Battery equalization control method and device, terminal equipment and readable storage medium

Abstract

The invention relates to a battery equalization control method and device, terminal equipment and a readable storage medium, the method is applied to the terminal equipment comprising a first battery and a second battery, the first battery and the second battery are connected in series, and the capacity of the first battery and the capacity of the second battery are different. Determining current open-circuit voltages of the first battery and the second battery; determining an absolute value of a difference value between the current open-circuit voltage of the first battery and the current open-circuit voltage of the second battery to obtain a first absolute value; and under the condition that the first absolute value is greater than or equal to the first voltage threshold, adjusting the charging current of the first battery and the second battery according to the first preset current so as to reduce the voltage difference between the open-circuit voltage of the first battery and the open-circuit voltage of the second battery. By adopting the method, the equalization charging of the two batteries can be controlled according to the open-circuit voltage of the two batteries.

Description

Technical Field

[0001] The present application relates to the field of terminal technology, and in particular to a battery balancing control method, device, terminal equipment and readable storage medium. Background Art

[0002] With the continuous development of electronic technology, the performance requirements of terminal devices are getting higher and higher, resulting in higher and higher power consumption of terminal devices. In order to extend the battery life of the terminal device, two batteries can be set in the terminal device. When the two batteries are connected in parallel, the battery in the charging circuit will be shunted by the two batteries, resulting in a slower charging speed of the battery. In order to solve the above problem, the two batteries can be set in series. However, when the two batteries are set in series, it is very important to ensure that the two batteries are charged evenly. Summary of the invention

[0003] Based on this, it is necessary to provide a battery balancing control method, device, terminal equipment and readable storage medium that can control the balanced charging of two batteries according to the open circuit voltages of the two batteries in order to solve the above technical problems.

[0004] In a first aspect, the present application provides a battery balancing control method, which is applied to a terminal device including a first battery and a second battery, wherein the first battery and the second battery are connected in series, and the capacities of the first battery and the second battery are different, and the method includes:

[0005] When the terminal device is in a charging state, determining a current open circuit voltage of the first battery and a current open circuit voltage of the second battery;

[0006] determining an absolute value of a difference between a current open circuit voltage of the first battery and a current open circuit voltage of the second battery to obtain a first absolute value;

[0007] When the first absolute value is greater than or equal to a first voltage threshold, the charging current of the first battery and the charging current of the second battery are adjusted according to a first preset current to reduce the voltage difference between the open circuit voltage of the first battery and the open circuit voltage of the second battery.

[0008] In a second aspect, the present application further provides a battery balancing control device, which is applied to a terminal device including a first battery and a second battery, wherein the first battery and the second battery are connected in series, and the capacities of the first battery and the second battery are different, and the device includes:

[0009] A first determining unit, configured to determine a current open circuit voltage of the first battery and a current open circuit voltage of the second battery when the terminal device is in a charging state;

[0010] a second determining unit, configured to determine an absolute value of a difference between a current open circuit voltage of the first battery and a current open circuit voltage of the second battery, to obtain a first absolute value;

[0011] an adjusting unit, for adjusting the charging current of the first battery and the charging current of the second battery according to a first preset current when the first absolute value is greater than or equal to a first voltage threshold, so as to reduce the voltage difference between the open circuit voltage of the first battery and the open circuit voltage of the second battery.

[0012] In a third aspect, the present application further provides a terminal device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0013] When the terminal device is in a charging state, determining a current open circuit voltage of a first battery and a current open circuit voltage of a second battery, wherein the first battery and the second battery are connected in series, and the capacities of the first battery and the second battery are different;

[0014] determining an absolute value of a difference between a current open circuit voltage of the first battery and a current open circuit voltage of the second battery to obtain a first absolute value;

[0015] When the first absolute value is greater than or equal to a first voltage threshold, the charging current of the first battery and the charging current of the second battery are adjusted according to a first preset current to reduce the voltage difference between the open circuit voltage of the first battery and the open circuit voltage of the second battery.

[0016] In a fourth aspect, the present application further provides a terminal device, including a processor, the terminal device also including a first battery and a second battery, the first battery and the second battery are connected in series, the first battery and the second battery have different capacities, and the processor is used to:

[0017] When the terminal device is in a charging state, determining a current open circuit voltage of the first battery and a current open circuit voltage of the second battery;

[0018] determining an absolute value of a difference between a current open circuit voltage of the first battery and a current open circuit voltage of the second battery to obtain a first absolute value;

[0019] When the first absolute value is greater than or equal to a first voltage threshold, the charging current of the first battery and the charging current of the second battery are adjusted according to a first preset current to reduce the voltage difference between the open circuit voltage of the first battery and the open circuit voltage of the second battery.

[0020] In a fifth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the following steps are implemented:

[0021] When the terminal device is in a charging state, determining a current open circuit voltage of a first battery and a current open circuit voltage of a second battery, wherein the first battery and the second battery are connected in series, and the capacities of the first battery and the second battery are different;

[0022] determining an absolute value of a difference between a current open circuit voltage of the first battery and a current open circuit voltage of the second battery to obtain a first absolute value;

[0023] When the first absolute value is greater than or equal to a first voltage threshold, the charging current of the first battery and the charging current of the second battery are adjusted according to a first preset current to reduce the voltage difference between the open circuit voltage of the first battery and the open circuit voltage of the second battery.

[0024] In a sixth aspect, the present application further provides a computer program product, including a computer program, which implements the following steps when executed by a processor:

[0025] When the terminal device is in a charging state, determining a current open circuit voltage of a first battery and a current open circuit voltage of a second battery, wherein the first battery and the second battery are connected in series, and the capacities of the first battery and the second battery are different;

[0026] determining an absolute value of a difference between a current open circuit voltage of the first battery and a current open circuit voltage of the second battery to obtain a first absolute value;

[0027] When the first absolute value is greater than or equal to a first voltage threshold, the charging current of the first battery and the charging current of the second battery are adjusted according to a first preset current to reduce the voltage difference between the open circuit voltage of the first battery and the open circuit voltage of the second battery.

[0028] In an embodiment of the present application, the terminal device includes a first battery and a second battery connected in series, and the first battery and the second battery have different capacities. When the terminal device is in a charging state, the current open circuit voltage of the first battery and the current open circuit voltage of the second battery are determined, and the absolute value of the difference between the current open circuit voltage of the first battery and the current open circuit voltage of the second battery is determined to obtain a first absolute value. When the first absolute value is greater than or equal to the first voltage threshold, the charging current of the first battery and the charging current of the second battery are adjusted according to the first preset current to reduce the voltage difference between the open circuit voltage of the first battery and the open circuit voltage of the second battery. When the terminal device is in a charging state, and the absolute value of the difference between the open circuit voltages of the first battery and the second battery is greater than or equal to the first voltage threshold, the charging current of the first battery and the second battery can be adjusted so that the voltage difference between the open circuit voltages of the first battery and the second battery can be reduced, so that the two batteries can be balanced according to the open circuit voltages of the two batteries. Charge control. In addition, since the open circuit voltage of the battery is the voltage of the battery cell, it will not change with the change of ambient temperature and battery aging, so the accuracy of voltage balancing control between the two batteries connected in series can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments of the present application or the related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 is a structural schematic diagram of a battery balancing device provided in an embodiment of the present application;

[0031] Figure 2 It is a flowchart of a battery balancing control method provided in an embodiment of the present application;

[0032] Figure 3 is a flow chart of another battery balancing control method provided in an embodiment of the present application;

[0033] Figure 4 It is a structural schematic diagram of a first-order equivalent circuit of a battery provided in an embodiment of the present application;

[0034] Figure 5 It is a flowchart of another battery balancing control method provided in an embodiment of the present application;

[0035] Figure 6 It is a flowchart of another battery balancing control method provided in an embodiment of the present application;

[0036] Figure 7 is a structural schematic diagram of a battery balancing control device provided in an embodiment of the present application;

[0037] Figure 8 It is a structural diagram of a terminal device provided in an embodiment of the present application;

[0038] Fig. 9 It is a structural diagram of another terminal device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0040] In order to better understand the embodiments of the present application, the battery balancing control device of the present application is first introduced below.

