CN118174393A - Equalization control circuit and method of battery pack and terminal equipment - Google Patents
Equalization control circuit and method of battery pack and terminal equipment Download PDFInfo
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- CN118174393A CN118174393A CN202211583178.4A CN202211583178A CN118174393A CN 118174393 A CN118174393 A CN 118174393A CN 202211583178 A CN202211583178 A CN 202211583178A CN 118174393 A CN118174393 A CN 118174393A
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
- H01M10/44—Methods for charging or discharging
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
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- Charge And Discharge Circuits For Batteries Or The Like (AREA)
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Abstract
The embodiment of the application discloses a balance control circuit, a balance control method and terminal equipment of a battery pack. Comprising the following steps: the device comprises a controller, a load switch and a voltage reduction circuit; the first end of the load switch is connected between the first battery pack and the second battery pack which are connected in series, the second end of the load switch is connected with the system circuit, and the first battery pack is connected with the second end of the load switch through the voltage reduction circuit; in the discharging process, when the electric quantity difference between the residual electric quantity of the first battery pack and the residual electric quantity of the second battery pack is larger than a preset electric quantity interval, the controller sends a first control signal to the load switch; the load switch is closed, and the second battery pack is independently discharged to the system circuit; when the electric quantity difference is in a preset electric quantity interval, the controller sends a second control signal to the voltage reduction circuit; the voltage reducing circuit is in a working state, and discharges the voltage after the voltage of the first battery pack and the voltage of the second battery pack which are connected in series to the system circuit after the voltage is reduced.
Description
Technical Field
The present application relates to the field of circuit technologies, and in particular, to a equalization control circuit, a equalization control method, and a terminal device for a battery pack.
Background
With the development of technology, the functions carried by the terminal equipment are more and more, the corresponding power consumption is correspondingly increased, and the required battery capacity is larger and larger. In view of the endurance capability of the terminal device, two batteries (or a plurality of batteries) are generally required to be used in series or in parallel in order to satisfy the battery capacity of the intelligent terminal. For a battery in which two unequal cells are connected in series, the weakest of the series cells determines the capacity of the entire battery. With the increase of the service time, in the continuous charging and discharging process, the voltage of the two batteries is unbalanced due to the difference of the internal resistance and other characteristics of each battery, the performance of the two batteries is differentiated, and the service life of the batteries and the capacity of the whole battery pack are reduced.
In the related art, a battery balancing method is generally adopted to balance the charging current and the discharging current of the whole battery pack, so that the battery capacities of two batteries in the battery pack can be simultaneously full or empty, and the service life of the batteries is prolonged.
However, for the discharging process, the discharging process of the whole battery pack is controlled by the battery balancing method in the related art, and the components have loss by matching among various components, so that the discharging loss is higher in the process of realizing balanced discharging.
Disclosure of Invention
The embodiment of the application provides a balance control circuit, a balance control method and terminal equipment of a battery pack, which reduce discharge loss.
The technical scheme of the embodiment of the application is realized as follows:
In a first aspect, an embodiment of the present application provides an equalization control circuit of a battery pack, where the equalization control circuit of the battery pack includes: the device comprises a controller, a load switch and a voltage reduction circuit; the battery pack includes a first battery pack and a second battery pack connected in series, the battery capacity of the first battery pack being smaller than the battery capacity of the second battery pack;
the first end of the load switch is connected between the first battery pack and the second battery pack, the second end of the load switch is connected with a system circuit, and the first battery pack is connected with the second end of the load switch through the voltage reduction circuit; the controller is used for sending a first control signal to the load switch when the electric quantity difference between the acquired residual electric quantity of the second battery pack and the acquired residual electric quantity of the first battery pack is larger than a preset electric quantity interval in the discharging process of the first battery pack and the second battery pack; the load switch is used for being closed under the action of the first control signal, so that the second battery pack is independently discharged to the system circuit; the controller is further configured to send a second control signal to the step-down circuit when the electric quantity difference is located in the preset electric quantity interval; the voltage reducing circuit is used for being in a working state under the action of the second control signal, reducing the voltage of the first battery pack and the voltage of the second battery pack after being connected in series, and discharging the voltage to the system circuit.
In a second aspect, an embodiment of the present application provides a terminal device, including: a first battery pack and a second battery pack connected in series, and an equalization control circuit of the battery packs as described in the first aspect; the battery capacity of the first battery pack is smaller than that of the second battery pack, the full charge voltage and the empty voltage of the first battery pack are the same as those of the second battery pack, the first battery pack belongs to a first battery cell system, and the second battery pack belongs to a second battery cell system; a first end of the load switch in the balance control circuit of the battery pack is connected between the first battery pack and the second battery pack, and a positive electrode of the first battery pack is connected with a second end of the load switch through a voltage reduction circuit in the balance control circuit of the battery pack; the balance control circuit of the battery pack is used for closing the load switch under the action of a first control signal when the electric quantity difference between the residual electric quantity of the second battery pack and the residual electric quantity of the first battery pack is larger than a preset electric quantity interval in the discharging process of the first battery pack and the second battery pack, and the second battery pack is communicated with the system circuit; the second battery pack is used for discharging to the system circuit independently; the equalization control circuit of the battery pack is further used for enabling the voltage reduction circuit to be in a working state under the action of the second control signal when the electric quantity difference is located in the preset electric quantity interval; the first battery pack and the second battery pack are used for discharging to the system circuit after being subjected to voltage reduction through the voltage reduction circuit.
In a third aspect, an embodiment of the present application provides a method for controlling equalization of a battery pack, where the method includes: in the discharging process of the first battery pack and the second battery pack, when the electric quantity difference between the obtained residual electric quantity of the second battery pack and the obtained residual electric quantity of the first battery pack is larger than a preset electric quantity interval, a load switch is closed under the action of a first control signal, so that the second battery pack is independently discharged to the system circuit; wherein the second battery pack is connected in series with the first battery pack, and the battery capacity of the first battery pack is smaller than the battery capacity of the second battery pack; when the electric quantity difference is located in the preset electric quantity interval, the step-down circuit is in a working state under the action of a second control signal; and the voltage of the first battery pack and the voltage of the second battery pack which are connected in series are reduced by the voltage reducing circuit, and then the voltage is discharged to the system circuit.
The embodiment of the application provides a balance control circuit, a balance control method and terminal equipment of a battery pack. According to the scheme provided by the embodiment of the application, the equalization control circuit of the battery pack comprises: the equalization control circuit of the battery pack includes: the device comprises a controller, a load switch and a voltage reduction circuit; the battery pack comprises a first battery pack and a second battery pack which are connected in series, wherein the battery capacity of the first battery pack is smaller than that of the second battery pack; the first end of the load switch is connected between the first battery pack and the second battery pack, the second end of the load switch is connected with the system circuit, the first battery pack is connected with the second end of the load switch through the step-down circuit, the load switch is added on the basis of the original circuit, other structures of the original circuit are not required to be changed, and the reusability of the circuit is improved. The controller is used for sending a first control signal to the load switch when the electric quantity difference between the acquired residual electric quantity of the second battery pack and the acquired residual electric quantity of the first battery pack is larger than a preset electric quantity interval in the discharging process of the first battery pack and the second battery pack; the load switch is used for being closed under the action of the first control signal to realize the conduction between the second battery pack and the system circuit, so that the second battery pack is independently discharged to the system circuit; the controller is also used for sending a second control signal to the voltage reduction circuit when the electric quantity difference is in a preset electric quantity interval; and the voltage reducing circuit is used for being in a working state under the action of a second control signal, reducing the voltage of the first battery pack and the second battery pack which are connected in series, and discharging the voltage to the system circuit. In the process of starting discharging or discharging, when the difference of the residual electric quantity of the second battery pack and the residual electric quantity of the first battery pack is larger than a preset electric quantity interval, the second battery pack is controlled to directly discharge to a system circuit through a load switch, namely, the high-capacity battery pack is singly discharged, when the difference of the residual electric quantity of the second battery pack and the residual electric quantity of the first battery pack is in the preset electric quantity interval, the load switch is disconnected, and the voltage is reduced through a voltage reducing circuit in a working state to supply power, so that the whole discharging process is completed. The load switch only plays a role in on-off, has no other components, has less circuit energy loss, reduces discharge loss compared with an equalizing discharge mode through an equalizing circuit and a voltage reduction circuit, and improves the cruising ability of the terminal equipment.
Drawings
Fig. 1 is an alternative schematic diagram of an equalization control circuit of a battery pack according to an embodiment of the present application;
fig. 2 is an alternative schematic diagram of an equalization control circuit of another battery pack according to an embodiment of the present application;
FIG. 3 is an alternative schematic diagram of a discharge equalization path for a non-constant volume battery according to an embodiment of the present application;
Fig. 4 is an alternative schematic diagram of an equalization control circuit of a battery pack according to another embodiment of the present application;
FIG. 5 is an alternative schematic diagram of a discharge path for a non-constant volume battery according to an embodiment of the present application;
FIG. 6 is an alternative schematic diagram of a voltage discharge curve according to an embodiment of the present application;
Fig. 7 is an alternative schematic diagram of an equalization control circuit of a battery pack according to another embodiment of the present application;
Fig. 8 is a schematic diagram of an alternative structure of a discharge equalization circuit according to an embodiment of the present application;
FIG. 9 is an alternative schematic diagram of another voltage discharge curve provided by an embodiment of the present application;
fig. 10 is an alternative schematic diagram of an equalization control circuit of a battery pack according to another embodiment of the present application;
FIG. 11 is an alternative schematic diagram of a variable volume battery charging path provided by an embodiment of the present application;
FIG. 12 is an alternative schematic diagram of a voltage charging curve according to an embodiment of the present application;
fig. 13 is an alternative schematic diagram of an equalization control circuit of a battery pack according to another embodiment of the present application;
Fig. 14 is a schematic diagram of an alternative structure of a charge equalization circuit according to an embodiment of the present application;
FIG. 15 is a schematic diagram showing another alternative voltage charging curve according to an embodiment of the present application;
fig. 16 is an alternative structural schematic diagram of a terminal device according to an embodiment of the present application;
Fig. 17 is an alternative schematic structural diagram of a charge/discharge balancing circuit for unequal batteries in a terminal device according to an embodiment of the present application;
Fig. 18 is a flowchart illustrating optional steps of a method for controlling equalization of a battery pack according to an embodiment of the present application.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. It should be understood that some embodiments described herein are merely for explaining the technical solution of the present application, and are not intended to limit the technical scope of the present application.
In the following description, the terms "first", "second", "third" and the like are used merely to distinguish similar objects and do not represent a specific ordering of the objects, it being understood that the "first", "second", "third" may be interchanged with a specific order or sequence, as permitted, to enable embodiments of the application described herein to be practiced otherwise than as illustrated or described herein.
In order to better understand the equalization control circuit of the battery pack provided in the embodiment of the present application, before the technical scheme of the embodiment of the present application is introduced, an application background and related technologies are described.
The related technology comprises the following two technical schemes: the abnormal-shape constant volume batteries are connected in series and the abnormal-shape constant volume batteries are connected in parallel. In general, the battery used in the terminal equipment such as a straight-plate mobile phone and a flat plate is generally connected in series with the double battery cells of the same system, and the two battery cells are required to have the same size, capacity and other parameters, so that the charge/discharge balance of the two battery cells is ensured, and therefore, the shape of the battery is basically centrosymmetric, and the structural stacking of the terminal equipment is limited. The terminal device with the folded configuration generally needs to have two single-cell batteries built in, for example, a folding screen mobile phone, and the two single-cell batteries generally have different volumes and different battery capacities due to the volume difference of the main screen and the auxiliary screen. The terminal equipment with the folding form can adopt abnormal-shape constant-volume batteries to be connected in series or abnormal-shape unequal-volume batteries to be connected in parallel, the abnormal-shape constant-volume batteries are connected in series, the volumes and the sizes of the electric cores are determined, the structural space of the terminal equipment cannot be fully utilized, and the cruising ability of the terminal equipment is reduced.
In the related art, a terminal device (for example, a mobile phone) adopts a dual-battery serial connection mode with the same system, the capacity is the same, the structural space of the terminal device cannot be effectively utilized, and the capacity waste is caused. The terminal equipment (for example, a folding screen mobile phone) adopts a mode of connecting the special-shaped unequal capacity batteries of the same system in parallel, so that the battery capacity loss is larger when the capacity difference is large, and the cruising ability of the terminal equipment is reduced.
The equalization control circuit of the battery pack in the embodiment of the application can be applied to terminal Equipment, and the terminal Equipment can include, but is not limited to, user Equipment (UE), mobile phones, folding screen mobile phones, charger, wearable Equipment (for example, smart watches, smart necklaces, wearable electronic socks, wearable glasses, smart clothes, and the like), notebook computers, personal computers (Personal DIGITAL ASSISTANT, PDA), tablet computers, electronic books, game machines, and other electronic Equipment requiring dual-core serial connection.
An embodiment of the present application provides an equalization control circuit of a battery pack, as shown in fig. 1, fig. 1 is an optional schematic diagram of the equalization control circuit of the battery pack provided in the embodiment of the present application, and an equalization control circuit 100 of the battery pack includes: a controller 10, a load switch 20, and a step-down circuit 30; the battery pack includes a first battery pack 200 and a second battery pack 300 connected in series, the first battery pack 200 being smaller than the battery capacity of the second battery pack 300; a first end of the load switch 20 is connected between the first battery pack 200 and the second battery pack 300, a second end of the load switch 20 is connected with the system circuit 400, and the first battery pack 200 is connected with the second end of the load switch 20 through the voltage dropping circuit 30; the controller 10 is configured to send a first control signal to the load switch 20 when a difference between the obtained remaining power of the second battery pack 300 and the obtained remaining power of the first battery pack 200 is greater than a preset power interval during discharging of the first battery pack 200 and the second battery pack 300; a load switch 20 for being closed by the first control signal so that the second battery pack 300 is individually discharged to the system circuit 400; the controller 10 is further configured to send a second control signal to the step-down circuit 30 when the power difference is within a preset power interval; the voltage reducing circuit 30 is configured to be in an operating state under the action of the second control signal, and to reduce the voltage of the first battery pack 200 and the second battery pack 300 and then discharge the voltage to the system circuit 400.
