Lithium battery charging speed control circuit

Abstract

The utility model relates to the technical field of lithium batteries, in particular to a lithium battery charging speed control circuit which comprises a lithium battery, a voltage stabilizing module, a main control module, a charging module and a temperature measuring module, the voltage stabilizing module is used for providing stable voltage for the main control module, the main control module comprises a first AD chip, a second AD chip and a main control chip, and the charging module is used for charging the lithium battery. The charging module comprises a charging unit and a control unit, the charging unit is used for controlling the charging process of the lithium battery, the control unit is used for controlling charging voltage to directly supply power to the main control module during charging, and the temperature measuring module is used for acquiring the temperature of the lithium battery during charging. According to the utility model, the MAX846A in the charging unit can detect the voltage and current during charging, then the main control chip is used for controlling the charging speed, and meanwhile, the temperature measuring module can obtain the temperature of the lithium battery during charging, so that more information is provided for the main control chip, the charging stability is ensured, and the practicability is stronger.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium batteries, in particular to a lithium battery charging speed control circuit. Background Art

[0002] Lithium batteries are a common type of storage battery. During the charging process of lithium batteries, the charging speed of lithium batteries needs to be controlled. Too fast charging speed may cause the battery to overheat, causing fire or explosion. By controlling the charging speed, these risks can be reduced. Too fast charging speed may cause the battery capacity to decay rapidly, thus shortening the battery life. The appropriate charging speed can extend the battery life.

[0003] A utility model patent with publication number CN218829148U discloses a lithium battery charging control circuit, including a charging circuit, the charging circuit is connected to a lithium battery pack, the lithium battery pack is provided with a protection board, a sampling circuit and a control module are provided between the protection board and the charging circuit, the sampling circuit is used to collect the voltage of the lithium battery pack, the sampling circuit includes a sampling resistor and an operational amplifier unit, one end of the sampling resistor is electrically connected to the protection board and the other end is electrically connected to the same direction end of the operational amplifier unit, the reverse end of the operational amplifier unit is connected to the output end to form a voltage follower circuit, the output end of the operational amplifier unit is also connected to an AD module, the AD module is used to convert analog signals into digital signals, and the output end of the AD module is connected to the control module; the control module includes an MCU chip and a battery charging controller, the MCU chip and the AD module are connected via UART serial port communication; the battery charging controller is electrically connected to the charging circuit.

[0004] Although the utility model can realize voltage detection of lithium battery packs, the battery charging controller used therein already has a corresponding voltage detection function, the design is redundant, and the practicality is not strong. Utility Model Content

[0005] The purpose of the utility model is to provide a lithium battery charging speed control circuit to solve the problems raised in the above background technology.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] A lithium battery charging speed control circuit comprises a lithium battery, a voltage stabilizing module, a main control module, a charging module and a temperature measuring module, wherein the voltage stabilizing module is used to provide a stable voltage to the main control module, the main control module comprises a first AD chip, a second AD chip and a main control chip, the charging module comprises a charging unit and a control unit, the charging unit is used to control the charging process of the lithium battery, the control unit is used to control the charging voltage to directly supply power to the main control module during charging, and the temperature measuring module is used to obtain the temperature of the lithium battery during charging.

[0008] Preferably, the charging unit includes MAX846, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a first diode D1 and a first PMOS tube PMOS1;

