Charging circuit, charging method and electronic equipment

Abstract

A charging circuit, a charging method and an electronic device relate to the technical field of power supplies. The charging circuit includes a fast charging circuit and a first switched capacitor converter. The first end of the quick charging circuit is connected with the charger; when the quick charging circuit works, the second end of the quick charging circuit is connected with the first pole of the first battery and the first end of the first switched capacitor converter, the second pole of the first battery is connected with the first pole of the second battery and the second end of the first switched capacitor converter, and the second pole of the second battery is grounded. The quick charging circuit works in a first time period, the ratio of the voltage of the first end of the first switched capacitor converter to the voltage of the second end of the first switched capacitor converter is 2: 1, and the voltage of the first battery is larger than or equal to the voltage of the second battery at the beginning moment of the first time period. The quick charging circuit works in a second time period, the ratio of the voltage of the first end to the voltage of the second end of the first switched capacitor converter is 1: 2, and the voltage of the first battery is smaller than the voltage of the second battery at the starting moment of the second time period.

Description

Technical Field

[0001] The present application relates to the field of power supply technology, and in particular to a charging circuit, a charging method and an electronic device. Background Art

[0002] At present, electronic devices, such as foldable screen mobile phones, are powered by dual batteries. Affected by the internal device layout of foldable screen mobile phones, the capacity of the dual batteries is generally different, that is, foldable screen mobile phones generally include a large-capacity battery and a small-capacity battery.

[0003] Related art proposes a method of charging two batteries in series. During fast charging, the two batteries are connected in series, and a buck circuit is connected in parallel at both ends of the small-capacity battery. This makes the charging current of the large-capacity battery equal to the sum of the charging current of the small-capacity battery and the current of the power conversion circuit. That is, the charging current of the large-capacity battery is increased, thereby achieving charging compensation for the large-capacity battery so that the two can be fully charged at the same time.

[0004] However, the above solution can only compensate for the situation where the voltage of the large-capacity battery is lower than that of the small-capacity battery during fast charging, and cannot compensate for the situation where the voltage of the large-capacity battery is higher than that of the small-capacity battery. Therefore, when the voltage of the large-capacity battery is higher than that of the small-capacity battery, the two batteries cannot be fully charged at the same time, reducing the charging speed and charging efficiency of fast charging. Summary of the Invention

[0005] In order to solve the above problems, the present application provides a charging circuit, a charging method and an electronic device, which can achieve balanced charging of batteries of different capacities and improve the charging speed and charging efficiency.

[0006] In a first aspect, the present application provides a charging circuit for charging an electronic device comprising two batteries. The charging circuit includes a fast charging circuit and a first switched capacitor converter. The first terminal of the fast charging circuit is connected to a charger. When the fast charging circuit is in operation, the second terminal of the fast charging circuit is connected to the first terminal of the first battery and the first terminal of the first switched capacitor converter, the second terminal of the first battery is connected to the first terminal of the second battery and the second terminal of the first switched capacitor converter, and the second terminal of the second battery is grounded. During a first time period, the fast charging circuit is in operation, and the ratio of the voltage at the first terminal of the first switched capacitor converter to the voltage at the second terminal of the first switched capacitor converter is 2:1. At the start of the first time period, the voltage of the first battery is greater than or equal to the voltage of the second battery. During a second time period, the fast charging circuit is in operation, and the ratio of the voltage at the first terminal of the first switched capacitor converter to the voltage at the second terminal of the first switched capacitor converter is 1:2. At the start of the second time period, the voltage of the first battery is less than the voltage of the second battery.

[0007] Using the solution of the present application, when the first battery and the second battery are rapidly charged in a first time period, because the voltage of the first battery is greater than or equal to the voltage of the second battery, the ratio of the voltage input to the first terminal of the first switched capacitor converter to the voltage output at the second terminal is 2:1. Since the input voltage to the first terminal of the first switched capacitor converter is the sum of the voltages of the first battery and the second battery, and the output voltage of the second terminal of the first switched capacitor converter is the voltage of the second battery, the first switched capacitor converter can automatically achieve voltage balancing between the first battery and the second battery, so that the voltage of the first battery is equal to the voltage of the second battery. When the first battery and the second battery are rapidly charged in a second time period, because the voltage of the first battery is less than the voltage of the second battery, the ratio of the voltage input to the second terminal of the first switched capacitor converter to the voltage output at the first terminal is 1:2. Since the input voltage to the second terminal of the first switched capacitor converter is the voltage of the second battery, and the output voltage of the first terminal of the first switched capacitor converter is the sum of the voltages of the first battery and the second battery, the first switched capacitor converter can automatically achieve voltage balancing between the first battery and the second battery, so that the voltage of the first battery is equal to the voltage of the second battery. The capacity relationship between the first battery and the second battery can be that the first battery is larger, or the second battery is larger, and both can achieve voltage balance.

[0008] To sum up, the technical solution provided by the present application can compensate for the situation where the voltage of the large-capacity battery is lower than that of the small-capacity battery during the fast charging process, and compensate for the situation where the voltage of the large-capacity battery is higher than that of the small-capacity battery, thereby allowing the two batteries to be fully charged at the same time, thereby improving the charging speed and charging efficiency of fast charging.

[0009] In one possible implementation, the charging circuit further includes: a power conversion circuit, a first switch, a second switch, and a third switch. The first end of the power conversion circuit is used to connect to the charger, the second end of the power conversion circuit is used to output the system voltage of the electronic device, and the third end of the power conversion circuit is connected to the first end of the first switch. The first end of the first switch is connected to the first terminal of the second battery, the second end of the third switch, and the second end of the first switched-capacitor converter. The first end of the second switch is connected to the second terminal of the first battery and the first end of the third switch, and the second end of the second switch is grounded. During the first and second time periods, the first and second switches are off, and the third switch is closed.

[0010] In one possible implementation, the charging circuit further includes a controller. The controller is configured to control the first and second switches to be turned off, the third switch to be closed, and the first switched capacitor converter to achieve a 2:1 ratio between the voltage at the first terminal of the first switched capacitor converter and the voltage at the second terminal of the first switched capacitor converter during a first time period. At this point, the charging current of the second battery is equal to the sum of the charging current of the first battery and the current of the branch in which the switched capacitor converter is located, thereby increasing the charging current of the second battery and improving the charging speed of the second battery. Furthermore, because the first switched capacitor converter operates in a 2:1 step-down state, voltage balancing between the first and second batteries can be achieved.

[0011] During the second time period, the controller controls the first and second switches to be off, controls the third switch to be closed, and controls the first switched capacitor converter to achieve a voltage ratio of 1:2 between the first terminal of the first switched capacitor converter and the second terminal of the first switched capacitor converter. At this time, the current output from the first terminal of the first switched capacitor converter and the current provided by the fast charging circuit are combined to charge the first battery. This increases the charging current for the first battery, speeding up the charging of the first battery. Furthermore, the first switched capacitor converter draws power from the second battery, thereby achieving balanced charging.

[0012] In one possible implementation, the power conversion circuit includes a Buck circuit and a bypass circuit. The first end of the Buck circuit is connected to the first end of the power conversion circuit, the second end of the Buck circuit is used to output a system voltage, and the Buck circuit is used to step down the voltage input to the first end. The first end of the bypass circuit is connected to the second end of the Buck circuit, and the second end of the bypass circuit is connected to the third end of the power conversion circuit. When the bypass voltage is turned on, the second and third ends of the power conversion circuit are connected.

[0013] In one possible implementation, during a third time period, the first end of the fast charging circuit is not connected to a charger, the first and second switches are closed, the third switch is off, and the bypass circuit is turned on. During this time, the first and second batteries are connected in parallel and output the system voltage through the bypass circuit. Since the first and second batteries are discharged in parallel, the voltages of the first and second batteries are balanced during the discharge process.

[0014] In one possible implementation, the charging circuit further includes a controller configured to control the first switch and the second switch to be closed, the third switch to be closed, and the bypass circuit to be turned on during a third time period, so that the first battery and the second battery are discharged in parallel during the third time period.

[0015] In one possible implementation, during the fourth time period, the first end of the power conversion circuit is connected to the charger, the first switch and the second switch are turned on, the third switch is turned off, and the bypass circuit is turned on, so that the charging circuit charges the first battery and the second battery in parallel.

[0016] At this time, the fast charging circuit is not operating, and the first and second batteries are not in the fast charging process. Instead, the first and second batteries are being slowly charged. The power conversion circuit steps down the voltage provided by the charger and outputs it to the second terminal of the power conversion circuit. Because the bypass circuit is conductive, the second terminal of the power conversion circuit is now connected to the third terminal of the power conversion circuit.