[0041] Figure 1 is a schematic diagram of the structure of a battery balancing device provided in an embodiment of the present application. Figure 1 As shown, the battery balancing control device may include two batteries connected in series, namely, battery 1 and battery 2. The capacity of battery 1 may be smaller than that of battery 2.

[0042] After the terminal device is connected to the charger through the Universal Serial Bus (USB) interface, after the USB interface receives the electrical signal from the charger, the electrical signal can be sent to the bidirectional charge pump through the overvoltage protection module and the power management integrated circuit (PMIC) charger. The bidirectional charge pump can determine whether the charging mode is fast charging, that is, fast charging, based on the electrical signal. In the case of determining that the charging mode is fast charging, the bidirectional charge pump can control the first switch device to turn on, and the first switch device can be used to charge battery 1 and battery 2. In the case of determining that the charging mode is slow charging, the bidirectional charge pump can control the first switch device to turn off, and the electrical signal can be converted into voltage before charging battery 1 and battery 2.

[0043] During the charging process of battery 1 and battery 2, the terminal device can detect the voltage of battery 1 and the voltage of battery 2. When the voltage of battery 1 or the voltage of battery 2 reaches the specified full voltage, it indicates that battery 1 and / or battery 2 are fully charged, and charging of battery 1 and battery 2 will be stopped.

[0044] It can be seen that as long as one of the batteries 1 and 2 is fully charged, the charging of the batteries 1 and 2 will stop. Therefore, in order to avoid a large voltage difference between the batteries 1 and 2 after they are fully charged, during the charging process of the batteries 1 and 2, the balancing module can perform voltage balancing control on the batteries 1 and 2 according to the voltage of the batteries 1 and 2, so that after they are fully charged, the voltage difference between the batteries 1 and 2 can be controlled within a certain range.

[0045] When the terminal device is not connected to a charger via the USB interface, i.e., is discharged, battery 1 and battery 2 can power the internal circuit in the terminal device through a bidirectional charge pump. Battery 2 can also power the internal circuit in the terminal device through a second switch device.

[0046] The overvoltage protection module is used to provide overvoltage protection for battery 1 and battery 2 during the process of charging battery 1 and battery 2.

[0047] The PMIC charger is used to control the current flow and direction to meet the needs of the main system.

[0048] The bidirectional charge pump is used to control the charging circuit to be USB interface-second switch device-battery 1-battery 2, or USB interface-overvoltage protection module-PMIC charger-bidirectional charge pump-battery 2 during the charging process, and convert the discharge voltage during the discharging process.

[0049] The level conversion module is used for performing level conversion so that during the discharge process of the battery 1 and the battery 2, the battery 1 and the battery 2 can be converted into a parallel connection.

[0050] The first fuel meter is used to collect the terminal voltage of the battery 1.

[0051] The second fuel meter is used to collect the terminal voltage of battery 2.

[0052] The equalization module is used to perform voltage equalization control on battery 1 and battery 2 during the charging process of battery 1 and battery 2.

[0053] The first switch device and the second switch device may be metal oxide semiconductor (MOS) tubes or other switch devices.

[0054] It should be understood that Figure 1 This is an exemplary description of the structure of a battery balancing device in a terminal device, and does not limit the structure of the battery balancing device. It only needs to ensure that the two batteries are connected in series and have different capacities.

[0055] In order to better understand the embodiments of the present application, the relevant technologies are first introduced below.

[0056] During the charging process of the terminal device, in order to ensure voltage balance between the two batteries connected in series, the terminal voltages of the two batteries can be determined. When the voltage difference between the terminal voltages of the two batteries exceeds a certain range, current can be transferred between the first battery and the second battery so that the voltage difference between the terminal voltages of the first battery and the second battery can be kept within a certain range.

[0057] However, the impedance of a battery is not fixed. It changes with temperature and battery aging.

[0058] At normal temperature, the voltage balance of the two batteries can be achieved by current transfer, but under low temperature conditions, the impedance of the battery will increase. During the current transfer process, a slight change in current may cause a large voltage difference between the two batteries, making it difficult to achieve voltage balance.

[0059] For example, at normal temperature, the voltage difference can be set to be controlled within 5 millivolts (millivolt, mV), and 100 milliamperes (mA) of current can be adjusted each time. However, at low temperatures (such as below 5°), the voltage difference can be set to be controlled within 50mV, and 25mA of current can be adjusted each time. Since the internal resistance of the battery is large in a low temperature environment, a slight adjustment of the current will cause the voltage difference between the two batteries to exceed the voltage difference control. Therefore, the adjustable current at low temperature is less than the adjustable current at normal temperature, and the voltage difference control at low temperature is greater than the voltage difference control at normal temperature. Assume that the terminal voltage of the first battery is 3550mV at low temperature, the terminal voltage of the second battery is 3600mV, and the voltage difference between the first battery and the second battery is 50mV. Since the voltage difference between the first battery and the second battery is equal to the voltage difference control 50mV, it is necessary to transfer 25mA of current from the second battery to the first battery. When the internal resistance of the first battery and the second battery is 1 ohm (Ω), after transferring 25mA of current, the terminal voltage of the first battery is 3600mV, and the terminal voltage of the second battery is 3550mV. Since the voltage difference between the first battery and the second battery is equal to the voltage difference control 50mV after the current is transferred, it is necessary to transfer current from the first battery to the second battery, resulting in a "vicious cycle balance" situation in which either the terminal voltage of the first battery is high or the terminal voltage of the second battery is high.

[0060] When the first battery and the second battery have different aging degrees, or one of the first battery and the second battery is a new battery and the other is an aged battery, the impedance of one battery is large and the impedance of the other battery is small, so that the terminal voltage of the battery with large impedance is greater than the terminal voltage of the battery with small impedance, and current may be transferred from the battery with large impedance to the battery with small impedance. The terminal voltage of the battery with large impedance is greater than the terminal voltage of the battery with small impedance may be caused by impedance change. In fact, the voltage of the battery cell of the battery with large impedance is not necessarily greater than the voltage of the battery cell of the battery with small impedance, resulting in incorrect equalization.

[0061] Therefore, it is very important to ensure the accuracy of voltage balance between two batteries connected in series.

[0062] Figure 2 1 is a flow chart of a battery balancing control method provided in an embodiment of the present application. The battery balancing control method is applied to a terminal device. The terminal device may include a first battery and a second battery. The first battery and the second battery are connected in series. The capacities of the first battery and the second battery are different. Figure 2 As shown, the battery balancing control method may include the following steps.

[0063] 201. When the terminal device is in a charging state, determine a current open circuit voltage of a first battery and a current open circuit voltage of a second battery.

[0064] The open circuit voltage (OCV) of a battery is the voltage of a battery cell when the battery is open circuit, that is, the voltage of the battery cell. The current open circuit voltage of the first battery can be understood as the open circuit voltage of the first battery at the current moment. The current open circuit voltage of the second battery can be understood as the open circuit voltage of the second battery at the current moment.

[0065] When the terminal device is in a charging state, that is, the terminal device detects that a charger is connected and is being charged by the charger, the terminal device can periodically determine the current open circuit voltage of the first battery and the current open circuit voltage of the second battery. The period can be 2 seconds (s) or other time periods.