In the embodiment of the present application, a first output end of the controller 10 is connected to a first control end of the load switch 20, and is used for sending a driving signal to the load switch 20; a second output terminal of the controller 10 is connected to a second control terminal of the step-down circuit 30 for transmitting a driving signal to the step-down circuit 30. The system voltage Vsys in fig. 1 represents the discharge voltage required by the system circuit 400. During the discharging process of the first battery pack 200 and the second battery pack 300, the voltage and current of the battery pack (the first battery pack 200 or the second battery pack 300) may be detected by using an electricity meter, and then the controller 10 determines the amount of electricity discharged from the battery pack according to the discharging current and the discharging time of the battery pack, and then determines the remaining amount of electricity of the battery pack in combination with the rated amount of electricity or the initial amount of electricity of the battery pack. Or when the first battery pack 200 and the second battery pack 300 start to discharge, the remaining capacity of the battery pack (the first battery pack 200 or the second battery pack 300) is the rated capacity of the battery pack, and the controller 10 can obtain the remaining capacity of the battery pack without calculating according to the discharge current and the discharge time because the battery pack does not actually discharge the capacity when the discharge is started. When the difference between the two electric quantities is greater than the preset electric quantity interval, the preset electric quantity interval may be a cell (for example, [0,1], [0.5,5] etc.) with a small value (for example, 0,1 etc.) as an origin, which indicates that the remaining electric quantity of the second battery pack 300 is far greater than or close to the first battery pack 200, or may be at the beginning of the discharging process or at any time in the discharging process, as long as the remaining electric quantity of the second battery pack 300 is not less than the first battery pack 200. The controller 10 controls the load switch 20 to be closed, so that the second battery pack 300 and the system circuit 400 are conducted, the second battery pack 300 discharges independently to the system circuit 400, the load switch 20 only plays a role in on-off, no other components are arranged, and the circuit energy loss is low, so that the part of the load switch is independently discharged, the discharging efficiency is improved, the discharging loss is reduced, and the cruising ability of the terminal equipment is improved.
In some embodiments, the controller 10 is further configured to send a third control signal to the load switch 20 when the power difference is within a preset power interval; the load switch 20 is further configured to change from closed to open under the action of the third control signal.
In the embodiment of the present application, the load switch 20 and the voltage reduction circuit 30 do not work simultaneously, when the difference of the electric power is within the preset electric power interval, it is indicated that the residual electric power of the second battery pack 300 is close to (or smaller than) the first battery pack 200, the controller 10 controls the load switch 20 to be turned off from being turned on (to realize the disconnection of the second battery pack 300 from the system circuit 400), and controls the voltage reduction circuit 30 to be in an operating state, and the series voltage of the first battery pack 200 and the second battery pack 300 after being connected in series is greater than the voltage required by the system circuit 400, for example, the voltages of the first battery pack 200, the second battery pack 300 and the voltage required by the system circuit 400 are both 4V, and the voltage after being connected in series is 8V, so the series voltage still needs to be discharged to the system circuit 400 after being reduced by the voltage reduction circuit 30.
In the embodiment of the present application, the first battery pack 200 and the second battery pack 300 may be single-cell batteries, for example, include one battery a, or may be a battery pack formed by connecting multiple batteries in series, parallel or a combination of series and parallel, for example, two batteries a are connected in series, three batteries B are connected in parallel, and two batteries connected in series are connected in parallel with another battery, so long as the full charge voltage and the drain voltage of the first battery pack 200 and the second battery pack 300 are the same, which is not limited to the embodiment of the present application.
In the embodiment of the present application, the controller 10 (controller) may be an application processor (Application Processor, AP), a central processing unit (central processing unit, CPU), or the like, so long as the controller 10 has a calculation processing function and performs a driving control function (for example, turning on, off, controlling the resistance of the device, etc.) on other devices through a driving signal (or control logic).
In the embodiment of the present application, the load switch 20 may be a controllable power device, or may be any other mechanical physical structure or device with a controllable on-off function, or may be a reaction vessel based on a chemical principle, so long as the load switch can perform an on-off function under the control of the controller 10, and no other complex components need to be included, which is not limited to the embodiment of the present application.
In the embodiment of the application, the battery capacity represents the magnitude of the stored electric quantity of the battery, the unit of the battery capacity is milliampere hours (mAh), 1000 mah=3600c, and the multiplying power C represents the multiplying power of the charge/discharge capacity of the battery. Here, the rated power or the initial power of the battery pack is represented by the battery capacity, the remaining power is the remaining power after the battery pack emits a certain period of time or a certain amount of power, and the emitted power is subtracted from the battery capacity to obtain the remaining power.
In the embodiment of the present application, the preset power interval represents the time for controlling the on/off of the load switch 20, and the preset power interval may be a numerical point, for example, 0,1mAh, etc. For example, taking the preset power interval of 0 as an example, when the second battery pack 300 is larger than the battery capacity of the first battery pack 200 at the beginning of discharging, or during discharging (for example, the first battery pack 200 and the second battery pack 300 are firstly discharged by a discharging equalization method, and after a period of time, the situation is reached), the second battery pack 300 is larger than the remaining power of the first battery pack 200, and the second battery pack 300 can be discharged independently by closing the load switch 20 and the step-down circuit 30 in a non-operating state. The preset power interval may be a cell interval, for example, [0,1mAh ], [2mAh,10mAh ], etc., and by taking the preset power interval as an example, the preset power interval is [0, 10mAh ], in the process of starting discharging or discharging, the second battery pack 300 is larger than the battery capacity of the first battery pack 200, the condition that the power difference is larger than [0,1mAh ] is satisfied, and the second battery pack 300 can be discharged independently by closing the load switch 20 and the step-down circuit 30 in a non-operating state.
In the embodiment of the application, the load switch 20 is utilized to realize a low-loss discharge balancing method, and the balancing circuit 60 does not work during discharge, and switches two discharge paths of single discharge and series discharge of double batteries of a large-capacity battery by controlling the on-off of the load switch 20, so that the batteries with different capacities are simultaneously discharged, and the discharge efficiency is improved on the premise of ensuring the discharge balancing of the batteries. For example, it is possible to ensure that the remaining amounts of the batteries of different capacities are the same, and then discharge in series through the step-down circuit 30, thereby reducing discharge loss and improving the cruising ability of the terminal device.
According to the solution provided in the embodiment of the present application, the equalization control circuit 100 of the battery pack includes: a controller 10, a load switch 20, and a step-down circuit 30; the battery pack includes a first battery pack 200 and a second battery pack 300 connected in series, the first battery pack 200 being smaller than the battery capacity of the second battery pack 300; the first end of the load switch 20 is connected between the first battery pack 200 and the second battery pack 300, the second end of the load switch 20 is connected with the system circuit 400, the first output end of the controller 10 is connected with the first control end of the load switch 20, the second output end of the controller 10 is connected with the second control end of the voltage reduction circuit 30, the first battery pack 200 is connected with the second end of the load switch 20 through the voltage reduction circuit 30, the load switch 20 is added on the basis of an original circuit, other structures of the original circuit do not need to be changed, and the circuit multiplexing performance is improved. The controller 10 is configured to send a first control signal to the load switch 20 when a difference between the obtained remaining power of the second battery pack 300 and the obtained remaining power of the first battery pack 200 is greater than a preset power interval during discharging of the first battery pack 200 and the second battery pack 300; the load switch 20 is configured to be closed under the action of the first control signal, so as to realize conduction between the second battery pack 300 and the system circuit 400, so that the second battery pack 300 discharges to the system circuit 400 separately; the controller 10 is further configured to send a third control signal to the load switch 20 and send a second control signal to the step-down circuit 30 when the electric quantity difference is within a preset electric quantity interval; the load switch 20 is further configured to change from closed to open under the action of the third control signal, so as to realize that the second battery pack 300 is disconnected from the system circuit 400; the step-down circuit 30 is configured to be in an operating state under the action of the second control signal, step down the voltage of the first battery pack 200 and the second battery pack 300 after being connected in series, and then discharge the voltage to the system circuit 400. In the process of starting discharging or discharging, when the difference between the residual electric quantities of the second battery pack 300 and the first battery pack 200 is larger than the preset electric quantity interval, the second battery pack 300 is controlled to directly discharge to the system circuit 400 through the load switch 20, that is, the high-capacity battery pack is singly discharged, and when the difference between the residual electric quantities of the two battery packs is in the preset electric quantity interval, the load switch 20 is disconnected, and the voltage is reduced by the voltage reducing circuit 30 in a working state to supply power, so that the whole discharging process is completed. The load switch 20 only plays a role of on-off, has no other components, has less circuit energy loss, reduces the discharge loss and improves the cruising ability of the terminal equipment compared with the balanced discharge mode through the balanced circuit 60 and the voltage reduction circuit 30. The on-off time of the load switch 20 is judged according to the residual electric quantity, the first half period of time is independently discharged through the load switch 20, and when the residual electric quantity of the load switch 20 and the residual electric quantity are close, the second half period of time is serially discharged through the voltage reduction circuit 30, so that the discharging efficiency is improved.
In some embodiments, based on the foregoing fig. 1, an embodiment of the present application further provides an equalization control circuit of a battery pack, as shown in fig. 2, fig. 2 is an optional schematic diagram of an equalization control circuit of another battery pack provided in the embodiment of the present application, where the equalization control circuit 100 of the battery pack further includes: a first fuel gauge 40 and a second fuel gauge 50; the two measuring ends of the first fuel gauge 40 are respectively connected with the positive electrode and the negative electrode of the first battery pack 200, and the output end of the first fuel gauge 40 is connected with the first input end of the controller 10; the two measurement ends of the second fuel gauge 50 are respectively connected with the positive electrode and the negative electrode of the second battery pack 300, and the output end of the second fuel gauge 50 is connected with the second input end of the controller 10; a first electricity meter 40 for outputting a discharge current of the first battery pack 200 to the controller 10; a second electricity meter 50 for outputting a discharge current of the second battery pack 300 to the controller 10; the controller 10 is further configured to determine a remaining power of the first battery pack 200 according to the battery capacity of the first battery pack 200, the discharge current of the first battery pack 200, and the first discharge time, and determine a remaining power of the second battery pack 300 according to the battery capacity of the second battery pack 300, the discharge current of the second battery pack 300, and the second discharge time.
In the embodiment of the present application, a fuel gauge (coulomb counter) is connected to the positive and negative poles of the battery pack (the first battery pack 200 or the second battery pack 300) for measuring the voltage across the battery pack and the current passing through the battery pack, and transmits the voltage and the discharge current to the controller 10. The controller 10 may determine the discharged power amount according to the discharge current and the discharge time of the battery pack (the discharge time refers to the discharge time of the battery pack alone), and integrate the current and the discharge time to obtain the discharged power amount, where the unit of the discharged power amount is mAh. The discharged power is subtracted from the battery capacity (i.e., the rated power) of the battery pack to obtain the remaining power of the battery pack.
In the embodiment of the application, the measurement of the current and the voltage of the battery pack is realized through the electricity meter and is output to the controller 10, so that the controller 10 can judge whether the residual electricity difference meets the preset electricity interval according to the voltage and the discharge current, thereby determining the time for controlling the on/off of the load switch 20, completing the discharge process, reducing the discharge loss and improving the cruising ability of the terminal equipment.
In the following, an exemplary application of the embodiment of the present application in a practical application scenario will be described.
In the embodiment of the present application, in order to facilitate understanding of the operation modes of the load switch 20 and the voltage reduction circuit 30 during the discharging process, the following description is made by using a discharging equalization path, as shown in fig. 3, and fig. 3 is an optional schematic diagram of a discharging equalization path of a non-constant volume battery according to the embodiment of the present application. In fig. 3, the system voltage Vsys represents a discharge voltage required for the system circuit 400, the small capacity Bat1 represents the first battery pack 200, the large capacity Bat2 represents the second battery pack 300, and the voltage of the small capacity Bat1, the voltage of the large capacity Bat2, and Vsys are the same, and for example, the voltage may be set to 4V. The unequal capacity battery discharge balancing path comprises a discharge path 1 and a discharge path 2, wherein the discharge path 1 is that the Bat2 is singly discharged through a load switch 20, the discharge path 2 is that the serial voltage of the Bat2 and the Bat1 is discharged after being reduced by a voltage reducing circuit 30 (2:1). The unequal capacity battery discharge balancing path provided in fig. 3 is applied to the discharging process, and the load switch 20 only plays a role in on-off, but cannot balance the charging current of Bat2 during the charging process, so is not suitable for the charging process. Based on this, fig. 3 also shows an active equalization circuit 60, where the active equalization circuit 60 can equalize the charging currents of Bat2 and Bat1 in the charging process, so as to reduce the phenomenon that the voltages of Bat2 and Bat1 are unbalanced and the performance is differentiated, and improve the service life of the battery pack. Similarly, the active equalization circuit 60 may also equalize the discharge currents of Bat2 and Bat1 during discharge.