[0017] In one possible implementation, the charging circuit further includes a controller configured to control the first switch and the second switch to be turned on, the third switch to be turned off, the Buck circuit to operate, and the bypass circuit to be turned on during a fourth time period.

[0018] In one possible implementation, during the fifth time period, the fast charging circuit operates, the first switch and the second switch are disconnected, the third switch is turned on, the ratio of the voltage at the first end of the first switch capacitor converter to the voltage at the second end of the first switch capacitor converter is 2:1, and the bypass circuit is turned on.

[0019] During the fast charging process, there is a load in the system, causing the first battery and the second battery to be in a state of simultaneous charging and discharging. The second battery outputs current to the third terminal of the power conversion circuit; and the first battery and the second battery discharge simultaneously, and the input voltage of the first terminal of the first switching capacitor converter is the sum of the voltage of the first battery and the voltage of the second battery. The second terminal of the first switching capacitor converter outputs a voltage to the third terminal of the power conversion circuit. The output voltage of the second terminal of the first switching capacitor converter is the voltage of the second battery. Since the ratio of the first terminal voltage to the second terminal voltage of the first switching capacitor converter is 2:1, the circuit can ensure that the voltage of the first battery and the second battery is automatically balanced during the simultaneous charging and discharging process, so that the voltage of the first battery is equal to the voltage of the second battery.

[0020] In a possible implementation, the charging circuit further includes a controller configured to control the first switch and the second switch to be turned off, the third switch to be turned on, and the bypass circuit to be turned on during a fifth time period.

[0021] In one possible implementation, the first switched-capacitor converter includes: a fourth switch, a fifth switch, a sixth switch, a seventh switch, a first capacitor, and a second capacitor. A first end of the first switched-capacitor converter is connected to a first end of the fourth switch, a second end of the fourth switch is connected to a first end of the first capacitor and a first end of the fifth switch, a second end of the fifth switch is connected to a first end of the sixth switch and a first end of the second capacitor, a second end of the sixth switch is connected to a second end of the first capacitor and a first end of the seventh switch, a second end of the seventh switch is grounded and connected to a second end of the second capacitor, and a first end of the second capacitor is connected to a second end of the first switched-capacitor converter.

[0022] In one possible implementation, the charging circuit further includes a controller. The controller is configured to control the fourth and sixth switches to be closed and the fifth and seventh switches to be closed during a sixth time period, and then control the fourth and sixth switches to be closed and the fifth and seventh switches to be closed during a seventh time period, so that the ratio of the voltage at the first end of the first switched capacitor converter to the voltage at the second end of the first switched capacitor converter is 2:1. The controller is further configured to control the fourth and sixth switches to be closed and the fifth and seventh switches to be closed during an eighth time period, and then control the fourth and sixth switches to be closed and the fifth and seventh switches to be closed during a ninth time period, so that the ratio of the voltage at the first end of the first switched capacitor converter to the voltage at the second end of the first switched capacitor converter is 1:2.

[0023] In one possible implementation, the bypass circuit includes an eighth switch. A first end of the eighth switch is connected to a first end of the bypass circuit, and a second end of the eighth switch is connected to a second end of the bypass circuit. When the eighth switch is closed, the bypass circuit is turned on, and when the eighth switch is closed, the bypass circuit is turned off.

[0024] In a possible implementation, the fast charging circuit includes a Buck-Boost circuit or a second switched capacitor converter.

[0025] In a second aspect, the present application further provides a charging method, which can be applied to the charging circuit provided in the first aspect and any one of the implementations of the first aspect, the method comprising:

[0026] When the fast charging circuit is operating and the voltage of the first battery is greater than or equal to the voltage of the second battery at the start of the first time period, the ratio of the voltage at the first terminal of the first switched capacitor converter to the voltage at the second terminal of the first switched capacitor converter is controlled to be 2:1 during the first time period;

[0027] When the fast charging circuit is operating and the voltage of the first battery is less than the voltage of the second battery at the start of the second time period, during the second time period, the ratio of the voltage at the first end of the first switched capacitor converter to the voltage at the second end of the first switched capacitor converter is controlled to be 1:2.

[0028] In a possible implementation, the method further includes:

[0029] When the first end of the fast charging circuit is not connected to the charger within the third time period, the first switch and the second switch are controlled to be closed, the third switch is controlled to be closed, and the bypass circuit is controlled to be turned on.

[0030] In a possible implementation, the method further includes:

[0031] In the fourth time period, when the first end of the power conversion circuit is connected to the charger, the first switch and the second switch are controlled to be turned on, the third switch is controlled to be turned off, the Buck circuit is controlled to operate, and the bypass circuit is controlled to be turned on.

[0032] In a possible implementation, the method further includes:

[0033] In the fifth time period, when the fast charging circuit is working, the first switch and the second switch are controlled to be disconnected, the third switch is controlled to be turned on, and the ratio of the voltage at the first end of the first switch capacitor converter to the voltage at the second end of the first switch capacitor converter is controlled to be 2:1, and the bypass circuit is controlled to be turned on.

[0034] In a possible implementation, the method further includes:

[0035] During a sixth time period, the fourth switch and the sixth switch are controlled to be closed, and the fifth switch and the seventh switch are controlled to be closed. Then, during a seventh time period, the fourth switch and the sixth switch are controlled to be closed, and the fifth switch and the seventh switch are controlled to be closed, so that the ratio of the voltage at the first end of the first switched capacitor converter to the voltage at the second end of the first switched capacitor converter is 2:1.

[0036] And, in the eighth time period, the fourth switch and the sixth switch are controlled to be turned off, and the fifth switch and the seventh switch are controlled to be closed, and then in the ninth time period, the fourth switch and the sixth switch are controlled to be closed, and the fifth switch and the seventh switch are controlled to be turned off, so that the ratio of the voltage at the first end of the first switch capacitor converter to the voltage at the second end of the first switch capacitor converter is 1:2.

[0037] In a third aspect, the present application further provides an electronic device comprising a first battery, a second battery, and a charging circuit provided in the first aspect and any one of the implementations of the first aspect. The charging circuit is configured to charge the first battery and the second battery.

[0038] In a possible implementation, the capacity of the first battery is smaller than the capacity of the second battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1A A schematic diagram of an electronic device provided in an embodiment of the present application;

[0040] Figure 1B A schematic diagram of a charging circuit for an electronic device;

[0041] Figure 2A A schematic diagram of a charging circuit provided in an embodiment of the present application;

[0042] Figure 2B Schematic diagram 1 of the working principle of the charging circuit provided in an embodiment of the present application;

[0043] Figure 2C Schematic diagram 2 of the working principle of the charging circuit provided in an embodiment of the present application;

[0044] Figure 3A A schematic diagram of another charging circuit provided in an embodiment of the present application;

[0045] Figure 3B A schematic diagram of another charging circuit provided in an embodiment of the present application;

[0046] Figure 4 A schematic diagram of a switched capacitor converter provided in an embodiment of the present application;

[0047] Figure 5 Schematic diagram 1 of the working principle of the switched capacitor converter provided in an embodiment of the present application;

[0048] Figure 6 Schematic diagram 2 of the working principle of the switched capacitor converter provided in an embodiment of the present application;

[0049] Figure 7 Schematic diagram 3 of the working principle of the charging circuit provided in an embodiment of the present application;

[0050] Figure 8 The working principle of the charging circuit provided in the embodiment of the present application is shown as follows: Figure 4 ;

[0051] Figure 9 The working principle of the charging circuit provided in the embodiment of the present application is shown as follows: Figure 5 ;

[0052] Figure 10 The working principle of the charging circuit provided in the embodiment of the present application is shown as follows: Figure 6 ;

[0053] Figure 11The working principle of the charging circuit provided in the embodiment of the present application is shown as follows: Figure 7 ;

[0054] Figure 12 A flowchart of a charging method provided in an embodiment of the present application;

[0055] Figure 13 A schematic diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0056] In order to enable people skilled in the art to more clearly understand the solution of the present application, the application scenario of the technical solution of the present application is first described below.

[0057] The method provided in the embodiments of the present application can be applied to electronic devices including multiple batteries. Such electronic devices may include mobile phones, tablet computers, laptop computers, personal computers (PCs), ultra-mobile personal computers (UMPCs), handheld computers, netbooks, personal digital assistants (PDAs), wearable devices (e.g., smart watches, smart bracelets, etc.), in-vehicle devices, virtual reality devices, etc., and the embodiments of the present application do not impose any restrictions on this.