[0066] The current open circuit voltage of the first battery and the current open circuit voltage of the second battery can be determined in parallel (i.e., simultaneously) or in series. When the current open circuit voltage of the first battery and the current open circuit voltage of the second battery are determined in parallel, the efficiency of battery balancing control can be improved. When the current open circuit voltage of the first battery and the current open circuit voltage of the second battery are determined in series, the terminal device can first determine the current open circuit voltage of the first battery and then determine the current open circuit voltage of the second battery, or first determine the current open circuit voltage of the second battery and then determine the current open circuit voltage of the first battery.

[0067] 202. Determine an absolute value of a difference between a current open circuit voltage of the first battery and a current open circuit voltage of the second battery to obtain a first absolute value.

[0068] After the terminal device determines the current open circuit voltage of the first battery and the current open circuit voltage of the second battery, it can determine the absolute value of the difference between the current open circuit voltage of the first battery and the current open circuit voltage of the second battery, that is, calculate the absolute value of the difference between the current open circuit voltage of the first battery and the current open circuit voltage of the second battery to obtain a first absolute value.

[0069] 203. When the first absolute value is greater than or equal to the first voltage threshold, adjust the charging current of the first battery and the charging current of the second battery according to the first preset current to reduce the voltage difference between the open circuit voltage of the first battery and the open circuit voltage of the second battery.

[0070] The first voltage threshold is the maximum allowable voltage difference between the open circuit voltage of the first battery and the open circuit voltage of the second battery when the terminal device is charged. Exemplarily, the first voltage threshold may be 5 mV.

[0071] The first preset current is the current value that can be adjusted each time when the terminal device is charged and the open circuit voltage is used to perform voltage balancing control on the battery. Exemplarily, the first preset current can be 100mA.

[0072] The terminal device can determine whether the first absolute value is greater than or equal to the first voltage threshold. If the first absolute value is greater than or equal to the first voltage threshold, it indicates that the voltage difference between the current open circuit voltage of the first battery and the current open circuit voltage of the second battery is large, and the charging current of the first battery and the charging current of the second battery can be adjusted according to the first preset current to reduce the voltage difference between the open circuit voltage of the first battery and the open circuit voltage of the second battery. If it is determined that the first absolute value is less than the first voltage threshold, it indicates that the voltage difference between the current open circuit voltage of the first battery and the current open circuit voltage of the second battery is small, and step 201 can be continued, that is, the open circuit voltage of the first battery and the open circuit voltage of the second battery are determined when the next cycle arrives, that is, the next open circuit voltage of the first battery and the next open circuit voltage of the second battery are determined, that is, the open circuit voltage of the first battery and the open circuit voltage of the second battery at the next moment are determined. The time interval between the next moment and the current moment is the above cycle.

[0073] The terminal device can transfer the first preset current of a battery to the second battery, that is, transfer the first preset current of the first target battery to the second target battery. After adjustment, the charging current of the first target battery is reduced by the first preset current, and the charging current of the second target battery is increased by the first preset current. It can be seen that the charging currents of the two batteries differ by 2*the first preset current after adjustment. The larger the charging current of the battery, the faster the charging speed of the battery. Therefore, after adjustment, the charging speed of the second target battery is accelerated, and the charging speed of the first target battery is slowed down, so that the voltage difference between the open circuit voltage of the first battery and the open circuit voltage of the second battery can be reduced, so as to ensure that the voltage difference between the open circuit voltage of the first battery and the open circuit voltage of the second battery after full charge is within a certain range. The first target battery is the battery with the larger current open circuit voltage among the first battery and the second battery, and the second target battery is the battery with the smaller current open circuit voltage among the first battery and the second battery.

[0074] Exemplarily, the first preset current is 25 mA. After adjustment, the charging current of the first target battery is reduced by 25 mA, and the charging current of the second target battery is increased by 25 mA. After adjustment, the charging currents of the two batteries differ by 50 mA.

[0075] exist Figure 2 In the battery balancing control method shown, when the terminal device is in a charging state and the absolute value of the difference between the current open circuit voltages of the first battery and the second battery is greater than or equal to the first voltage threshold, the charging current of the first battery and the second battery can be adjusted so as to reduce the voltage difference between the open circuit voltages of the first battery and the second battery, thereby performing balanced charging control on the two batteries according to the open circuit voltages of the two batteries. In addition, since the open circuit voltage of the battery is the voltage of the battery cell, it will not change with the change of the ambient temperature and the aging degree of the battery, so the accuracy of the voltage balancing control between the two batteries connected in series can be improved.

[0076] Figure 3 1 is a flow chart of another battery balancing control method provided in an embodiment of the present application. The battery balancing control method is applied to a terminal device. The terminal device may include a first battery and a second battery. The first battery and the second battery are connected in series. The capacities of the first battery and the second battery are different. Figure 3 As shown, the battery balancing control method may include the following steps.

[0077] 301. When the terminal device is in a charging state, determine a current open circuit voltage of a first battery and a current open circuit voltage of a second battery.

[0078] When the terminal device is in a charging state, the terminal device may periodically determine a current open circuit voltage of the first battery and a current open circuit voltage of the second battery.

[0079] The terminal voltage of a battery is the absolute value of the difference between the voltages at the two ends of the battery, that is, the difference between the voltages at the positive and negative electrodes of the battery. The charging current of a battery is the current that flows through the battery during the charging process.

[0080] In some embodiments, the terminal device can determine the current charging current of the first battery and the current charging current of the second battery, can determine the current terminal voltage of the first battery and the current terminal voltage of the second battery, and can use an online parameter identification algorithm to determine the current open circuit voltage of the first battery and the current open circuit voltage of the second battery based on the current charging current and the current terminal voltage of the first battery, and the current charging current and the current terminal voltage of the second battery. The online parameter identification algorithm can be a least squares method, a recursive least squares method, a Kalman filter, a neural network model, etc.

[0081] The current charging current of the first battery (or the second battery) can be understood as the charging current of the first battery (or the second battery) at the current moment. The current terminal voltage of the first battery (or the second battery) can be understood as the terminal voltage of the first battery (or the second battery) at the current moment.

[0082] Figure 4 Schematic diagram of the first-order equivalent circuit of a battery provided in an embodiment of the present application. Figure 4 As shown, the first-order equivalent circuit of the battery can include a battery cell, an ohmic resistor R o , diffusion resistance R P and diffusion capacitance C P . R o It can represent the resistance of the battery as the charge in the double layer accumulates and dissipates. P and diffusion capacitance C P The RC network can simulate the diffusion voltage. The change trend of the diffusion voltage is relatively slow. This is due to the polarization phenomenon caused by the imbalance of electrode ion concentration caused by the slow diffusion of lithium ions in the battery. The voltage of the first-order equivalent circuit of the battery can be expressed as follows:

[0083]

[0084] Among them, U p (k+1) represents the voltage across the RC network at time k+1, U P (k) represents the voltage across the RC network at time k, ΔT represents the sampling time interval, i.e., the above cycle, I(k) represents the charging current of the battery at time k, and U t (k) represents the terminal voltage of the battery at time k, U ocv (k) represents the open circuit voltage of the battery at time k. The dynamic voltage of the battery at time k can be expressed as follows:

[0085] U e (k) = U t (k)-U ocv (k) = U P (k)+R o I(k) (2)

[0086] According to formula (1), formula (2) can be rearranged to obtain:

[0087]

[0088] Substituting formula (3) into the expression of the battery terminal voltage in formula (1) yields:

[0089]

[0090] It can be assumed The identification vector of the online parameter identification algorithm can be defined as θ k ,φ k and It can be expressed as follows:

[0091]

[0092] Through the above formula, we can get:

[0093] U ocv (k) = θ k (4)U ocv (k-1)+θ k (3) (6)

[0094] From formula (6), we can know that the terminal device identifies (or determines) θ through the online parameter identification algorithm. k (3) and θ k (4) Afterwards, the open circuit voltage at time k can be iteratively determined based on the open circuit voltage of the battery at time k-1.

