CN117060549B

CN117060549B - Charging and discharging circuit and electronic equipment

Info

Publication number: CN117060549B
Application number: CN202311285576.2A
Authority: CN
Inventors: 王勇
Original assignee: Honor Device Co Ltd
Current assignee: Honor Device Co Ltd
Priority date: 2023-10-07
Filing date: 2023-10-07
Publication date: 2024-04-26
Anticipated expiration: 2043-10-07
Also published as: CN117060549A

Abstract

The application provides a charge-discharge circuit and electronic equipment, wherein the charge-discharge circuit comprises at least two charge-discharge branches which are arranged in parallel between a first node and a grounding node, each charge-discharge branch comprises a rechargeable battery, the product of the respective total impedance of each charge-discharge branch and the electric quantity of each rechargeable battery is equal to each other, and the total impedance of each charge-discharge branch comprises the line impedance, the device impedance and the battery impedance of each charge-discharge branch. The charge-discharge circuit can ensure that the voltage of each battery synchronously increases in the charge and discharge processes, the current accords with respective multiplying power, the full charge capacity and the discharge capacity are improved, and the problem that the aging degrees of the batteries are different is avoided.

Description

Charging and discharging circuit and electronic equipment

Technical Field

The present application relates to the field of foldable electronic technologies, and in particular, to a charge and discharge circuit and an electronic device.

Background

As flexible folding screen technology has matured, flexible folding end products have become a major trend, and folding cell phones have become increasingly popular star products for consumer appeal. Folding mobile phones are generally classified into inner folding type, outer folding type, vertical folding type, etc. according to the folding manner. Compared with the internal space of the traditional board straightening machine, the folding machine is added with a plurality of components such as a hinge, an auxiliary screen and the like, and severely extrudes the battery space in the mobile phone. Therefore, in order to improve the cruising ability of the folding mobile phone, reduce the weight, and pursue the characteristics of lightness and thinness, two or more batteries with different capacities and sizes are usually connected in parallel to supply power to the mobile phone system. However, the current folder products do not reasonably restrict the charge-discharge loop impedance of the battery cells in the main board and the auxiliary board, so that the voltages of the battery cells in the battery pack are inconsistent in the charge and discharge processes, and the condition is generally affected when one battery reaches the full charge voltage and the cut-off current or the discharge cut-off voltage, and the other battery does not reach the condition, so that the full charge capacity and the discharge capacity of the battery pack are affected. In addition, the current entering the battery cells is not distributed according to the capacity proportion of the battery cells, so that the aging degree among the battery cells is different, and the service life of the battery is influenced.

Disclosure of Invention

In order to solve the technical problems, the application provides a charge-discharge circuit and electronic equipment. The charge-discharge circuit can ensure that the voltage of a plurality of battery monomers of the electronic equipment synchronously increases or decreases in the charge-discharge process, and the current flowing into each battery monomer is suitable for the charge-discharge multiplying power of the battery monomers, so that the consistency of the aging degree of the battery pack is further ensured, and the service life of the battery pack is prolonged.

In a first aspect, the present application provides a charge-discharge circuit comprising: at least two charge and discharge branches arranged in parallel between a first node and a ground node, each of the charge and discharge branches comprising a rechargeable battery, the product of the respective total impedance of each of the charge and discharge branches and the respective charge of the rechargeable battery being equal to each other, the total impedance of the charge and discharge branches comprising the line impedance, the device impedance and the battery impedance of the charge and discharge branch.

According to the first aspect, the charge-discharge circuit of the application adopts the design that the products of the total impedance of each charge-discharge branch and the electric quantity of the corresponding rechargeable battery are equal to each other, so that the voltages of a plurality of battery cells synchronously increase or decrease in the charge-discharge process, and the current flowing into each battery cell is suitable for the charge-discharge multiplying power of the battery cell, thereby further ensuring the consistent aging degree of the battery pack and prolonging the service life of the battery pack.

According to a first aspect, or any implementation manner of the first aspect, the charge and discharge circuit further includes: a first charging chip and a second charging chip arranged in parallel between the charging port and the first node;

The first battery is arranged between the first node and the grounding node, the impedance of a line of the first node reaching the grounding node through the first battery is R10, the impedance of the first battery is R11, the impedance of other devices on a branch of the first node reaching the grounding node through the first battery is R12, and the electric quantity of the first battery is Q1;

The second battery is arranged between the first node and the grounding node, the impedance of a line of the first node reaching the grounding node through the second battery is R20, the impedance of the second battery is R21, the impedance of other devices on a branch of the first node reaching the grounding node through the second battery is R22, and the electric quantity of the second battery is Q2;

（R10+R11+R12）×Q1=（R20+R21+R22）×Q2。

The arrangement can ensure that the voltage of each battery synchronously increases in the charging and discharging processes, the current accords with respective multiplying power, the full charge capacity and the discharge capacity are improved, and the problem that the aging degree of each battery is different is avoided.

