Battery sample device capable of recovering discharge capacity

Abstract

The invention discloses a battery sample device capable of recovering discharge capacity, which is provided with a battery, a main control unit and a switch unit, the main control unit comprises a voltameter module and a circuit control chip, the circuit control chip receives the discharge capacity of the battery detected by the voltameter module, and the circuit control chip controls the on / off of the switch unit according to the discharge capacity. And the discharge capacity of the battery is sent to the external terminal, so that the electricity meter module can accurately record the discharge capacity of the battery and can reproduce the discharge capacity so as to obtain a discharge capacity test result of the battery sample device, the circuit has the characteristics of simple structure and convenience in operation, and the working stability of the battery sample device is improved to a certain extent.

Description

Technical Field

[0001] The invention belongs to the technical field of battery testing, and in particular relates to a battery sample device capable of restoring discharge capacity. Background Art

[0002] The discharge capacity of lithium-ion batteries is an important indicator to measure their performance. Many domestic and international standards specify the test methods for the discharge capacity of lithium-ion batteries under different conditions, such as normal temperature discharge capacity, high and low temperature discharge capacity, rate discharge capacity, cycle life, capacity recovery after storage, etc. In addition, the calculation of battery energy density, energy conversion efficiency and other indicators also requires the use of battery discharge capacity. However, the discharge capacity of lithium-ion batteries is affected by many factors. In laboratory testing, the test results often deviate greatly from the actual situation, and the laboratory testing capacity is insufficient, but due to technical means, it is impossible to verify and evaluate the laboratory technical capabilities. The factors that affect the accuracy of battery discharge capacity testing can be roughly divided into: environment, equipment and test methods. First, the battery discharge capacity varies greatly under different ambient temperatures; second, the test equipment only calibrates the voltage and current during measurement, and the other parameter "time" required to calculate the capacity is not included in the measurement range. Factors such as time accuracy, calculation algorithm, sampling interval, etc. may cause the measured equipment to be unable to accurately measure the battery discharge capacity. In addition, the impedance of the fixture that connects the positive and negative terminals of the battery to the equipment will also affect the capacity test results.

[0003] At present, laboratory management agencies at home and abroad use "laboratory proficiency verification" to assess laboratory technical capabilities and management status, and continue to carry out effective supervision of laboratories after the laboratories pass relevant qualification certification. In the process of proficiency verification of battery laboratories, most of them choose lithium-ion batteries as test samples, but due to the individual differences and their own characteristics of lithium-ion batteries, the test results are difficult to reproduce and cause a lot of controversy. The individual differences of lithium-ion batteries are specifically manifested in differences in consistency. The discharge capacity of lithium-ion battery products from the same enterprise and the same batch must have large or small differences, and this difference cannot be eliminated by technology or manpower. In addition, the characteristics of lithium-ion batteries themselves are manifested in that the same lithium-ion battery is tested in different environments, using different charging and discharging methods, or undergoing multiple charging and discharging cycles. The capacity test results will be different, which makes the sample capacity retained by the laboratory review agency deviate from the actual measured results of the evaluated laboratory. It is precisely because of these problems with lithium-ion batteries themselves that the test data is controversial and laboratory evaluation work is difficult to carry out. As a result, a large number of laboratories with insufficient capabilities and irregular testing are difficult to be discovered.

[0004] Therefore, how to reproduce the battery discharge capacity test is a problem that people in this field need to solve. Summary of the invention

[0005] In view of this, the present invention provides a battery sample device with reproducible discharge capacity, which can solve the problem that the prior art is difficult to reproduce the discharge capacity test of the battery. The battery sample device uses a fuel meter module to accurately record the discharge capacity and actively cuts off the discharge circuit after reaching the set capacity. It can accurately reproduce the discharge capacity data, thereby improving the accuracy of the discharge capacity test. The following technical scheme is specifically adopted to achieve this.

[0006] The present invention provides a battery sample device with restorable discharge capacity, the battery sample device comprises a battery, a main control unit and a switch unit, the main control unit comprises an electric meter module and a circuit control chip connected to the electric meter module, the battery is connected to the electric meter module, the circuit control chip comprises a control interface module and a communication interface module, the control interface module is connected to one end of the switch unit, the other end of the switch unit is connected to the battery, and the communication interface module is used to connect to an external terminal;

[0007] The circuit control chip receives the discharge capacity of the battery detected by the fuel gauge module, controls the opening and closing of the switch unit according to the discharge capacity of the battery, and sends the discharge capacity of the battery to the external terminal.