[0095] The following is an explanation using the recursive least squares method as an online parameter identification algorithm.

[0096] You can initialize P0 of the recursive least squares method, and λ, the recursive least squares method can be expressed as follows:

[0097]

[0098]

[0099] Among them, λ is the forgetting factor, which is generally 0.95 to 0.995. When λ is 1, it means there is no forgetting. The above is the recursive least squares method with forgetting factor. The recursive least squares method with forgetting factor introduces the forgetting factor on the basis of the recursive least squares method, so that the new data has a greater weight than the old data, thereby speeding up the response to parameter changes. In the case of low sampling frequency, a smaller λ value (such as 0.95) can forget the old data faster and adapt to the new data more quickly, so as to better track dynamic changes.

[0100] The terminal device may initialize relevant parameters first. For example, the terminal device may determine the open circuit voltage of the battery as the terminal voltage of the battery, and the initial P may be set as large as possible, such as 1e6, so that the initial iteration result is closer to the measured value.

[0101] The following is an example in which the current moment is moment k and the previous moment is moment k-1.

[0102] The terminal device can first obtain the terminal voltage U of the battery at time k t (k) and charging current I(k).

[0103] The terminal device can calculate the charging current I(k) at time k and the terminal voltage U of the battery at time k-1. t (k-1) and the charging current I(k-1) determine φ k . You can use the code phi(:,k)=[I(k-1),I(k),1,U t (k-1)] T Determine φ k .

[0104] The terminal device can calculate the terminal voltage U of the battery at time k. t The measurement error is determined by the terminal voltage U of the battery at time k. t The difference between (k) and the predicted terminal voltage is determined as the measurement error. The predicted terminal voltage of the battery at time k is θ k-1 *φ k The measurement error can be determined using the code y_tidle(k) = (Ut(k) - theta(:, k-1)'*phi(:, k)).

[0105] The terminal device can be based on φ k Determine K k K can be determined using the code L(:,k)=P(:,k-1)*phi(:,k) / (lambda+phi(:,k)'*P(:,k-1)*phi(:,k)) k .

[0106] The terminal device can be based on K k ,φ k and P k-1 Determine P k P can be determined using the code P = (P(:,k-1)-L(:,k)*phi(:,k)'*P(:,k-1)) / lambda k .

[0107] The terminal device can be based on K k and measurement error determination It can be determined using the code theta(:,k)=theta(:,k-1)+L(:,k)*y_tidle(k)

[0108] The terminal device can be based on θ k (3) θ k (4) and U ocv (k-1) Determine U ocv (k). U can be determined using the code OCV(k)=theta(4,k)*OCV(k-1)+theta(3,k) ocv (k).

[0109] For other descriptions of step 301 , please refer to the relevant descriptions below step 201 .

[0110] 302. Determine whether the current open circuit voltage of the first battery and the current open circuit voltage of the second battery are available. If both the current open circuit voltage of the first battery and the current open circuit voltage of the second battery are available, execute step 303. If the current open circuit voltage of the first battery or the current open circuit voltage of the second battery is not available, execute step 306.

[0111] The terminal device can determine whether the current open circuit voltage of the first battery and the current open circuit voltage of the second battery are available. When the current open circuit voltage of the first battery and the current open circuit voltage of the second battery are both available, it indicates that the determined current open circuit voltage of the first battery and the current open circuit voltage of the second battery are valid open circuit voltages, and step 303 can be executed. When the current open circuit voltage of the first battery or the current open circuit voltage of the second battery is not available, it indicates that at least one of the determined current open circuit voltage of the first battery and the current open circuit voltage of the second battery is invalid, and the current open circuit voltage of the first battery and the current open circuit voltage of the second battery cannot be used for voltage balancing, and step 306 can be executed.

[0112] The terminal device can determine whether the current open circuit voltage of the first battery has converged. If the current open circuit voltage of the first battery has converged, it can be determined that the current open circuit voltage of the first battery is available. If the current open circuit voltage of the first battery has not converged, it can be determined that the current open circuit voltage of the first battery is not available. The terminal device can determine whether the current open circuit voltage of the second battery has converged. If the current open circuit voltage of the second battery has converged, it can be determined that the current open circuit voltage of the second battery is available. If the current open circuit voltage of the second battery has not converged, it can be determined that the current open circuit voltage of the second battery is not available.

[0113] The terminal device can determine whether the current open circuit voltage of the first battery is less than the current terminal voltage of the first battery. If the current open circuit voltage of the first battery is greater than or equal to the current terminal voltage of the first battery, it indicates that the current open circuit voltage of the first battery is inaccurate, and it can be determined that the current open circuit voltage of the first battery does not converge. If the current open circuit voltage of the first battery is less than the current terminal voltage of the first battery, it can continue to determine whether the voltage difference between the current open circuit voltage of the first battery and the previous open circuit voltage of the first battery is less than the third voltage threshold, that is, it is determined whether the absolute value of the difference between two consecutive open circuit voltages is less than the third voltage threshold. If the voltage difference between the current open circuit voltage of the first battery and the previous open circuit voltage of the first battery is not less than (that is, greater than or equal to) the third voltage threshold, it indicates that the current open circuit voltage of the first battery is inaccurate, and it can be determined that the current open circuit voltage of the first battery does not converge. If the voltage difference between the current open circuit voltage of the first battery and the previous open circuit voltage of the first battery is less than the third voltage threshold, it indicates that the determined current open circuit voltage of the first battery is accurate, and it can be determined that the current open circuit voltage of the first battery converges. Exemplarily, the third voltage threshold can be 3mV.

[0114] Similarly, the terminal device can determine whether the current open circuit voltage of the second battery is less than the current terminal voltage of the second battery. When the current open circuit voltage of the second battery is greater than or equal to the current terminal voltage of the second battery, it can be determined that the current open circuit voltage of the second battery does not converge. When the current open circuit voltage of the second battery is less than the current terminal voltage of the second battery, it can continue to determine whether the voltage difference between the current open circuit voltage of the second battery and the previous open circuit voltage of the second battery is less than the third voltage threshold. When the voltage difference between the current open circuit voltage of the second battery and the previous open circuit voltage of the second battery is not less than (i.e., greater than or equal to) the third voltage threshold, it can be determined that the current open circuit voltage of the second battery does not converge. When the voltage difference between the current open circuit voltage of the second battery and the previous open circuit voltage of the second battery is less than the third voltage threshold, it can be determined that the current open circuit voltage of the second battery converges.

[0115] The previous terminal voltage of the first battery (or the second battery) can be understood as the terminal voltage of the first battery (or the second battery) at the previous moment. The time interval between the current moment and the previous moment is the above period.

[0116] 303. Determine an absolute value of a difference between a current open circuit voltage of the first battery and a current open circuit voltage of the second battery to obtain a first absolute value.

[0117] For a detailed description of step 303 , reference may be made to the description of step 202 .

[0118] 304. Determine whether the first absolute value is greater than or equal to the first voltage threshold. If the first absolute value is greater than or equal to the first voltage threshold, execute step 305; if the first absolute value is less than the first voltage threshold, execute step 301.

[0119] The terminal device may determine whether the first absolute value is greater than or equal to the first voltage threshold. If it is determined that the first absolute value is greater than or equal to the first voltage threshold, it indicates that the voltage difference between the current open circuit voltage of the first battery and the current open circuit voltage of the second battery is large, and step 305 may be performed. If it is determined that the first absolute value is less than the first voltage threshold, it indicates that the voltage difference between the current open circuit voltage of the first battery and the current open circuit voltage of the second battery is small, and step 301 may be continued.