In some embodiments, based on the foregoing fig. 1 and fig. 2, an embodiment of the present application further provides an equalization control circuit of a battery pack, as shown in fig. 4, fig. 4 is an optional schematic diagram of an equalization control circuit of another battery pack provided in the embodiment of the present application, where the equalization control circuit 100 of a battery pack further includes: an equalizing circuit 60; the positive electrode of the first battery pack 200 is connected with the first end of the equalization circuit 60 through the voltage reduction circuit 30, and the second end of the equalization circuit 60 is connected with the positive electrode of the second battery pack 300; the controller 10 is further configured to send a fourth control signal to the equalization circuit 60 and a fifth control signal to the step-down circuit 30 when the electric quantity difference is greater than a preset electric quantity interval; the equalization circuit 60 is configured to be in a constant-resistance working state under the action of the fourth control signal, so as to equalize the discharge currents of the first battery pack 200 and the second battery pack 300, so that the second battery pack 300 discharges to the system circuit 400 through the equalization circuit 60; the step-down circuit 30 is further configured to be in an operating state under the action of the fifth control signal, step down the voltage of the first battery pack 200 and the second battery pack 300 after being connected in series, and discharge the voltage to the system circuit 400.
In the embodiment of the present application, the third output terminal of the controller 10 is connected to the third control terminal of the equalization circuit 60, and is used for sending the driving signal to the equalization circuit 60. When the difference is greater than the preset power interval, it is indicated that the remaining power of the second battery pack 300 is much greater than or close to the first battery pack 200. In a case where the remaining amount of electricity of the second battery pack 300 is much larger than that of the first battery pack 200 at the start of discharge, the equalization circuit 60 and the step-down circuit 30 are directly controlled to be in an operating state, and discharge is performed by a scheme of equalizing the discharge current, the load switch 20 is not involved. In another case, the second battery pack 300 is initially discharged separately through the load switch 20, and after a period of time, the load switch 20 is turned off at a certain moment, at this time, (1) the remaining capacity of the second battery pack 300 may be larger than that of the first battery pack 200, and the balancing circuit 60 and the voltage reducing circuit 30 are controlled to be in an operating state, and the discharging is performed by a scheme of balancing the discharging current. (2) The residual capacity of the second battery pack 300 may be equal to that of the first battery pack 200, the voltage reduction circuit 30 is controlled to be in an operating state, the voltage reduction circuit 30 performs voltage reduction and then discharges, since the residual capacities of the second battery pack 300 and the first battery pack 200 are equal, the residual capacity units are mAh, the residual capacities are the same, and in the same discharging time, the discharging voltage can be reached at the same time, the equalizing circuit 60 is not required to be opened, the discharging process is simple to realize, the discharging efficiency is high, and the discharging loss is reduced. Of course, the equalization circuit 60 may be turned on to perform the discharge by equalizing the discharge current. (3) The remaining capacity of the second battery pack 300 may be smaller than the first battery pack 200, the equalization circuit 60 and the voltage reduction circuit 30 are controlled to be in an operating state, and the discharging is performed by a scheme of equalizing the discharging current, and since the second battery pack 300 is smaller than the remaining capacity of the first battery pack 200, the first battery pack 200 charges the second battery pack 300 through the voltage reduction circuit 30 and the equalization circuit 60 during the discharging process to equalize the remaining capacities of the two.
For example, taking the first battery pack 200 being Bat1, the battery capacity of Bat1 being 2000mAh, the second battery pack 300 being Bat2, the battery capacity of Bat2 being 2800mAh, the remaining capacity being the remaining capacity as an example, in the first case, when the discharging is started, the controller 10 controls the load switch 20 to be closed, bat2 to be discharged to 2000mAh alone (i.e. the remaining capacity of Bat2 is 2000 mAh), then the controller 10 controls the load switch 20 to be opened, and controls the voltage reduction circuit 30 to be in an operating state (here, the equalizing circuit 60 is not required to be opened), since the remaining capacities of Bat2 and Bat1 are the same, the unit of the remaining capacity is mAh, and the capacities released by the two are the same in the same discharging time, so that the simultaneous emptying can be achieved. In the second case, when the discharging is started, the controller 10 controls the load switch 20 to be turned on, the Bat2 is discharged to 1400mAh or 2400mAh separately, and then the controller 10 controls the load switch 20 to be turned off, controls the step-down circuit 30 and the equalization circuit 60 to be in an operating state, and realizes the serial discharging of the Bat1 and the Bat2 through active equalization.
In the embodiment of the present application, the full charge voltage and the empty voltage of the first battery pack 200 and the second battery pack 300 are the same, and the balanced discharging process is described by taking the example that the load switch 20 is not involved, and the balanced circuit 60 and the voltage reducing circuit 30 implement the balanced discharging process, when the first battery pack 200 and the second battery pack 300 start to discharge, the first battery pack 200 and the second battery pack 300 both decrease from the full charge voltage, and the voltage decreasing speed of the first battery pack 200 is greater than that of the second battery pack 300. When the first battery pack 200 and the second battery pack 300 start to discharge, the equalizing circuit 60 is in a constant-resistance operation state (the equalizing circuit 60 corresponds to a constant resistance having a small resistance value) under the action of the fourth control signal. The discharge equalization current of the equalization circuit 60 is proportional to the discharge voltage difference between the first battery pack 200 and the second battery pack 300, and the discharge current ratio of the first battery pack 200 to the second battery pack 300 is greater than the battery capacity ratio of the first battery pack 200 to the second battery pack 300, which indicates that the discharge current of the first battery pack 200 is too large. During the discharging of the first battery pack 200 and the second battery pack 300, the discharge voltage difference increases with time, and the discharge balance current increases accordingly until the discharge current ratio is equal to the battery capacity ratio, and the voltage decrease rates of the first battery pack 200 and the second battery pack 300 are the same. During the discharging process, the gear of the pumping current Isys corresponding to the system circuit 400 will decrease, when the discharging current decreases, the discharging current ratio is smaller than the battery capacity ratio, the discharging voltage difference decreases with time, and the discharging balance current decreases accordingly until the discharging current ratio is equal to the battery capacity ratio. The discharge current is reduced again, the discharge voltage difference is reduced along with the time again, and the discharge balance current is reduced again until the discharge voltage difference is reduced to zero, so that the first battery pack 200 and the second battery pack 300 reach the discharge voltage simultaneously, the phenomenon that the voltages of the battery packs are unbalanced is reduced, and the service life of the battery packs is prolonged.
In the embodiment of the present application, the equalization circuit 60 may include any combination of at least two components such as a transistor, a diode, a resistor, a capacitor, an inductor, a field effect transistor (MOSFET, MOS transistor), etc., so that current can flow in both directions, and under the action of a driving signal (or control logic) of the controller 10, the equalization circuit can operate in a constant resistance state (corresponding to a resistor with a small resistance value) through the on-off combination of the components, and can also control the flowing current (corresponding to an adjustable resistor) through the on-off combination of the components, thereby operating in a constant voltage state. The equalization circuit 60 may be a bidirectional low dropout linear regulator (low dropout regulator, LDO), a C-UK (Care Unite Skin) chopper circuit, or a bidirectional BUCK-BOOST (BUCK-BOOST) circuit, which is not limited in this embodiment of the application.
In the embodiment of the present application, when the difference of electric quantity is greater than the preset electric quantity interval, the controller 10 controls the equalization circuit 60 to be in a constant-resistance working state, and controls the voltage reduction circuit 30 to be in a working state, so that the discharging currents of the first battery pack 200 and the second battery pack 300 are equalized, the second battery pack 300 is discharged to the system circuit 400 through the equalization circuit 60, the voltage of the first battery pack 200 and the second battery pack 300 after being connected in series is reduced by the voltage reduction circuit 30 and then discharged to the system circuit 400, and the discharging voltage can be achieved at the same time, so that the imbalance of the voltages of the battery packs is reduced, the phenomenon of differential performance is generated, and the service life of the battery packs is prolonged.
In the embodiment of the present application, the load switch 20, the equalizing circuit 60 and the voltage reducing circuit 30 do not work at the same time, and when the load switch 20 is closed, the equalizing circuit 60 and the voltage reducing circuit 30 are in a non-working state; the load switch 20 is turned off, the voltage reduction circuit 30 is in an operating state, as in the equalization control method corresponding to fig. 1; the load switch 20 is turned off, and the equalizing circuit 60 and the step-down circuit 30 are both in an operating state, as in the equalizing control method corresponding to fig. 4. The corresponding equalization control method of fig. 4 may be applied to the discharge process alone, that is, fig. 4 may not include the load switch 20.
It should be noted that, the second control signal related in fig. 1 and the fifth control signal related in fig. 4 are the same type of signals with the same function, and are driving signals for controlling the voltage-reducing circuit 30 to be in an operating state, in an actual application scenario, since in fig. 1, an application scenario is shown in which the load switch 20 is turned off and the electric quantity difference is located in a preset electric quantity interval, and in fig. 4, an application scenario is shown in which the voltage-reducing circuit 30 is controlled to be in an operating state when the electric quantity difference is greater than the preset electric quantity interval, in order to avoid confusion between the two application scenarios, in the embodiment of the application, the second control signal and the fifth control signal are respectively used in different application scenarios to describe.
In the following, an exemplary application of the embodiment of the present application in a practical application scenario will be described.
In the embodiment of the present application, in order to facilitate understanding of the operation modes of the equalization circuit 60 and the step-down circuit 30 in the discharging process, the following describes the process of implementing the discharging equalization by mutually cooperating the equalization circuit 60 and the step-down circuit 30, and since the load switch 20 is turned off in this process, this may be equivalent to the element without the load switch 20, as shown in fig. 5, fig. 5 is an optional schematic diagram of a discharging path of a non-constant volume battery provided in the embodiment of the present application. Typically, one circuit includes both a charging process and a discharging process, and thus a charging circuit 80 is also shown in fig. 5, maintaining circuit integrity. In fig. 5, the small-capacity Bat1 represents the first battery pack 200, the large-capacity Bat2 represents the second battery pack 300, the bidirectional LDO represents the equalizing circuit 60, the adapter output voltage Vin represents the charging voltage of the charging circuit 80, the system voltage Vsys represents the discharging voltage required by the system circuit 400, and in this example, the rated voltage of Bat1, the rated voltage of Bat2 and Vsys are all the same, for example, the voltage may be set to 4V, and the corresponding voltage Vin may be set to 8V. The unequal capacity battery discharging path comprises two paths, one path is that Bat2 is discharged through a bidirectional LDO, and the other path is that the series voltage of Bat2 and Bat1 is discharged after the voltage is reduced by a reducing circuit.
In the embodiment of the present application, based on the above-mentioned fig. 5, the overall discharge curve of the large-and-small-capacity battery is shown in fig. 6, and fig. 6 is an alternative schematic diagram of a voltage discharge curve according to the embodiment of the present application. The change in the voltages of the first battery pack 200 and the second battery pack 300 with time will be described using, as examples, the current of the first battery pack 200 being Ibat1, the current of the second battery pack 300 being Ibat2, the voltage of the first battery pack 200 being Vbat1, the voltage of the second battery pack 300 being Vbat2, the battery capacity of the first battery pack 200 being Cap1, the battery capacity of the second battery pack 300 being Cap2, and the balance current being Ib. Since the battery pack still has residual power (to maintain normal equipment) after the discharge is completed, but also Bat1 and Bat2 store a part of the voltage after the discharge, the discharge voltage is not 0, and therefore, bat1 and Bat2 in fig. 6 are not 0 after the discharge is completed, and simultaneously the discharge means that Bat1 and Bat2 reach the discharge voltage at the same time. When the LDO is operated in the on state, the constant resistor Rb with a small resistance is equivalent, the voltage vb= (Vbat 1-Vbat 2)/2 at the two ends of the LDO is proportional to the equalizing current Ib, i.e. ib=vb/Rb. At the start of discharge (corresponding to time 0 in fig. 6), vbat1=vbat2, balance current ib=vb/rb= (Vbat 1-Vbat 2)/(2×rb) =0, the large-capacity battery is discharged with the same current, vbat2> Vbat1, and balance current ib=vb/rb= (Vbat 1-Vbat 2)/(2×rb) >0 rapidly with the increase of time. When the voltage difference between the large-capacity batteries is small, ibat 1/ibat2= (Ibat 2-Ib)/Ibat 2> Cap1/Cap2, the voltage difference between the large-capacity batteries is increased continuously with time until Ibat 1/ibat2= (Ibat 2-Ib)/ibat2=cap 1/Cap2, and then the voltage difference between the large-capacity batteries is kept unchanged. When the system pumping current Isys decreases, the decreased current Ibat 1/ibat2= (Ibat 2-Ib)/Ibat 2< Cap1/Cap2, the voltage difference between the large-capacity batteries decreases, and the equalizing current Ib decreases accordingly until Ibat 1/ibat2= (ibat2+ib)/ibat2=cap 1/Cap2, and thereafter the voltage difference between the large-capacity batteries remains unchanged. In the discharging process of continuously reducing the current, the voltage differences Vbat1-Vbat2 between the large-capacity batteries are continuously reduced (the voltage difference Vb2 at the time t3 in fig. 6 is smaller than the voltage difference Vb1 at the time t 1) until the current is finally 0, and at this time, the large-capacity batteries are just emptied (i.e. reach the emptying voltage).
In the embodiment of the present application, as shown in fig. 6, the abscissa represents time and the ordinate represents voltage. The voltage changes of Bat1 and Bat2 with time at the time of discharge are shown in fig. 6. LDO constant resistance is balanced in a time period of 0-t 1, and voltage difference between large and small capacity batteries is continuously increased, wherein Ibat1/Ibat2> Cap1/Cap2; LDO constant resistance equalization is carried out in a time period of t 1-t 2, and voltage difference between large and small capacity batteries is kept unchanged, wherein Ibat1/Ibat 2=Cap 1/Cap2; and the discharging current is reduced at the moment t2, the voltage difference between the large-capacity batteries is continuously reduced in the time period from t2 to t3, at the moment, ibat1/Ibat2 is smaller than Cap1/Cap2, the voltage difference between the large-capacity batteries is kept unchanged until the moment t4, the current reducing process from t2 to t4 is continuously repeated until the large-capacity batteries and the large-capacity batteries are simultaneously discharged at the moment tL.