According to a first aspect, or any implementation manner of the first aspect, the charge and discharge circuit further includes:

the third battery is arranged between the first node and the grounding node, the impedance of a line of the first node reaching the grounding node through the third battery is R30, the impedance of the third battery is R31, the impedance of other devices on a branch of the first node reaching the grounding node through the third battery is R32, and the electric quantity of the third battery is Q3;

（R10+R11+R12）×Q1=（R20+R21+R22）×Q2=（R30+R31+R32）×Q3。

According to a first aspect, or any implementation manner of the first aspect, the charge and discharge circuit further includes: the first charging chip, the second charging chip and the third charging chip are arranged in parallel between the first node and the eighth node;

The first battery is arranged between the first node and the grounding node, the impedance of a line of the first node reaching the grounding node through the second charging chip and the first battery is R10, the impedance of the first battery is R11, the impedance of other devices of the first node on a branch line of the first node reaching the grounding node through the second charging chip and the first battery is R12, and the electric quantity of the first battery is Q1;

the second battery is arranged between the first node and the grounding node, the impedance of a line of the first node reaching the grounding node through the third charging chip and the second battery is R20, the impedance of the second battery is R21, the impedance of other devices of the first node reaching a branch of the grounding node through the third charging chip and the second battery is R22, and the electric quantity of the second battery is Q2;

（R10+R11+R12）×Q1=（R20+R21+R22）×Q2，

the first battery is further arranged between the eighth node and the grounding node, the eighth node is connected with the first charging chip, the impedance of a line of the eighth node reaching the grounding node through the first battery is R40, the impedance of the first battery is R41, and the impedance of other devices on a branch of the eighth node reaching the grounding node through the first battery is R42;

The second battery is further arranged between the eighth node and the grounding node, the eighth node is connected with the first charging chip, the impedance of a line of the eighth node reaching the grounding node through the second battery is R50, the impedance of the second battery is R51, and the impedance of other devices on a branch of the eighth node reaching the grounding node through the second battery is R52;

（R40+R41+R42）×Q1=（R50+R51+R52）×Q2。

According to a first aspect, or any implementation manner of the first aspect, each of the charge and discharge branches includes a sampling resistor and an electricity meter connected in parallel across the sampling resistor. The arrangement can be that in the charging and discharging process, the electricity meter reads the voltage and the current of each battery through the sampling resistor, then calculates the electric quantity of each battery through the algorithm of the electricity meter, and finally gathers together to calculate the total electric quantity of the battery, so that more accurate electric quantity statistics can be realized conveniently.

In a second aspect, the present application provides an electronic device comprising a charge-discharge circuit as claimed in any one of the first aspects.

According to the second aspect, due to the adoption of the charge-discharge circuit of the first aspect, the voltages of the plurality of battery cells are synchronously increased or decreased in the charge-discharge process, and the current flowing into each battery cell is suitable for the charge-discharge multiplying power of the battery cell, so that the consistency of the aging degree of the battery pack is further ensured, and the service life of the battery pack is prolonged.

According to a second aspect, or any implementation manner of the second aspect, the electronic device is a foldable terminal. Therefore, the voltage of each battery of the foldable terminal can be ensured to synchronously increase in the charging and discharging processes, the current accords with respective multiplying power, the full charge capacity and the discharge capacity can be improved, and the problem that the aging degrees of the batteries are different is avoided.

Drawings

Fig. 1 is a schematic structural diagram of a foldable mobile phone in a flattened state according to an embodiment of the present application:

Fig. 2 is a schematic structural diagram of a foldable mobile phone in a semi-folded state according to an embodiment of the present application;

fig. 3 is a schematic diagram of a charge-discharge circuit according to an embodiment of the present application;

FIG. 4 is a graph showing a change in battery voltage during charging of a charge/discharge circuit according to an embodiment of the present application;

FIG. 5 is a graph showing a change in battery voltage during discharging of a charge/discharge circuit according to an embodiment of the present application;

fig. 6 is a schematic diagram of a charge-discharge circuit according to another embodiment of the present application;

FIG. 7 is a graph showing a voltage change of a battery during charging of a charge/discharge circuit according to another embodiment of the present application;

FIG. 8 is a graph showing a voltage change of a battery during discharging of a charge/discharge circuit according to another embodiment of the present application;

fig. 9 is a schematic diagram of a charge-discharge circuit according to another embodiment of the present application.

Detailed Description

The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

The term "and/or" is herein merely an association relationship describing an associated object, meaning that there may be three relationships, e.g., a and/or B, may represent: a exists alone, A and B exist together, and B exists alone.

The terms first and second and the like in the description and in the claims of embodiments of the application, are used for distinguishing between different objects and not necessarily for describing a particular sequential order of objects. For example, the first target object and the second target object, etc., are used to distinguish between different target objects, and are not used to describe a particular order of target objects.

In embodiments of the application, words such as "exemplary" or "such as" are used to mean serving as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" or "e.g." in an embodiment should not be taken as preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "such as" is intended to present related concepts in a concrete fashion.

In the description of the embodiments of the present application, unless otherwise indicated, the meaning of "a plurality" means two or more. For example, the plurality of processing units refers to two or more processing units; the plurality of systems means two or more systems.

As mentioned above, in order to improve the cruising ability of the folding mobile phone, reduce the weight, and pursue the characteristics of light and thin, two or more batteries with different capacities and sizes are usually connected in parallel to supply power to the mobile phone system. However, the current folder products do not reasonably restrict the charge-discharge loop impedance of the battery cells in the main board and the auxiliary board, so that the voltages of the battery cells in the battery pack are inconsistent in the charge and discharge processes, and the condition is generally affected when one battery reaches the full charge voltage and the cut-off current or the discharge cut-off voltage, and the other battery does not reach the condition, so that the full charge capacity and the discharge capacity of the battery pack are affected. In addition, the current entering the battery cells is not distributed according to the capacity proportion of the battery cells, so that the aging degree among the battery cells is different, and the service life of the battery is influenced.