[0120] For other descriptions of step 304 , please refer to the relevant descriptions below step 203 .

[0121] 305. Regulate the charging current of the first battery and the charging current of the second battery according to the first preset current to reduce the voltage difference between the open circuit voltage of the first battery and the open circuit voltage of the second battery.

[0122] The terminal device can adjust the charging current of the first battery and the charging current of the second battery according to the first preset current to reduce the voltage difference between the open circuit voltage of the first battery and the open circuit voltage of the second battery.

[0123] In some embodiments, the terminal device may further include a balancing module. The balancing module is connected to the first battery and the second battery respectively. The balancing module is connected to the first battery and the second battery, which may be understood as the balancing module directly connecting the first battery and the second battery, or indirectly connecting the first battery and the second battery.

[0124] The balancing module has a current carrying function, that is, a voltage balancing function. The terminal device can control the balancing module to adjust the charging current of the first battery and the charging current of the second battery according to the first preset current. For a detailed description, please refer to Figure 2 The corresponding related embodiments will not be described in detail here.

[0125] In some embodiments, the terminal device may further include a first variable resistor and a second variable resistor. The first variable resistor is connected in parallel to the first battery, and the second variable resistor is connected in parallel to the second battery.

[0126] The terminal device can adjust the resistance value of the first variable resistor and the resistance value of the second variable resistor according to the first preset current to adjust the charging current of the first battery and the charging current of the second battery.

[0127] Exemplarily, when the current open circuit voltage of the first battery is greater than the current open circuit voltage of the second battery, the terminal device can reduce the resistance of the first variable resistor to reduce the charging current of the first battery by a first preset current, and can increase the resistance of the second variable resistor to increase the charging current of the second battery by a first preset current.

[0128] It should be understood that during the charging of the first battery and the second battery, the charging process can be divided into multiple charging intervals, and the currents of the charging circuits corresponding to different charging intervals are different, but the currents of the charging circuits corresponding to the same charging interval remain unchanged. For example, the multiple charging intervals can be divided according to the voltage of the battery.

[0129] For other descriptions of step 305 , please refer to the relevant descriptions below step 203 .

[0130] 306. Determine a current terminal voltage of the first battery and a current terminal voltage of the second battery.

[0131] In the case where the current open circuit voltage of the first battery or the current open circuit voltage of the second battery is not available, the terminal device may determine the current terminal voltage of the first battery and the current terminal voltage of the second battery.

[0132] The current terminal voltage of the first battery and the current terminal voltage of the second battery can be determined in parallel or in series. In the case where the current terminal voltage of the first battery and the current terminal voltage of the second battery are determined in parallel, the efficiency of battery balancing control can be improved. In the case where the current terminal voltage of the first battery and the current terminal voltage of the second battery are determined in series, the terminal device can first determine the current terminal voltage of the first battery and then determine the current terminal voltage of the second battery, or first determine the current terminal voltage of the second battery and then determine the current terminal voltage of the first battery.

[0133] 307. Determine an absolute value of a difference between a current terminal voltage of the first battery and a current terminal voltage of the second battery to obtain a second absolute value.

[0134] After the terminal device determines the current terminal voltage of the first battery and the current terminal voltage of the second battery, it can determine the absolute value of the difference between the current terminal voltage of the first battery and the current terminal voltage of the second battery, that is, calculate the absolute value of the difference between the current terminal voltage of the first battery and the current terminal voltage of the second battery to obtain the second absolute value.

[0135] 308. Determine whether the second absolute value is greater than or equal to the second voltage threshold. If the second absolute value is greater than or equal to the second voltage threshold, execute step 309; if the second absolute value is less than the second voltage threshold, execute step 301.

[0136] The second voltage threshold is the maximum allowable voltage difference between the terminal voltage of the first battery and the terminal voltage of the second battery when the terminal device is charged.

[0137] The terminal device can determine whether the second absolute value is greater than or equal to the second voltage threshold. When the second absolute value is greater than or equal to the second voltage threshold, it indicates that the voltage difference between the current terminal voltage of the first battery and the current terminal voltage of the second battery is large, and step 309 can be executed. When the second absolute value is less than the second voltage threshold, it indicates that the voltage difference between the current terminal voltage of the first battery and the current terminal voltage of the second battery is small, and step 301 can be executed.

[0138] 309. Regulate the charging current of the first battery and the charging current of the second battery according to the second preset current to reduce the voltage difference between the terminal voltage of the first battery and the terminal voltage of the second battery.

[0139] The second preset current is the current value that can be adjusted each time during the process of using the terminal voltage to perform voltage balancing control on the battery when the terminal device is charged.

[0140] The terminal device can adjust the charging current of the first battery and the charging current of the second battery according to the second preset current to reduce the voltage difference between the terminal voltage of the first battery and the terminal voltage of the second battery.

[0141] The terminal device can transfer the second preset current of a battery to the second battery, that is, transfer the second preset current of the third target battery to the fourth target battery. After adjustment, the charging current of the third target battery is reduced by the second preset current, and the charging current of the fourth target battery is increased by the second preset current. It can be seen that the charging currents of the two batteries differ by 2*the second preset current after adjustment. The larger the charging current of the battery, the faster the charging speed of the battery. Therefore, after adjustment, the charging speed of the fourth target battery is accelerated, and the charging speed of the third target battery is slowed down, so that the voltage difference between the terminal voltage of the first battery and the terminal voltage of the second battery can be reduced, so as to ensure that the voltage difference between the terminal voltage of the first battery and the terminal voltage of the second battery after full charge is within a certain range. The third target battery is the battery with the larger current terminal voltage among the first battery and the second battery, and the fourth target battery is the battery with the smaller current terminal voltage among the first battery and the second battery.

[0142] In some embodiments, since the ambient temperature has a great influence on the battery impedance, the battery impedance may be different at different ambient temperatures. Therefore, the terminal device may determine the second voltage threshold and the second preset current according to the ambient temperature. The terminal device may first obtain the current ambient temperature, and then determine the second voltage threshold and the second preset current according to the current ambient temperature.

[0143] The terminal device may store the correspondence between the ambient temperature and the voltage threshold and the preset current. Therefore, the terminal device may determine the voltage threshold and the preset current corresponding to the current ambient temperature according to the correspondence to obtain the second voltage threshold and the second preset current.

[0144] Exemplarily, the corresponding relationship may be shown in Table 1:

[0145] Ambient temperature (℃) Voltage threshold (mV) Preset current (mA) [-10,0) 50 25 [0,12) 20 50 [12,+∞) 5 100

[0146] Table 1

[0147] It should be understood that Table 1 is an exemplary description of the above correspondence relationship and does not limit the above correspondence relationship.

[0148] exist Figure 3In the battery balancing control method shown, when the terminal device is in a charging state, the current open circuit voltages of the first battery and the second battery are both available, and the absolute value of the difference between the current open circuit voltages of the first battery and the second battery is greater than or equal to the first voltage threshold, the charging currents of the first battery and the second battery can be adjusted so as to reduce the voltage difference between the open circuit voltages of the first battery and the second battery, so that the two batteries can be balanced and charged according to the open circuit voltages of the two batteries. In addition, since the open circuit voltage of the battery is the voltage of the battery cell, it will not change with the change of the ambient temperature and the degree of battery aging, so the accuracy of the voltage balancing control between the two batteries connected in series can be improved. When the terminal device is in a charging state, the current open circuit voltage of the first battery or the second battery is not available, and the absolute value of the difference between the current terminal voltages of the first battery and the second battery is greater than or equal to the second voltage threshold, the charging currents of the first battery and the second battery are adjusted so as to reduce the voltage difference between the terminal voltages of the first battery and the second battery, so that the two batteries can be balanced and charged according to the terminal voltages of the two batteries, and the balance of the terminal voltage and the short-circuit voltage can be ensured.