[0058] The following description will be made using a foldable screen mobile phone as an example of an electronic device.

[0059] See also Figure 1A , which is a schematic diagram of an electronic device provided in an embodiment of the present application.

[0060] The electronic device 100 includes a first battery 40 and a second battery 50 .

[0061] A battery's capacity indicates the total amount of charge it can discharge under certain conditions (e.g., discharge rate, temperature, and cut-off voltage). For example, the length of time a battery can discharge at a specified current is its capacity; this is usually expressed in ampere-hours (A·h) or milliampere-hours (mA·h). For example, a battery with a capacity of 5000mA·h can operate for approximately 5 hours when discharged at a current of 1A.

[0062] The capacity of the first battery 40 is smaller than that of the second battery 50. For example, the capacity of the first battery 40 may be 3000 milliampere hours (mA·h), and the capacity of the second battery 50 may be 4000 mA·h. It should be noted that the embodiment of the present application is described by taking the electronic device 10 including the first battery 40 and the second battery 50 as an example. It is understandable that the electronic device 10 may also include a larger number of batteries. When including a larger number of batteries, the implementation principle is similar to that when including the first battery 40 and the second battery 50, and examples are not given one by one in the embodiment of the present application.

[0063] See also Figure 1B , which is a schematic diagram of a charging circuit of an electronic device.

[0064] When an electronic device includes two batteries, series charging is generally used because series charging is more efficient. Figure 1B In the illustrated embodiment, a step-down (Buck) circuit 10 is connected in parallel across a small-capacity first battery 40, ensuring that the charging current of a large-capacity second battery 50 is equal to the sum of the charging current of the first battery 40 and the current of the power conversion circuit 10. This increases the charging current of the second battery 50, thereby providing charging compensation for the large-capacity battery. By controlling the operating state of the power conversion circuit 10, the ratio of the charging current of the first battery 40 to the charging current of the second battery 50 is equal to the ratio of the capacities of the first battery 40 and the second battery 50, allowing both batteries to be fully charged simultaneously.

[0065] However, in the related solution, the power conversion circuit 10 operates continuously during the charging process. However, the charging efficiency of the power conversion circuit 10 is low, resulting in severe heat generation, which limits the charging speed of the electronic device. In particular, when the electronic device is performing high-power rapid charging, the power conversion circuit 10 significantly reduces the charging speed. Because the power conversion circuit 10 operates in a step-down state, it can only compensate for situations where the voltage of the large-capacity battery is lower than that of the small-capacity battery, but cannot compensate for situations where the voltage of the large-capacity battery is higher than that of the small-capacity battery, which also affects the charging speed.

[0066] In addition, in actual applications, the electronic device may be in a heavy-load state during the charging process. At this time, the charging current may not be able to meet the load requirements of the electronic device system, causing the second battery 50 to be in a discharging state. The voltage of the large-capacity second battery 50 will decrease with discharge, and the voltage of the small-capacity first battery 40 will remain unchanged. This causes the voltage difference between the large and small batteries to gradually increase, resulting in the two batteries being unable to be fully charged at the same time. It may also cause a large mutual charging current to appear if the two batteries are connected in parallel during the discharge process after charging is completed, affecting battery safety.

[0067] In order to solve the above technical problems, the present application provides a charging circuit, a charging method and an electronic device, wherein the first end of the fast charging circuit of the charging circuit is used to connect to a charger. When the fast charging circuit is working, the second end of the fast charging circuit is connected to the first pole of the first battery and the first end of the first switched capacitor converter, the second end of the first battery is connected to the first pole of the second battery and the second end of the first switched capacitor converter, and the second pole of the second battery is grounded. When the fast charging circuit is working, when the voltage of the first battery is greater than or equal to the voltage of the second battery, the ratio of the voltage input to the first end of the first switched capacitor converter to the voltage output from the second end is 2:1; when the voltage of the first battery is less than the voltage of the second battery, the ratio of the voltage input to the second end of the first switched capacitor converter to the voltage output from the first end is 1:2. Therefore, this solution can achieve balanced charging of batteries of different capacities under different working conditions, thereby improving charging speed and charging efficiency.

[0068] The terms "coupling" and "connection" involved in the embodiments of this application should be understood in a broad sense. For example, they may refer to a physical direct connection, or an indirect connection achieved through electronic devices, such as a connection achieved through resistors, inductors, capacitors or other electronic devices.

[0069] References to "one embodiment" or "some embodiments" etc. described in this specification mean that the specific features, structures or characteristics described in conjunction with the embodiment are included in one or more embodiments of the present application. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. appearing in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in another way. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in another way. The term "connected" includes direct and indirect connections, unless otherwise stated. "First" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated.

[0070] The present application provides a charging circuit, which is described in detail below with reference to the accompanying drawings.

[0071] See also Figure 2A , which is a schematic diagram of a charging circuit provided in an embodiment of the present application.

[0072] The charging circuit includes a fast charging circuit 20 and a switched capacitor converter 30 .

[0073] A first terminal of the fast charging circuit 20 is used to connect to the charger 60 .

[0074] A first terminal of the switched capacitor converter 30 is connected to a second terminal of the fast charging circuit 20 , a second terminal of the switched capacitor converter 30 is connected to a first terminal of the second battery 50 , and a second terminal of the second battery 50 is grounded.

[0075] When the first terminal of the fast charging circuit 20 is connected to the charger 60 and the fast charging circuit is in operation, the first battery 40 and the second battery 50 are fast charged. At this time, the second terminal of the fast charging circuit 20 is connected to the first terminal of the first battery 40 and the first terminal of the switched capacitor converter 30, and the second terminal of the first battery 40 is connected to the first terminal of the second battery 50 and the second terminal of the switched capacitor converter 30.

[0076] The switched capacitor converter 30 can operate in a 2:1 buck mode and a 1:2 boost mode. When the switched capacitor converter 30 operates in the 2:1 buck mode, the ratio of the voltage at the first terminal of the switched capacitor converter 30 to the voltage at the second terminal of the switched capacitor converter 30 is 2:1. When the switched capacitor converter 30 operates in the 1:2 boost mode, the ratio of the voltage at the second terminal of the switched capacitor converter 30 to the voltage at the first terminal of the switched capacitor converter 30 is 1:2.

[0077] The working principle of the charging circuit is described in detail below.

[0078] See also Figure 2B , this figure is a schematic diagram of the working principle of the charging circuit provided in an embodiment of the present application.

[0079] At the beginning of the first time period, the voltage of the first battery is greater than or equal to the voltage of the second battery. During the first time period, the fast charging circuit operates, and the ratio of the voltage at the first end of the switching capacitor converter 30 to the voltage at the second end of the switching capacitor converter 30 is 2:1.

[0080] At this time, the fast charging circuit 20 Figure 2B The circuit a in the first battery 40 is charged by Figure 2B Line a and line b in the circuit charge the second battery 40. The charging current of the second battery 40 is the sum of the charging current of the first battery 40 and the current of the branch where the switched capacitor converter 30 is located, which increases the charging current of the second battery 50 and improves the charging speed of the second battery.

[0081] The input voltage of the first end of the switching capacitor converter 30 is the sum of the voltage of the first battery 40 and the voltage of the second battery 50, and the output voltage of the second end of the switching capacitor converter 30 is the voltage of the second battery 50. Therefore, the switching capacitor converter 30 can automatically achieve voltage balancing between the first battery 40 and the second battery 50, so that the voltage of the first battery 40 is equal to the voltage of the second battery 50.

[0082] See also Figure 2C, this figure is a schematic diagram of the working principle of the charging circuit provided in an embodiment of the present application.

[0083] At the beginning of the second time period, the voltage of the first battery 40 is less than the voltage of the second battery 50. During the second time period, the fast charging circuit 20 operates, and the ratio of the voltage at the first end of the switching capacitor converter 30 to the voltage at the second end of the switching capacitor converter 30 is 1:2.

[0084] The current output by the fast charging circuit 20 can charge the first battery 40 and the second battery 50. The charging circuit is as follows: Figure 2C As shown in line a in FIG. The switched capacitor transformer 30 draws power from the second battery 50. The current of the branch where the switched capacitor transformer 30 is located and the current output by the fast charging circuit 20 are combined to charge the first battery 40 and the second battery 50. This part of the charging circuit is shown in FIG. Figure 2C As shown in line c in FIG. At this point, the charging current for the first battery 40 is increased, and the fast charging circuit 20 draws power from the second battery 40, thereby enabling power transfer between the two batteries. Furthermore, since the input voltage at the second terminal of the switched capacitor converter 30 is the voltage of the second battery 50, the output voltage at the first terminal of the switched capacitor converter 30 is the sum of the voltages of the first battery 40 and the second battery 50, and the ratio of the second terminal voltage to the first terminal voltage is 1:2, the switched capacitor converter 30 can automatically achieve voltage balancing between the first battery 40 and the second battery 50, so that the voltage of the first battery 40 is equal to the voltage of the second battery 50.

