Charging circuit and charging system
By designing a charging circuit and using a charging control chip and switch module to achieve a charging consistency balance for multiple lithium batteries, the problem of difficult to achieve battery consistency and high cost in the prior art is solved, and an efficient solution for battery charge and voltage consistency is achieved.
Patent Information
- Application Number
- CN202421786066.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-24
- Publication Date
- 2025-05-30
- Estimated Expiration
- 2034-07-24
AI Technical Summary
In the prior art, consistent balance of multi-cell lithium batteries is difficult to achieve, and the existing balance circuit schemes lead to increased battery structure size and high cost.
A charging circuit is designed, including a charging control chip, a first switch module, a second switch module, and a first battery and a second battery connected in series. Through the two voltage output terminals and two drive control terminals of the charging control chip, the driving switch module is constantly switched to realize the charging of the two batteries, ensuring that each battery is full and the voltage consistency between the batteries is high.
The charging consistency balance of multiple batteries is achieved, the circuit structure is simplified, the battery size and cost is reduced, while ensuring full charge and voltage consistency of each battery.
Smart Images
Figure CN222928117U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of lithium batteries, in particular to a charging circuit and a charging system. Background Art
[0002] As the power consumption of electronic products increases, the voltage of the supporting battery also becomes higher. Due to the limitation of lithium battery technology, high voltage must be solved in a series form. The more the number of series cells, the higher the requirement for battery consistency. How to achieve the consistency balance problem in the use of multiple batteries has become an important research direction.
[0003] Currently, the main measures for the consistency balance of multiple batteries include selecting cells with consistent production to reduce the polarization phenomenon of the cells during the use of electronic products. However, as the number of cycles increases, the trend of the voltage difference between cells cannot be avoided. There is also a method of adding a balancing circuit, but a balancing circuit needs to be set for each battery, resulting in an increase in the structural size of the battery and an increase in battery cost. There is also a solution of adding a charging balancing circuit to the charging IC, but there are fewer IC models with a charging balancing circuit, and the selectivity is low. Moreover, after the balance is started, the discharge current is small. When the charging current is large, the balancing function is very limited.
[0004] Therefore, it is crucial for those skilled in the art to design a charging circuit and a charging system that can meet the consistency balance requirements of multiple batteries and have a small volume and low cost. Summary of the Utility Model
[0005] The technical problem to be solved in the embodiment of the utility model is to provide a charging circuit and a charging system that can meet the consistency balance requirements of multiple batteries and have a small volume and low cost, so as to solve the problems of limited balancing function, high cost and large size in the prior art.
[0006] The utility model discloses a charging circuit, which includes: a charging control chip, a first switch module, a second switch module, and a first battery and a second battery connected in series. The voltage input end of the charging control chip is connected to an external power supply. The first voltage output end of the charging control chip is connected to the voltage input end of the first switch module. The voltage output end of the first switch module is connected to the positive electrode of the first battery. The second voltage output end of the charging control chip is connected between the first battery and the second battery. The voltage output end of the second switch module is connected to the negative electrode of the second battery. The first driving end of the charging control chip is connected to the control input end of the first switch module. The second driving end of the charging control chip is connected to the control input end of the second switch module.
[0007] Optionally, the first switch module includes a first MOS transistor and a second MOS transistor. The gates of the first MOS transistor and the second MOS transistor are both connected to the first driving terminal of the charging control chip. The source of the first MOS transistor is connected to the first voltage output terminal of the charging control chip. The source of the second MOS transistor is connected to the drain of the first MOS transistor. The drain of the second MOS transistor is connected to the positive electrode of the first battery.
[0008] Optionally, the second switch includes a third MOS transistor and a fourth MOS transistor. The gates of the third MOS transistor and the fourth MOS transistor are both connected to the second voltage output terminal of the charging control chip. The source of the third MOS transistor is grounded. The source of the fourth MOS transistor is connected to the drain of the third MOS transistor. The source of the fourth MOS transistor is connected to the negative electrode of the second battery.