[0149] Figure 5 1 is a flow chart of another battery balancing control method provided in an embodiment of the present application. The battery balancing control method is applied to a terminal device. The terminal device may include a first battery and a second battery. The first battery and the second battery are connected in series. The capacities of the first battery and the second battery are different. Figure 5 As shown, the battery balancing control method may include the following steps.

[0150] 501. When the terminal device is in a charging state, determine the current power of the first battery and the current power of the second battery.

[0151] The battery capacity is the amount of charge stored in the battery. The current battery capacity can be understood as the battery capacity at the current moment.

[0152] When the terminal device is in a charging state, the terminal device may periodically determine the current power of the first battery and the power of the second battery. The period may be 2s or other time periods.

[0153] The current power of the first battery and the current power of the second battery can be determined in parallel or in series. When the current power of the first battery and the current power of the second battery are determined in parallel, the efficiency of battery balancing control can be improved. When the current power of the first battery and the current power of the second battery are determined in series, the terminal device can first determine the current power of the first battery and then determine the current power of the second battery, or first determine the current power of the second battery and then determine the current power of the first battery.

[0154] 502. Determine whether the current power of the first battery is less than the power threshold, and whether the current power of the second battery is less than the power threshold. If the current power of the first battery is greater than or equal to the power threshold, or the current power of the second battery is greater than or equal to the power threshold, execute step 503. If the current power of the first battery is less than the power threshold, and the current power of the second battery is less than the power threshold, execute step 507.

[0155] The terminal device can determine whether the current power of the first battery is greater than or equal to the power threshold, and whether the current power of the second battery is greater than or equal to the power threshold. When the current power of the first battery is less than the power threshold, and the current power of the second battery is less than the power threshold, it indicates that the power of the first battery and the second battery is low, the error of the parameter identified by the online parameter identification algorithm is large, the open circuit voltage of the battery in the low power interval is prone to deviation after aging, and the impedance fluctuation of the battery in the low power interval is large, so that the error of the determined open circuit voltage is large, generally above 20mV, and step 507 can be executed. When the current power of the first battery is greater than or equal to the power threshold, or the current power of the second battery is greater than or equal to the power threshold, it indicates that the error of the determined open circuit voltage is small, and step 503 can be executed.

[0156] Exemplarily, the power threshold may be 30% of the full power of the battery, or may be other power values.

[0157] 503. Determine a current open circuit voltage of the first battery and a current open circuit voltage of the second battery.

[0158] For a detailed description of step 503 , reference may be made to the related description below step 301 .

[0159] 504. Determine an absolute value of a difference between a current open circuit voltage of the first battery and a current open circuit voltage of the second battery to obtain a first absolute value.

[0160] The detailed description of step 504 may refer to the description of step 202 .

[0161] 505. Determine whether the first absolute value is greater than or equal to the first voltage threshold. If the first absolute value is greater than or equal to the first voltage threshold, execute step 506; if the first absolute value is less than the first voltage threshold, execute step 503.

[0162] The detailed description of step 505 may refer to the description of step 304 .

[0163] 506. Regulate the charging current of the first battery and the charging current of the second battery according to the first preset current to reduce the voltage difference between the open circuit voltage of the first battery and the open circuit voltage of the second battery.

[0164] For a detailed description of step 506 , reference may be made to the description of step 305 .

[0165] 507. Determine a current terminal voltage of the first battery and a current terminal voltage of the second battery.

[0166] When the current power level of the first battery is less than the power threshold, and the current power level of the second battery is less than the power threshold, the terminal device can determine the current terminal voltage of the first battery and the current terminal voltage of the second battery.

[0167] For other descriptions of step 507 , please refer to the relevant descriptions below step 306 .

[0168] 508. Determine an absolute value of a difference between a current terminal voltage of the first battery and a current terminal voltage of the second battery to obtain a second absolute value.

[0169] For a detailed description of step 508 , reference may be made to the description of step 307 .

[0170] 509. Determine whether the second absolute value is greater than or equal to the second voltage threshold. If the second absolute value is greater than or equal to the second voltage threshold, execute step 510; if the second absolute value is less than the second voltage threshold, execute step 501.

[0171] The terminal device can determine whether the second absolute value is greater than or equal to the second voltage threshold. When the second absolute value is greater than or equal to the second voltage threshold, it indicates that the voltage difference between the current terminal voltage of the first battery and the current terminal voltage of the second battery is large, and step 510 can be executed. When the second absolute value is less than the second voltage threshold, it indicates that the voltage difference between the current terminal voltage of the first battery and the current terminal voltage of the second battery is small, and step 501 can be executed.

[0172] 510. Regulate the charging current of the first battery and the charging current of the second battery according to the second preset current to reduce the voltage difference between the terminal voltage of the first battery and the terminal voltage of the second battery.

[0173] For a detailed description of step 510 , reference may be made to the description of step 309 .

[0174] exist Figure 5In the battery balancing control method shown, when the terminal device is in a charging state, the current power of the first battery or the current power of the second battery is greater than or equal to the power threshold, and the absolute value of the difference between the current open circuit voltages of the first battery and the second battery is greater than or equal to the first voltage threshold, the charging current of the first battery and the second battery can be adjusted so as to reduce the voltage difference between the open circuit voltages of the first battery and the second battery, so that the two batteries can be balanced and charged according to the open circuit voltages of the two batteries. In addition, since the open circuit voltage of the battery is the voltage of the battery cell, it will not change with the change of the ambient temperature and the degree of battery aging, so that the accuracy of the voltage balancing control between the two batteries connected in series can be improved. When the terminal device is in a charging state, the current power of the first battery and the current power of the second battery are both less than the power threshold, and the absolute value of the difference between the current terminal voltages of the first battery and the second battery is greater than or equal to the second voltage threshold, the charging current of the first battery and the second battery can be adjusted so as to reduce the voltage difference between the terminal voltages of the first battery and the second battery, so that the two batteries can be balanced and charged according to the terminal voltages of the two batteries, and the balance of the terminal voltage and the short-circuit voltage can be ensured.

[0175] Figure 6 1 is a flow chart of another battery balancing control method provided in an embodiment of the present application. The battery balancing control method is applied to a terminal device. The terminal device may include a first battery and a second battery. The first battery and the second battery are connected in series. The capacities of the first battery and the second battery are different. Figure 6 As shown, the battery balancing control method may include the following steps.

[0176] 601. When the terminal device is in a charging state, determine the current power of the first battery and the current power of the second battery.

[0177] The detailed description of step 601 may refer to the description of step 501 .

[0178] 602. Determine whether the current power of the first battery is less than the power threshold, and whether the current power of the second battery is less than the power threshold. If the current power of the first battery is greater than or equal to the power threshold, or the current power of the second battery is greater than or equal to the power threshold, execute step 603. If the current power of the first battery is less than the power threshold, and the current power of the second battery is less than the power threshold, execute step 608.

[0179] For a detailed description of step 602 , reference may be made to the description of step 502 .

[0180] 603. Determine a current open circuit voltage of the first battery and a current open circuit voltage of the second battery.

[0181] For a detailed description of step 603 , reference may be made to the description of step 503 .

[0182] 604. Determine whether the current open circuit voltage of the first battery and the current open circuit voltage of the second battery are available. If both the current open circuit voltage of the first battery and the current open circuit voltage of the second battery are available, execute step 605. If the current open circuit voltage of the first battery or the current open circuit voltage of the second battery is not available, execute step 608.

[0183] The detailed description of step 604 may refer to the description of step 302 .