[0085] To summarize, when the charging circuit quickly charges the first battery and the second battery, it uses a switched capacitor converter to achieve efficient balancing of the two batteries with inconsistent capacities under different operating conditions, so that the two batteries can be fully charged at the same time, thereby improving the charging speed and efficiency. Furthermore, during the fast charging process of the electronic device, there is no need for a power conversion circuit to perform charging compensation work on the battery, thereby reducing heat generation and further improving the charging speed and efficiency.

[0086] The implementation of the charging circuit is described in detail below.

[0087] See also Figure 3A , which is a schematic diagram of another charging circuit provided in an embodiment of the present application.

[0088] The charging circuit shown in the figure includes: a power conversion circuit 10, a fast charging circuit 20, a switched capacitor converter 30, a first switch S1, a second switch S2 and a third switch S3.

[0089] The fast charging circuit 20 can be connected to an external power source via a charger 60. The external power source can be a mains or other power source. During the fast charging process, the first battery 40 and the second battery 50 are connected in series, and the fast charging circuit 20 quickly charges the two batteries.

[0090] The fast charging circuit 20 may include a fast charging integrated circuit (IC), and its specific implementation circuit may be a switched capacitor converter or a buck-boost converter.

[0091] A first terminal of the power conversion circuit 10 can be connected to the charger 60 through a first interface, a second terminal of the power conversion circuit 10 is connected to the system power VPH_PWR of the electronic device, and a third terminal of the power conversion circuit 10 is connected to the battery voltage VBATT.

[0092] A first terminal of the fast charging circuit 20 can be connected to the charger 60 via a first interface. A second terminal of the fast charging circuit 20 is connected to a first electrode of the first battery 40 .

[0093] The first interface in the embodiment of the present application may be a universal serial bus (USB) interface. The USB interface is an interface that complies with USB standard specifications, for example, it may be a USB Type-C interface.

[0094] A third terminal of the power conversion circuit 10 is connected to a first terminal of the first switch S1 , and a second terminal of the first switch S1 is connected to a first electrode of the first battery 40 and a second terminal of the fast charging circuit 20 .

[0095] A first end of the first switch S1 is connected to a first terminal of the second battery 50 , and a second terminal of the second battery 50 is grounded.

[0096] A first terminal of the first battery 40 is connected to the switched capacitor converter 30 , and a second terminal of the switched capacitor converter 30 is connected to a first terminal of the second battery 50 .

[0097] The switched capacitor converter 30 can step down a voltage input from a first end and output the voltage from a second end, or step up a voltage input from a second end and output the voltage from a first end.

[0098] The switched capacitor converter 30 can operate in a step-down 2:1 state, in which case the ratio of the voltage input to the first end of the switched capacitor converter 30 to the voltage output from the second end of the switched capacitor converter 30 is 2:1; or, the switched capacitor converter 30 can operate in a step-up 1:2 state, in which case the ratio of the voltage input to the second end of the switched capacitor converter 30 to the voltage output from the first end of the switched capacitor converter 30 is 1:2.

[0099] The second end of the first battery 40 is connected to the first end of the second switch S2 and the first end of the third switch S3. The second end of the second switch S2 is grounded. The second end of the third switch S3 is connected to the first terminal of the second battery 50.

[0100] In the embodiment of the present application, the first electrode of the first battery 40 and the first electrode of the second battery 50 are positive electrodes, and the second electrode of the first battery 40 and the second electrode of the second battery 50 are negative electrodes.

[0101] The first switch S1, the second switch S2, the third switch S3 and the switches included in the switched capacitor converter 30 are all controllable switches, which can be insulated gate bipolar transistors (IGBTs), metal oxide semiconductor field effect transistors (MOSFETs, hereinafter referred to as MOS tubes), silicon carbide metal oxide semiconductors (SiC MOSFETs), gallium nitride (GaN) transistors or integrated chips, etc.

[0102] For the sake of convenience, the switches appearing in the following embodiments of the present application are all MOS tubes as an example. In this case, the first end of the controllable switch is the drain, the second end is the source, and the control end is the gate.

[0103] See also Figure 3B , this figure is a schematic diagram of another charging circuit provided in an embodiment of the present application.

[0104] Figure 3B The implementation of the power conversion circuit is further illustrated in FIG. The power conversion circuit 10 specifically includes a Buck circuit 11 and a bypass circuit. The bypass circuit includes an eighth switch K1.

[0105] A first end of the Buck circuit 11 is connected to a first end of the power conversion circuit 10 , and a second end of the Buck circuit 11 is used to output a system voltage.

[0106] The Buck circuit 11 is used to step down the voltage input to the first end of the Buck circuit.

[0107] The first end of the bypass circuit is connected to the second end of the Buck circuit, and the second end of the bypass circuit is connected to the third end of the power conversion circuit.

[0108] When K1 is closed, the bypass circuit is disconnected, and when K1 is closed, the bypass circuit is closed.

[0109] for Figure 3B The charging circuit shown can achieve efficient balancing of two batteries with different capacities under various charging conditions by controlling the operating states of S1, S2 and S3, as described in detail below.

[0110] During a first time period, after the charger 60 is connected to a power source, the fast charging circuit 20 operates, with the first and second switches S1 and S2 turned off and the third switch S2 turned on, connecting the first and second batteries 40 and 50 in series. At this time, if the voltage of the first battery 40 is greater than or equal to the voltage of the second battery 50, a portion of the current provided by the fast charging circuit 20 flows sequentially through the first battery 40, the third switch S3, and the second battery 50, charging the first and second batteries 40 and 50 in series. The remaining portion of the current flows through the switched capacitor converter 30, which operates in a 2:1 step-down mode. This means that the ratio of the voltage input at the first terminal of the switched capacitor converter 30 to the voltage output at the second terminal is 2:1. At this time, the charging current of the second battery 50 is equal to the sum of the charging current of the first battery 40 and the current of the branch in which the switched capacitor converter 30 is located. This increases the charging current of the second battery 50, speeding up the charging of the second battery 50 and achieving balanced charging.

[0111] During the second time period, after the charger 60 is connected to a power source, the fast charging circuit 20 operates, the first switch S1 and the second switch S2 are turned off, and the third switch S2 is turned on, thereby connecting the first battery 40 and the second battery 50 in series. At this time, if the voltage of the first battery 40 is lower than that of the second battery 50, the current provided by the fast charging circuit 20 flows sequentially through the first battery 40, the third switch S3, and the second battery 50, charging the first battery 40 and the second battery 50 in series. Furthermore, the second battery 50 outputs current to the branch where the switched capacitor converter 30 is located. The switched capacitor converter 30 operates in a 1:2 boost mode, meaning that the ratio of the voltage input to the second terminal of the switched capacitor converter 30 to the voltage output from the first terminal is 1:2. The current output from the first terminal of the switched capacitor converter 30 and the current provided by the fast charging circuit 20 together charge the first battery 40, increasing the charging current of the first battery 40, improving the charging speed of the first battery 40, and achieving balanced charging.

[0112] During the first time period and the second time period, the Buck circuit 11 does not work and K1 is closed, thereby realizing power supply to the system.

[0113] During the third time period, the electronic device is not connected to the adapter 60 to charge the first and second batteries 40, 50. The first and second batteries 40, 50 are in a discharged state. The first and second switches S1, S2 are turned on during the third time period, while the third switch S3 is turned off. K1 is closed during the third time period to enable the bypass circuit. At this point, the first and second batteries 40, 50 are connected in parallel, and the bypass circuit of the power conversion circuit 10 provides system power VPH_PWR.

[0114] During the fourth time period, after the charger 60 is connected to a power source, the fast charging circuit 20 is inactive. The first and second switches S1 and S2 are turned on, while the third switch S2 is turned off, connecting the first and second batteries 40 and 50 in parallel. K1 is also turned off, activating the bypass circuit. During this time, the charger 60 generates the system power supply VPH_PWR through the power conversion circuit 10. The current from the system power supply VPH_PWR flows through the bypass path within the power conversion circuit 10 and is output from the third terminal of the power conversion circuit 10, simultaneously charging the first and second batteries 40 and 50.