In some embodiments, based on the foregoing fig. 1 and fig. 2, an embodiment of the present application further provides an equalization control circuit of a battery pack, as shown in fig. 7, fig. 7 is an optional schematic diagram of an equalization control circuit of a battery pack according to another embodiment of the present application, where the equalization control circuit 100 of a battery pack further includes: an equalization circuit 60 and a current sampling circuit 70; the positive electrode of the first battery pack 200 is connected with a first end of a current sampling circuit 70 through a voltage reduction circuit 30, a second end of the current sampling circuit 70 is connected with a first end of an equalization circuit 60, and a third end of the current sampling circuit 70 is connected with a third input end of the controller 10; a second end of the equalization circuit 60 is connected to the positive electrode of the second battery pack 300; the current sampling circuit 70 is configured to monitor the discharge balancing current of the balancing circuit 60 in real time and send the discharge balancing current to the controller 10 during the discharge of the first battery pack 200 and the second battery pack 300; the controller 10 is further configured to send a fifth control signal to the step-down circuit 30 when the electric quantity difference is greater than a preset electric quantity interval; and determining a sixth control signal according to the discharge balance current, the current of the first battery pack 200, and the current of the second battery pack 300 and transmitting the sixth control signal to the balance circuit 60 when the difference in electric quantity is greater than the preset electric quantity interval and the discharge voltage difference between the voltage of the first battery pack 200 output by the first electric quantity meter 40 and the voltage of the second battery pack 300 output by the second electric quantity meter 50 is equal to the first preset threshold; the equalization circuit 60 is configured to adjust its own resistance in real time under the action of a sixth control signal, so as to achieve a constant voltage operating state, so as to equalize the discharge currents of the first battery pack 200 and the second battery pack 300, so that the second battery pack 300 discharges to the system circuit 400 through the equalization circuit 60; the step-down circuit 30 is further configured to be in an operating state under the action of the fifth control signal, step down the voltage of the first battery pack 200 and the second battery pack 300 after being connected in series, and discharge the voltage to the system circuit 400.
In the embodiment of the present application, the third output terminal of the controller 10 is connected to the third control terminal of the equalization circuit 60, and is used for sending the driving signal to the equalization circuit 60. When the difference of the electric power is greater than the preset electric power interval, it is indicated that the remaining electric power of the second battery pack 300 is far greater than or close to the first battery pack 200, and the controller 10 controls the voltage step-down circuit 30 to be in an operating state. When the discharge voltage difference between the voltage of the first battery pack 200 and the voltage of the second battery pack 300 is equal to the first preset threshold, the controller 10 controls the equalization circuit 60 to be in an operating state, monitors the discharge equalization current in real time through the current sampling circuit 70 during the discharge process, adjusts the self resistance of the equalization circuit 60 according to the discharge equalization current, the current of the first battery pack 200 and the current of the second battery pack 300, and realizes the real-time adjustment of the discharge equalization current, thereby enabling the equalization circuit 60 to be in a constant voltage operating state, wherein the constant voltage of the equalization circuit 60 is equal to half of the first preset threshold, and the voltage reduction speeds of the first battery pack 200 and the second battery pack 300 are the same. Second battery pack 300 is discharged to system circuit 400 through equalization circuit 60 on the one hand, and is discharged to system circuit 400 after being stepped down by step-down circuit 30 in combination with first battery pack 200 on the other hand.
It should be noted that, the first preset threshold may be set appropriately by a person skilled in the art according to the operating voltage of the equalizing circuit 60, so long as the equalizing circuit 60 can operate normally, and in general, taking the equalizing circuit 60 as an example of a bidirectional LDO, the operating voltage of the bidirectional LDO is about several tens millivolts, for example, 50mv.
In some embodiments, the controller 10 is further configured to send a seventh control signal to the equalization circuit 60 when the discharge voltage of the first battery pack 200 is equal to the first threshold voltage; wherein the first threshold voltage is greater than the discharge voltage of the first battery pack 200; the equalizing circuit 60 is further configured to adjust its own resistance again under the action of the seventh control signal, increase the discharging equalizing current, and achieve that the first battery pack 200 and the second battery pack 300 reach the emptying voltage at the same time.
In the embodiment of the present application, as the discharging time increases, the discharging voltage of the first battery pack 200 and the second battery pack 300 approaches the discharging voltage, and during discharging, the voltage of the first battery pack 200 is smaller than the voltage of the second battery pack 300. When the discharge voltage of the first battery pack 200 is equal to the first threshold voltage, i.e., close to the vent voltage. The controller 10 controls the resistance of the equalization circuit 60 to increase the discharge equalization current, and to break the balance (the voltage decrease speed of the first battery pack 200 and the second battery pack 300 are the same), so that the voltage decrease speed of the second battery pack 300 is greater than that of the first battery pack 200, thereby enabling both to reach the purge voltage at the same time (which can also be understood as a simultaneous purge).
The first threshold voltage may be appropriately set by those skilled in the art according to the purge voltage, and may be set to be close to the purge voltage, and in general, the purge voltage is not 0, and for example, the purge voltage is 1.3V, and the first threshold voltage may be set to be 1.5V, 1.7V, or the like.
In the embodiment of the present application, the load switch 20, the equalizing circuit 60 and the voltage reducing circuit 30 do not work at the same time, the load switch 20 is turned off, the voltage reducing circuit 30 is in a working state, and then the equalizing circuit 60 is in a constant voltage working state, as in the equalizing control method corresponding to fig. 7. The corresponding equalization control method of fig. 7 may be applied to the discharge process alone, that is, fig. 7 may not include the load switch 20.
In the embodiment of the present application, the full charge voltage and the empty voltage of the first battery pack 200 and the second battery pack 300 are the same, and the balanced discharging process is illustrated by taking the example that the load switch 20 is not involved, and the balanced circuit 60 and the voltage reducing circuit 30 implement the balanced discharging process, when the first battery pack 200 and the second battery pack 300 start to discharge, the voltage reducing circuit 30 is in a working state under the action of the fifth control signal, and the voltage of the first battery pack 200 and the voltage of the second battery pack 300 are reduced from the full charge voltage, and the voltage of the first battery pack 200 is greater than the voltage reducing speed of the second battery pack 300. During the discharging of the first battery pack 200 and the second battery pack 300, the discharging balance current of the balance circuit 60 is monitored in real time by the current sampling circuit 70. During the discharging process of the first battery pack 200 and the second battery pack 300, the discharging voltage difference increases with time until the discharging voltage difference is equal to the first preset threshold value, and the equalizing circuit 60 is in a constant voltage operation state (the equalizing circuit 60 is equivalent to an adjustable resistor) under the action of the sixth control signal. By monitoring the discharging equalization current of the equalization circuit 60 in real time, the corresponding resistance of the equalization circuit 60 is adjusted in real time, so that the equalization circuit 60 works under constant voltage (the constant voltage is one half of the first preset threshold value), the discharging current ratio is equal to the battery capacity ratio, and the voltage reduction speeds of the first battery pack 200 and the second battery pack 300 are the same. When the discharge voltage of the first battery pack 200 reaches the first critical voltage, under the action of the seventh control signal, the corresponding resistance of the equalization circuit 60 is adjusted again, so that the discharge equalization current is increased, the discharge current ratio is smaller than the battery capacity ratio, the first battery pack 200 and the second battery pack 300 reach the discharge voltage at the same time, the phenomenon that the voltages of the battery packs are unbalanced is reduced, and the service life of the battery packs is prolonged.
In the following, an exemplary application of the embodiment of the present application in a practical application scenario will be described.
In the embodiment of the present application, in order to facilitate understanding of the working modes of the equalization circuit 60 and the step-down circuit 30 in the discharging process, the following describes the process of implementing the discharging equalization by mutually matching the equalization circuit 60 and the step-down circuit 30, and since the load switch 20 is turned off in this process, this may be equivalent to the component without the load switch 20, as shown in fig. 8, fig. 8 is an optional structural schematic diagram of the discharging equalization circuit 60 provided in the embodiment of the present application; in fig. 8, the adapter is disconnected, the small-capacity Bat1 represents the first battery pack 200, the large-capacity Bat2 represents the second battery pack 300, the bidirectional LDO represents the equalizing circuit 60, and the system current Isys represents the discharge current required by the system circuit 400. In fig. 8, two discharge paths are shown in the discharge equalization circuit 60, one is that Bat2 is discharged through the bidirectional LDO, and one is that the series voltage of Bat2 and Bat1 is discharged after the voltage is reduced by the reduction circuit. Also shown in fig. 8 is a controller 10, the controller 10 is configured to receive the equalizing current Ib flowing through the LDO, and send a driving signal (corresponding to the sixth control signal) to the LDO according to the equalizing current Ib, so that the LDO operates in the Vb constant voltage mode. Since the voltage drop rate of Bat1 is greater than Bat2 during a period of time when discharge is started, and the voltage drop rate of Bat1 and Bat2 tend to be equal after LDO is turned on, the voltage Vbat1 of Bat1 is smaller than the voltage Vbat2 of Bat2, i.e., vbat1< Vbat2, during the entire discharge.
In the embodiment of the present application, after the adapter is disconnected, the serial dual battery is stepped down by the step-down circuit 30 according to 2:1, and then the power is supplied to the system circuit 400, if the bi-directional LDO is turned off (i.e. is in a non-operating state), under the same discharging current, the voltage dropping speed of Bat1 is greater than Bat2, and then Vbat1< Vbat2. Under the condition, the bidirectional LDO is switched on for shunt, so that the discharging current of the small-capacity battery Bat1 is smaller than that of the large-capacity battery Bat2, and the voltage difference between the large-capacity battery and the small-capacity battery (namely, the large-capacity battery Bat2 and the large-capacity battery Bat 1) is basically equal, and the logic thinking of discharging balance and charging balance are the inverse process.
In the embodiment of the present application, based on the above-mentioned fig. 8, the overall discharge curve of the large-and-small-capacity battery is shown in fig. 9, and fig. 9 is an alternative schematic diagram of another voltage discharge curve provided in the embodiment of the present application. The change in the voltages of the first battery pack 200 and the second battery pack 300 with time will be described by taking the example in which the current of the first battery pack 200 is Ibat1, the current of the second battery pack 300 is Ibat2, the voltage of the first battery pack 200 is Vbat1, the voltage of the second battery pack 300 is Vbat2, the first preset threshold is Vth, the first threshold voltage is Vf, the battery capacity of the first battery pack 200 is Cap1, the battery capacity of the second battery pack 300 is Cap2, and the balance current is Ib. Since the battery pack still has residual power (to maintain normal equipment) after the discharge is completed, but also Bat1 and Bat2 store a part of the voltage after the discharge, the discharge voltage is not 0, and therefore, bat1 and Bat2 in fig. 9 are not 0 after the discharge is completed, and simultaneously the discharge means that Bat1 and Bat2 reach the discharge voltage at the same time. The voltage threshold Vth is set to be very small, and the value of Vth can be determined according to the operating voltage of the bidirectional LDO, and in general, the voltage of the bidirectional LDO when operating is small, so Vth needs to be set to be a small voltage, for example, 50mV. When Vbat 2-vbat1=vth, the battery capacity of the low-capacity battery Bat1 is Cap1 and the battery capacity of the high-capacity battery Bat2 is Cap2 when the bidirectional LDO (i.e., in an operating state) is turned on, and in order to maintain a small voltage difference of Vbat 2-vbat1=vth in the discharging process of the high-capacity battery, it is necessary to ensure that Ibat 1/ibat2=cap 1/Cap2 and the voltage dropping speed of the high-capacity battery is the same. At this time, the system pump current isys=ibat2, the equalizing current ib=ibat2-ibat1 flowing through the LDO, the voltage across the LDO is vb=vbat2- (vbat1+vbat2)/2= (vbat2-vbat1)/2=vth/2, in this example, the LDO is operated in a constant voltage state, which is equivalent to an adjustable resistor, and the voltage across the LDO remains Vth/2 unchanged. The control method of the LDO constant voltage state is as follows: the current sampling circuit 70 (not shown in fig. 8) monitors the equalizing current Ib flowing through the LDO in real time, and the controller 10 controls the LDO driving signal (which may be understood as control logic) in a closed loop manner, so that the LDO operates in a constant voltage mode. Setting a voltage threshold Vf close to the battery voltage (corresponding to the voltage of the drain), when Vbat 1=vf, adjusting LDO balancing current Ib by controller 10, so that Iba1/Iba2< Cap1/Cap2, the voltage difference of the large-capacity battery is reduced to 0, and Bat1 and Bat2 just drain.
In the embodiment of the present application, as shown in fig. 9, the abscissa represents time and the ordinate represents voltage. Fig. 9 shows the change of the voltages of Bat1 and Bat2 with time during discharging, the LDO is turned off in the time period of 0 to t1, the discharge current of the large-capacity battery is equal to ibat1=ibat2, and the voltage reduction speed of Bat1 is greater than Bat2; the LDO is opened and balanced in a time period of t 1-t 2, balanced current Ib is regulated, the LDO works in a constant voltage state and is equivalent to an adjustable resistor, ibat1 is smaller than Ibat2, ibat1/Ibat 2=Cap 1/Cap2, and the voltage reduction speed of Bat1 is the same as that of Bat2; LDO is opened and balanced in a time period of t 2-t 3, and balanced current Ib, ibat1< Ibat2 (compared with t 1-t 2, ib is larger), ibat1/Ibat2< Cap1/Cap2; at time t3, bat1 and Bat2 reach the dump voltage simultaneously.