[0184] 605. Determine an absolute value of a difference between a current open circuit voltage of the first battery and a current open circuit voltage of the second battery to obtain a first absolute value.

[0185] For a detailed description of step 605 , reference may be made to the description of step 202 .

[0186] 606. Determine whether the first absolute value is greater than or equal to the first voltage threshold. If the first absolute value is greater than or equal to the first voltage threshold, execute step 607; if the first absolute value is less than the first voltage threshold, execute step 603.

[0187] For a detailed description of step 606 , reference may be made to the description of step 304 .

[0188] 607. Regulate the charging current of the first battery and the charging current of the second battery according to the first preset current to reduce the voltage difference between the open circuit voltage of the first battery and the open circuit voltage of the second battery.

[0189] For a detailed description of step 607 , reference may be made to the description of step 305 .

[0190] 608. Determine a current terminal voltage of the first battery and a current terminal voltage of the second battery.

[0191] For a detailed description of step 608 , reference may be made to the description of step 306 .

[0192] 609. Determine the absolute value of the difference between the current terminal voltage of the first battery and the current terminal voltage of the second battery to obtain a second absolute value.

[0193] For a detailed description of step 609 , reference may be made to the description of step 307 .

[0194] 610. Determine whether the second absolute value is greater than or equal to the second voltage threshold. If the second absolute value is greater than or equal to the second voltage threshold, execute step 611; if the second absolute value is less than the second voltage threshold, execute step 601.

[0195] For a detailed description of step 610 , reference may be made to the description of step 509 .

[0196] 611. Regulate the charging current of the first battery and the charging current of the second battery according to the second preset current to reduce the voltage difference between the terminal voltage of the first battery and the terminal voltage of the second battery.

[0197] For a detailed description of step 611 , reference may be made to the description of step 309 .

[0198] exist Figure 6 In the battery balancing control method shown, when the terminal device is in a charging state, the current power of the first battery or the current power of the second battery is greater than or equal to the power threshold, the current open circuit voltages of the first battery and the second battery are both available, and the absolute value of the difference between the current open circuit voltages of the first battery and the second battery is greater than or equal to the first voltage threshold, the charging current of the first battery and the second battery can be adjusted so as to reduce the voltage difference between the open circuit voltages of the first battery and the second battery, so that the two batteries can be balanced and charged according to the open circuit voltages of the two batteries. In addition, since the open circuit voltage of the battery is the voltage of the battery cell, it will not change with the change of the ambient temperature and the degree of battery aging, so the accuracy of the voltage balancing control between the two batteries connected in series can be improved. When the terminal device is in a charging state, the absolute value of the difference between the current terminal voltages of the first battery and the second battery is greater than or equal to the second voltage threshold, and the current power of the first battery and the current power of the second battery are both less than the power threshold, or the current open circuit voltage of the first battery or the second battery is unavailable, the charging current of the first battery and the second battery can be adjusted so as to reduce the voltage difference between the terminal voltages of the first battery and the second battery, so that the two batteries can be balancedly charged and controlled according to the terminal voltages of the two batteries, thereby ensuring the balance of the terminal voltage and the short-circuit voltage.

[0199] It should be understood that the same or corresponding contents in different embodiments may be referenced to each other.

[0200] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0201] Based on the same inventive concept, the embodiment of the present application also provides a battery balancing control device for implementing the battery balancing control method involved above. The implementation scheme for solving the problem provided by the battery balancing control device is similar to the implementation scheme recorded in the above battery balancing control method, so the specific limitations in one or more battery balancing control device embodiments provided below can refer to the limitations of the battery balancing control method above, and will not be repeated here.

[0202] Figure 7 1 is a schematic diagram of the structure of a battery balancing control device provided in an embodiment of the present application. The battery balancing control device can be applied to a terminal device including a first battery and a second battery. The first battery and the second battery are connected in series. The capacities of the first battery and the second battery are different. The battery balancing control device may include:

[0203] A first determining unit 701 is used to determine a current open circuit voltage of the first battery and a current open circuit voltage of the second battery when the terminal device is in a charging state;

[0204] A second determining unit 702 is used to determine an absolute value of a difference between a current open circuit voltage of the first battery and a current open circuit voltage of the second battery to obtain a first absolute value;

[0205] The regulating unit 703 is used to regulate the charging current of the first battery and the charging current of the second battery according to the first preset current when the first absolute value is greater than or equal to the first voltage threshold, so as to reduce the voltage difference between the open circuit voltage of the first battery and the open circuit voltage of the second battery.

[0206] In some embodiments, the first determining unit 701 is specifically configured to:

[0207] determining a present charging current of the first battery and a present charging current of the second battery;

[0208] determining a current terminal voltage of the first battery and a current terminal voltage of the second battery;

[0209] According to the current charging current and the current terminal voltage of the first battery and the current charging current and the current terminal voltage of the second battery, an online parameter identification algorithm is used to determine the current open circuit voltage of the first battery and the current open circuit voltage of the second battery.

[0210] In some embodiments, the terminal device further includes a balancing module, and the balancing module is connected to the first battery and the second battery respectively;

[0211] The regulating unit 703 is specifically configured to control the balancing module to regulate the charging current of the first battery and the charging current of the second battery according to the first preset current.

[0212] In some embodiments, the second determination unit 702 is specifically used to determine the absolute value of the difference between the current open circuit voltage of the first battery and the current open circuit voltage of the second battery when both the current open circuit voltage of the first battery and the current open circuit voltage of the second battery are available, so as to obtain a first absolute value.

[0213] In some embodiments, the battery balancing control device may include a third determining unit, and the third determining unit is used to:

[0214] When the current open circuit voltage of the first battery converges, determining that the first battery is available;

[0215] In a case where the current open circuit voltage of the second battery converges, it is determined that the second battery is available.

[0216] In some embodiments, the battery balancing control device may include:

[0217] a fourth determining unit, configured to determine a current power level of the first battery and a current power level of the second battery;

[0218] The first determining unit 701 is specifically configured to determine a current open circuit voltage of the first battery and a current open circuit voltage of the second battery when the current power of the first battery or the current power of the second battery is greater than or equal to a power threshold.

[0219] In some embodiments, the battery balancing control device may include a fifth determining unit, and the fifth determining unit is used to:

[0220] When the current open circuit voltage of the first battery or the current open circuit voltage of the second battery is unavailable, or the current power of the first battery and the current power of the second battery are both less than the power threshold, determining the current terminal voltage of the first battery and the current terminal voltage of the second battery;

[0221] determining an absolute value of a difference between a current terminal voltage of the first battery and a current terminal voltage of the second battery to obtain a second absolute value;

[0222] The regulating unit 703 is further used to regulate the charging current of the first battery and the charging current of the second battery according to the second preset current when the second absolute value is greater than or equal to the second voltage threshold, so as to reduce the voltage difference between the terminal voltage of the first battery and the terminal voltage of the second battery.

[0223] In some embodiments, the battery balancing control device may include:

[0224] An acquisition unit, used to acquire the current ambient temperature;

[0225] The fifth determining unit is further used to determine the second voltage threshold and the second preset current according to the current ambient temperature.

[0226] Each unit in the above-mentioned battery balancing control device can be implemented in whole or in part by software, hardware or a combination thereof. Each of the above-mentioned units can be embedded in or independent of the processor in the terminal device in the form of hardware, or can be stored in the memory in the terminal device in the form of software, so that the processor can call and execute the corresponding operations of each of the above-mentioned units.