[0115] During the fifth time period, after the charger 60 is connected to a power source, the fast charging circuit 20 operates, and a load is present in the electronic device system, allowing the first battery 40 and the second battery 50 to be charged and discharged simultaneously. At this time, S1 and S2 are disconnected, S3 is closed, and K1 is turned on, connecting the first battery 40 and the second battery 50 in series. Current provided by the fast charging circuit 20 flows sequentially through the first battery 40, the third switch S3, and the second battery 50, charging the first battery 40 and the second battery 50 in series. Furthermore, the second battery 50 outputs current to the third terminal of the power conversion circuit 10, and the first and second batteries 40, 50, connected in series, output a voltage to the first terminal of the switched capacitor converter 30. The switched capacitor converter 30 operates in a 2:1 step-down mode, meaning that the ratio of the voltage input to the first terminal of the switched capacitor converter 30 to the voltage output from the second terminal is 2:1. The second terminal of the switched capacitor converter 30 outputs a voltage to the third terminal of the power conversion circuit 10, which, after passing through the bypass circuit, allows the second terminal of the power conversion circuit 10 to provide the power VPH_PWR required by the system load. During this process, the first and second batteries 40, 50 charge and discharge simultaneously, rather than relying solely on the larger-capacity second battery 50. Therefore, the voltage difference between the first and second batteries 40, 50 does not increase, but remains relatively balanced. Therefore, even if the first and second batteries 40, 50 are connected in parallel during discharge after charging, significant mutual charging current will not occur, ensuring battery safety.

[0116] In summary, by utilizing the technical solution provided by the embodiments of the present application, by controlling the controllable switch under different charging and discharging conditions, efficient balancing of two batteries with inconsistent capacities under different operating conditions is achieved, so that both batteries can be fully charged at the same time, improving the charging speed and efficiency. Furthermore, during the fast charging process of the electronic device when it is not heavily loaded, the buck circuit does not need to operate in a buck state, thereby reducing heat generation and improving the charging speed and efficiency. During the fast charging process of the electronic device when it is heavily loaded, the voltage balance between the first battery 40 and the second battery 50 can also be maintained, avoiding the large mutual current caused by the parallel connection of the batteries, thereby improving safety.

[0117] The following describes the specific implementation method.

[0118] In order for those skilled in the art to more clearly understand the technical solution of the present application, the working principle of the switched capacitor converter is first described below.

[0119] See also Figure 4 , which is a schematic diagram of a switched capacitor converter provided in an embodiment of the present application.

[0120] The illustrated switched capacitor converter includes a fourth switch Q1, a fifth switch Q2, a sixth switch Q3, and a seventh switch Q4, as well as a first capacitor C1 and a second capacitor C2. A first terminal of the switched capacitor converter is connected to the drain of Q1, the source of Q1 is connected to the first terminal of C1 and the drain of Q2, the source of Q2 is connected to the drain of Q3 and the first terminal of C2, the source of Q3 is connected to the second terminal of C1 and the drain of Q4, the source of Q4 is grounded and connected to the second terminal of C2, and the first terminal of C2 is connected to the second terminal of the switched capacitor converter.

[0121] The following describes the working principle of the switched capacitor converter when the ratio of the voltage input to the first terminal to the voltage output from the second terminal is 2:1.

[0122] See also Figure 5 , this figure is a schematic diagram of the working principle of the switched capacitor converter provided in an embodiment of the present application.

[0123] In the sixth time period, when the first terminal is connected to input Vin and the second terminal outputs Vout, Figure 5 As shown in Figure 5-(a), by controlling Q1 and Q3 of the switched capacitor converter to be on and Q2 and Q4 to be off, C1 and C2 are connected in series. At this time, Vin charges capacitors C1 and C2, and the voltage across C1 and C2 is Vin / 2. At this time, the voltage on C1 is equal to Vout.

[0124] After C1 and C2 are charged, in the seventh time period, if Figure 5As shown in 5-(b) in FIG, Q1 and Q3 of the switched capacitor converter are turned off, and Q2 and Q4 are turned on. At this time, C1 and C2 are connected in parallel, C1 discharges to Vout, and the voltage of C1 is equal to Vout.

[0125] The above working principle can make Vin equal to twice Vout. When the Vin voltage is equal to the sum of the voltages of the first battery and the second battery, Vout is equal to the voltage of the second battery. Since Vin is equal to twice Vout, the above circuit can automatically achieve the balancing effect of the first battery voltage being equal to the second battery voltage.

[0126] When the switched capacitor converter operates in the above 2:1 step-down mode, the above sixth time period and seventh time period appear alternately. For example, the first time period may include multiple sixth time periods and seventh time periods arranged in sequence.

[0127] The following describes the working principle of the switched capacitor converter when the ratio of the voltage input to the second terminal to the voltage output from the first terminal is 1:2.

[0128] See also Figure 6 , this figure is a second schematic diagram of the working principle of the switched capacitor converter provided in an embodiment of the present application.

[0129] In the eighth time period, when the second terminal is connected to the input Vin and the first terminal outputs Vout, Figure 6 As shown in Figure 6-(a), by controlling Q1 and Q3 of the switched capacitor converter to turn off and Q2 and Q4 to turn on, C1 and C2 are connected in parallel. At this time, Vin charges capacitors C1 and C2, and the voltages across C1 and C2 are each Vin.

[0130] After C1 and C2 are charged, in the ninth time period, if Figure 6 As shown in Figure 6-(b), Q1 and Q3 of the switched capacitor converter are turned on, and Q2 and Q4 are turned off. At this time, C1 and C2 are connected in series and discharge to Vout, and the Vout voltage is equal to twice Vin.

[0131] According to the above working principle, Vout can be equal to twice Vin. When the Vin voltage is equal to the sum of the voltages of the first battery and the second battery, Vout is equal to the voltage of the second battery. Therefore, the above circuit can automatically achieve the balancing effect of the first battery voltage being equal to the second battery voltage.

[0132] When the switched capacitor converter operates in the above 1:2 boost mode, the above eighth time period and ninth time period appear alternately. For example, the second time period may include a plurality of eighth time periods and ninth time periods arranged in sequence.

[0133] Based on the working principle of the switched capacitor converter described in the above embodiments, the working principle of the charging circuit in various working states is described in detail below.

[0134] The following first describes the working principle of the charging circuit when the electronic device is discharging.

[0135] See also Figure 7 , this figure is a third schematic diagram of the working principle of the charging circuit provided in an embodiment of the present application.

[0136] The charging circuit includes a controller (not shown in the figure), which is used to control the working state of S1, S2, S3, the switched capacitor converter 30 and the power conversion circuit 10. The controller can be a hardware chip, or multiple hardware chips, and the embodiment of the present application does not specifically limit this. When the controller includes multiple hardware chips, taking the controller including 3 hardware chips as an example, the first hardware chip at this time can be used to control S1, S2, S3, the second hardware chip can be used to control the working state of the power conversion circuit 10, and the third hardware chip can be used to control the switched capacitor converter 30. For another example, when the controller includes 2 hardware chips as an example, the first hardware chip can be used to control S1, S2, S3, and control the switched capacitor converter 30, and the second hardware chip can be used to control the working state of the power conversion circuit 10. The above is only an example of the implementation of the controller and does not constitute a limitation on the technical solution of the present application.

[0137] The hardware chip included in the controller can be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The above-mentioned PLD can be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof.

[0138] When the electronic device is not connected to a charger to charge the first battery 40 and the second battery 50 , the first battery 40 and the second battery 50 are in a discharging state.

[0139] At this time, the controller controls S1 and S2 to be turned on, controls S3 to be turned off, and controls the bypass circuit of the power conversion circuit 10 to be turned on. The equivalent circuit diagram at this time is as follows: Figure 7 shown.

[0140] The first battery 40 and the second battery 50 are connected in parallel, and the discharge circuit of the first battery 40 is as follows Figure 7 As shown in ①, the discharge circuit of the second battery 50 is as follows Figure 7 At this time, the first battery 40 and the second battery 50 output voltage to the third terminal of the power conversion circuit 10, and the power conversion circuit 10 provides the system power VPH_PWR.

[0141] Since the first battery 40 and the second battery 50 are connected in parallel, the voltages of the first battery 40 and the second battery 50 are consistent, for example, both are 4V, and the power conversion circuit 10 can provide a 4V system power supply VPH_PWR.

[0142] The following describes the working principle of the charging circuit when the first battery and the second battery are in the charging process.