Based on the above description, the embodiments of the present application provide a charge and discharge circuit and an electronic device, where the charge and discharge circuit may be applied to an electronic device such as a foldable mobile phone, and the electronic device includes a terminal device that may further include a foldable tablet computer, a foldable game machine, a foldable Personal Digital Assistant (PDA), and the like, and has a folding function. Of course, for other non-folding devices using a plurality of battery cells, the charge and discharge circuit provided in the embodiment of the present application is also used, and the embodiment of the present application is not limited to the specific form of the electronic device described above.

As shown in fig. 1 to 2, the electronic device 100 includes a housing 10, a folding hinge 20, and a flexible screen 30. The flexible screen 30 is fixed to one side surface of the housing 10. The electronic device 100 can be folded along the center thereof, and when the foldable mobile phone is in a folded state, that is, the folding angle of the foldable mobile phone is 0, the size of the foldable mobile phone can be reduced; when the foldable cellular phone is in a flattened state, that is, the folding angle of the foldable cellular phone is 180 °, the flexible screen 30 is in a state of a maximum display area, and a user can operate on the flexible screen 30. It should be noted that the folding angle refers to an included angle between the left and right parts of the foldable mobile phone.

In the embodiment of the present application, the folding hinge 20 is capable of being deformed to enable the first housing 11 and the second housing 12 to be folded or unfolded relatively. As shown in fig. 1, the first housing 11 and the second housing 12 can be relatively unfolded to a flattened state, so that the electronic device 100 is in the flattened state. By way of example, when first housing 11 and second housing 12 are in a flattened state, both may be substantially 180 ° (also allowing for a few deviations, such as 165 °, 177 °, or 185 °). As shown in fig. 2, the first housing 11 and the second housing 12 can be relatively rotated (unfolded or folded) to an intermediate state, so that the electronic apparatus 100 is in the intermediate state. Further, the first housing 11 and the second housing 12 can be relatively folded to a closed state, so that the electronic device 100 is in the closed state. For example, when the first housing 11 and the second housing 12 are in the closed state, they can be completely folded to be parallel to each other (a small deviation is allowed). The intermediate state shown in fig. 2 may be any state between the flattened state and the closed state. Thus, the electronic device 100 can be switched between the flattened state and the closed state by deformation of the folding hinge 20. Illustratively, in an embodiment of the present application, the electronic device 100 may be a folding-in mobile phone, that is, the flexible screen 30 is located on the inner side of the housing 10, in other words, when the electronic device 100 is in the closed state, the flexible screen 30 is located on the inner side of the housing 10.

In this embodiment, the flexible screen 30 is capable of unfolding or folding with the folding hinge 20. When the electronic device 100 is in the flattened state, the flexible screen 30 is in the flattened state, and can be displayed in full screen, so that the electronic device 100 has a larger display area, and the viewing experience of a user is improved. When the electronic device 100 is in the closed state, the electronic device 100 has a small planar size (has a small width size), and is convenient for a user to carry and store.

It should be understood that, in this embodiment, the electronic device 100 can be rotated left and right, and the folding and unfolding of the electronic device 100 affects the width of the electronic device 100, by taking the case that the rotation center of the electronic device 100 is parallel to the length direction of the electronic device 100 as an example. In other embodiments, the rotation center of the electronic device 100 may be parallel to the width direction of the electronic device 100, and the electronic device 100 can rotate up and down, so that the folding and unfolding of the electronic device 100 affects the length dimension of the electronic device 100.

In the embodiment of the present application, a main board and an auxiliary board (which may also be referred to as a first circuit board and a second circuit board) are respectively provided in the first housing 11 and the second housing 12, a processor, a camera, a power management chip, a charging chip, and the like are provided on the main board, and other electronic devices are provided on the auxiliary board. Meanwhile, a first battery and a second battery are respectively provided in the first and second cases 11 and 12, and power is supplied to the main board and other devices through the first and second batteries, thereby supplying power to the electronic apparatus 100.

Fig. 3 is a schematic diagram of a charge-discharge circuit according to an embodiment of the present application.

As shown in fig. 3, the charge-discharge circuit 200 provided in the embodiment of the present application is disposed between a charge port (e.g., a USB interface) and a ground, and can charge batteries (203, 204) during the charging process and can supply power to a load 209 during the discharging process. As shown in fig. 3, the charge-discharge circuit 200 provided in the embodiment of the present application includes a first charging chip 201, a second charging chip 202, a first battery 203, a second battery 204, a first sampling resistor 205, a second sampling resistor 206, a first electricity meter 207, and a second electricity meter 208.

The first charging chip 201 and the second charging chip 202 are connected in parallel between a charging port (e.g., a USB interface) and the first node a, the first charging chip 201 is, for example, a regular charging chip (buck charger), and the second charging chip 202 is, for example, a fast charging chip (SC CHARGER). The charging power of the second charging chip 202 is greater than the charging power of the first charging chip 201, for example, the charging power of the first charging chip 201 is 5W or 10W, and the charging power of the second charging chip 202 is 18W, 22W, 40W, 66W or other greater charging power. The first charging chip 201 is used for the charge-cut process and the discharge process of the charge-discharge circuit 200. The second charging chip 202 is used for a fast charging process of the charging and discharging circuit 200.