[0009] Pin 1 of MAX846A is connected to the charging voltage, pin 2 of MAX846A is connected to the VDD1 pin of the main control chip, the first end of the first capacitor C1 is connected to pin 2 of MAX846A, the second end of the first capacitor C1 is grounded, the first end of the first resistor R1 is connected to the first end of the first capacitor C1, the second end of the first resistor R1 is connected to pin 9 of MAX846A, the first end of the second capacitor C2 is connected to the first end of the first resistor R1, the second end of the second capacitor C2 is connected to pin 3 of MAX846A, the first end of the third capacitor C3 is connected to the first end of the first resistor R1, the second end of the third capacitor C3 is connected to pin 5 of MAX846A, pin 4 of MAX846A is grounded, and the second resistor R2 The first end is connected to the PWM1 pin of the main control chip, the second end of the second resistor R2 is connected to the 6th pin of MAX846A, the first end of the third resistor R3 is connected to the PWM2 pin of the main control chip, the second end of the third resistor R3 is connected to the 7th pin of MAX846A, the 7th pin of MAX846A is also connected to the input pin of the second AD chip, the first end of the fourth resistor R4 is connected to the I / O3 pin of the main control chip, the second end of the fourth resistor R4 is connected to the 8th pin of MAX846A, the 9th pin of MAX846A is connected to the RST pin of the main control chip, the first end of the fourth capacitor C4 is connected to the 9th pin of MAX846A, the second end of the fourth capacitor C4 is grounded, and the MAX846A The 10th pin of MAX846A is connected to the I / O2 pin of the main control chip, the 11th pin of MAX846A is connected to the I / O1 pin of the main control chip, the 12th pin of MAX846A is connected to the first end of the fifth resistor R5, the second end of the fifth resistor R5 is connected to the first end of the sixth resistor R6, the first end of the sixth resistor R6 is also connected to the input pin of the first AD chip, the second end of the sixth resistor R6 is grounded, the 13th pin of MAX846A is connected to the first end of the seventh resistor R7, the first end of the seventh resistor R7 is also connected to the charging voltage, the second end of the seventh resistor R7 is connected to the source of the first PMOS tube PMOS1, the drain of the first PMOS tube PMOS1 is connected to the anode of the first diode D1, and the first diode D 1 is connected to the positive electrode of the lithium battery, the first end of the fifth resistor R5 is also connected to the negative electrode of the first diode D1, the negative electrode of the lithium battery is grounded, the 14th pin of MAX846A is connected to the second end of the seventh resistor R7, the 15th pin of MAX846A is grounded, the 16th pin of MAX846A is connected to the second end of the fifth capacitor C5, the first end of the fifth capacitor C5 is connected to the second end of the seventh resistor R7, the first end of the eighth resistor R8 is connected to the first end of the fifth capacitor C5, the second end of the eighth resistor R8 is connected to the second end of the fifth capacitor C5, the gate of the first PMOS tube PMOS1 is connected to the second end of the fifth capacitor C5, the first end of the sixth capacitor C6 is connected to the negative electrode of the first diode D1, and the second end of the sixth capacitor C6 is grounded.

[0010] Preferably, the control unit includes a ninth resistor R9, a tenth resistor R10, a second diode D2 and a second PMOS transistor PMOS2;

[0011] The first end of the ninth resistor R9 is connected to the charging voltage, the second end of the ninth resistor R9 is connected to the gate of the second PMOS tube PMOS2, the first end of the tenth resistor R10 is connected to the second end of the ninth resistor R9, the second end of the tenth resistor R10 is grounded, the anode of the second diode D2 is connected to the first end of the ninth resistor R9, the second end of the second diode D2 is connected to the input end of the voltage stabilizing module, the drain of the second PMOS tube PMOS2 is connected to the positive electrode of the lithium battery, and the source of the second PMOS tube PMOS2 is connected to the cathode of the second diode D2.

[0012] Preferably, the output end of the voltage stabilizing module is connected to the VDD1 pin of the main control chip, the output pin of the first AD chip is correspondingly connected to the input pin of the main control chip, and the output pin of the second AD chip is correspondingly connected to the input pin of the main control chip.

[0013] Preferably, the temperature measurement module includes DS18B20 and an eleventh resistor R11;

[0014] The GND pin of DS18B20 is grounded, the VDD2 pin of DS18B20 is connected to the VDD1 pin of the main control chip, the first end of the eleventh resistor R11 is connected to the VDD2 pin of DS18B20, the second end of the eleventh resistor R11 is connected to the I / O4 pin of the main control chip, and the DO pin of DS18B20 is connected to the second end of the eleventh resistor R11.