[0008] As a preferred embodiment of the above technical solution, the main control unit also includes a temperature sampling module connected to the circuit control chip, the temperature sampling module is used to collect ambient temperature data of the battery, and the circuit control chip receives the ambient temperature data to adjust the discharge capacity limit of the battery.

[0009] As a preferred embodiment of the above technical solution, the main control unit also includes a storage chip connected to the circuit control chip, and the storage chip is used to store the discharge capacity limit and operation information of the battery sample device, wherein the operation information includes at least one of a low-power sleep mode, a capacity test, adjusting the discharge capacity limit or cutting off the discharge circuit.

[0010] As a preferred embodiment of the above technical solution, the main control unit also includes a clock chip connected to the circuit control chip, the clock chip is used to provide time information to the circuit control chip, and the clock chip cooperates with the fuel meter module to detect the discharge capacity of the battery.

[0011] As a preferred embodiment of the above technical solution, the power meter module includes a chip U1, a first interface circuit, a second interface circuit and a third interface circuit, the first interface circuit, the second interface circuit and the third interface circuit are all connected to the chip U1, the first interface circuit is connected to the circuit control chip, the second interface circuit is connected to the switch unit, and the third interface circuit is connected to the storage chip.

[0012] As a preferred embodiment of the above technical solution, the storage chip includes a chip U3 with a model number of AT24C04, and the clock chip includes a chip U4 with a model number of DS3231.

[0013] As a preferred embodiment of the above technical solution, the chip U1 has a model number of BQ4050RSM, and the circuit control chip includes a chip U2 with a model number of HR7P169B.

[0014] As a preferred embodiment of the above technical solution, the discharge capacity of the battery sample device is 80% of the discharge capacity of the battery.

[0015] As a preferred embodiment of the above technical solution, when the discharge capacity of the battery sample device reaches the discharge capacity limit of the battery, the circuit control chip cuts off the discharge circuit where the switch unit is located.

[0016] The present invention provides a battery sample device with reproducible discharge capacity. The device comprises a battery, a main control unit and a switch unit. The main control unit comprises a fuel gauge module and a circuit control chip. The circuit control chip receives the discharge capacity of the battery detected by the fuel gauge module. The circuit control chip controls the opening and closing of the switch unit according to the discharge capacity and sends the discharge capacity of the battery to an external terminal. The fuel gauge module can accurately record the discharge capacity of the battery and reproduce the discharge capacity to obtain the discharge capacity test result of the battery sample device. The device has the characteristics of simple circuit structure and convenient operation, and improves the working stability of the battery sample device to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 A structural block diagram of a battery sample device with recoverable discharge capacity provided by the present invention;

[0019] Figure 2 A working principle diagram of a battery sample device provided by the present invention;

[0020] Figure 3 A circuit diagram of the fuel meter module provided by the present invention;

[0021] Figure 4 A circuit diagram of the circuit control chip provided by the present invention;

[0022] Figure 5 A circuit diagram of the memory chip provided by the present invention;

[0023] Figure 6 A circuit diagram of the clock chip provided by the present invention.

[0024] The main component symbols are described as follows:

[0025] 100 - battery; 200 - main control unit; 210 - fuel gauge module; 220 - circuit control chip; 221 - control interface module; 222 - communication interface module; 223 - temperature sampling module; 224 - storage chip; 225 - clock chip; 300 - switch unit. DETAILED DESCRIPTION

[0026] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0027] See also Figure 1 and Figure 2 The present invention provides a battery sample device with a restorable discharge capacity, the battery sample device comprises a battery 100, a main control unit 200 and a switch unit 300, the main control unit 200 comprises an electric meter module 210, and a circuit control chip 220 connected to the electric meter module 210, the battery 100 is connected to the electric meter module 210, the circuit control chip 220 comprises a control interface module 221 and a communication interface module 222, the control interface module 221 is connected to one end of the switch unit 300, the other end of the switch unit 300 is connected to the battery 100, and the communication interface module 222 is used to connect to an external terminal;

[0028] The circuit control chip 220 receives the discharge capacity of the battery detected by the fuel gauge module 210, controls the opening and closing of the switch unit 300 according to the discharge capacity of the battery, and sends the discharge capacity of the battery 100 to the external terminal.