[0143] When an electronic device is connected to a charger via a wired or wireless connection, the charger charges the first and second batteries. The charging current of the batteries during charging is a dynamic process. In one implementation, the charging process for the two batteries includes three phases: a pre-charging phase, a constant current charging phase, and a constant voltage charging phase. When the initial / no-load voltage of the battery is below the pre-charging threshold (e.g., 3.0V), the pre-charging phase occurs, and the charging current for each battery is approximately 10% of the charging current during the constant current charging phase. During the constant current charging phase, the charging current is constant (at its maximum current) and the voltage gradually increases, representing the rapid charging phase. For a single battery, the constant voltage charging phase begins when the battery voltage reaches a certain value, such as 4.2V. During the constant voltage charging phase, the voltage remains constant and the charging current decreases. Charging terminates when the charging current reaches the termination current (e.g., 0.01C). Once charging is complete, the charging current drops to zero. The controller can determine the current charging current of the first and second batteries based on the specific charging stages of the first and second batteries.

[0144] The following first describes the principle of slow charging of the first and second batteries during the pre-charging or constant-voltage charging phases. When the battery voltage is detected to be less than a pre-charging threshold (e.g., 3.0V), the battery enters the pre-charging phase. When the battery voltage is detected to be greater than a constant-voltage charging threshold (e.g., 4.2V), the battery enters the constant-voltage charging phase.

[0145] See also Figure 8 , which is a schematic diagram of the working principle of the charging circuit provided in the embodiment of the present application Figure 4 .

[0146] After the charger 60 is connected to the power source, the fast charging circuit 20 is not working, the first switch S1 and the second switch S2 are turned on, and the third switch S2 is turned off to connect the first battery 40 and the second battery 50 in parallel. The bypass circuit in the power conversion circuit 10 is controlled to be turned on. At this time, the charging circuit of the first battery 40 is as follows: Figure 8 As shown in ③, the charging circuit of the second battery 50 is as follows Figure 8 As shown in ④.

[0147] The voltage provided by the charger 60 is stepped down by the Buck circuit in the power conversion circuit 10 to generate the system power VPH_PWR. The current of the system power VPH_PWR passes through the bypass circuit inside the power conversion circuit 10 to charge the first battery 40 and the second battery 50 simultaneously.

[0148] The following describes the principle when the first battery and the second battery are in the constant current charging stage, that is, when the first battery and the second battery are rapidly charged.

[0149] When the charger 60 is connected to a power source, the fast charging circuit 20 operates, the first switch S1 and the second switch S2 are turned off, and the third switch S2 is turned on. When the voltages of the first battery 40 and the second battery 50 are different, the switched capacitor converter 30 operates in different power conversion states, as described in detail below.

[0150] The following first describes the principle of fast charging when the voltage of the first battery 40 is greater than or equal to the voltage of the second battery 50.

[0151] See also Figure 9 , which is a schematic diagram of the working principle of the charging circuit provided in the embodiment of the present application Figure 5 .

[0152] At this time, a portion of the current provided by the fast charging circuit 20 flows through the first battery 40, the third switch S3 and the second battery 50 in sequence, charging the first battery 40 and the second battery 50 in series. Figure 9 Another portion of the current provided by the fast charging circuit 20 flows through the switched capacitor converter 30, as shown in FIG. Figure 9 As shown in line ⑥ in FIG, the controller controls the switched capacitor converter 30 to operate in a step-down 2:1 mode, that is, at this time, the ratio of the voltage input to the first end of the switched capacitor converter 30 to the voltage output from the second end is 2:1, and the current output by the switched capacitor converter 30 and the charging current of the first battery 40 are combined to charge the second battery 50.

[0153] At this time, the charging current of the second battery 50 is equal to the sum of the charging current of the first battery 40 and the current of the branch where the switched capacitor converter 30 is located, that is, the charging current of the second battery 50 is increased, and the charging speed of the second battery 50 is improved.

[0154] Furthermore, the input voltage Vin at the first end of the switched capacitor converter 30 is the sum of the voltage VBATT1 of the first battery 40 and the voltage VBATT2 of the second battery 50, and the output voltage Vout at the second end of the switched capacitor converter 30 is the voltage VBATT2 of the second battery 50, and Vin is twice Vout. Therefore, the switched capacitor converter 30 can automatically achieve voltage balancing between the first battery 40 and the second battery 50 so that VBATT1 is equal to VBATT2.

[0155] The following describes the principle when the voltage of the first battery 40 is lower than the voltage of the second battery 50 during fast charging.

[0156] See also Figure 10 , which is a schematic diagram of the working principle of the charging circuit provided in the embodiment of the present application Figure 6 .

[0157] At this time, a portion of the current provided by the fast charging circuit 20 flows through the first battery 40, the third switch S3 and the second battery 50 in sequence to charge the first battery 40 and the second battery 50. Figure 9 As shown in line ⑤ in .

[0158] The controller controls the switched capacitor converter 30 to operate in a boost 1:2 mode, that is, at this time, the ratio of the voltage input to the second end of the switched capacitor converter 30 to the voltage output from the first end is 1:2.

[0159] The second battery 50 outputs current to the branch where the switched capacitor converter 30 is located. The ratio of the voltage input to the second terminal of the switched capacitor converter 30 to the voltage output from the first terminal of the switched capacitor converter 30 is 1:2. The current output from the first terminal of the switched capacitor converter 30 is combined with the current provided by the fast charging circuit 20 to charge the first battery 40 and the second battery 50. In other words, the power is drawn from the second battery 50, which has a higher voltage, and the charging current for the first battery 40 is increased, thereby improving the charging speed of the first battery 40 and achieving balanced charging.

[0160] Furthermore, the input voltage Vin of the second end of the switching capacitor converter 30 is the voltage VBATT2 of the second battery 50, and the output voltage Vout of the first end of the switching capacitor converter 30 is the sum of the voltage VBATT1 of the first battery 40 and the voltage VBATT2 of the second battery 50, and Vin is twice Vout. Therefore, the switching capacitor converter 30 can automatically achieve voltage balance between the first battery 40 and the second battery 50 so that VBATT1 is equal to VBATT2.

[0161] In the above fast charging process, when there is a system load, the bypass circuit in the power conversion circuit 10 is turned on. At this time, the first battery 40 and the second battery 50 jointly provide system power through the bypass circuit, and can still maintain voltage balance between the first battery 40 and the second battery 50.

[0162] In summary, the charging circuit provided by the embodiment of the present application achieves efficient voltage balancing of two batteries with inconsistent capacities under different operating conditions by controlling the controllable switch under different charging and discharging conditions. This allows both batteries to be fully charged simultaneously, improving charging speed and efficiency and simplifying the balancing control method. Furthermore, because the present application solution does not require the Buck circuit to operate in a step-down state for charging compensation to achieve voltage balancing during the fast charging process when the electronic device is under low load, it also reduces device heating and improves charging speed and efficiency.

[0163] The following specifically describes the principle of the electronic device being in a fast charging process when there is a load in the system, causing the first battery and the second battery to be in a state of simultaneous charging and discharging.

[0164] See also Figure 11 , which is a schematic diagram of the working principle of the charging circuit provided in the embodiment of the present application Figure 7 .

[0165] In the solution of the present application, in order to achieve voltage balance between the first battery 40 and the second battery 50, it is necessary to control the first battery 40 and the second battery 50 to discharge simultaneously. This is because when only one battery is discharged, for example, the second battery is discharged, the voltage difference between the two batteries will increase.

[0166] Under this operating condition, the controller controls S1 and S2 to be turned off, controls S3 to be closed, and controls the switched capacitor converter 30 to operate in a step-down 2:1 mode. That is, at this time, the ratio of the voltage input to the first terminal of the switched capacitor converter 30 to the voltage output from the second terminal is 2:1.

[0167] At this time, the charging current provided by the fast charging circuit 20 passes through the first battery 40, S3 and the second battery 50 in sequence, and the first battery 40 and the second battery 50 are charged in series. The specific charging circuit is as follows: Figure 11 As shown in ⑤.

[0168] When supplying power to the outside, the second battery 50 outputs current to the third terminal of the power conversion circuit 10. The specific discharge circuit is as follows: Figure 11As shown in ⑧. And, the first battery 40 and the second battery 50 are discharged simultaneously, and the input voltage of the first terminal of the switching capacitor converter 30 is the sum of the voltage VBATT1 of the first battery 40 and the voltage VBATT2 of the second battery 50. The second terminal of the switching capacitor converter 30 outputs a voltage to the third terminal of the power conversion circuit 10. The specific discharge circuit is as follows Figure 11 As shown in ⑨.