[0015] Compared with the prior art, the beneficial effects of the utility model are:

[0016] 1. The utility model can detect the voltage and current during charging by setting the MAX846A in the charging unit, and then use the main control chip to control the charging speed. At the same time, the temperature measurement module can obtain the temperature of the lithium battery during charging, providing more information for the main control chip to ensure stable charging and stronger practicality.

[0017] 2. The utility model provides a control unit. When the charging voltage is used to charge the lithium battery, the control unit cuts off the power supply of the lithium battery, and the charging voltage directly supplies power to the voltage stabilizing module, the main control module and the temperature measuring module, thereby shortening the charging time of the lithium battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0019] Figure 2 It is a circuit diagram of the charging module in the utility model;

[0020] Figure 3 It is a circuit diagram of the charging unit in the utility model;

[0021] Figure 4 A circuit diagram of a control unit in the utility model;

[0022] Figure 5 It is the circuit diagram of the main control module and the temperature measurement module in the utility model;

[0023] Figure 6 It is the circuit diagram of the temperature measurement module in the utility model.

[0024] In the figure:

[0025] 1. Lithium battery;

[0026] 2. Voltage stabilizing module;

[0027] 3. Main control module; 30. First AD chip; 31. Second AD chip; 32. Main control chip;

[0028] 4. Charging module; 40. Charging unit; 41. Control unit;

[0029] 5. Temperature measurement module. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the utility model to clearly and completely describe the technical solution in the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0031] See also Figure 1-Figure 6 , the utility model provides a technical solution:

[0032] A lithium battery charging speed control circuit comprises a lithium battery 1, a voltage stabilizing module 2, a main control module 3, a charging module 4 and a temperature measuring module 5. The voltage stabilizing module 2 is used to provide a stable voltage to the main control module 3. The main control module 3 comprises a first AD chip 30, a second AD chip 31 and a main control chip 32. The charging module 4 comprises a charging unit 40 and a control unit 41. The charging unit 40 is used to control the charging process of the lithium battery 1. The control unit 41 is used to control the charging voltage to directly supply power to the main control module 3 during charging. The temperature measuring module 5 is used to obtain the temperature of the lithium battery 1 during charging. The main control chip 32 can use a common single-chip microcomputer. Then, the voltage stabilizing module 2 is selected according to the specifications of the first AD chip 30, the second AD chip 31 and the main control chip 32. In addition, the operating voltages of the first AD chip 30, the second AD chip 31 and the main control chip 32 are kept consistent as much as possible. The lithium battery 1 is a single lithium battery or a lithium battery pack. The voltage, current and temperature of the lithium battery 1 during charging are obtained, and the charging speed is controlled to extend the service life of the lithium battery 1.

[0033] In this embodiment, the charging unit 40 includes MAX846, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a first diode D1 and a first PMOS tube PMOS1;