The first battery 203 (i.e., BAT 1) is disposed between the second node b and the third node c, the electric quantity of the first battery 203 is Q1, the internal resistance of the battery core is RS1, and the impedance of the battery protection board is RP1.

The second battery 204 (i.e., BAT 2) is disposed between the fourth node e and the fifth node f, the electric quantity of the second battery 204 is Q2, the internal resistance of the battery cell is RS2, and the impedance of the battery protection board is RP2.

The first sampling resistor 205 is disposed between the third node c and the sixth node d, and the first sampling resistor 205 is, for example, a precision resistor, and the resistance value thereof is R0, and R0 is, for example, 1mΩ.

The second sampling resistor 206 is disposed between the fifth node f and the sixth node d, and the second sampling resistor 206 is identical in size and model to the first sampling resistor 205.

The first electricity meter 207 is connected in parallel to two ends of the first sampling resistor 205, and is used for determining the voltage and the current of the first battery 203 by sampling parameters such as the voltage of the first sampling resistor 205, and then determining the electric quantity of the first battery 203 by self algorithm.

The second electricity meter 208 is connected in parallel to two ends of the second sampling resistor 206, and is used for determining the voltage and the current of the second battery 204 by sampling parameters such as the voltage of the second sampling resistor 206, and then determining the electric quantity of the second battery 204 by self algorithm.

Illustratively, the charge-discharge circuit 200 according to the embodiment of the present application is suitable for a double-folded (with a rotating shaft) folding screen scheme, which has a main board and a sub-board, wherein the first charging chip 201, the second charging chip 202, the first sampling resistor 205, the first fuel gauge 207 are disposed on the main board, and the first battery 203 is connected to the main board. A second sampling resistor 206, a second fuel gauge 208 are provided on the sub-board, and the second battery 204 is connected to the sub-board. Wherein the main board, the sub-board, and the battery are connected to the main board and the sub-board through, for example, an FPC.

In the charge-discharge circuit 200 according to the embodiment of the present application, the branch between the first node a and the sixth node d through the second node b and the third node c is the first branch, that is, the charge-discharge circuit of the first battery 203. The first node a and the second node b are connected through a line, and the line impedance is R1. The third node c and the sixth node d are connected by a line, and the line impedance is R2. The total resistance of the first branch is: r0+r1+r2+r1+rp1.

The branch between the first node a and the sixth node d through the fourth node e and the fifth node f is the second branch, that is, the charge-discharge loop of the second battery 204. The first node a and the fourth node e are connected through a line, and the line impedance is R3. The fifth node f and the sixth node d are connected by a line, and the line impedance is R4. The total resistance of the second branch is: r0+r3+r4+r2+rp2.

The charging process of the charge-discharge circuit 200 according to the embodiment of the present application is, for example: the fast charging phase is performed first, the current reaches the first node a through the second charging chip 202, then the current is shunted from the first node a to the second node b and the fourth node e, the current enters the first battery 203 and the second battery 204 through the second node b and the fourth node e, respectively, and finally the current flowing out of the first battery 203 reaches the sixth node d (i.e. reference ground) through the third node c, and the current flowing out of the second battery 204 reaches the sixth node d (i.e. reference ground) through the fifth node f. Then, the charge stopping phase is performed, the current is switched from the second charging chip 202 to the first charging chip 201 to continuously fill the first battery 203 and the second battery 204, and the current flow path is the same as that of the fast charge phase.

The discharging process of the charging and discharging circuit 200 according to the embodiment of the application is as follows: the current flows out from the second node b of the first battery 203 and the fourth node e of the second battery 204 to the first node a, flows to the output terminal of the first charging chip 201 after the first node a is mixed, then to the load 209, and finally flows to the third node c and the fifth node f through the sixth node d, thereby returning to the negative electrodes of the first battery 203 and the second battery 204.

During the charge and discharge process, the voltages and currents of the first battery 203 and the second battery 204 are respectively read by the first fuel gauge 207 and the second fuel gauge 208, then the electric quantities of the first battery 203 and the second battery 204 are calculated by the algorithm of the device, and finally the total electric quantity of the batteries is calculated together.

In order to achieve balanced charge and discharge of the batteries in the embodiment of the present application, when designing the charge and discharge circuit 200, a design is adopted in which the total impedance of the charge and discharge circuits (the first branch and the second branch) of each of the first battery 203 and the second battery 204 is inversely proportional to the capacities of the first battery 203 and the second battery 204 themselves. Wherein, the total resistance of the first branch is: the total resistance of the second branch is R0+R1+R2+Rs1+Rp1: the design of R0+R3+R4+R2+Rp2, (R0+R1+R2+R1+RP (R0+R3+R4+Rp2+R2) =Q2: Q1. can ensure that the voltages of the two batteries synchronously increase in the charging and discharging processes, the current accords with respective multiplying power, the full charge capacity and the discharge capacity are improved, and the problem that the aging degrees of the first battery 203 and the second battery 204 are different is avoided.