[0169] The output voltage at the second terminal of the switched capacitor converter 30 is VBATT2, the voltage of the second battery 50. Since the ratio of the voltage at the first terminal to the voltage at the second terminal of the switched capacitor converter 30 is 2:1, the circuit can automatically achieve voltage balancing between the first battery 40 and the second battery 50 during the simultaneous charging and discharging process, such that VBATT1 equals VBATT2. This is illustrated below with an example.

[0170] Assuming that during the fast charging process, the current voltage of the first battery 40 and the second battery 50 are both 4.0V, a portion of the current output by the second battery 50 flows directly into the power conversion circuit 10, and the controller controls the bypass circuit of the power conversion circuit 10 to be turned on to generate the system power supply VPH_PWR. The voltage of VPH_PWR is 4V. The input voltage at the first end of the switching capacitor converter 30 is the sum of the voltages of the first battery 40 and the second battery 50, that is, 8.0V. At this time, the output voltage at the second end of the switching capacitor converter 30 is 4.0V, which is used to provide the system power supply VPH_PWR after passing through the bypass circuit inside the power conversion circuit 10.

[0171] In summary, in the present application's solution, during the rapid charging and discharging process, the first battery 40 and the second battery 50 are charged and discharged simultaneously, rather than the larger-capacity second battery 50 discharging alone. Therefore, the voltage difference between the first battery 40 and the second battery 50 does not increase, but remains balanced, simplifying the balancing control method. Therefore, even after charging is complete, if the first and second batteries 40, 50 are connected in parallel during discharge, no significant mutual charging current will occur, ensuring battery safety.

[0172] Based on the charging circuit provided in the above embodiments, the embodiments of the present application further provide a charging method, which is described in detail below with reference to the accompanying drawings.

[0173] See also Figure 12 , which is a flow chart of a charging method provided in an embodiment of the present application.

[0174] The method is applied to the charging circuit provided in the above embodiment. The specific working principle of the charging circuit can be found in the relevant description of the above embodiment and will not be repeated here. The method includes the following steps:

[0175] S11: When the fast charging circuit is working and the voltage of the first battery is greater than or equal to the voltage of the second battery at the beginning of the first time period, the ratio of the voltage at the first end of the first switched capacitor converter to the voltage at the second end of the first switched capacitor converter is controlled to be 2:1 during the first time period.

[0176] S12: When the fast charging circuit is working and the voltage of the first battery is less than the voltage of the second battery at the beginning of the second time period, the ratio of the voltage at the first end of the first switched capacitor converter to the voltage at the second end of the first switched capacitor converter is controlled to be 1:2 during the second time period.

[0177] By utilizing the method provided in the embodiment of the present application, it is possible to compensate for the situation where the voltage of a large-capacity battery is lower than that of a small-capacity battery, and to compensate for the situation where the voltage of a large-capacity battery is higher than that of a small-capacity battery during fast charging, thereby achieving voltage balance between different batteries, and thus allowing the two batteries to be fully charged at the same time, thereby improving the charging speed and charging efficiency of fast charging.

[0178] Optionally, the method further includes: when the first end of the fast charging circuit is not connected to the charger within a third time period, controlling the first switch and the second switch to close, controlling the third switch to turn off, and controlling the bypass circuit of the power conversion circuit to turn on.

[0179] At this time, the first battery and the second battery are connected in parallel for discharge, and the first battery and the second battery can maintain voltage balance during the discharge process.

[0180] Optionally, the method further includes: in a fourth time period, when the first end of the power conversion circuit is connected to the charger, controlling the first switch and the second switch to be turned on, controlling the third switch to be turned off, controlling the Buck to operate in a step-down state, and controlling the bypass circuit to be turned on, so that the charging circuit charges the first battery and the second battery in parallel.

[0181] At this time, the charging circuit slowly charges the first battery and the second battery. The first battery and the second battery are connected in parallel during the charging process, so that power balance can be achieved.

[0182] Optionally, the method also includes: in a fifth time period, when the fast charging circuit is operating, controlling the first switch and the second switch to be disconnected, controlling the third switch to be turned on, controlling the bypass circuit to be turned on, and controlling the ratio of the voltage at the first end of the first switch capacitor converter to the voltage at the second end of the first switch capacitor converter to be 2:1.

[0183] During the rapid charging process, the first and second batteries must output the system voltage through the power conversion circuit because the system is under load. During this simultaneous charging and discharging process, the first and second batteries can achieve charge balance. During this process, the first and second batteries discharge together, rather than just one battery with a higher voltage.

[0184] Optionally, the method further includes:

[0185] During a sixth time period, the fourth switch and the sixth switch are controlled to be closed, and the fifth switch and the seventh switch are controlled to be closed. Then, during a seventh time period, the fourth switch and the sixth switch are controlled to be closed, and the fifth switch and the seventh switch are controlled to be closed, so that the ratio of the voltage at the first end of the first switched capacitor converter to the voltage at the second end of the first switched capacitor converter is 2:1.

[0186] And, in the eighth time period, the fourth switch and the sixth switch are controlled to be turned off, and the fifth switch and the seventh switch are controlled to be closed, and then in the ninth time period, the fourth switch and the sixth switch are controlled to be closed, and the fifth switch and the seventh switch are controlled to be turned off, so that the ratio of the voltage at the first end of the first switch capacitor converter to the voltage at the second end of the first switch capacitor converter is 1:2.

[0187] Based on the charging circuit provided in the above embodiment, an embodiment of the present application further provides an electronic device, which is described in detail below with reference to the accompanying drawings.

[0188] See also Figure 13 , which is a schematic diagram of an electronic device provided in an embodiment of the present application.

[0189] The embodiments of the present application do not limit the specific type of electronic device, and may be, for example, a mobile phone, a laptop computer, a wearable electronic device (such as a smart watch), a tablet computer, an augmented reality (AR) device, a virtual reality (VR) device, etc., and the electronic device includes multiple batteries.

[0190] The electronic device provided in the embodiment of the present application includes: a processor 110, an external memory interface 120, an internal memory 121, a universal serial bus (USB) interface 130, a charging management module 140, a power management module 141, a first battery 40, a second battery 50, an antenna 1, an antenna 2, a mobile communication module 150, a wireless communication module 160, an audio module 170, a speaker 170A, a receiver 170B, a microphone 170C, an earphone interface 170D, a sensor module 180, a button 190, a motor 191, an indicator 192, a camera 193, a display screen 194, and a subscriber identification module (SIM) card interface 195, etc.

[0191] It should be understood that the structure illustrated in the embodiments of the present invention does not constitute a specific limitation on the electronic device 100. In other embodiments of the present application, the electronic device 100 may include more or fewer components than shown, or may combine or separate certain components, or arrange the components differently. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0192] The processor 110 may include one or more processing units. For example, the processor 110 may include an application processor (AP), a modem processor, a graphics processing unit (GPU), an image signal processor (ISP), a controller, a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural-network processing unit (NPU). The different processing units may be independent devices or integrated into one or more processors.

[0193] The controller can generate operation control signals according to the instruction operation code and timing signal to complete the control of instruction fetching and execution.

[0194] The processor 110 may also include a memory for storing instructions and data.

[0195] The wireless communication function of the electronic device 100 can be implemented through the antenna 1, the antenna 2, the mobile communication module 150, the wireless communication module 160, the modem processor and the baseband processor.

[0196] The charging management module 140 is configured to receive charging input from a charger. The charger can be either a wireless charger or a wired charger. In some wired charging embodiments, the charging management module 140 can receive charging input from the wired charger via the USB interface 130. In some wireless charging embodiments, the charging management module 140 can receive wireless charging input via the wireless charging coil of the electronic device 100. While the charging management module 140 is charging the first battery 40 and the second battery 50, it can also provide power to the electronic device via the power management module 141.

[0197] The charging management module 140 may include the charging circuit 141 described in the above embodiments of the present application. The charging circuit can charge the first battery 40 and the second battery 50, and can automatically realize automatic balanced charging and discharging of batteries of different capacities under various working conditions, simplifying the software control method, improving charging efficiency, optimizing battery balancing capabilities, and increasing battery charging speed.

[0198] The first battery 40 and the second battery 50 can be connected in series or in parallel during the power supply process. For example, when the power levels of the first battery 40 and the second battery 50 are both relatively high and the output voltages are both relatively high, the first battery 40 and the second battery 50 can be connected in parallel. When the power levels of the first battery 40 and the second battery 50 are both relatively low and the output voltages are relatively low, and / or the electronic device is heavily loaded and / or is in a low-temperature environment, the first battery 40 and the second battery 50 can be connected in series.