[0029] In this embodiment, refer to Figure 3 , Figure 4, Figure 5 and Figure 6 The main control unit 200 further includes a temperature sampling module 223 connected to the circuit control chip 220, the temperature sampling module 223 is used to collect the ambient temperature data of the battery 100, and the circuit control chip 220 receives the ambient temperature data to adjust the discharge capacity limit of the battery 100. The main control unit 200 further includes a storage chip 224 connected to the circuit control chip 220, the storage chip 224 is used to store the discharge capacity limit and the operation information of the battery sample device, wherein the operation information includes at least one of low power sleep mode, capacity test, adjustment of discharge capacity limit or cutting off the discharge circuit. The main control unit 200 further includes a clock chip 225 connected to the circuit control chip 220, the clock chip 225 is used to provide time information to the circuit control chip 220, and the clock chip 225 cooperates with the fuel gauge module 210 to detect the discharge capacity of the battery 100. The fuel meter module 210 includes a chip U1, a first interface circuit, a second interface circuit and a third interface circuit. The first interface circuit, the second interface circuit and the third interface circuit are all connected to the chip U1. The first interface circuit is connected to the circuit control chip 220, the second interface circuit is connected to the switch unit 300, and the third interface circuit is connected to the storage chip 224.

[0030] It should be noted that the storage chip 224 includes a chip U3 of model AT24C04, the clock chip 225 includes a chip U4 of model DS3231, the chip U1 is of model BQ4050RSM, the circuit control chip 220 includes a chip U2 of model HR7P169B, the discharge capacity of the battery sample device is 80% of the discharge capacity of the battery 100, and when the discharge capacity of the battery sample device reaches the discharge capacity limit of the battery 100, the circuit control chip 220 cuts off the discharge circuit where the switch unit 300 is located. The output end of the battery sample device is provided with a sample positive electrode and a sample negative electrode, which can be connected to a load. When the lithium battery is discharged, the battery voltage gradually increases over time and decreases.

[0031] like Figure 2As shown, the battery 100 is a lithium battery, the circuit control chip 220 is an MCU, the control interface module 221 is a GPIO interface, the communication interface module 222 can be a host computer communication interface such as RS232 or RS485, etc., the switch unit 300 mainly includes a charging switch and a discharging switch corresponding to the MOS chip, and the battery 100 is connected in parallel to the power meter module 210 with a precision resistor R, and the power meter module 210 can detect the voltage or current of the lithium battery. The storage chip 224 is recorded as an EEPROM, which can store control instructions, operation information or preset discharge capacity, etc. The MCU is also connected to the burner to realize program burning. Since the discharge capacity is sensitive to temperature, the temperature acquisition module 223 can collect ambient temperature data and transmit the ambient temperature data to the circuit control chip 220. The circuit control chip 220 can modify the discharge capacity limit value according to the collected ambient temperature data, thereby reflecting the improper ambient temperature control results of the laboratory in the discharge capacity test results.

[0032] Among them, Figure 3As shown, the fuel gauge module 210 mainly includes a chip U1, a circuit connected to the positive electrode of the battery, a circuit connected to the negative electrode of the battery, a first interface circuit, a second interface circuit and a third interface circuit. The circuit connected to the positive electrode of the battery includes a diode D1, a capacitor C1, a capacitor C5 and a capacitor C6. D1 and C6 are connected in parallel to pin 32 of the chip U1. C5 is connected to pins 1 and 33 of the chip U1. R1 and one end of C1 are connected in parallel to pin 2 of the chip U1. The other end of C1 is connected to pins 7 and 9 of the chip U1. The circuit connected to the negative electrode of the battery includes capacitors C8, C9, C10, resistors R13, RS1, RS2 and resistor R14. C8, C9 and C10 are connected in parallel to pins 6 and 8 of the chip U1. , one end of R13, one end of R14, RS1 and RS2 are connected in parallel to the other end of R13, the other end of R14, one end of RS1 is connected to the negative electrode of the battery, and the other end of RS1 is connected to the negative electrode of the test port (black clip); the first interface circuit includes resistors R43, R44 and RT1, RT1 is connected to pin 10 of chip U1, one end of R43 is connected to R44, and the other end of R43 is connected to pin 16 of chip U1; the second interface circuit includes resistors R6, R7, R8, R9, R10, R11, R12, power tube group (Q1, Q3, Q5, Q7), power tube group (Q2, Q4, Q6, Q8), capacitor C 7. Capacitor C11, capacitor C12 and power tube Q9, power tube group (Q1, Q3, Q5, Q7), C11, R6 are connected in parallel to the positive electrode of the battery, the power tube group (Q1, Q3, Q5, Q7), one end of R6 and R7, the other end of R7 is connected to pin 31 of chip U1, the power tube group (Q1, Q3, Q5, Q7) and the power tube group (Q2, Q4, Q6, Q8) are connected to one end of R10, the other end of R10 is connected to C7 and pin 26 of chip U1, the power tube group (Q2, Q4, Q6, Q8) and C12 are connected in parallel to the source of R8, Q9, the positive electrode of the test port (red clip), one end of R9 is connected to the power tube group (Q2, Q4, Q6, Q8), R8, The drain of Q9 is connected, R11 is connected to the gate of Q9, the other end of R9 is connected to pin 28 (DSG) of chip U1, one end of R12 is connected to the positive pole of the test port, and the other end of R12 is connected to pin 27 of chip U1; the third interface circuit includes resistor R15, resistor R16, resistor R17, resistor R18, resistor R19, resistor R20, diode Z1, and diode Z2, R15 is connected to R17 and R18, R17 is connected to pin 19 of chip U1, R16 is connected to R19 and R20, R19 is connected to pin 18 of chip U1, R15 is connected to R18, Z2 is connected to R17 and R18, Z1 is connected to R19 and R20, and Z1 is connected to Z2.