Illustratively, in one embodiment of the present application, the capacity of the first battery 203 is 3000mAh, the internal resistance of the battery core is RS1 is 18mΩ, the impedance of the battery protection plate RP1 is 10mΩ, the line impedance of the corresponding ab segment R1 is 5mΩ, the line impedance of the cd segment is 5mΩ, and the sampling resistor R0 is 1mΩ. The capacity of the second battery 204 is 2000mAh. The internal resistance RS2 of the battery core is 20mΩ, the impedance RP2 of the battery protection board is 12mΩ, the corresponding line impedance R3 of ae section is 15mΩ, the line impedance R4 of fd section is 10mΩ, and the sampling resistor R0 is 1mΩ. The example charge-discharge circuit was subjected to a charge-discharge test and the voltage and current of both batteries were monitored simultaneously, and the results are shown in fig. 4 and 5. As can be seen from fig. 4 and fig. 5, with the design of the embodiment of the present application, the cell voltages of the two batteries increase and decrease synchronously during the charge and discharge processes, and the current distribution ratio is BAT1: BAT2 = 3:2.

Fig. 6 is a schematic diagram of a charge-discharge circuit according to another embodiment of the application.

As shown in fig. 6, a charging and discharging circuit 300 provided in an embodiment of the present application is disposed between a charging port (e.g., a USB interface) and a ground, and can charge a battery (303, 304, 305) during a charging process and can supply power to a load 312 during a discharging process. As shown in fig. 6, a charge-discharge circuit 300 provided in an embodiment of the present application includes a first charge chip 301, a second charge chip 302, a first battery 303, a second battery 304, a third battery 305, a first sampling resistor 306, a second sampling resistor 307, a third sampling resistor 308, a first fuel gauge 309, a second fuel gauge 310, and a third fuel gauge 311.

The first charging chip 301 and the second charging chip 302 are connected in parallel between a charging port (e.g., a USB interface) and the first node a, the first charging chip 301 is, for example, a regular charging chip (buck charger), and the second charging chip 302 is, for example, a fast charging chip (SC CHARGER). The charging power of the second charging chip 302 is greater than the charging power of the first charging chip 301, for example, the charging power of the first charging chip 301 is 5W or 10W, and the charging power of the second charging chip 302 is 18W, 22W, 40W, 66W, or other greater charging power. The first charging chip 301 is used for the charge-blocking process and the discharge process of the charge-discharge circuit 300. The second charging chip 302 is used for a fast charging process of the charging and discharging circuit 300.

The first battery 303 (i.e., BAT 1) is disposed between the second node b and the third node c, the electric quantity of the first battery 303 is Q1, the internal resistance of the battery cell is RS1, and the impedance of the battery protection board is RP1.

The second battery 304 (i.e., BAT 2) is disposed between the fourth node e and the fifth node f, the electric quantity of the second battery 304 is Q2, the internal resistance of the battery core is RS2, and the impedance of the battery protection board is RP2.

The third battery 305 (i.e., BAT 3) is disposed between the seventh node g and the eighth node h, the electric quantity of the third battery 305 is Q3, the internal resistance of the battery cell is RS3, and the impedance of the battery protection board is RP3.

The first sampling resistor 306 is disposed between the third node c and the sixth node d, and the first sampling resistor 306 is, for example, a precision resistor, and the resistance value thereof is R0, and R0 is, for example, 1mΩ.

The second sampling resistor 307 is disposed between the fifth node f and the sixth node d, and the second sampling resistor 307 is identical in size and model to the first sampling resistor 306.

The third sampling resistor 308 is disposed between the eighth node h and the sixth node d, and the third sampling resistor 308 has a specification and model identical to those of the third sampling resistor 308.

The first electricity meter 309 is connected in parallel to two ends of the first sampling resistor 306, and is used for determining the voltage and the current of the first battery 303 by sampling parameters such as the voltage of the first sampling resistor 306, and then determining the electric quantity of the first battery 303 by self algorithm.

The second electricity meter 310 is connected in parallel to two ends of the second sampling resistor 307, and is used for determining the voltage and the current of the second battery 304 by sampling parameters such as the voltage of the second sampling resistor 307, and then determining the electric quantity of the second battery 304 by self algorithm.

Third electricity meter 311 is connected in parallel to two ends of third sampling resistor 308, and is used for determining the voltage and current of third battery 305 by sampling parameters such as the voltage of third sampling resistor 308, and then determining the electric quantity of third battery 305 by self algorithm.

Illustratively, the charge-discharge circuit 300 of the embodiment of the present application is suitable for a three-fold (with two axes of rotation) folding screen scheme, which has one main board and two sub-boards, wherein the first charging chip 301, the second charging chip 302, the first sampling resistor 306, the first fuel gauge 309 are disposed on the sub-board 1, and the first battery 303 is connected to the sub-board 1. The second sampling resistor 307 and the second fuel gauge 310 are disposed on the motherboard, and the second battery 304 is connected to the motherboard. A third sampling resistor 308 and a third electricity meter 311 are provided on the sub-board 2, and a third battery 305 is connected to the sub-board 2. Wherein the main board, the sub-board, and the battery are connected to the main board and the sub-board through, for example, an FPC.

In the charge-discharge circuit 300 according to the embodiment of the present application, the branch between the first node a and the sixth node d through the second node b and the third node c is the first branch, that is, the charge-discharge circuit of the first battery 303. The first node a and the second node b are connected through a line, and the line impedance is R1. The third node c and the sixth node d are connected by a line, and the line impedance is R2. The total resistance of the first branch is: r0+r1+r2+r1+rp1.

The branch between the first node a and the sixth node d through the fourth node e and the fifth node f is the second branch, that is, the charge-discharge loop of the second battery 304. The first node a and the fourth node e are connected through a line, and the line impedance is R3. The fifth node f and the sixth node d are connected by a line, and the line impedance is R4. The total resistance of the second branch is: r0+r3+r4+r2+rp2.