The discharge equalization method may include not only the first method shown in fig. 5 and 6, but also the second method shown in fig. 8 and 9, and may use the first method and the second method simultaneously to form a new discharge method by using a strategy such as time division multiplexing, and may use the strategy such as time division multiplexing to form a new discharge method by simultaneously turning on/off the load switch 20 and the first and second methods. The time division multiplexing refers to presetting the execution time length of each method, and in the same discharging process, the method can be a single discharging equalization mode or a combination of multiple modes, and the actual time of each mode is controlled by the execution time length. In practical application, the different methods are matched with each other to complete the discharging process, and the embodiment of the application is not limited.
In some embodiments, based on the foregoing fig. 1 and fig. 2, an embodiment of the present application further provides an equalization control circuit of a battery pack, as shown in fig. 10, fig. 10 is an optional schematic diagram of an equalization control circuit of a battery pack according to another embodiment of the present application, where the equalization control circuit 100 of a battery pack further includes: a charging circuit 80 and an equalizing circuit 60; the charging circuit 80 is connected to the positive electrode of the first battery pack 200; the positive electrode of the first battery pack 200 is connected with the first end of the equalization circuit 60 through the voltage reduction circuit 30, and the second end of the equalization circuit 60 is connected with the positive electrode of the second battery pack 300; a charging circuit 80 for charging the first battery pack 200 and the second battery pack 300; the controller 10 is further configured to send an eighth control signal to the equalization circuit 60 and a ninth control signal to the step-down circuit 30 when the charging circuit 80 starts charging the first battery pack 200 and the second battery pack 300; an equalizing circuit 60, configured to be in a constant-resistance operating state under the action of an eighth control signal, so as to equalize charging currents of the first battery pack 200 and the second battery pack 300; the step-down circuit 30 is further configured to be in an operating state under the action of the ninth control signal, step down the charging voltage of the charging circuit 80, and then charge the second battery pack 300.
In the embodiment of the present application, the third output terminal of the controller 10 is connected to the third control terminal of the equalization circuit 60, and is used for sending the driving signal to the equalization circuit 60. The full charge voltage and the discharge voltage of the first battery pack 200 and the second battery pack 300 are the same, and the equalizing circuit 60 and the step-down circuit 30 are taken as an example to implement the equalizing charge process, and when the first battery pack 200 and the second battery pack 300 start charging, the first battery pack 200 and the second battery pack 300 both rise from the discharge voltage, and the first battery pack 200 is greater than the voltage rise speed of the second battery pack 300; when the first battery pack 200 and the second battery pack 300 start to charge, the equalizing circuit 60 is in a constant-resistance operation state (the equalizing circuit 60 corresponds to a constant resistance having a small resistance value) under the action of the eighth control signal. The charge equalization current of the equalization circuit 60 is proportional to the charge voltage difference between the first battery pack 200 and the second battery pack 300, and the charge current ratio of the first battery pack 200 to the second battery pack 300 is greater than the battery capacity ratio, which indicates that the charge current of the first battery pack 200 is too large. During the charging of the first battery pack 200 and the second battery pack 300, the charging voltage difference increases with time, and the charge balance current increases accordingly until the charging current ratio is equal to the battery capacity ratio, and the voltage rise rates of the first battery pack 200 and the second battery pack 300 are the same. In the charging process, due to the reasons of temperature rise of the charged equipment or temperature rise of the adapter, the total charging current gradually decreases in steps, when the charging current step of the charging circuit 80 decreases, the charging current ratio is smaller than the battery capacity ratio, the charging voltage difference decreases with time, and the charging balance current decreases until the charging current ratio is equal to the battery capacity ratio; the charging current gear of the charging circuit 80 is reduced again, the charging voltage difference is reduced again along with time, and the charging balance current is reduced again until the charging voltage difference and the charging balance current are reduced to zero, so that the first battery pack 200 and the second battery pack 300 reach full charging voltage at the same time, the phenomenon that the voltages of the battery packs are unbalanced is reduced, and the service life of the battery packs is prolonged.
In the following, an exemplary application of the embodiment of the present application in a practical application scenario will be described.
In the embodiment of the present application, in order to facilitate understanding of the working modes of the equalizing circuit 60 and the voltage reducing circuit 30 in the charging process, the following describes a process of implementing charge equalization by mutually matching the equalizing circuit 60 and the voltage reducing circuit 30, and in this process, the load switch 20 is turned off (the load switch 20 is adapted to the discharging process), which may be equivalent to a component without the load switch 20, as shown in fig. 11, fig. 11 is an alternative schematic diagram of a charging path of an unequal capacity battery provided in the embodiment of the present application. In fig. 11, the small-capacity Bat1 represents the first battery pack 200, the large-capacity Bat2 represents the second battery pack 300, the bidirectional LDO represents the equalizing circuit 60, the adapter output voltage Vin represents the charging voltage of the charging circuit 80, the system voltage Vsys represents the discharging voltage required by the system circuit 400, and in this example, the rated voltage of Bat1, the rated voltage of Bat2 and Vsys are all the same, for example, the voltage may be set to 4V, and the corresponding Vin may be set to 8V. The unequal battery charging path includes two, one for charging Bat2 through the buck circuit 30 and the bi-directional LDO, and one for directly charging Bat1 and Bat 2.
In the embodiment of the present application, based on the foregoing fig. 11, the overall charging curve of the large-and-small-capacity battery is shown in fig. 12, and fig. 12 is an alternative schematic diagram of a voltage charging curve according to the embodiment of the present application. The change with time of the voltages of the first battery pack 200 and the second battery pack 300 at the time of charging will be described taking, as an example, the current of the first battery pack 200 is Ibat1, the current of the second battery pack 300 is Ibat2, the voltage of the first battery pack 200 is Vbat1, the voltage of the second battery pack 300 is Vbat2, the battery capacity of the first battery pack 200 is Cap1, the battery capacity of the second battery pack 300 is Cap2, and the balance current is Ib. When the LDO is operated in the on state, the constant resistor Rb with a small resistance is equivalent, the voltage vb= (Vbat 1-Vbat 2)/2 at the two ends of the LDO is proportional to the equalizing current Ib, i.e. ib=vb/Rb. When charging is started (corresponding to time 0), vbat1=vbat2, balance current ib=vb/rb= (Vbat 1-Vbat 2)/(2×rb) =0, the large-sized capacity battery is charged with the same current, vbat1> Vbat2, and balance current ib=vb/rb= (Vbat 1-Vbat 2)/(2×rb) >0 rapidly with the increase of time. When the voltage difference between the large-capacity batteries is small, ibat 1/ibat2= (Ibat 2-Ib)/Ibat 2> Cap1/Cap2, the voltage difference between the large-capacity batteries is increased continuously with time until Ibat 1/ibat2= (Ibat 2-Ib)/ibat2=cap 1/Cap2, after which the voltage difference between the large-capacity batteries is kept unchanged. In the constant current charging stage, the total charging current Ich gradually decreases in steps due to an increase in the temperature of the charged device or an increase in the temperature of the adapter, and when a shift change occurs, the state in which the front voltage difference remains unchanged is broken. For example, when the total charging current Ich decreases, the post-decrease current Ibat 1/ibat2= (Ibat 2-Ib)/Ibat 2< Cap1/Cap2, the voltage difference between the large-capacity batteries decreases, and the balance current Ib decreases accordingly until Ibat 1/ibat2= (ibat2+ib)/ibat2=cap 1/Cap2, after which the voltage difference between the large-capacity batteries remains unchanged. In the charging process of continuously reducing the current, the voltage differences Vbat1-Vbat2 between the large-capacity batteries are continuously reduced (the voltage difference Vb2 at the time t3 is smaller than the voltage difference Vb1 at the time t1 in fig. 12) until the last 0, at which time Bat1 and Bat2 are just full (i.e. the full charge voltage is reached).
In the embodiment of the present application, as shown in fig. 12, the abscissa represents time and the ordinate represents voltage. FIG. 12 shows the change of the voltage of Bat1 and Bat2 with time during charging, the constant resistance of LDO is balanced in the time period of 0 to t1, and the voltage difference between large and small capacity batteries is continuously increased, wherein Ibat1/Ibat2> Cap1/Cap2; LDO constant resistance equalization is carried out in a time period of t 1-t 2, and voltage difference between large and small capacity batteries is kept unchanged, wherein Ibat1/Ibat 2=Cap 1/Cap2; and the charging current is reduced at the moment t2, the voltage difference between the large-capacity batteries and the small-capacity batteries in the time period t 2-t 3 is continuously reduced, at the moment Ibat1/Ibat2 is smaller than Cap1/Cap2 until the voltage difference between the large-capacity batteries and the small-capacity batteries at the moment t4 is kept unchanged, and the current reducing process of t 2-t 3-t 4 is continuously repeated until the large-capacity batteries and the small-capacity batteries are simultaneously full at the moment tL.
In some embodiments, based on the foregoing fig. 1 and fig. 2, an embodiment of the present application further provides an equalization control circuit of a battery pack, as shown in fig. 13, fig. 13 is an optional schematic diagram of an equalization control circuit of a battery pack according to another embodiment of the present application, where the equalization control circuit 100 of a battery pack further includes: a charging circuit 80, a current sampling circuit 70, and an equalizing circuit 60; the charging circuit 80 is connected to the positive electrode of the first battery pack 200; the positive electrode of the first battery pack 200 is connected with a first end of a current sampling circuit 70 through a voltage reduction circuit 30, a second end of the current sampling circuit 70 is connected with a first end of an equalization circuit 60, and a third end of the current sampling circuit 70 is connected with a third input end of the controller 10; a second end of the equalization circuit 60 is connected to the positive electrode of the second battery pack 300; the current sampling circuit 70 is further configured to monitor a charge balance current of the balancing circuit 60 in real time and send the charge balance current to the controller 10 during the charging process of the first battery pack 200 and the second battery pack 300 by the charging circuit 80; the controller 10 is further configured to send an eighth control signal to the step-down circuit 30 when the charging circuit 80 starts charging the first battery pack 200 and the second battery pack 300; and determining a tenth control signal according to the charge equalization current, the current of the first battery pack 200, and the current of the second battery pack 300 when the charge voltage difference between the voltage of the first battery pack 200 output by the first fuel gauge 40 and the voltage of the second battery pack 300 output by the second fuel gauge 50 is equal to a second preset threshold value, and transmitting the tenth control signal to the equalization circuit 60; the equalizing circuit 60 is further configured to adjust its own resistance in real time under the action of a tenth control signal, so as to achieve a constant voltage operation state, so as to equalize charging currents of the first battery pack 200 and the second battery pack 300, so that the charging circuit 80 charges the first battery pack 200 and the second battery pack 300; the step-down circuit 30 is further configured to be in an operating state under the action of the eighth control signal, step down the charging voltage of the charging circuit 80, and then charge the second battery pack 300.
In the embodiment of the present application, the third output terminal of the controller 10 is connected to the third control terminal of the equalization circuit 60, and is used for sending the driving signal to the equalization circuit 60. When the charging voltage difference between the voltage of the first battery pack 200 and the voltage of the second battery pack 300 is equal to the second preset threshold, the controller 10 controls the equalizing circuit 60 to be in an operating state, and monitors the charging equalizing current in real time through the current sampling circuit 70 during charging, and adjusts the self resistance of the equalizing circuit 60 according to the charging equalizing current, the current of the first battery pack 200 and the current of the second battery pack 300, so that the real-time adjustment of the charging equalizing current is realized, thereby the equalizing circuit 60 is in a constant voltage operating state, wherein the constant voltage of the equalizing circuit 60 is equal to half of the second preset threshold, and the voltage rising speeds of the first battery pack 200 and the second battery pack 300 are the same. The charging circuit 80 charges the second battery pack 300 through the step-down circuit 30 and the equalization circuit 60 on the one hand, and directly charges the first battery pack 200 and the second battery pack 300 on the other hand.
It should be noted that, the second preset threshold may be set appropriately by a person skilled in the art according to the operating voltage of the equalizing circuit 60, so long as the equalizing circuit 60 can operate normally, and in general, taking the equalizing circuit 60 as an example of a bidirectional LDO, the operating voltage of the bidirectional LDO is about several tens millivolts, for example, 50mv.
In some embodiments, the controller 10 is further configured to send an eleventh control signal to the equalization circuit 60 when the charging voltage of the first battery pack 200 reaches the second threshold voltage; wherein the second threshold voltage is less than the full charge voltage of the first battery pack 200; the equalizing circuit 60 is further configured to adjust its own resistance again under the action of the eleventh control signal, and increase the charge equalization current, so as to achieve that the first battery pack 200 and the second battery pack 300 reach full charge voltage at the same time.
In the embodiment of the present application, as the charging time increases, the charging voltage of the first battery pack 200 and the second battery pack 300 approaches the full charge voltage, and the voltage of the first battery pack 200 is greater than the voltage of the second battery pack 300 during the charging process. When the charging voltage of the first battery pack 200 is equal to the second threshold voltage, i.e., close to the full charge voltage. The controller 10 controls the resistance of the equalizing circuit 60 to increase the charge equalizing current, and to break the balance (the voltage rising speeds of the first battery pack 200 and the second battery pack 300 are the same), so that the voltage rising speed of the second battery pack 300 is greater than that of the first battery pack 200, thereby allowing both to reach the full charge voltage at the same time (which can also be understood as full charge at the same time).
The second threshold voltage may be appropriately set by those skilled in the art according to the full charge voltage, and may be set to 3.8V, 3.9V, or the like, as long as the full charge voltage is close to the full charge voltage, for example, 4V.