[0034] Pin 1 of MAX846A is connected to the charging voltage, pin 2 of MAX846A is connected to the 32VDD1 pin of the main control chip, the first end of the first capacitor C1 is connected to pin 2 of MAX846A, the second end of the first capacitor C1 is grounded, the first end of the first resistor R1 is connected to the first end of the first capacitor C1, the second end of the first resistor R1 is connected to pin 9 of MAX846A, the first end of the second capacitor C2 is connected to the first end of the first resistor R1, the second end of the second capacitor C2 is connected to pin 3 of MAX846A, the first end of the third capacitor C3 is connected to the first end of the first resistor R1, the second end of the third capacitor C3 is connected to pin 5 of MAX846A, pin 4 of MAX846A is grounded, the second resistor R2 The first end is connected to the PWM1 pin of the main control chip 32, the second end of the second resistor R2 is connected to the 6th pin of MAX846A, the first end of the third resistor R3 is connected to the PWM2 pin of the main control chip 32, the second end of the third resistor R3 is connected to the 7th pin of MAX846A, the 7th pin of MAX846A is also connected to the input pin of the second AD chip 31, the first end of the fourth resistor R4 is connected to the I / O3 pin of the main control chip 32, the second end of the fourth resistor R4 is connected to the 8th pin of MAX846A, the 9th pin of MAX846A is connected to the RST pin of the main control chip 32, the first end of the fourth capacitor C4 is connected to the 9th pin of MAX846A, the second end of the fourth capacitor C4 is grounded, and the Pin 10 is connected to pin 32I / O2 of the main control chip, pin 11 of MAX846A is connected to pin 32I / O1 of the main control chip, pin 12 of MAX846A is connected to the first end of the fifth resistor R5, the second end of the fifth resistor R5 is connected to the first end of the sixth resistor R6, the first end of the sixth resistor R6 is also connected to the input pin of the first AD chip 30, the second end of the sixth resistor R6 is grounded, pin 13 of MAX846A is connected to the first end of the seventh resistor R7, the first end of the seventh resistor R7 is also connected to the charging voltage, the second end of the seventh resistor R7 is connected to the source of the first PMOS tube PMOS1, the drain of the first PMOS tube PMOS1 is connected to the anode of the first diode D1, and the first diode D1 The negative electrode is connected to the positive electrode of the lithium battery 1, the first end of the fifth resistor R5 is also connected to the negative electrode of the first diode D1, the negative electrode of the lithium battery 1 is grounded, the 14th pin of the MAX846A is connected to the second end of the seventh resistor R7, the 15th pin of the MAX846A is grounded, the 16th pin of the MAX846A is connected to the second end of the fifth capacitor C5, the first end of the fifth capacitor C5 is connected to the second end of the seventh resistor R7, the first end of the eighth resistor R8 is connected to the first end of the fifth capacitor C5, the second end of the eighth resistor R8 is connected to the second end of the fifth capacitor C5, the gate of the first PMOS tube PMOS1 is connected to the second end of the fifth capacitor C5, the first end of the sixth capacitor C6 is connected to the negative electrode of the first diode D1, and the second end of the sixth capacitor C6 is grounded;

[0035] Pins 1-16 of MAX846A correspond to DCIM, VL, CCL, GND, CCV, VEST, ISET, OFFV, PWROK, CELL2, ON, BATT, CS+, CS-, PGND and DRV. Pin 12 of MAX846A is used for voltage measurement, and pin 7 of MAX846A is used for current measurement. PWM1 and PWM2 pins of the main control chip 32 are used as control pins, and the PWM signal is used to control the charging speed. I / O1, I / O2 and I / O3 of the main control chip 32 can control the charging process such as the charging switch and the charging mode. In addition, the spare pins of the main control chip 32 can also be used for other purposes.

[0036] Specifically, the control unit 41 includes a ninth resistor R9, a tenth resistor R10, a second diode D2 and a second PMOS transistor PMOS2;

[0037] A first end of the ninth resistor R9 is connected to the charging voltage, a second end of the ninth resistor R9 is connected to the gate of the second PMOS tube PMOS2, a first end of the tenth resistor R10 is connected to the second end of the ninth resistor R9, a second end of the tenth resistor R10 is grounded, an anode of the second diode D2 is connected to the first end of the ninth resistor R9, a second end of the second diode D2 is connected to the input end of the voltage regulator module 2, a drain of the second PMOS tube PMOS2 is connected to the positive electrode of the lithium battery 1, and a source of the second PMOS tube PMOS2 is connected to the cathode of the second diode D2;

[0038] When the charging voltage is used to charge the lithium battery 1 , the second PMOS tube PMOS2 cuts off the power supply of the lithium battery 1 , and the charging voltage is used to directly charge the voltage stabilizing module 2 , the main control module 3 and the temperature measuring module 5 , thereby shortening the charging time of the lithium battery 1 .