The branch between the first node a and the sixth node d through the seventh node g and the eighth node h is the third branch, that is, the charge-discharge circuit of the third battery 305. The first node a and the seventh node g are connected through a line, and the line impedance of the first node a and the seventh node g is R5. The eighth node h and the sixth node d are connected by a line, and the line impedance is R6. The total resistance of the third branch is: r0+r5+r5+r3+rp3.

The charging process of the charge-discharge circuit 300 according to the embodiment of the present application is, for example: the fast charging phase is performed first, the current reaches the first node a through the second charging chip 302, then the current is shunted from the first node a to the second node b, the fourth node e and the seventh node g, the current respectively enters the first battery 303, the second battery 304 and the third battery 305 through the second node b, the fourth node e and the seventh node g, finally the current flowing out of the first battery 303 reaches the sixth node d (i.e. reference ground) through the third node c, the current flowing out of the second battery 304 reaches the sixth node d (i.e. reference ground) through the fifth node f, and the current flowing out of the third battery 305 reaches the sixth node d (i.e. reference ground) through the eighth node h. Then, the charge cutoff phase is performed, the current is switched from the second charging chip 302 to the first charging chip 301 to continue to charge the first battery 303, the second battery 304 and the third battery 305, and the current flow path is the same as that of the fast charge phase.

The discharging process of the charge-discharge circuit 300 according to the embodiment of the present application is as follows: the current flows from the second node b of the first battery 303, the fourth node e of the second battery 304, and the seventh node g of the third battery 305 to the first node a, flows to the output terminal of the first charging chip 301 after the first node a is mixed, then to the load 312, and finally flows to the third node c, the fifth node f, and the eighth node h through the sixth node d, thereby returning to the negative electrodes of the first battery 303, the second battery 304, and the third battery 305, respectively.

During the charge and discharge process, the voltages and currents of the first battery 303, the second battery 304 and the third battery 305 are respectively read by the first fuel gauge 309, the second fuel gauge 310 and the third fuel gauge 311, then the electric quantities of the first battery 303, the second battery 304 and the third battery 305 are calculated by the algorithm of the battery voltage and current calculating device, and finally the total electric quantity of the batteries is calculated by summing up.

In order to achieve balanced charge and discharge of the batteries in the embodiment of the present application, when designing the charge and discharge circuit 300, a design is adopted in which the products of the total impedance and the respective capacities of the charge and discharge circuits (the first branch, the second branch, and the third branch) of the first battery 303, the second battery 304, and the third battery 305 are equal. Wherein, the total resistance of the first branch is: the total resistance of the second branch is R0+R1+R2+Rs1+Rp1: the total impedance of the third branch is R0+R3+R4+RS2+RP 2: r0+r5+r5+r3+rp3, (r0+r1+r2+rp1+r1) ×q1= (r0+r3+r4+rp2+r2) ×q2=r0+ (r5+r6+rp3+r3) ×q3. The design can ensure that the voltages of the three batteries synchronously increase in the charging and discharging processes, the current accords with respective multiplying power, the full charge capacity and the discharge capacity are improved, and the problem that the aging degrees of the first battery 303, the second battery 304 and the third battery 305 are different is avoided.

Illustratively, in one embodiment of the present application, the capacity of the first battery 303 is 2000mAh, the internal resistance of the battery core is RS1 is 18mΩ, the impedance of the battery protection plate RP1 is 12mΩ, the line impedance of the corresponding ab segment R1 is 15mΩ, the line impedance of the cd segment is 10mΩ, and the sampling resistor R0 is 1mΩ. The capacity of the second battery 304 is 2200mAh. The internal resistance RS2 of the battery core is 17mΩ, the impedance RP2 of the battery protection board is 10mΩ, the corresponding line impedance R3 of ae section is 12mΩ, the line impedance R4 of fd section is 11mΩ, and the sampling resistor R0 is 1mΩ. The capacity of the third battery 305 is 2400mAh. The internal resistance RS2 of the battery core is 16mΩ, the impedance RP2 of the battery protection board is 8mΩ, the corresponding ag section line impedance R5 is 13.8mΩ, the hd section line impedance R6 is 8mΩ, and the sampling resistor R0 is 1mΩ. The example charge-discharge circuit was subjected to a charge-discharge test and the voltages and currents of three batteries were monitored simultaneously, and the results are shown in fig. 7 and 8. As can be seen from fig. 7 and 8, with the design of the embodiment of the present application, the cell voltages of the three batteries increase and decrease synchronously during the charge and discharge processes, and the current distribution ratio BAT1: BAT2: BAT3 = 11:10:12.

As shown in fig. 9, a charging and discharging circuit 400 provided in an embodiment of the present application is disposed between a charging port (e.g., a USB interface) and a ground, and can charge batteries (404, 405) during charging and can supply power to a load 410 during discharging. As shown in fig. 9, a charge-discharge circuit 400 provided by an embodiment of the present application includes a first charge chip 401, a second charge chip 402, a third charge chip 403, a first battery 404, a second battery 405, a first sampling resistor 406, a second sampling resistor 407, a first fuel gauge 408, and a second fuel gauge 409.