[0009] Optionally, the first driving terminal of the charging control chip includes a first driving pin for connecting to the gate of the first MOS transistor and a second driving pin for connecting to the gate of the second MOS transistor.
[0010] Optionally, both the first MOS transistor and the second MOS transistor are PMOS transistors.
[0011] Optionally, the second driving terminal of the charging control chip includes a third driving pin for connecting to the gate of the third MOS transistor and a fourth driving pin for connecting to the gate of the fourth MOS transistor.
[0012] Optionally, both the third MOS transistor and the fourth MOS transistor are NMOS transistors.
[0013] Optionally, a protection resistor is provided between the voltage input terminal and the ground terminal of the charging control chip.
[0014] Optionally, the charging control chip is a CC1130T chip.
[0015] To solve the problems existing in the prior art, the present utility model provides a charging system, the solution of which lies in including a power interface and at least two charging circuits as described above, and at least two of the charging circuits are connected in series.
[0016] Compared with the prior art, the beneficial effects of the charging circuit provided by the embodiment of the present utility model are as follows: By designing a charging circuit, including a charging control chip, a first switch module, a second switch module, and a first battery and a second battery connected in series, the charging control chip includes two voltage output terminals and two drive control terminals. By continuously switching the first switch module and the second switch module, the function of charging two batteries with one charging control chip is realized. When one battery is fully charged, the uncharged battery can continue to be charged. Each battery can be fully charged, and the voltage consistency between the batteries is high when charging finally stops. Moreover, every two batteries share one charging control chip, which can effectively simplify the circuit, reduce the size of the battery structure, and lower the battery cost. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The technical solutions of the present utility model will be further described in detail below with reference to the drawings and embodiments. In the drawings:
[0018] Figure 1 is the system block diagram of the charging circuit provided by the embodiment of the present utility model;
[0019] Figure 2 is the circuit diagram of the charging circuit provided by the embodiment of the present utility model;
[0020] Figure 3 is the internal circuit diagram of the charging control chip provided by the embodiment of the present utility model;
[0021] Figure 4 is the circuit diagram of the charging system provided by the embodiment of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0022] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. Now, with reference to the drawings, the preferred embodiments of the present utility model will be described in detail.
[0023] As Figures 1 to 3 shown, the present utility model provides a specific embodiment of a charging circuit.
[0024] A charging circuit, referring to Figure 1 , the charging circuit includes a charging control chip 100, a first switch module 200, a second switch module 300, and a first battery 400 and a second battery 500 connected in series.
[0025] Among them, referring to Figure 1, the voltage input terminal VCC of the charging control chip 100 is connected to an external power supply 600, the first voltage output terminal BAT of the charging control chip 100 is connected to the voltage input terminal of the first switch module 200, the voltage output terminal of the first switch module 200 is connected to the positive electrode of the first battery 400, the second voltage output terminal BAT2 of the charging control chip 100 is connected between the first battery 400 and the second battery 500, the voltage output terminal of the second switch module 300 is connected to the negative electrode of the second battery 500, the first driving terminal of the charging control chip 100 is connected to the control input terminal of the first switch module 200, and the second driving terminal of the charging control chip 100 is connected to the control input terminal of the second switch module 300.
[0026] Specifically, referring to Figure 1 and Figure 2 , the charging control chip 100 includes a VCC pin as its voltage input terminal for connecting to the external power supply 600; the charging control chip 100 includes two voltage output terminals for supplying power to the first battery 400 and the second battery 500 respectively; the charging control chip 100 further includes two driving control terminals for controlling the opening or closing of the first switch module 200 and the second switch module 300 respectively; an output control unit is also provided inside the charging control chip 100, and the output control unit is used to control voltage output, that is, to control the opening or shutting down of the first voltage output terminal and the second voltage output terminal to form two charging paths.