[0227] Figure 8 It is a structural diagram of a terminal device provided in an embodiment of the present application. The terminal device may include a processor, a memory, an input / output interface (Input / Output, referred to as I / O), a communication interface, a display device and an input device. Among them, the processor, the memory and the input / output interface are connected through a system bus, and the communication interface, the display device and the input device are connected to the system bus through the input / output interface. Among them, the processor of the terminal device is used to provide computing and control capabilities. The memory of the terminal device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the terminal device is used to exchange information between the processor and an external device. The communication interface of the terminal device is used to communicate with an external terminal or server through a network connection. When the computer program is executed by the processor, a battery balancing control method is implemented. The display device of the terminal device is used to form a visually visible picture, which can be a display screen, a projection device or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen, and the input device of the terminal device can be a touch layer covering the display screen, or a button, trackball or touchpad set on the terminal device shell, or an external keyboard, touchpad or mouse.

[0228] Those skilled in the art will understand that Figure 8The structure shown in the figure is only a block diagram of a partial structure related to the scheme of the present application, and does not constitute a limitation on the terminal device to which the scheme of the present application is applied. The specific terminal device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0229] Fig. 9 is a schematic diagram of the structure of another terminal device provided in an embodiment of the present application. Fig. 9 As shown, the terminal device may include a processor, a first battery and a second battery, the first battery and the second battery are connected in series, the first battery and the second battery have different capacities, and the processor is connected to the first battery and the second battery respectively. The processor may be used for:

[0230] When the terminal device is in a charging state, determining a current open circuit voltage of the first battery and a current open circuit voltage of the second battery;

[0231] determining an absolute value of a difference between a current open circuit voltage of the first battery and a current open circuit voltage of the second battery to obtain a first absolute value;

[0232] When the first absolute value is greater than or equal to the first voltage threshold, the charging current of the first battery and the charging current of the second battery are adjusted according to the first preset current to reduce the voltage difference between the open circuit voltage of the first battery and the open circuit voltage of the second battery.

[0233] In some embodiments, the terminal device may further include a balancing module, wherein the balancing module is respectively connected to the first battery, the second battery, and the processor;

[0234] When the first absolute value is greater than or equal to the first voltage threshold, the processor adjusts the charging current of the first battery and the charging current of the second battery according to the first preset current, including:

[0235] When the first absolute value is greater than or equal to the first voltage threshold, the processor sends a balancing instruction to the balancing module, where the balancing instruction includes a first preset current;

[0236] The balancing module is used to adjust the charging current of the first battery and the charging current of the second battery according to the first preset current.

[0237] The processor can also implement other steps of the above-mentioned battery balancing control method.

[0238] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned battery balancing control method are implemented.

[0239] It should be noted that the information of the energy storage equipment involved in this application (including but not limited to the demand value of the energy storage equipment) is information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0240] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0241] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0242] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A battery balancing control method, characterized in that: Applied to a terminal device including a first battery and a second battery, the first battery and the second battery are connected in series, and the first battery and the second battery have different capacities, the method comprising: When the terminal device is in a charging state, determining a current open circuit voltage of the first battery and a current open circuit voltage of the second battery; determining an absolute value of a difference between a current open circuit voltage of the first battery and a current open circuit voltage of the second battery to obtain a first absolute value; When the first absolute value is greater than or equal to a first voltage threshold, the charging current of the first battery and the charging current of the second battery are adjusted according to a first preset current to reduce the voltage difference between the open circuit voltage of the first battery and the open circuit voltage of the second battery.

2. The method according to claim 1, characterized in that: The determining the current open circuit voltage of the first battery and the current open circuit voltage of the second battery comprises: determining a present charging current of the first battery and a present charging current of the second battery; determining a current terminal voltage of the first battery and a current terminal voltage of the second battery; According to the current charging current and the current terminal voltage, an online parameter identification algorithm is used to determine a current open circuit voltage of the first battery and a current open circuit voltage of the second battery.

3. The method according to claim 1, characterized in that The terminal device further includes a balancing module, wherein the balancing module is connected to the first battery and the second battery respectively; The step of adjusting the charging current of the first battery and the charging current of the second battery according to the first preset current includes: The equalization module is controlled to adjust the charging current of the first battery and the charging current of the second battery according to a first preset current.

4. The method according to claim 1, characterized in that: Determining the absolute value of the difference between the current open circuit voltage of the first battery and the current open circuit voltage of the second battery to obtain a first absolute value includes: When both the current open circuit voltage of the first battery and the current open circuit voltage of the second battery are available, an absolute value of a difference between the current open circuit voltage of the first battery and the current open circuit voltage of the second battery is determined to obtain a first absolute value.

5. The method according to claim 4, characterized in that The method further comprises: When the current open circuit voltage of the first battery converges, determining that the first battery is available; In a case where the current open circuit voltage of the second battery converges, it is determined that the second battery is available.

6. The method according to claim 1 or 4, characterized in that: The method further comprises: determining a current charge of the first battery and a current charge of the second battery; The determining the current open circuit voltage of the first battery and the current open circuit voltage of the second battery comprises: When the current power of the first battery or the current power of the second battery is greater than or equal to a power threshold, a current open circuit voltage of the first battery and a current open circuit voltage of the second battery are determined.

7. The method according to claim 6, characterized in that The method further comprises: When the current open circuit voltage of the first battery or the current open circuit voltage of the second battery is unavailable, or the current power of the first battery and the current power of the second battery are both less than the power threshold, determining the current terminal voltage of the first battery and the current terminal voltage of the second battery; determining an absolute value of a difference between a current terminal voltage of the first battery and a current terminal voltage of the second battery to obtain a second absolute value; When the second absolute value is greater than or equal to a second voltage threshold, the charging current of the first battery and the charging current of the second battery are adjusted according to a second preset current to reduce the voltage difference between the terminal voltage of the first battery and the terminal voltage of the second battery.

8. The method according to claim 7, characterized in that The method further comprises: Get the current ambient temperature; The second voltage threshold and the second preset current are determined according to the current ambient temperature.

9. A battery balancing control device, characterized in that: Applied to a terminal device including a first battery and a second battery, the first battery and the second battery are connected in series, and the first battery and the second battery have different capacities, the device comprising: A first determining unit, configured to determine a current open circuit voltage of the first battery and a current open circuit voltage of the second battery when the terminal device is in a charging state; a second determining unit, configured to determine an absolute value of a difference between a current open circuit voltage of the first battery and a current open circuit voltage of the second battery, to obtain a first absolute value; an adjusting unit, for adjusting the charging current of the first battery and the charging current of the second battery according to a first preset current when the first absolute value is greater than or equal to a first voltage threshold, so as to reduce the voltage difference between the open circuit voltage of the first battery and the open circuit voltage of the second battery.

10. A terminal device, comprising a processor, characterized in that: The terminal device further includes a first battery and a second battery, the first battery and the second battery are connected in series, and the first battery and the second battery have different capacities, and the processor is configured to: When the terminal device is in a charging state, determining a current open circuit voltage of the first battery and a current open circuit voltage of the second battery; determining an absolute value of a difference between a current open circuit voltage of the first battery and a current open circuit voltage of the second battery to obtain a first absolute value; When the first absolute value is greater than or equal to a first voltage threshold, the charging current of the first battery and the charging current of the second battery are adjusted according to a first preset current to reduce the voltage difference between the open circuit voltage of the first battery and the open circuit voltage of the second battery.

11. The terminal device according to claim 10, characterized in that: The terminal device further includes a balancing module, wherein the balancing module is respectively connected to the first battery, the second battery and the processor; When the first absolute value is greater than or equal to a first voltage threshold, the processor adjusts the charging current of the first battery and the charging current of the second battery according to a first preset current, including: The processor sends a balancing instruction to the balancing module when the first absolute value is greater than or equal to a first voltage threshold, wherein the balancing instruction includes a first preset current; The balancing module is used to adjust the charging current of the first battery and the charging current of the second battery according to a first preset current.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 8 are implemented.

13. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 8 are implemented.

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