[0039] Furthermore, the output terminal of the voltage stabilizing module 2 is connected to the VDD1 pin of the main control chip 32, the output pin of the first AD chip 30 is connected to the input pin of the main control chip 32 correspondingly, and the output pin of the second AD chip 31 is connected to the input pin of the main control chip 32 correspondingly.

[0040] In addition, the temperature measurement module 5 includes DS18B20 and an eleventh resistor R11;

[0041] The GND pin of DS18B20 is grounded, the VDD2 pin of DS18B20 is connected to the VDD1 pin of the main control chip 32, the first end of the eleventh resistor R11 is connected to the VDD2 pin of DS18B20, the second end of the eleventh resistor R11 is connected to the I / O4 pin of the main control chip 32, and the DO pin of DS18B20 is connected to the second end of the eleventh resistor R11;

[0042] A plurality of temperature measuring modules 5 may be used to obtain temperatures at multiple points, and the average value may be used as the temperature of the lithium battery 1 . The temperature measuring module 5 should fit the lithium battery 1 as closely as possible to obtain an accurate temperature.

[0043] When the lithium battery charging speed control circuit of the utility model is in use, when the charging voltage is used to charge the lithium battery 1, the charging unit 40 uses MAX846A as the charging control chip, and the PWM1, PWM2, I / O1, I / O2 and I / O3 pins of the main control chip 32 are used as control pins to control MAX846A, thereby controlling the charging speed of the lithium battery 1, and at the same time using the voltage and current measurement functions of MAX846A, and performing analog-to-digital conversion through the first AD chip 30 and the second AD chip 31, and inputting the temperature data measured in the temperature measurement module 5 into the main control chip 32;

[0044] In addition, when charging, the second PMOS tube PMOS2 cuts off the power supply of the lithium battery 1, and the charging voltage directly supplies power to the voltage stabilizing module 2, the main control module 3 and the temperature measuring module 5, thereby shortening the charging time of the lithium battery 1.

[0045] The above shows and describes the basic principle, main features and advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the utility model and are not used to limit the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, which fall within the scope of the utility model to be protected. The scope of protection of the utility model is defined by the attached claims and their equivalents.

Claims

1. A lithium battery charging speed control circuit, comprising a lithium battery (1), a voltage stabilizing module (2), a main control module (3), a charging module (4) and a temperature measuring module (5), characterized in that: The voltage stabilizing module (2) is used to provide a stable voltage to the main control module (3); the main control module (3) comprises a first AD chip (30), a second AD chip (31) and a main control chip (32); the charging module (4) comprises a charging unit (40) and a control unit (41); the charging unit (40) is used to control the charging process of the lithium battery (1); the control unit (41) is used to control the charging voltage to directly supply power to the main control module (3) during charging; and the temperature measuring module (5) is used to obtain the temperature of the lithium battery (1) during charging.