[0027] Referring to Figure 1 and Figure 2 , the charging path 1 is: the voltage input terminal VCC of the charging control chip 100 is connected to the external power supply 600 to obtain electric energy, the output control unit of the charging control chip 100 controls the switch to the first voltage output terminal, and the input voltage passes through the first voltage output terminal - the first switch module 200 - the positive electrode of the first battery 400 - the negative electrode of the first battery 400 - the second voltage output terminal - the output control unit - GND in sequence; the charging path 2 is: the voltage input terminal VCC of the charging control chip 100 is connected to the external power supply 600 to obtain electric energy, the output control unit of the charging control chip 100 controls the switch to the second voltage output terminal, and the input voltage passes through the second voltage output terminal - the positive electrode of the second battery 500 - the negative electrode of the second battery 500 - the second switch module 300 - GND in sequence.
[0028] Current main measures for multi-cell consistency balance:
[0029] 1. Battery manufacturers strictly perform matching according to standards during production; this method reduces the phenomenon of intensified cell polarization during the use of electronic products through the selection of cell production consistency; however, with the increase in the number of cycles, the increasing trend of the voltage difference between cells cannot be avoided.
[0030] 2. The battery protection board adds a balancing circuit. This method uses a lithium protection IC or an external balancing IC to detect when the voltage difference between battery cells exceeds a certain threshold, and then discharges between the batteries to reduce the voltage of the battery cell with a higher voltage, thereby reducing the voltage difference between the battery cells. However, one balancing circuit is required for each battery cell, which will increase the battery structure size and the battery cost. In addition, the balancing circuit will increase the battery power consumption and reduce the battery usage and storage time.
[0031] 3. The charging IC adds a charging balancing circuit. This method uses the charging IC to detect the voltage difference between the batteries during charging. When the voltage difference exceeds a certain threshold, the charging of the high-voltage battery is stopped and it is discharged. However, there are fewer IC models with a charging balancing circuit, the selectivity is relatively low, and after the balancing is started, the discharge current is small. When the charging current is large, the balancing function is very limited.
[0032] In this embodiment, by designing a charging circuit including a charging control chip, a first switch module, a second switch module, and a first battery and a second battery connected in series, the charging control chip includes two voltage output terminals and two drive control terminals. By continuously switching the first switch module and the second switch module, the function of one charging control chip charging two batteries is realized. When one battery is fully charged, the uncharged battery can continue to be charged. Each battery can be fully charged, and the voltage consistency between the batteries is high when the charging finally stops. Moreover, every two batteries share one charging control chip, which can effectively simplify the circuit, reduce the size of the battery structure, and lower the battery cost.
[0033] In one of the embodiments, referring to Figure 2 , the first switch module 200 includes a first MOS transistor Q1 and a second MOS transistor Q2. The gates of the first MOS transistor Q1 and the second MOS transistor Q2 are both connected to the first drive terminal of the charging control chip 100. The source of the first MOS transistor Q1 is connected to the first voltage output terminal BAT of the charging control chip 100. The source of the second MOS transistor Q2 is connected to the drain of the first MOS transistor Q1. The drain of the second MOS transistor Q2 is connected to the positive electrode of the first battery 400.
[0034] Specifically, referring to Figure 2 , the charging control chip 100 includes a first drive pin PG2 and a second drive pin PG1. The first drive pin PG2 and the second drive pin PG1 serve as its first drive terminal. The first drive pin PG2 is connected to the gate of the first MOS transistor Q1 to control the on and off of the first MOS transistor Q1. The second drive pin PG1 is connected to the gate of the second MOS transistor Q2 to control the on and off of the second MOS transistor Q2.
[0035] When charging the first battery 400, the output control unit of the charging control chip 100 controls the switch to the first voltage output terminal, pulls down its second voltage output terminal to the ground terminal, and the first driving pin PG2 and the second driving pin PG1 respectively control the first MOS transistor Q1 and the second MOS transistor Q2 to turn on. The first voltage output terminal outputs current to the source of the first MOS transistor Q1, and enters the drain of the second MOS transistor Q2 through the drain of the first MOS transistor Q1, and enters the first battery 400 through the source of the second MOS transistor Q2. Since the negative electrode of the first battery 400 is connected to the second voltage output terminal BAT2 of the charging control chip 100, it is also pulled down to the ground terminal to form a closed charging loop.