In the embodiment of the present application, the full charge voltage and the dump voltage of the first battery pack 200 and the second battery pack 300 are the same, and the equalizing circuit 60 and the step-down circuit 30 are used for implementing the equalizing charge process, and when the first battery pack 200 and the second battery pack 300 start charging, the charging current of the first battery pack 200 is the same as that of the second battery pack 300, and the first battery pack 200 and the second battery pack 300 both rise from the dump voltage, and the first battery pack 200 is greater than the voltage rising speed of the second battery pack 300; during the charging process of the first battery pack 200 and the second battery pack 300, the charging voltage difference increases with time until the charging voltage difference is equal to the second preset threshold value, and the equalization circuit 60 is in a constant voltage operation state (the equalization circuit 60 is equivalent to an adjustable resistor) under the action of the tenth control signal. The charging equalization current of the equalization circuit 60 is monitored in real time through the current sampling circuit 70, and the corresponding resistance of the equalization circuit 60 is adjusted in real time, so that the equalization circuit 60 works under constant voltage (the constant voltage is one half of a second preset threshold value), the charging current ratio is equal to the battery capacity ratio, and the voltage rising speeds of the first battery pack 200 and the second battery pack 300 are the same; when the charging voltage of the first battery pack 200 reaches the second critical voltage, the second critical voltage is smaller than the full charging voltage, and the corresponding resistance of the equalization circuit 60 is adjusted again, so that the charging equalization current is increased, the charging current ratio is smaller than the battery capacity ratio, the first battery pack 200 and the second battery pack 300 reach the full charging voltage at the same time, the phenomenon that the voltages of the battery packs are unbalanced is reduced, and the service life of the battery packs is prolonged.
In the following, an exemplary application of the embodiment of the present application in a practical application scenario will be described.
In the embodiment of the present application, in order to facilitate understanding of the working modes of the equalizing circuit 60 and the step-down circuit 30 in the charging process, the following describes a process of implementing charge equalization by mutually matching the equalizing circuit 60 and the step-down circuit 30, and since the load switch 20 is turned off (the load switch 20 is adapted to the discharging process) in this process, this may be equivalent to a component without the load switch 20, as shown in fig. 14, fig. 14 is a schematic diagram of an alternative structure of the charge equalizing circuit 60 provided in the embodiment of the present application; in fig. 14, the small-capacity Bat1 represents the first battery pack 200, the large-capacity Bat2 represents the second battery pack 300, the bidirectional LDO represents the equalizing circuit 60, the adapter output voltage Vin represents the charging voltage of the charging circuit 80, the system voltage Vsys represents the discharging voltage required by the system circuit 400, and in this example, the rated voltage of the first battery pack 200, the rated voltage of the second battery pack 300, and Vsys are the same, for example, the voltage may be set to 4V, and the corresponding Vin may be set to 8V. In fig. 14, two charging paths are shown in the charge equalization circuit 60, one for charging Bat2 through the step-down circuit 30 and the bidirectional LDO, and one for directly charging Bat1 and Bat2. Also shown in fig. 14 is a controller 10, the controller 10 is configured to receive the equalizing current Ib flowing through the LDO, and send a driving signal (corresponding to the tenth control signal) to the LDO according to the equalizing current Ib, so that the LDO operates in the Vb constant voltage mode. Since the voltage rising speed of Bat1 is greater than Bat2 for a period of time after charging is started, and the voltage rising speed of Bat1 and Bat2 tend to be equal after LDO is turned on, the voltage Vbat1 of Bat1 is greater than the voltage Vbat2 of Bat2, i.e., vbat1> Vbat2, throughout the charging process.
In the embodiment of the present application, when the adapter is plugged in, the unequal double-battery is charged in series through the charging circuit 80, if the bidirectional LDO is turned off (i.e., is in an inactive state), under the same charging current, the voltage rising speed of the small-capacity battery Bat1 is greater than that of the large-capacity battery Bat2, and then Vbat1> Vbat2. In this case, the bidirectional LDO turns on the shunt, so that the charging current of the small-capacity battery Bat1 is smaller than that of the large-capacity battery Bat2, and the voltages of the large-capacity battery and the small-capacity battery (i.e., bat2 and Bat 1) are kept substantially equal. The charge equalization logic thinking and the discharge equalization are the inverse process. Here, the change with time of the voltages of the first battery pack 200 and the second battery pack 300 during charging will be described by taking the example in which the current of the first battery pack 200 is Ibat1, the current of the second battery pack 300 is Ibat2, the voltage of the first battery pack 200 is Vbat1, the voltage of the second battery pack 300 is Vbat2, the second preset threshold is Vth, the second threshold voltage is Vf, the battery capacity of the first battery pack 200 is Cap1, the battery capacity of the second battery pack 300 is Cap2, and the balance current is Ib.
In the embodiment of the present application, a small voltage threshold Vth is set, where Vth can be determined according to the operating voltage of the bidirectional LDO, and in general, the voltage during operation of the bidirectional LDO is small, so Vth needs to be set to a small voltage, for example, 50mV. When Vbat 1-vbat2=vth, the bidirectional LDO is turned on (i.e., in an operating state). The battery capacity of the small-capacity battery Bat1 is Cap1, the battery capacity of the large-capacity battery Bat2 is Cap2, and in order to maintain a small voltage difference of Vbat 1-vbat2=vth in the charging process of the large-capacity battery, it is necessary to ensure Ibat 1/ibat2=cap 1/Cap2 so that the voltage rising speeds of the large-capacity battery and the small-capacity battery are the same. At this time, the charging circuit 80 outputs a current (i.e., a total charging current Ich) ich=ibat2, an equalizing current ib=ibat2-ibat1 flowing through the LDO, and a voltage across the LDO of vb= (vbat1+vbat2)/2-vbat2= (Vbat 1-vbat2)/2=vth/2, in this example, the LDO operates in a constant voltage state, which corresponds to an adjustable resistor, and the voltage across the LDO remains Vth/2 unchanged. The control method of the LDO constant voltage state is as follows: the current sampling circuit 70 (not shown in fig. 14) monitors the equalizing current Ib flowing through the LDO in real time, and the controller 10 controls the LDO driving signal (which may be understood as control logic) in a closed loop manner to implement real-time regulation of the equalizing current Ib, so that the LDO operates in a constant voltage mode. Setting a voltage threshold Vf close to the full charge battery voltage (i.e. full charge voltage), when Vbat 1=vf, regulating LDO balancing current Ib by controller 10, so that Iba1/Iba2< Cap1/Cap2, the voltage difference of the large-capacity battery is reduced to 0, and Bat1 and Bat2 are just full.
In the embodiment of the present application, based on the foregoing fig. 14, the overall charging curve of the large-and-small-capacity battery is shown in fig. 15, and fig. 15 is an alternative schematic diagram of another voltage charging curve provided in the embodiment of the present application; since Bat1 and Bat2 still store a part of the voltage after the air-vent, the air-vent voltage is not 0, and therefore, bat1 and Bat2 in fig. 15 do not start from 0 at the start of charging.
In the embodiment of the application, as shown in fig. 15, the abscissa represents time, the ordinate represents voltage, fig. 15 shows the change of the voltage of Bat1 and Bat2 with time during charging, the LDO is turned off in the time period of 0 to t1, the charging current of the battery with the same capacity ibat1=ibat2, and the voltage rising speed of Bat1 is greater than Bat2; the LDO is opened and balanced in a time period t 1-t 2, balanced current Ib is regulated, the LDO works in a constant voltage state and is equivalent to an adjustable resistor, ibat1 is smaller than Ibat2, ibat1/Ibat 2=Cap 1/Cap2, and the voltage rising speed of Bat1 is the same as that of Bat2; the LDO is opened and balanced in a time period of t 2-t 3, balanced current Ib is regulated, ibat1< Ibat2 (Ib is larger than that in a time period of t 1-t 2), ibat1/Ibat2< Cap1/Cap2, and at the time of t3, bat1 and Bat2 reach full charge voltage simultaneously.
Based on the equalization control circuit 100 of the battery pack described in any of the foregoing embodiments, the embodiment of the present application further provides a terminal device, as shown in fig. 16, fig. 16 is a schematic structural diagram of an alternative terminal device proposed in the embodiment of the present application, where the terminal device 1000 proposed in the embodiment of the present application includes a first battery pack 200 and a second battery pack 300 connected in series, and the equalization control circuit 100 of the battery pack described in any of the foregoing embodiments, where the first battery pack 200 is smaller than the battery capacity of the second battery pack 300, the full charge voltage and the discharge voltage of the first battery pack 200 and the second battery pack 300 are the same, the first battery pack 200 belongs to a first battery cell system, and the second battery pack 300 belongs to a second battery cell system; a first end of a load switch 20 in the battery pack balance control circuit 100 is connected between the first battery pack 200 and the second battery pack 300, and an anode of the first battery pack 200 is connected with a second end of the load switch 20 through a voltage reduction circuit 30 in the battery pack balance control circuit 100; the battery equalization control circuit 100 is configured to close the load switch 20 under the action of the first control signal when a difference between a remaining power of the second battery pack 300 and a remaining power of the first battery pack 200 is greater than a preset power interval during discharging of the first battery pack 200 and the second battery pack 300, and the second battery pack 300 is connected to the system circuit 400; second battery pack 300 for discharging individually to system circuit 400; the battery equalization control circuit 100 is further configured to disconnect the load switch 20 under the action of the third control signal when the electric quantity difference is within the preset electric quantity interval, and disconnect the second battery 300 from the system circuit 400; and, the step-down circuit 30 is in an operating state under the action of the second control signal; first battery pack 200 and second battery pack 300 are configured to be discharged to system circuit 400 after being step down by step-down circuit 30.
In the embodiment of the present application, a dual-battery serial scheme of different capacities and different systems is adopted, the first battery pack 200 adopts an a-system battery cell (corresponding to a first battery cell system), and the second battery pack 300 adopts a B-system battery cell (corresponding to a second battery cell system). The low-temperature discharge performance of the terminal equipment 1000 is between the weakest temperature discharge performance and the strongest low-temperature discharge performance in the A-system battery cell and the B-system battery cell; the energy density of terminal device 1000 is between the lowest and highest energy densities in the a-system cells and the B-system cells.
In the embodiment of the present application, during the discharging process of the first battery pack 200 and the second battery pack 300, when the difference between the remaining electric power of the second battery pack 300 and the remaining electric power of the first battery pack 200 is greater than the preset electric power interval, the load switch 20 is closed, and the second battery pack 300 is conducted with the system circuit 400 through the battery pack balance control circuit 100; second battery pack 300 may be individually discharged to system circuit 400. When the electric quantity difference is within the preset electric quantity interval, the load switch 20 is turned off, and the second battery pack 300 is disconnected from the system circuit 400; and controls the step-down circuit 30 to be in an operating state; the voltage after the first battery pack 200 and the second battery pack 300 are connected in series is reduced by the voltage reducing circuit 30 and then discharged to the system circuit 400, thereby completing the entire discharging process. In this scheme, the load switch 20 only plays a role in on-off, no other components are provided, the circuit energy loss is less, compared with the balanced discharging mode through the balancing circuit 60 and the voltage reduction circuit 30, the discharging loss of the double batteries of different volumes and different systems is reduced, and the endurance capacity of the terminal equipment is improved. The on-off time of the load switch 20 is judged according to the residual electric quantity, the first half period of time is independently discharged through the load switch 20, and when the residual electric quantity of the two is close, the second half period of time is serially discharged through the voltage reduction circuit 30, so that the discharging efficiency of the double batteries with different capacities and different systems is improved.
Illustratively, an a-architecture cell (corresponding to a first cell architecture) may include: the silicon negative electrode system battery cell, the graphite negative electrode system battery cell and the lithium metal system battery cell, the multiplying power system of each of the A system battery cell comprises ：0.5C、0.7C、0.9C、1C、1.5C、2C、2.5C、3C、3.5C、4C、4.5C、5C、5.5C、6C、6.5C、7C、7.5C、8C、8.5C、9C、9.5C、10C、10.5C、11C、11.5C、12C、12.5C、13C、13.5C、14C、14.5C、15C.B system battery cells, and the A system battery cell comprises: the multiplying power systems of the silicon negative electrode system battery cell, the graphite negative electrode system battery cell and the lithium metal system battery cell respectively comprise ：0.5C、0.7C、0.9C、1C、1.5C、2C、2.5C、3C、3.5C、4C、4.5C、5C、5.5C、6C、6.5C、7C、7.5C、8C、8.5C、9C、9.5C、10C、10.5C、11C、11.5C、12C、12.5C、13C、13.5C、14C、14.5C、15C. first battery pack 200 and second battery pack 300, and the battery cell combinations of different systems in the A system battery cell and the B system battery cell are adopted. The rate C represents the battery charge/discharge capacity rate, and is proportional to the charge/discharge current, with charge/discharge rate=charge/discharge current/rated capacity, with larger charge/discharge current being larger.
In an embodiment of the application, the energy density (ENERGY DENSITY) characterizes the amount of stored energy in a unit of space or mass. The energy density of a battery is the electrical energy released by the average unit volume or mass of the battery. The discharge capacity of a battery can be affected by low temperature conditions, which characterize the performance of the battery when used in an environment at a prescribed temperature (e.g., below 0 ℃, or-20 ℃ or-30 ℃), with lower temperatures having weaker discharge capacities. The low-temperature discharge capacity can be measured by the ratio of the capacity that can be discharged to the end voltage according to a predetermined current in an environment of a predetermined temperature after the battery is fully charged at normal temperature to the capacity that can be discharged at normal temperature.