2. The lithium battery charging speed control circuit according to claim 1, characterized in that: The charging unit (40) comprises MAX846, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a first diode D1 and a first PMOS transistor PMOS1; Pin 1 of MAX846A is connected to the charging voltage, pin 2 of MAX846A is connected to the VDD1 pin of the main control chip (32), a first end of the first capacitor C1 is connected to pin 2 of MAX846A, a second end of the first capacitor C1 is grounded, a first end of the first resistor R1 is connected to the first end of the first capacitor C1, a second end of the first resistor R1 is connected to pin 9 of MAX846A, a first end of the second capacitor C2 is connected to the first end of the first resistor R1, a second end of the second capacitor C2 is connected to pin 3 of MAX846A, a first end of the third capacitor C3 is connected to the first end of the first resistor R1, a second end of the third capacitor C3 is connected to pin 5 of MAX846A, pin 4 of MAX846A is grounded, a first end of the second resistor R2 is connected to the main The second end of the second resistor R2 is connected to the 6th pin of the MAX846A, the first end of the third resistor R3 is connected to the PWM2 pin of the main control chip (32), the second end of the third resistor R3 is connected to the 7th pin of the MAX846A, the 7th pin of the MAX846A is also connected to the input pin of the second AD chip (31), the first end of the fourth resistor R4 is connected to the I / O3 pin of the main control chip (32), the second end of the fourth resistor R4 is connected to the 8th pin of the MAX846A, the 9th pin of the MAX846A is connected to the RST pin of the main control chip (32), the first end of the fourth capacitor C4 is connected to the 9th pin of the MAX846A, the second end of the fourth capacitor C4 is grounded, and the MAX846A is connected to the PWM1 pin of the main control chip (32). Pin 10 of MAX846A is connected to the I / O2 pin of the main control chip (32), pin 11 of MAX846A is connected to the I / O1 pin of the main control chip (32), pin 12 of MAX846A is connected to the first end of a fifth resistor R5, the second end of the fifth resistor R5 is connected to the first end of a sixth resistor R6, the first end of the sixth resistor R6 is also connected to the input pin of the first AD chip (30), the second end of the sixth resistor R6 is grounded, pin 13 of MAX846A is connected to the first end of a seventh resistor R7, the first end of the seventh resistor R7 is also connected to the charging voltage, the second end of the seventh resistor R7 is connected to the source of the first PMOS tube PMOS1, the drain of the first PMOS tube PMOS1 is connected to the anode of the first diode D1, and the first The cathode of the diode D1 is connected to the anode of the lithium battery (1), the first end of the fifth resistor R5 is also connected to the cathode of the first diode D1, the cathode of the lithium battery (1) is grounded, the 14th pin of the MAX846A is connected to the second end of the seventh resistor R7, the 15th pin of the MAX846A is grounded, the 16th pin of the MAX846A is connected to the second end of the fifth capacitor C5, the first end of the fifth capacitor C5 is connected to the second end of the seventh resistor R7, the first end of the eighth resistor R8 is connected to the first end of the fifth capacitor C5, the second end of the eighth resistor R8 is connected to the second end of the fifth capacitor C5, the gate of the first PMOS tube PMOS1 is connected to the second end of the fifth capacitor C5, the first end of the sixth capacitor C6 is connected to the cathode of the first diode D1, and the second end of the sixth capacitor C6 is grounded.

3. The lithium battery charging speed control circuit according to claim 1, characterized in that: The control unit (41) comprises a ninth resistor R9, a tenth resistor R10, a second diode D2 and a second PMOS transistor PMOS2; The first end of the ninth resistor R9 is connected to the charging voltage, the second end of the ninth resistor R9 is connected to the gate of the second PMOS tube PMOS2, the first end of the tenth resistor R10 is connected to the second end of the ninth resistor R9, the second end of the tenth resistor R10 is grounded, the anode of the second diode D2 is connected to the first end of the ninth resistor R9, the second end of the second diode D2 is connected to the input end of the voltage stabilizing module (2), the drain of the second PMOS tube PMOS2 is connected to the anode of the lithium battery (1), and the source of the second PMOS tube PMOS2 is connected to the cathode of the second diode D2.

4. The lithium battery charging speed control circuit according to claim 1, characterized in that: The output end of the voltage stabilizing module (2) is connected to the VDD1 pin of the main control chip (32), the output pin of the first AD chip (30) is connected to the input pin of the main control chip (32) correspondingly, and the output pin of the second AD chip (31) is connected to the input pin of the main control chip (32) correspondingly.

5. The lithium battery charging speed control circuit according to claim 1, characterized in that: The temperature measurement module (5) comprises a DS18B20 and an eleventh resistor R11; The GND pin of the DS18B20 is grounded, the VDD2 pin of the DS18B20 is connected to the VDD1 pin of the main control chip (32), the first end of the eleventh resistor R11 is connected to the VDD2 pin of the DS18B20, the second end of the eleventh resistor R11 is connected to the I / O4 pin of the main control chip (32), and the DO pin of the DS18B20 is connected to the second end of the eleventh resistor R11.

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