The first charging chip 401, the second charging chip 402, and the third charging chip 403 are connected in parallel between the first node a and the eighth node h, specifically, the first charging chip 401 is disposed between the second node b and the third node c, the second charging chip 402 is disposed between the seventh node g and the eighth node h, the third charging chip 403 is disposed between the ninth node i and the tenth node j, the second node b, the seventh node g, and the ninth node are connected to the first node a, and the third node, the tenth node j, and the eighth node h are connected. The first charging chip 401 is, for example, a regular charging chip (buck charger), and the second charging chip 402 and the third charging chip 403 are, for example, quick charging chips (SC CHARGER). The charging power of the second charging chip 402 and the third charging chip 403 is greater than the charging power of the first charging chip 401, for example, the charging power of the first charging chip 401 is 5W or 10W, and the charging power of the second charging chip 402 and the third charging chip 403 is 18W, 22W, 40W, 66W, or other greater charging power. The charging power of the second charging chip 402 and the third charging chip 403 may be the same or different. The first charging chip 401 is used for the charge-intercepting process and the discharge process of the charge-discharge circuit 400. The second charging chip 402 and the third charging chip are used for a fast charging process of the charge-discharge circuit 400.

The first battery 404 (i.e., BAT 1) is disposed between the sixth node d and the fourth node e, the electric quantity of the first battery 404 is Q1, the internal resistance of the battery cell is RS1, and the impedance of the battery protection board is RP1.

The second battery 405 (i.e., BAT 2) is disposed between the eleventh node k and the twelfth node m, the electric quantity of the second battery 405 is Q2, the internal resistance of the battery cell is RS2, and the impedance of the battery protection board is RP2.

The first sampling resistor 406 is disposed between the fourth node e and the fifth node ff, and the first sampling resistor 406 is, for example, a precision resistor, and the resistance value thereof is R0, and R0 is, for example, 1mΩ.

The second sampling resistor 407 is disposed between the twelve nodes m and the fifth node f, and the second sampling resistor 407 has a specification and model identical to those of the first sampling resistor 406.

The first electricity meter 408 is connected in parallel to two ends of the first sampling resistor 406, and is used for determining the voltage and the current of the first battery 404 by sampling parameters such as the voltage of the first sampling resistor 406, and then determining the electric quantity of the first battery 404 by self algorithm.

The second electricity meter 409 is connected in parallel to two ends of the second sampling resistor 407, and is used for determining the voltage and the current of the second battery 405 by sampling parameters such as the voltage of the second sampling resistor 407, and then determining the electric quantity of the second battery 405 by using an algorithm of the second electricity meter 409.

Illustratively, the charge-discharge circuit 400 according to the embodiment of the present application is suitable for a double-folded (with a rotating shaft) folding screen scheme, which has a main board and a sub-board, wherein the first charging chip 401, the second charging chip 402, the first sampling resistor 406, and the first fuel gauge 408 are disposed on the main board, and the first battery 404 is connected to the main board. The third charging chip 403, the second sampling resistor 407, and the second fuel gauge 409 are provided on a sub-board, and the second battery 405 is connected to the sub-board. Wherein the main board, the sub-board, and the battery are connected to the main board and the sub-board through, for example, an FPC.

In the charge-discharge circuit 400 according to the embodiment of the present application, the branch between the first node a and the fifth node f through the second node b, the third node c, the sixth node d, and the fourth node e is the first branch, that is, the fast charge loop of the first battery 404. The first node a and the second node b are connected through a line, and the line impedance is R1. The third node c and the sixth node d are connected by a line, and the line impedance is R2. The fourth node e and the fifth node f are connected through a line, and the line impedance is R3. The total resistance of the first branch is: r0+r1+r2+r3+r1+rp1.

The branch between the first node a and the fifth node f through the ninth node i, the tenth node j, the eleventh node k and the twelfth node m is the second branch, that is, the fast charge loop of the second battery 405. The first node a and the ninth node i are connected through a line, and the line impedance of the first node a and the ninth node i is R4. The tenth node j and the eleventh node k are connected by a line, and the line impedance is R5. The twelfth node m and the fifth node f are connected by a line, and the line impedance is R6. The total resistance of the second branch is: r0+r4+r5+r6+r2+rp2.

The branches between the eighth node h and the fifth node f through the sixth node d and the fourth node e are third branches, namely, the charge intercepting branch and the discharge intercepting branch of the first battery 404. The eighth node h and the sixth node d are connected through a line, and the line impedance of the eighth node h and the sixth node d is R7. The fourth node e and the fifth node f are connected through a line, and the line impedance is R3. The total resistance of the third branch is: r0+r3+r7+r1+rp1.

The branches between the eighth node h and the fifth node f through the eleventh node k and the twelfth node m are fourth branches, that is, the charge intercepting branch and the discharge intercepting branch of the second battery 405. The eighth node h and the eleventh node k are connected through a line, and the line impedance of the eighth node h and the eleventh node k is R8. The twelfth node m and the fifth node f are connected by a line, and the line impedance is R6. The total resistance of the fourth branch is: r0+r6+r8+r2+rp2.

The charging process of the charge-discharge circuit 400 according to the embodiment of the present application is, for example: the fast charging phase is performed first, the current is shunted through the first node a to the second node b and the ninth node i, then enters the second charging core 402 and the third charging core 403, respectively, finally enters the first battery 404 and the second battery 405, respectively, and then the current returns from the fifth node e and the twelfth node m to the fifth node f (referenced to ground). Then, the charge cutoff phase is performed, the current is switched from the second charging core 402 and the third charging core 403 to the first charging core 401, the flow path of the current is from the first node a to the eighth node h, and then shunted to the fourth node d and the eleventh node k so as to enter the first battery 404 and the second battery 405, respectively, and then the current is returned from the fifth node e and the twelfth node m to the fifth node f (reference ground).