In the embodiment of the present application, the equalization control circuit 100 of the battery pack in the terminal device 1000 can implement not only the equalization discharging process but also the equalization charging process. As shown in fig. 17, fig. 17 is an optional schematic structural diagram of a charge/discharge balancing circuit for an unequal battery in a terminal device according to an embodiment of the present application, in the unequal battery charge/discharge balancing circuit provided in fig. 17, a small capacity Bat1 represents a first battery pack 200, a large capacity Bat2 represents a second battery pack 300, a bidirectional LDO represents a balancing circuit 60, an adapter output voltage Vin represents a charging voltage of the charging circuit 80, a system voltage Vsys represents a discharging voltage required by the system circuit 400, and the scheme adopts two single-cell batteries with unequal capacities, the small-capacity battery is placed at a high end, the large-capacity battery is placed at a low end, and a negative electrode of the small-capacity battery is connected with a positive electrode of the large-capacity battery. When the adapter is connected, the double batteries are charged in series through the charging circuit 80, and the small-capacity batteries are charged in balance through the voltage reduction circuit 30 and the bidirectional LDO, so that the large-capacity batteries and the small-capacity batteries are ensured to be charged simultaneously; when the adapter is disconnected, the serial double batteries are reduced in voltage by 2:1 through the voltage reducing circuit 30 to supply power to the system, and the large-capacity batteries are charged in an equalizing mode through the voltage reducing circuit 30 and the bidirectional LDO, so that the simultaneous emptying of the large-capacity batteries and the small-capacity batteries is ensured. The load switch 20 is not shown in fig. 17, and the bidirectional LDO and step-down circuit 30 in fig. 17 can achieve current balance during charging and discharging, and the specific process may refer to fig. 4-15, which are not described herein. In fig. 17, a load switch 20 may be added, and current equalization during charging and discharging is implemented by the on-off of the load switch 20 and the bidirectional LDO and step-down circuit 30, and the specific process may refer to fig. 1-3, which are not described herein.
The equalization control circuit 100 of the battery pack provided by the embodiment of the application can maximize and utilize the structural space of the terminal equipment with the folding screen form or the special-shaped battery compartment, and increase the battery capacity of the terminal equipment, thereby improving the cruising ability of the terminal equipment. The provided active equalization architecture suitable for charging and discharging of the serial batteries with different capacities can meet the structural space requirement of the mobile phone with the folding screen form or the special battery compartment, and improves the flexibility of terminal equipment design.
In some embodiments, the first cell system is a graphite negative electrode system and the second cell system is a silicon negative electrode system.
In the embodiment of the present application, since the battery capacities of the first battery pack 200 and the second battery pack 300 are different, the shapes of the first battery pack 200 and the second battery pack 300 may be different, and may be shaped batteries. In the mixed serial scheme of the abnormal-shaped unequal-capacity batteries provided by the embodiment of the application, the battery capacities of the first battery pack 200 and the second battery pack 300 are different, and the battery core systems are different. For example, the first battery pack 200 employs a 5C graphite negative electrode system cell with a battery capacity of 2000mAh, and the second battery pack 300 employs a 5C silicon negative electrode system cell with a battery capacity of 2800mAh. Because the graphite negative electrode has better low-temperature discharge performance than the silicon negative electrode, compared with the scheme that the first battery pack 200 and the second battery pack 300 adopt the silicon negative electrode system battery cells, the mixed series connection mode has better low-temperature discharge performance. Because the silicon negative electrode has a higher energy density than the graphite negative electrode, the hybrid serial mode has a higher energy density than the scheme in which the first battery pack 200 and the second battery pack 300 both use the graphite negative electrode system cell. Of course, different combinations have different benefits, and are not described herein, so long as the technical scheme of adopting the hybrid serial connection is within the protection scope of the embodiment of the present application.
In the embodiment of the present application, the large-capacity battery (i.e., the second battery pack 300) adopts a silicon negative electrode system, and the small-capacity battery (i.e., the first battery pack 200) adopts a graphite negative electrode system. The silicon negative electrode system has higher energy density than the graphite negative electrode system, but has poor low-temperature performance, and compared with the double-cell series scheme of adopting the graphite negative electrode system for two batteries, the mixing method can effectively improve the energy density of the combined battery. Compared with a double-cell series scheme in which two batteries adopt a silicon negative electrode system, the low-temperature discharge performance of the combined battery is improved.
The embodiment of the application provides a battery pack equalization control method, which is applied to the battery pack equalization control circuit 100 described in any of the above embodiments, as shown in fig. 18, fig. 18 is a flowchart of optional steps of the battery pack equalization control method provided in the embodiment of the application, and the battery pack equalization control method includes the following steps:
S101, closing a load switch under the action of a first control signal when the electric quantity difference between the acquired residual electric quantity of the second battery pack and the acquired residual electric quantity of the first battery pack is larger than a preset electric quantity interval in the discharging process of the first battery pack and the second battery pack, so that the second battery pack is independently discharged to a system circuit; the second battery pack is connected in series with the first battery pack, and the battery capacity of the first battery pack is smaller than that of the second battery pack.
S102, when the electric quantity difference is in a preset electric quantity interval, the step-down circuit is in a working state under the action of a second control signal.
S103, the voltage of the first battery pack and the voltage of the second battery pack which are connected in series are reduced through a voltage reducing circuit, and then the voltage is discharged to a system circuit.
In some embodiments, the equalization control method of a battery pack further includes the steps of: when the electric quantity difference is in the preset electric quantity interval, the load switch is changed from closed to open under the action of the third control signal.
According to the scheme provided by the embodiment of the application, the equalization control method of the battery pack comprises the following steps: in the discharging process of the first battery pack and the second battery pack, when the electric quantity difference between the obtained residual electric quantity of the second battery pack and the obtained residual electric quantity of the first battery pack is larger than a preset electric quantity interval, closing a load switch under the action of a first control signal, and conducting the second battery pack and a system circuit to enable the second battery pack to be independently discharged to the system circuit; the second battery pack is connected in series with the first battery pack, and the battery capacity of the first battery pack is smaller than that of the second battery pack. In the process of starting discharging or discharging, when the difference of the residual electric quantity of the second battery pack and the residual electric quantity of the first battery pack is larger than a preset electric quantity interval, the second battery pack directly discharges to a system circuit through a load switch, namely, the high-capacity battery pack is singly discharged, the load switch only plays a role in switching on and switching off, no other components exist, and the energy loss of the circuit is small. When the electric quantity difference is in a preset electric quantity interval, under the action of a third control signal, the load switch is changed from closed to open, so that the second battery pack is disconnected from the system circuit; and the step-down circuit is in a working state under the action of the second control signal; and the voltage of the first battery pack and the voltage of the second battery pack which are connected in series are reduced by the voltage reducing circuit, and then the voltage is discharged to the system circuit. When the difference of the residual electric quantity between the two is in a preset electric quantity interval, the load switch is disconnected, and the voltage is reduced by the voltage reducing circuit in a working state and then power is supplied, so that the whole discharging process is completed. Compared with an equalizing discharge mode through an equalizing circuit and a voltage reducing circuit, the discharging loss is reduced, and the endurance of the terminal equipment is improved.
In some embodiments, the remaining power in S101 described above may be obtained in the following manner. Determining the residual electric quantity of the first battery pack according to the battery capacity of the first battery pack, the discharge current of the first battery pack and the first discharge time; and determining the residual quantity of the second battery pack according to the battery capacity of the second battery pack, the discharge current of the second battery pack and the second discharge time.
In some embodiments, the equalization control method of the battery pack may further include the following steps. When the electric quantity difference is larger than a preset electric quantity interval, the equalization circuit is in a constant resistance working state under the action of a fourth control signal so as to equalize the discharge currents of the first battery pack and the second battery pack, and the second battery pack is discharged to the system circuit through the equalization circuit; the voltage reducing circuit is in a working state under the action of the fifth control signal, and the voltage of the first battery pack and the voltage of the second battery pack which are connected in series are reduced and then discharged to the system circuit.
In some embodiments, the equalization control method of the battery pack may further include the following steps. In the discharging process of the first battery pack and the second battery pack, the discharging balance current of the balance circuit is monitored in real time; when the electric quantity difference is larger than a preset electric quantity interval and the discharge voltage difference between the voltage of the first battery pack and the voltage of the second battery pack is equal to a first preset threshold value, determining a sixth control signal according to the discharge balance current, the current of the first battery pack and the current of the second battery pack; under the action of a sixth control signal, the corresponding resistor of the equalization circuit is regulated in real time, so that the equalization circuit is in a constant-voltage working state to equalize the discharge currents of the first battery pack and the second battery pack, and the second battery pack discharges to the system circuit through the equalization circuit; when the electric quantity difference is larger than a preset electric quantity interval, the voltage reducing circuit is in a working state under the action of a fifth control signal, and the voltage after the first battery pack and the second battery pack are connected in series is reduced and then discharged to the system circuit.
In some embodiments, when the discharge voltage of the first battery pack is equal to the first critical voltage, under the action of the seventh control signal, the resistance corresponding to the equalization circuit is adjusted again, and the discharge equalization current is increased, so that the first battery pack and the second battery pack reach the emptying voltage at the same time; the first critical voltage is larger than the emptying voltage of the first battery pack.
In some embodiments, the equalization control method of a battery pack further includes a charging process, and the charging process includes the following steps. When the charging circuit starts charging the first battery pack and the second battery pack, the equalization circuit is in a constant-resistance working state under the action of an eighth control signal so as to equalize the charging currents of the first battery pack and the second battery pack; the step-down circuit is in an operating state under the action of the ninth control signal, and the charging voltage of the charging circuit is stepped down and then is charged into the second battery pack.
In some embodiments, the equalization control method of a battery pack further includes a charging process, and the charging process includes the following steps. In the process of charging the first battery pack and the second battery pack by the charging circuit, the charging balance current of the balance circuit is monitored in real time; when the charging voltage difference between the voltage of the first battery pack and the voltage of the second battery pack is equal to a second preset threshold value, determining a tenth control signal according to the charging equalization current, the current of the first battery pack and the current of the second battery pack; under the action of a tenth control signal, the corresponding resistance of the equalization circuit is adjusted in real time, so that the equalization circuit is in a constant-voltage working state to equalize the charging currents of the first battery pack and the second battery pack; the step-down circuit is in an operating state under the action of the ninth control signal, and the charging voltage of the charging circuit is stepped down and then is charged into the second battery pack.
In some embodiments, when the charging voltage of the first battery pack reaches the second critical voltage, under the action of the eleventh control signal, the corresponding resistor of the equalizing circuit is adjusted again, and the charging equalizing current is increased, so that the first battery pack and the second battery pack reach full charging voltage at the same time; the second critical voltage is smaller than the full charge voltage of the first battery pack.
It should be noted that, the equalization control method of the battery pack provided in the embodiment of the present application may be executed by the equalization control circuit of the battery pack described in any of the foregoing embodiments, where the equalization control method of the battery pack provided in the foregoing embodiment and the equalization control circuit embodiment of the battery pack belong to the same concept, and detailed implementation processes and beneficial effects thereof are shown in the circuit embodiment and are not repeated herein. For technical details not disclosed in the method embodiments, please refer to the description of the circuit embodiments of the present application for understanding.
An embodiment of the present application provides a computer-readable storage medium storing a computer program for implementing the equalization control method of a battery pack according to any of the embodiments above when executed by a processor.
For example, the program instruction corresponding to the method for controlling the balance of a battery pack in the embodiment of the present application may be stored on a storage medium such as an optical disc, a hard disc, or a usb disc, and when the program instruction corresponding to the method for controlling the balance of a battery pack in the storage medium is read or executed by an electronic device, the method for controlling the balance of a battery pack according to any one of the embodiments described above may be implemented.
It will be appreciated by those skilled in the art that embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of a hardware embodiment, a software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, magnetic disk storage, optical storage, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of implementations of methods, apparatus (systems) and computer program products according to embodiments of the application. It will be understood that each block and/or flow of the flowchart illustrations and/or block diagrams, and combinations of blocks and/or flow diagrams in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart block or blocks and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart block or blocks and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks and/or block diagram block or blocks.
The foregoing description is only of the preferred embodiments of the present application, and is not intended to limit the scope of the present application.
Claims (18)
1. An equalization control circuit of a battery pack, characterized in that the equalization control circuit of the battery pack comprises: the device comprises a controller, a load switch and a voltage reduction circuit; the battery pack includes a first battery pack and a second battery pack connected in series, the battery capacity of the first battery pack being smaller than the battery capacity of the second battery pack;
the first end of the load switch is connected between the first battery pack and the second battery pack, the second end of the load switch is connected with a system circuit, and the first battery pack is connected with the second end of the load switch through the voltage reduction circuit;
the controller is used for sending a first control signal to the load switch when the electric quantity difference between the acquired residual electric quantity of the second battery pack and the acquired residual electric quantity of the first battery pack is larger than a preset electric quantity interval in the discharging process of the first battery pack and the second battery pack;
the load switch is used for being closed under the action of the first control signal, so that the second battery pack is independently discharged to the system circuit;
The controller is further configured to send a second control signal to the step-down circuit when the electric quantity difference is located in the preset electric quantity interval;
the voltage reducing circuit is used for being in a working state under the action of the second control signal, reducing the voltage of the first battery pack and the voltage of the second battery pack after being connected in series, and discharging the voltage to the system circuit.
2. The equalization control circuit of a battery pack as set forth in claim 1, wherein,
The controller is further configured to send a third control signal to the load switch when the electric quantity difference is located in the preset electric quantity interval;
The load switch is also used for being changed from closed to open under the action of the third control signal.