[0199] The power management module 141 is used to connect the first battery 40, the second battery 50, the charging management module 140 and the processor 110. The power management module 141 receives input from each battery and / or the charging management module 140, and provides power to the processor 110, the internal memory 121, the display 194, the camera 193, and the wireless communication module 160. The power management module 141 can also be used to monitor parameters such as the capacity of each battery, the number of battery cycles, and the battery health status (leakage, impedance). In some other embodiments, the power management module 141 can also be set in the processor 110. In other embodiments, the power management module 141 and the charging management module 140 can also be set in the same device.

[0200] The charging circuit used in the electronic device provided in the embodiments of the present application achieves efficient voltage balancing between two batteries with inconsistent capacities under different operating conditions by controlling a controllable switch under different charging and discharging conditions. This allows both batteries to be fully charged simultaneously, improving charging speed and efficiency and simplifying the balancing control method. Furthermore, because the present application solution does not require charging compensation using a Buck circuit to achieve voltage balancing during the fast charging process, it also reduces device heat generation and improves charging speed and efficiency.

[0201] Furthermore, when the electronic device experiences a high load during fast charging, the first and second batteries charge and discharge simultaneously, rather than discharging solely from the larger-capacity second battery. Therefore, the voltage difference between the first and second batteries does not increase, but remains balanced, simplifying the balancing control method. Therefore, even if the first and second batteries are connected in parallel after charging is complete and discharging, a large mutual charging current will not flow, ensuring battery safety.

[0202] It should be understood that in this application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0203] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A charging circuit, characterized in that: include: a fast charging circuit and a first switched capacitor converter; The first end of the fast charging circuit is used to connect to a charger; When the fast charging circuit is in operation, the second terminal of the fast charging circuit is connected to the first terminal of the first battery and the first terminal of the first switched capacitor converter, the second terminal of the first battery is connected to the first terminal of the second battery and the second terminal of the first switched capacitor converter, and the second terminal of the second battery is grounded; During a first time period, the fast charging circuit operates, and a ratio of a voltage at the first terminal of the first switched capacitor converter to a voltage at the second terminal of the first switched capacitor converter is 2:

1. At the start of the first time period, a voltage of the first battery is greater than or equal to a voltage of the second battery. During a second time period, the fast charging circuit operates, and a ratio of a voltage at the first end of the first switched capacitor converter to a voltage at the second end of the first switched capacitor converter is 1:

2. At the start of the second time period, a voltage of the first battery is less than a voltage of the second battery.

2. The charging circuit according to claim 1, wherein: The charging circuit further includes: a power conversion circuit, a first switch, a second switch and a third switch; The first end of the power conversion circuit is used to connect to the charger, the second end of the power conversion circuit is used to output the system voltage of the electronic device, and the third end of the power conversion circuit is connected to the first end of the first switch; The first end of the first switch is connected to the first electrode of the second battery, the second end of the third switch and the second end of the first switched capacitor converter; A first end of the second switch is connected to the second electrode of the first battery and the first end of the third switch, and a second end of the second switch is grounded; During the first time period and the second time period, the first switch and the second switch are turned off, and the third switch is closed.

3. The charging circuit according to claim 2, wherein: The charging circuit further includes a controller; the controller being configured to control the first switch and the second switch to be turned off, the third switch to be turned on, and the first switched capacitor converter to make a ratio of a voltage at a first terminal of the first switched capacitor converter to a voltage at a second terminal of the first switched capacitor converter be 2:1 during the first time period; It is also used to control the first switch and the second switch to be turned off, control the third switch to be closed, and control the first switch capacitor converter during the second time period so that the ratio of the voltage at the first end of the first switch capacitor converter to the voltage at the second end of the first switch capacitor converter is 1:

2.

4. The charging circuit according to claim 2, wherein: The power conversion circuit includes a step-down Buck circuit and a bypass circuit; The first end of the Buck circuit is connected to the first end of the power conversion circuit, and the second end of the Buck circuit is used to output the system voltage; The Buck circuit is used to step down the voltage input to the first end of the Buck circuit; The first end of the bypass circuit is connected to the second end of the Buck circuit, and the second end of the bypass circuit is connected to the third end of the power conversion circuit.

5. The charging circuit according to claim 4, characterized in that: In a third time period, the first end of the fast charging circuit is not connected to a charger, the first switch and the second switch are closed, the third switch is turned off, and the bypass circuit is turned on.

6. The charging circuit according to claim 5, characterized in that: The charging circuit further includes: a controller; The controller is configured to control the first switch and the second switch to be closed, control the third switch to be turned off, and control the bypass circuit to be turned on during the third time period.

7. The charging circuit according to claim 4, characterized in that: In a fourth time period, the first end of the power conversion circuit is connected to the charger, the first switch and the second switch are turned on, the third switch is turned off, and the bypass circuit is turned on.

8. The charging circuit according to claim 7, characterized in that: The charging circuit further includes: a controller; The controller is configured to control the first switch and the second switch to be turned on, control the third switch to be turned off, control the Buck circuit to operate, and control the bypass circuit to be turned on during the fourth time period.

9. The charging circuit according to claim 4, characterized in that: During a fifth time period, the fast charging circuit operates, the first switch and the second switch are disconnected, the third switch is turned on, a ratio of a voltage at the first end of the first switched capacitor converter to a voltage at the second end of the first switched capacitor converter is 2:1, and the bypass circuit is turned on.

10. The charging circuit according to claim 9, characterized in that: The charging circuit further includes: a controller; The controller is configured to control the first switch and the second switch to be disconnected, control the third switch to be turned on, and control the bypass circuit to be turned on during the fifth time period.

11. The charging circuit according to claim 1, wherein: The first switched capacitor converter includes: a fourth switch, a fifth switch, a sixth switch, a seventh switch, a first capacitor and a second capacitor; A first end of the first switched capacitor converter is connected to a first end of the fourth switch, a second end of the fourth switch is connected to a first end of the first capacitor and a first end of the fifth switch, a second end of the fifth switch is connected to a first end of the sixth switch and a first end of the second capacitor, a second end of the sixth switch is connected to a second end of the first capacitor and a first end of the seventh switch, a second end of the seventh switch is grounded and connected to a second end of the second capacitor, and a first end of the second capacitor is connected to a second end of the first switched capacitor converter.

12. The charging circuit according to claim 11, wherein: The charging circuit further includes a controller; the controller being configured to control the fourth switch and the sixth switch to be closed and the fifth switch and the seventh switch to be closed during a sixth time period, and then control the fourth switch and the sixth switch to be closed and the fifth switch and the seventh switch to be closed during a seventh time period, so that a ratio of a voltage at the first end of the first switched capacitor converter to a voltage at the second end of the first switched capacitor converter is 2:1; The device is further configured to control the fourth switch and the sixth switch to be turned off and the fifth switch and the seventh switch to be closed during an eighth time period, and then control the fourth switch and the sixth switch to be closed and the fifth switch and the seventh switch to be turned off during a ninth time period, so that the ratio of the voltage at the first end of the first switched capacitor converter to the voltage at the second end of the first switched capacitor converter is 1:

2.

13. The charging circuit according to claim 4, characterized in that: The bypass circuit includes an eighth switch; a first end of the eighth switch is connected to the first end of the bypass circuit, and a second end of the eighth switch is connected to the second end of the bypass circuit; When the eighth switch is closed, the bypass circuit is turned on, and when the eighth switch is turned off, the bypass circuit is turned off.

14. The charging circuit according to any one of claims 1 to 13, characterized in that: The fast charging circuit includes a Buck-Boost circuit or a second switched capacitor converter.

15. A charging method, characterized in that: The charging method is applied to the charging circuit according to any one of claims 1 to 14, and the method includes: When the fast charging circuit is in operation and the voltage of the first battery is greater than or equal to the voltage of the second battery at the start of a first time period, controlling the ratio of the voltage at the first terminal of the first switched capacitor converter to the voltage at the second terminal of the first switched capacitor converter to be 2:1 during the first time period; When the fast charging circuit is operating and the voltage of the first battery is less than the voltage of the second battery at the start of the second time period, during the second time period, the ratio of the voltage at the first end of the first switched capacitor converter to the voltage at the second end of the first switched capacitor converter is controlled to be 1:

2.

16. An electronic device, characterized in that: The electronic device comprises a first battery, a second battery and a charging circuit according to any one of claims 1 to 14; The charging circuit is used to charge the first battery and the second battery.

17. The electronic device according to claim 16, wherein: The capacity of the first battery is smaller than the capacity of the second battery.

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