[0033] Among them, Figure 4As shown, the circuit control chip 220 mainly includes a chip U2, a capacitor C15 and a resistor R21, C15 is connected to pins 20 and 21 of the chip U2, R21 is connected to pin 15 of the chip U2, pins 2 (SCL) and 3 (SDA) of the chip U2 are connected to the third interface circuit of the chip U1, and pin 11 (WKUP_CTL) of the chip U2 is connected to the second interface circuit of the chip U1. Figure 5 As shown, the storage chip 224 mainly includes a chip U3, a capacitor C16, a resistor R22, a resistor R23, a resistor R24, a resistor R25, a resistor R26, a resistor R27, a diode Z3 and a diode Z4, C16 is connected to the pin 8 of the chip U3, R22 is connected to the pin 6 of the chip U3, R23 is connected to the pin 5 of the chip U3, R26 is connected to R22, R24 and Z3, R27 is connected to R23, R25 and Z4, R24 of the chip U3 is connected to the pin 7 of the chip U2, and R25 of the chip U3 is connected to the pin 5 of the chip U2. Figure 6 As shown, the clock chip 225 mainly includes chip U4, capacitor C17, resistor R35, resistor R36, resistor R37, resistor R45 and resistor R46, C17 is connected to pin 2 of chip U4, R37 is connected to pins 9 to 14 of chip U4, R45 is connected to R35 and R46, R46 is connected to R36, R35 is connected to pin 16 of chip U4, R36 is connected to pin 15 of chip U4, R35 is connected to pin 17 of chip U2, and R36 is connected to pin 16 of chip U2.

[0034] Specifically, the positive electrode of the battery 100 is connected to the positive electrode of the battery, the negative electrode of the battery 100 is connected to the negative electrode of the battery, and U1 is connected to the positive electrode of the battery through the third interface circuit ( Figure 3 3) connects U2's 2nd and 3rd pins (SCL, SDA) to provide the MCU with battery current information; U3 is connected to U2's 5th and 7th pins (SDA1, SCL1) through the first interface circuit; U4 is connected to U1's 8th and 9th pins (SCL, SDA) through the third interface circuit to provide the MCU with time information. Figure 3 When the test port in the discharge, U1 feeds back the current value to U2. At this time, the clock chip U4 provides time information, and the MCU calculates the capacity by multiplying the time by the current. The MCU can preset a capacity threshold; when the time reaches the pre-capacity threshold, the 10th pin of the MCU (PRES_MCU0) will output a high level to connect to the first interface circuit of the fuel gauge module ( Figure 3 1), at this time, the second interface circuit of U1 ( Figure 32) in the figure will output a low level to shut down the discharge MOS and cut off the output, ensuring that the discharge time capacity is consistent with the preset value. After a delay of 1 minute, the 10th pin of U2 (PRES_MCU0) will output a low level, the MOS tube will be reopened and restored to the initial state. The MCU capacity threshold can be changed differently through the MCU program.

[0035] Specifically, the circuit control chip 220 tests the ambient temperature of the laboratory through the temperature acquisition module 223 in the circuit, and actively adjusts the set discharge capacity (discharge capacity limit) according to the ambient temperature and the pre-written algorithm, so as to effectively supervise the behavior of the laboratory that fails to reasonably control the test ambient temperature. When the fuel gauge module 210 detects that there is no current passing through the circuit, the circuit control chip 220 puts the battery sample device into sleep mode. In order to reduce the impact of system self-discharge, the battery sample device can enter a low-power sleep mode when there is no current passing through the loop, so that the battery sample device can start the capacity test after being fully charged for a period of time. The discharge capacity of the battery sample device is 80% of the battery capacity (battery discharge capacity). Because the discharge capacity of the built-in battery 100 will decay with the cycle use, the circuit components of the battery sample device may also have some power loss, so the discharge capacity should be set lower than the built-in battery and retain a certain margin. For example, the built-in battery uses a 10000mAh battery cell (the discharge capacity is higher than 90% after 300 cycles). When the discharge capacity is set to 8000mAh, the same discharge capacity can be reproduced hundreds of times within its cycle life.