The discharging process of the charge-discharge circuit 400 according to the embodiment of the present application is as follows: the current flows from the sixth node d of the first battery 404 and the eleventh node k of the second battery 405 to the eighth node h, flows to the output terminal of the first charging chip 401, i.e., the first node a, after being mixed to the eighth node h, then to the load 410, and finally is shunted to the fourth node e and the twelfth node m via the fifth node f (with reference to ground), thereby returning to the negative electrodes of the first battery 404 and the second battery 405.

In the charging and discharging process, the voltage and the current of the first battery 404 and the second battery 405 are respectively read by the first fuel gauge 408 and the second fuel gauge 409, then the electric quantity of the first battery 404 and the electric quantity of the second battery 405 are calculated by the algorithm of the device, and finally the total electric quantity of the batteries is calculated together.

In order to achieve balanced charge and discharge of the batteries in the embodiment of the present application, when designing the charge and discharge circuit 400, a design is adopted in which the total impedance of the charge and discharge circuits (the first branch and the second branch) of each of the first battery 404 and the second battery 405 is inversely proportional to the capacities of the first battery 404 and the second battery 405 themselves.

In particular, during the fast charge phase, the impedance of the charge loop of the first battery 404 is r0+r1+r2+r3+r1+rp1, the impedance of the charge loop of the second battery 405 is r0+r4+r5+r6+r2+rp2,

(R0+r1+r2+r3+r1+rp1): (r0+r4+r5+r6+r2+rp2) =q2: q1. The design can ensure that the voltage of the two batteries synchronously increases in the charging and discharging processes, the current accords with respective multiplying power, the full charge capacity and the discharge capacity are improved, and the problem that the first battery 203 and the second battery 204 are different in ageing degree is avoided.

In the charge cutoff phase, the impedance of the charge circuit of the first battery 404 is r0+r6+r8+r2+rp2, (r0+r6+r8+r2+rp2): (r0+r6+r8+r2+rp2) =q2: q1. The design can ensure that the voltage of the two batteries synchronously increases in the charging and discharging processes, the current accords with respective multiplying power, the full charge capacity and the discharge capacity are improved, and the problem that the first battery 203 and the second battery 204 are different in ageing degree is avoided.

It should be appreciated that although the above embodiments are described taking the folding device as an example, the embodiments of the present application are not limited to the folding device, but may be applied to other electronic devices that use a plurality of batteries to cooperatively power.

The above embodiments are only for illustrating the technical solution of the present application, and not for limiting the same; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the application.

Claims

1. A charge-discharge circuit, comprising: the first branch circuit and the second branch circuit are arranged in parallel between the first node and the grounding node and are used for supplying power to the same load;

The first branch comprises a first battery, the first battery is arranged between the first node and the grounding node, the impedance of a line of the first node reaching the grounding node through the first battery is R10, the impedance of the first battery is R11, the impedance of other devices on the branch of the first node reaching the grounding node through the first battery is R12, and the capacity of the first battery is Q1;

the second branch comprises a second battery, the second battery is arranged between the first node and the grounding node, the impedance of a line of the first node reaching the grounding node through the second battery is R20, the impedance of the second battery is R21, the impedance of other devices on the branch of the first node reaching the grounding node through the second battery is R22, and the electric quantity of the second battery is Q2;

The first branch and the second branch satisfy: (r10+r11+r12) ×q1= (r20+r21+r22) ×q2.

2. The charge-discharge circuit of claim 1, further comprising a third branch, the third branch comprising:

The first branch, the second branch and the third branch satisfy: (r10+r11+r12) ×q1= (r20+r21+r22) ×q2= (r30+r31+r32) ×q3.

3. The charge-discharge circuit of claim 2, further comprising a first charge chip and a second charge chip disposed in parallel between the charge port and the first node, the first charge chip and the second charge chip being connected to anodes of the first battery, the second battery, and the third battery via the first node.

4. The charge-discharge circuit of claim 1, further comprising: the first charging chip, the second charging chip and the third charging chip are arranged between the first node and the eighth node in parallel, the first node reaches the grounding node through the second charging chip and the first battery, the first node reaches the grounding node through the third charging chip and the second battery, and the first charging chip is connected with the first battery and the second battery through the eighth node;

The impedance of a line of the eighth node reaching the grounding node through the first battery is R40, the impedance of the first battery is R41, and the impedance of other devices on a branch of the eighth node reaching the grounding node through the first battery is R42;

the impedance of a line of the eighth node reaching the grounding node through the second battery is R50, the impedance of the second battery is R51, and the impedance of other devices on a branch of the eighth node reaching the grounding node through the second battery is R52;

Wherein, (r40+r41+r42) ×q1= (r50+r51+r52) ×q2.

5. The charge and discharge circuit of any one of claims 1-4, wherein the first and second branches each include a sampling resistor and an electricity meter connected in parallel across the sampling resistor.

6. An electronic device comprising a charge-discharge circuit as claimed in any one of claims 1-5.

7. The electronic device of claim 6, wherein the electronic device is a foldable terminal.