOC_THD is the first charge percentage in the relation table; IBAT_SOC_THD is the charging current corresponding to SOC=BATT_SOC in the relation table; N is a natural number, N≥2; And simultaneously satisfy the condition that the current charging VBAT_NOW ≥ VBAT_FULL for N consecutive cycles; VBAT_FULL is the full charge voltage; The preset condition for battery power is: satisfying the following for N consecutive cycles: IBAT_NOW≥IBAT_THD and BATT_SOC≥SOC_THD; or IBAT_NOW>IBAT_SOC_THD and BATT_SOC≥SOC_THD and VBAT_NOW≥VBAT_FULL.

4. The terminal device near full charge calibration method according to claim 2, characterized in that, Step S415 also includes a fuel meter error correction process: The cumulative error correction threshold SOC_ADJ_THD of the fuel meter is dynamically set within a preset range according to different charging temperatures; When BATT_SOC > IBAT_SOC + SOC_ADJ_THD, BATT_SOC is corrected to: BATT_SOC = IBAT_SOC + SOC_ADJ_THD; When BATT_SOC < IBAT_SOC - SOC_ADJ_THD, BATT_SOC is corrected to: BATT_SOC = IBAT_SOC - SOC_ADJ_THD.

5. The terminal device near full charge calibration method according to claim 2, characterized in that, The Time_need in the aforementioned time-limited incremental algorithm introduces a dynamic speed-limiting factor k(T, SOH): k(T, SOH)=1.8–0.02×(T–25)–0.01×SOH_loss; Where T is the real-time battery temperature, and SOH_loss is the percentage of battery capacity decay, which is obtained by cycle counting of the fuel gauge or OTA calibration. Then Time_need is corrected to: Time_need=k(T,SOH)×(SOC_NEXT–BATT_SOC_E)×FCC / IBAT_TABLE.

6. The method for calibrating the near-full charge level of a terminal device according to claim 2, characterized in that, Step S416 also includes a process of smoothing the output calibration charge CALI_SOC, the specific calculation method of which is as follows: S416-1 calculates the uncharged capacity SOC_TO_CHG: SOC_TO_CHG = FULL_SOC - CALI_SOC; FULL_SOC is the maximum usable capacity that the battery can be charged into under the current conditions. S416-2 calculates the remaining time TIME_TO_FULL: TIME_TO_FULL=SOC_TO_CHG×FCC / IBAT_NOW; S416-3 Calculation Steps STEPS: STEPS = TIME_TO_FULL / TSTEP; Where STEPS is a positive integer and ≥1; TSTEP is the power calculation period in seconds; S416-4 Calculates the compensation amount for each step: com_soc=SOC_GAP / STEPS; SOC_GAP is the difference between the calibration charge CALI_SOC calculated at the moment of this calibration and the output of the fuel meter in the previous cycle; S416-5 Periodic Compensation: The calibration power is updated every power calculation cycle: CALI_SOC = CALI_SOC + com_soc; Compensation stops when IBAT_NOW≤ITERM and CALI_SOC=FULL_SOC or com_soc=0.

7. A near-fully charged calibration chip, characterized in that, include: Memory for a power percentage-temperature-current relationship table; Temperature sensor interface, used to obtain real-time battery temperature; Current sampling interface, used to obtain the real-time charging current of the battery; The arithmetic unit is used to execute the calibration calculation step in the near-full charge calibration method for terminal devices according to any one of claims 1-6; The output interface is used to output the calibration power CALI_SOC to the terminal main controller or display driver. The computing unit is started when the terminal is in a constant voltage phase and SOC≥SOC_THD, and stopped when IBAT≤Iterm and CALI_SOC=100%.

8. The near-full charge calibration chip according to claim 7, wherein, The computing unit is a dedicated hardware microcode circuit.

9. A terminal device, characterized in that, include: Lithium-ion batteries; The near-full charge calibration chip as described in claim 7 or 8; The application processor is used to receive the calibration power CALI_SOC output by the near-fully charged calibration chip and drive the smooth display of the user interface; Display used to update the battery percentage (UISOC) in real time.

10. The terminal device according to claim 9, characterized in that, The terminal device can be any one of a smartphone, tablet, wearable device, or Bluetooth headset.

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