[0036] In one embodiment, referring to Figure 2 , both the first MOS transistor Q1 and the second MOS transistor Q2 are PMOS transistors.
[0037] Specifically, the channel of the PMOS transistor is P-type, and the control electrode is the negative electrode. When the gate voltage is at a low level, the P-type channel conducts, and charges flow from the drain to the source, forming a path and outputting a high level; when the gate voltage is at a high level, the P-type channel is cut off, and charges cannot flow from the drain to the source, breaking the path and outputting a low level.
[0038] In one embodiment, referring to Figure 2 , the second switch includes a third MOS transistor Q3 and a fourth MOS transistor Q4. The gates of the third MOS transistor Q3 and the fourth MOS transistor Q4 are both connected to the second voltage output terminal BAT2 of the charging control chip 100. The source of the third MOS transistor Q3 is grounded, the source of the fourth MOS transistor Q4 is connected to the drain of the third MOS transistor Q3, and the source of the fourth MOS transistor Q4 is connected to the negative electrode of the second battery 500.
[0039] Specifically, referring to Figure 2 , the charging control chip 100 includes a third driving pin NG2 and a fourth driving pin NG. The third driving pin NG2 and the fourth driving pin NG serve as its second driving end. The third driving pin NG2 is connected to the gate of the third MOS transistor Q3 to control the on and off of the third MOS transistor Q3, and the fourth driving pin NG is connected to the gate of the fourth MOS transistor Q4 to control the on and off of the fourth MOS transistor Q4.
[0040] When charging the second battery 500, the output control unit of the charging control chip 100 controls the switch to the second voltage output terminal. The third driving pin NG2 and the fourth driving pin NG respectively control the third MOS transistor Q3 and the fourth MOS transistor Q4 to turn on. The second voltage output terminal outputs current to the positive electrode of the second battery 500, and the negative electrode of the second battery 500 is grounded through the fourth MOS transistor Q4 and the third MOS transistor Q3 respectively to form a closed charging loop.
[0041] In one embodiment, referring to Figure 2 , both the third MOS transistor Q3 and the fourth MOS transistor Q4 are NMOS transistors.
[0042] Specifically, the channel of the NMOS transistor is of N type, and its control electrode is at a positive voltage. When the gate voltage is at a high level, the channel of the NMOS transistor conducts and outputs a high level; when the gate voltage is at a low level, the channel of the NMOS transistor is cut off and outputs a low level.
[0043] In one embodiment, referring to Figure 2 , a protection resistor R1 is provided between the voltage input terminal VCC of the charging control chip 100 and the ground terminal.
[0044] In one embodiment, referring to Figure 3 , the charging control chip 100 is a CC1130T chip.
[0045] Specifically, referring to Figure 3 , the internal logic circuit of the CC1130T chip includes a constant current control unit 110, a temperature compensation unit 120, a full charge control unit 130, an enable unit 140, an output control unit 150, and a charging protection module 160. Through the output control unit 150, the intermittent switching of two internal MOSs can be controlled, and in cooperation with the external first switching module 200 and second switching module 300, charging of two batteries can be achieved; the specific charging mode is linear charging, and a 5V adapter power supply can be externally connected, and linear buck processing is performed through a linear buck module to perform constant current and constant voltage charging for a single battery.
[0046] Furthermore, referring to Figure 2 and Figure 3 , when charging the first battery 400, the corresponding charging path is: 5V voltage input → M1200 → BAT → the first MOS transistor Q1 → the second MOS transistor Q2 → the positive electrode of the first battery 400 → the negative electrode of the first battery 400 → BAT2 → MOS2 of the output control unit 150 → GND; in this path, the high - end MOS1 connected between the output control unit 150 and BAT is off, while the low - end MOS2 connected to GND is on; at the same time, the third MOS transistor Q3 and the fourth MOS transistor Q4 are also in an off state; when charging the second battery 500, the charging path is: 5V input → M1200 → the high - end MOS1 of the output control unit 150 → BAT2 → the positive electrode of the second battery → the negative electrode of the second battery → the third MOS transistor Q3 → the fourth MOS transistor Q4 → GND; in this path, the high - end MOS1 connected between the output control unit 150 and BAT is on, while the low - end MOS2 connected to GND is off; at the same time, the first MOS transistor Q1 and the second MOS transistor Q2 are also in an off state.