3. The equalization control circuit of a battery pack of claim 1, wherein the equalization control circuit of a battery pack further comprises: a first fuel gauge and a second fuel gauge;
The two measuring ends of the first fuel gauge are respectively connected with the positive electrode and the negative electrode of the first battery pack, and the output end of the first fuel gauge is connected with the first input end of the controller; the two measuring ends of the second fuel gauge are respectively connected with the positive electrode and the negative electrode of the second battery pack, and the output end of the second fuel gauge is connected with the second input end of the controller;
The first electricity meter is used for outputting the discharge current of the first battery pack to the controller;
the second electricity meter is used for outputting the discharging current of the second battery pack to the controller;
The controller is further configured to determine a remaining power of the first battery pack according to the battery capacity of the first battery pack, the discharge current of the first battery pack, and the first discharge time, and determine a remaining power of the second battery pack according to the battery capacity of the second battery pack, the discharge current of the second battery pack, and the second discharge time.
4. A battery pack equalization control circuit as recited in any of claims 1-3, wherein said battery pack equalization control circuit further comprises: an equalizing circuit;
The positive electrode of the first battery pack is connected with the first end of the equalization circuit through the voltage reduction circuit, and the second end of the equalization circuit is connected with the positive electrode of the second battery pack;
The controller is further configured to send a fourth control signal to the equalization circuit and send a fifth control signal to the step-down circuit when the electric quantity difference is greater than the preset electric quantity interval;
The equalization circuit is used for being in a constant-resistance working state under the action of the fourth control signal so as to equalize the discharge currents of the first battery pack and the second battery pack, and the second battery pack discharges to the system circuit through the equalization circuit;
the voltage reducing circuit is further used for being in a working state under the action of the fifth control signal, reducing the voltage of the first battery pack and the voltage of the second battery pack after being connected in series, and discharging the voltage to the system circuit.
5. A battery pack equalization control circuit as recited in any of claims 1-3, wherein said battery pack equalization control circuit further comprises: an equalizing circuit and a current sampling circuit;
the positive electrode of the first battery pack is connected with the first end of the current sampling circuit through the voltage reduction circuit, the second end of the current sampling circuit is connected with the first end of the equalizing circuit, and the third end of the current sampling circuit is connected with the third input end of the controller; the second end of the equalization circuit is connected with the positive electrode of the second battery pack;
The current sampling circuit is used for monitoring the discharge balance current of the balance circuit in real time in the discharge process of the first battery pack and the second battery pack and sending the discharge balance current to the controller;
The controller is further configured to send a fifth control signal to the step-down circuit when the electric quantity difference is greater than the preset electric quantity interval; and when the electric quantity difference is larger than the preset electric quantity interval and a discharge voltage difference between the voltage of the first battery pack output by the first electric quantity meter and the voltage of the second battery pack output by the second electric quantity meter is equal to a first preset threshold value, determining a sixth control signal according to the discharge balance current, the current of the first battery pack and the current of the second battery pack, and sending the sixth control signal to the balance circuit;
The equalization circuit is used for adjusting the self resistance in real time under the action of the sixth control signal to realize a constant-voltage working state so as to equalize the discharge currents of the first battery pack and the second battery pack, and the second battery pack discharges to the system circuit through the equalization circuit;
the voltage reducing circuit is further used for being in a working state under the action of the fifth control signal, reducing the voltage of the first battery pack and the voltage of the second battery pack after being connected in series, and discharging the voltage to the system circuit.
6. The equalization control circuit of a battery pack as recited in claim 5, wherein,
The controller is further configured to send a seventh control signal to the equalization circuit when the discharge voltage of the first battery pack is equal to a first threshold voltage; wherein the first threshold voltage is greater than a vent voltage of the first battery pack;
The equalization circuit is further configured to adjust the self resistance again under the action of the seventh control signal, and increase the discharge equalization current, so that the first battery pack and the second battery pack reach the emptying voltage at the same time.
7. A battery pack equalization control circuit as recited in any of claims 1-3, wherein said battery pack equalization control circuit further comprises: a charging circuit and an equalizing circuit;
the charging circuit is connected with the positive electrode of the first battery pack; the positive electrode of the first battery pack is connected with the first end of the equalization circuit through the voltage reduction circuit, and the second end of the equalization circuit is connected with the positive electrode of the second battery pack;
the charging circuit is used for charging the first battery pack and the second battery pack;
The controller is further configured to send an eighth control signal to the equalization circuit and send a ninth control signal to the step-down circuit when the charging circuit starts charging the first battery pack and the second battery pack;
The equalization circuit is used for being in a constant-resistance working state under the action of the eighth control signal so as to equalize the charging currents of the first battery pack and the second battery pack;
The step-down circuit is further configured to be in a working state under the action of the ninth control signal, step down the charging voltage of the charging circuit, and then charge the second battery pack.
8. A battery pack equalization control circuit as recited in any of claims 1-3, wherein said battery pack equalization control circuit further comprises: a charging circuit, a current sampling circuit and an equalizing circuit;
the charging circuit is connected with the positive electrode of the first battery pack; the positive electrode of the first battery pack is connected with the first end of the current sampling circuit through the voltage reduction circuit, the second end of the current sampling circuit is connected with the first end of the equalizing circuit, and the third end of the current sampling circuit is connected with the third input end of the controller; the second end of the equalization circuit is connected with the positive electrode of the second battery pack;
the current sampling circuit is further configured to monitor a charge equalization current of the equalization circuit in real time and send the charge equalization current to the controller in a process that the charge circuit charges the first battery pack and the second battery pack;
the controller is further configured to send an eighth control signal to the step-down circuit when the charging circuit starts charging the first battery pack and the second battery pack; and determining a tenth control signal according to the charge equalization current, the current of the first battery pack, and the current of the second battery pack when a charge voltage difference between the voltage of the first battery pack output by the first fuel gauge and the voltage of the second battery pack output by the second fuel gauge is equal to a second preset threshold, and transmitting the tenth control signal to the equalization circuit;
The equalization circuit is further configured to adjust self-resistance in real time under the action of the tenth control signal, so as to achieve a constant-voltage working state, so as to equalize charging currents of the first battery pack and the second battery pack, so that the charging circuit charges the first battery pack and the second battery pack;
the step-down circuit is further configured to be in a working state under the action of the eighth control signal, step down the charging voltage of the charging circuit, and then charge the second battery pack.
9. The equalization control circuit of a battery pack as recited in claim 8, wherein,
The controller is further configured to send an eleventh control signal to the equalization circuit when the charging voltage of the first battery pack reaches a second threshold voltage; wherein the second threshold voltage is less than the full charge voltage of the first battery pack;
The equalization circuit is further configured to adjust the self-resistance again under the action of the eleventh control signal, and increase the charge equalization current, so that the first battery pack and the second battery pack reach the full charge voltage at the same time.
10. A terminal device, characterized in that the terminal device comprises: a first battery pack and a second battery pack connected in series, and an equalization control circuit of the battery packs according to any one of claims 1 to 9; the battery capacity of the first battery pack is smaller than that of the second battery pack, the full charge voltage and the empty voltage of the first battery pack are the same as those of the second battery pack, the first battery pack belongs to a first battery cell system, and the second battery pack belongs to a second battery cell system;
A first end of the load switch in the balance control circuit of the battery pack is connected between the first battery pack and the second battery pack, and a positive electrode of the first battery pack is connected with a second end of the load switch through a voltage reduction circuit in the balance control circuit of the battery pack;
The balance control circuit of the battery pack is used for closing the load switch under the action of a first control signal when the electric quantity difference between the residual electric quantity of the second battery pack and the residual electric quantity of the first battery pack is larger than a preset electric quantity interval in the discharging process of the first battery pack and the second battery pack, and the second battery pack is communicated with the system circuit;
The second battery pack is used for discharging to the system circuit independently;
The equalization control circuit of the battery pack is further used for enabling the voltage reduction circuit to be in a working state under the action of the second control signal when the electric quantity difference is located in the preset electric quantity interval;
The first battery pack and the second battery pack are used for discharging to the system circuit after being subjected to voltage reduction through the voltage reduction circuit.
11. The terminal device of claim 10, wherein the terminal device,
The first cell system is a graphite negative electrode system, and the second cell system is a silicon negative electrode system.
12. A method of equalization control of a battery pack, the method comprising:
In the discharging process of the first battery pack and the second battery pack, when the electric quantity difference between the obtained residual electric quantity of the second battery pack and the obtained residual electric quantity of the first battery pack is larger than a preset electric quantity interval, closing a load switch under the action of a first control signal, so that the second battery pack is independently discharged to a system circuit; wherein the second battery pack is connected in series with the first battery pack, and the battery capacity of the first battery pack is smaller than the battery capacity of the second battery pack;
when the electric quantity difference is located in the preset electric quantity interval, the step-down circuit is in a working state under the action of a second control signal;
and the voltage of the first battery pack and the voltage of the second battery pack which are connected in series are reduced by the voltage reducing circuit, and then the voltage is discharged to the system circuit.
13. The method according to claim 12, wherein the method further comprises:
when the electric quantity difference is located in the preset electric quantity interval, the load switch is changed from closed to open under the action of a third control signal.
14. The method according to claim 12, wherein the method further comprises:
determining the residual electric quantity of the first battery pack according to the battery capacity of the first battery pack, the discharge current of the first battery pack and the first discharge time;
And determining the residual electric quantity of the second battery pack according to the battery capacity of the second battery pack, the discharge current of the second battery pack and the second discharge time.
15. The method according to any one of claims 12-14, further comprising:
When the electric quantity difference is larger than the preset electric quantity interval, the equalization circuit is in a constant-resistance working state under the action of a fourth control signal so as to equalize the discharge currents of the first battery pack and the second battery pack, and the second battery pack is discharged to the system circuit through the equalization circuit;
And under the action of a fifth control signal, the voltage reducing circuit is in a working state, and the voltage of the first battery pack and the voltage of the second battery pack which are connected in series are reduced and then discharged to the system circuit.
16. The method according to any one of claims 12-14, further comprising:
In the discharging process of the first battery pack and the second battery pack, the discharging balance current of the balance circuit is monitored in real time;
when the electric quantity difference is larger than the preset electric quantity interval and the discharge voltage difference between the voltage of the first battery pack and the voltage of the second battery pack is equal to a first preset threshold value, determining a sixth control signal according to the discharge balance current, the current of the first battery pack and the current of the second battery pack;
Under the action of the sixth control signal, the corresponding resistor of the equalization circuit is adjusted in real time, so that the equalization circuit is in a constant-voltage working state, and the discharging currents of the first battery pack and the second battery pack are equalized, and the second battery pack discharges to the system circuit through the equalization circuit;
when the electric quantity difference is larger than the preset electric quantity interval, the voltage reduction circuit is in a working state under the action of a fifth control signal, and the voltage of the first battery pack and the voltage of the second battery pack which are connected in series are reduced and then discharged to the system circuit.
17. The method according to any one of claims 12-14, further comprising:
When the charging circuit starts charging the first battery pack and the second battery pack, the equalization circuit is in a constant-resistance working state under the action of an eighth control signal so as to equalize the charging currents of the first battery pack and the second battery pack;
And under the action of a ninth control signal, the voltage reducing circuit is in an operating state, and the charging voltage of the charging circuit is reduced and then the second battery pack is charged.
18. The method according to any one of claims 12-14, further comprising:
In the process of charging the first battery pack and the second battery pack by the charging circuit, charging balance current of the balance circuit is monitored in real time;
When the charging voltage difference between the voltage of the first battery pack and the voltage of the second battery pack is equal to a second preset threshold value, determining a tenth control signal according to the charging equalization current, the current of the first battery pack and the current of the second battery pack;
under the action of the tenth control signal, the corresponding resistor of the equalization circuit is adjusted in real time, so that the equalization circuit is in a constant-voltage working state to equalize the charging currents of the first battery pack and the second battery pack;
And under the action of a ninth control signal, the voltage reducing circuit is in an operating state, and the charging voltage of the charging circuit is reduced and then the second battery pack is charged.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211583178.4A CN118174393A (en) | 2022-12-09 | 2022-12-09 | Equalization control circuit and method of battery pack and terminal equipment |
| PCT/CN2023/122296 WO2024119989A1 (en) | 2022-12-09 | 2023-09-27 | Equalization control circuit and method for battery pack, and terminal device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211583178.4A CN118174393A (en) | 2022-12-09 | 2022-12-09 | Equalization control circuit and method of battery pack and terminal equipment |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN118174393A true CN118174393A (en) | 2024-06-11 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211583178.4A Pending CN118174393A (en) | 2022-12-09 | 2022-12-09 | Equalization control circuit and method of battery pack and terminal equipment |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN118174393A (en) |
| WO (1) | WO2024119989A1 (en) |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPWO2012157747A1 (en) * | 2011-05-18 | 2014-07-31 | 古河電気工業株式会社 | Control method and control apparatus for battery pack |
| CN104362695B (en) * | 2014-11-10 | 2016-08-24 | 中南民族大学 | A kind of series-connected batteries equalizing system and control method thereof |
| CN110224455A (en) * | 2019-04-08 | 2019-09-10 | 东莞新能德科技有限公司 | Series-parallel switching device and the battery pack comprising series-parallel switching device |
| CN110429673B (en) * | 2019-07-18 | 2021-10-01 | 华为技术有限公司 | Power supply system, method and chip of terminal equipment and terminal equipment |
| CN113708466B (en) * | 2021-10-25 | 2022-03-11 | 广东希荻微电子股份有限公司 | Battery charging and discharging circuit and terminal equipment |
-
2022
- 2022-12-09 CN CN202211583178.4A patent/CN118174393A/en active Pending
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- 2023-09-27 WO PCT/CN2023/122296 patent/WO2024119989A1/en unknown
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| Publication number | Publication date |
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| WO2024119989A1 (en) | 2024-06-13 |
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