[0036] Specifically, the main control unit 200 can read and store the operation information of the battery sample device, the discharge capacity can be set and modified by the program, and the discharge capacity of the battery sample device can be written and modified to the circuit control chip 220 through the serial port (communication interface module). When the control command is issued, the operation information stored in the storage chip 224 can also be read. The battery sample device is vacuum packaged and looks like a traditional battery sample. The entire on-chip system can be designed to be compact, leaving only the positive and negative electrodes of the battery standard in the form of pole pieces. The rest of the structure is packaged after vacuuming with a special aluminum-plastic film for the battery core. The appearance of the sample can be consistent with the mass-produced battery products of the enterprise.

[0037] It should be understood that by setting up the battery 100, the main control unit 200 and the switch unit 300, the main control unit 200 includes a fuel meter module 210 and a circuit control chip 220. The circuit control chip 220 receives the discharge capacity of the battery 100 detected by the fuel meter module 210. The circuit control chip 220 controls the opening and closing of the switch unit 300 according to the discharge capacity of the battery 100, and sends the discharge capacity of the battery 100 to the external terminal. The use of the fuel meter module 210 can accurately record the discharge capacity of the battery 100 and reproduce the discharge capacity to obtain the discharge capacity test result of the battery sample device. It has the characteristics of simple circuit structure and convenient operation, and improves the working stability of the battery sample device to a certain extent.

[0038] In all examples shown and described herein, any specific values ​​should be interpreted as merely exemplary and not as limiting, and thus other examples of the exemplary embodiments may have different values.

[0039] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0040] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A battery sample device with restorable discharge capacity, characterized in that: The battery sample device comprises a battery, a main control unit and a switch unit, wherein the main control unit comprises an electric meter module and a circuit control chip connected to the electric meter module, the battery is connected to the electric meter module, the circuit control chip comprises a control interface module and a communication interface module, the control interface module is connected to one end of the switch unit, the other end of the switch unit is connected to the battery, and the communication interface module is used to connect to an external terminal; The circuit control chip receives the discharge capacity of the battery detected by the fuel gauge module, controls the opening and closing of the switch unit according to the discharge capacity of the battery, and sends the discharge capacity of the battery to the external terminal.

2. The battery sample device with restorable discharge capacity according to claim 1, characterized in that: The main control unit also includes a temperature sampling module connected to the circuit control chip, the temperature sampling module is used to collect ambient temperature data of the battery, and the circuit control chip receives the ambient temperature data to adjust the discharge capacity limit of the battery.

3. The battery sample device with restorable discharge capacity according to claim 2, characterized in that: The main control unit also includes a storage chip connected to the circuit control chip, and the storage chip is used to store the discharge capacity limit and operation information of the battery sample device, wherein the operation information includes at least one of a low-power sleep mode, a capacity test, adjusting the discharge capacity limit, or cutting off the discharge circuit.

4. The battery sample device with restorable discharge capacity according to claim 3, characterized in that: The main control unit further comprises a clock chip connected to the circuit control chip, the clock chip is used to provide time information to the circuit control chip, and the clock chip cooperates with the fuel gauge module to detect the discharge capacity of the battery.

5. The battery sample device with restorable discharge capacity according to claim 4, characterized in that: The fuel gauge module includes a chip U1, a first interface circuit, a second interface circuit and a third interface circuit. The first interface circuit, the second interface circuit and the third interface circuit are all connected to the chip U1, the first interface circuit is connected to the circuit control chip, the second interface circuit is connected to the switch unit, and the third interface circuit is connected to the storage chip.

6. The battery sample device with restorable discharge capacity according to claim 4, characterized in that: The memory chip includes a chip U3 of model AT24C04, and the clock chip includes a chip U4 of model DS3231.

7. The battery sample device with restorable discharge capacity according to claim 5, characterized in that: The model of the chip U1 is BQ4050RSM, and the circuit control chip includes a chip U2 with a model HR7P169B.

8. The battery sample device with restorable discharge capacity according to claim 1, characterized in that: The discharge capacity of the battery sample device is 80% of the discharge capacity of the battery.

9. The battery sample device with restorable discharge capacity according to claim 8, characterized in that: When the discharge capacity of the battery sample device reaches the discharge capacity limit of the battery, the circuit control chip cuts off the discharge loop where the switch unit is located.

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