[0047] As Figure 4 shown, the present utility model also provides a specific embodiment of a charging system.
[0048] A charging system, referring to Figure 4 , includes a power interface J1 and at least two charging circuits as above, and the at least two charging circuits are connected in series.
[0049] Taking the charging system with two charging circuits as an example, referring to Figure 4 , the charging system includes a first charging circuit 11 and a second charging circuit 12. The VCC pin of the charging control chip 100 in the first charging circuit 11 is connected to the positive pole of the power interface J1, the GND pin of the charging control chip 100 in the first charging circuit 11 is connected to the VCC pin of the charging control chip 100 in the second charging circuit 12, and the GND pin of the charging control chip 100 in the second charging circuit 12 is grounded to form a series structure, so as to realize charging four batteries respectively, charging the low-voltage battery separately, fully ensuring the consistency between the batteries, and delaying the service life of the battery pack.
[0050] It should be understood that the above embodiments are only used to illustrate the technical solutions of the present utility model, rather than to limit it. For those skilled in the art, the technical solutions recorded in the above embodiments can be modified, or some of the technical features can be equivalently replaced; and all such modifications and replacements should fall within the protection scope of the appended claims of the present utility model.
Claims
1. A charging circuit, characterized in that: include: A charging control chip, a first switch module, a second switch module, and a first battery and a second battery connected in series, wherein the voltage input end of the charging control chip is connected to an external power supply, the first voltage output end of the charging control chip is connected to the voltage input end of the first switch module, the voltage output end of the first switch module is connected to the positive electrode of the first battery, the second voltage output end of the charging control chip is connected between the first battery and the second battery, the voltage output end of the second switch module is connected to the negative electrode of the second battery, the first driving end of the charging control chip is connected to the control input end of the first switch module, and the second driving end of the charging control chip is connected to the control input end of the second switch module.
2. The charging circuit according to claim 1, characterized in that: The first switch module includes a first MOS tube and a second MOS tube, the gate of the first MOS tube and the gate of the second MOS tube are both connected to the first driving end of the charging control chip, the source of the first MOS tube is connected to the first voltage output end of the charging control chip, the source of the second MOS tube is connected to the drain of the first MOS tube, and the drain of the second MOS tube is connected to the positive electrode of the first battery.
3. The charging circuit according to claim 1, characterized in that: The second switch includes a third MOS tube and a fourth MOS tube, the gates of the third MOS tube and the fourth MOS tube are both connected to the second voltage output terminal of the charging control chip, the source of the third MOS tube is grounded, the source of the fourth MOS tube is connected to the drain of the third MOS tube, and the source of the fourth MOS tube is connected to the negative electrode of the second battery.
4. The charging circuit according to claim 2, characterized in that: The first driving end of the charging control chip includes a first driving pin for connecting to the gate of the first MOS tube and a second driving pin for connecting to the gate of the second MOS tube.
5. The charging circuit according to claim 4, characterized in that: The first MOS tube and the second MOS tube are both PMOS tubes.
6. The charging circuit according to claim 3, characterized in that: The second driving end of the charging control chip includes a third driving pin connected to the gate of the third MOS tube and a fourth driving pin connected to the gate of the fourth MOS tube.
7. The charging circuit according to claim 6, characterized in that: The third MOS tube and the fourth MOS tube are both NMOS tubes.
8. The charging circuit according to claim 1, characterized in that: A protection resistor is arranged between the voltage input terminal and the ground terminal of the charging control chip.
9. The charging circuit according to claim 1, characterized in that: The charging control chip is a CC1130T chip.
10. A charging system, characterized in that: It comprises a power supply interface and at least two charging circuits as described in any one of claims 1 to 9, wherein at least two of the charging circuits are connected in series.