A testing device for photovoltaic lithium batteries

Abstract

This utility model belongs to the technical field of photovoltaic related equipment and discloses a testing device for photovoltaic lithium batteries. It includes a battery testing board, which is connected to a lithium battery pack via charging terminals, communication terminals, and discharging terminals. The battery testing board is also connected to an external DC power supply via an external power supply terminal. The battery testing board is equipped with a controller, a display screen, a step-down module, a battery internal resistance testing module, and a battery load testing module. Furthermore, the battery testing board is equipped with a high / low temperature protection function testing module, a heating function testing module, and a charging current detection module, which are connected between the controller and the lithium battery pack. This utility model enables scientific testing of the performance of lithium battery packs at the factory, solving the problem that scientific testing cannot be performed on lithium battery packs at the factory to ensure their operational stability.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic-related equipment technology, and in particular to a testing device for photovoltaic lithium batteries. Background Technology

[0002] With the continuous development of the photovoltaic industry, its development model is gradually shifting from "quantitative accumulation" to "qualitative improvement." How to further increase photovoltaic power generation has become the core development direction for photovoltaic companies.

[0003] Traditional photovoltaic systems mostly use DC power supply from photovoltaic panels. To ensure normal power generation from the panels the following morning, they need to be turned from a westward angle to an eastward angle in the evening. During this process, the power generation efficiency of the photovoltaic panels is extremely low when facing east. Furthermore, to ensure that the tracking brackets can rotate smoothly to the maximum eastward angle, the eastward rotation process often needs to be initiated in advance. This not only severely affects the power generation in the evening but also results in a significant waste of photovoltaic resources.

[0004] Therefore, to fully utilize the value of sunlight in the evening, an additional battery is added, allowing the tracking bracket to continuously track the sun until sunset. As night falls, the tracking bracket controller, powered by the battery, rotates eastward. This approach avoids occupying the evening power generation period and significantly increases the total photovoltaic power generation, effectively improving the utilization efficiency of photovoltaic resources.

[0005] Chinese utility model patent application number 202420264413.X proposes a drive control integrated system suitable for solar tracking brackets. This system integrates a battery, which not only needs to be precisely matched with the photovoltaic tracking controller, but its own stability is also crucial. Therefore, how to scientifically test photovoltaic-specific batteries to ensure their operational stability has become an important issue that the industry urgently needs to address. Utility Model Content

[0006] The main technical problem this invention aims to solve is to provide a testing device for photovoltaic lithium batteries, which enables scientific testing of the performance of lithium battery packs before they leave the factory, thus solving the problem that scientific testing cannot be performed on lithium battery packs at the time of leaving the factory to ensure their operational stability.

[0007] To solve the above-mentioned technical problems, this utility model provides the following technical solution: A testing device for photovoltaic lithium batteries includes a battery testing board for testing lithium battery packs. The battery testing board is connected to the charging cable, communication cable and discharge cable of the lithium battery pack through charging terminal, communication terminal and discharge terminal respectively. The battery testing board is also connected to an external DC power supply through an external power supply terminal. The battery testing board is equipped with a controller, a display screen, a step-down module, a battery internal resistance testing module, and a battery load testing module. The battery internal resistance testing module and the battery load testing module are both connected to the controller. An external DC power supply is connected to the input terminal of the step-down module through an external power supply terminal. The output terminal of the step-down module is connected to the display screen and the controller. The battery testing board is also equipped with a high and low temperature protection function test module, a heating function test module, a charging current detection module, and a battery voltage detection module. The high and low temperature protection function test module, the heating function test module, the charging current detection module, and the battery voltage detection module are all connected between the controller and the lithium battery pack.

[0008] The following are further optimizations of the above technical solution by this utility model: The heating function testing module includes a control unit and a detection unit; The control unit includes a heating control transistor Q5, a heating control MOSFET Q6, and a buzzer BZ1 connected in sequence. The base of the heating control transistor Q5 is connected to the PB9 pin of the controller. The emitter of the heating control transistor Q5 and the source of the heating control MOSFET Q6 are both connected to the positive terminal of the lithium battery pack. The collector of the heating control transistor Q5 and the buzzer BZ1 are both connected to the negative terminal of the lithium battery pack. The detection unit includes an alarm diode D1 and a Zener diode D2. The negative terminal of the alarm diode D1 is connected to the negative terminal of the lithium battery pack, and the positive terminal of the alarm diode D1 is connected to the positive terminal of the Zener diode D2. A nineteenth resistor R19 is connected in series between the positive terminals of the alarm diode D1 and the positive terminals of the Zener diode D2. The negative terminal of the Zener diode D2 is connected to the drain of the heating control MOSFET Q6.

[0009] Further optimization: A fourteenth resistor R14 is connected in series between the base of the heating control transistor Q5 and the PB9 pin of the controller. The two ends of the fourteenth resistor R14 are connected to the positive terminals of the fourth capacitor C4 and the fifteenth resistor R15, respectively. The negative terminals of the fourth capacitor C4 and the fifteenth resistor R15 are both connected to the negative terminal of the lithium battery pack. A sixteenth resistor R16 and a seventeenth resistor R17 are connected in series between the collector of the heating control transistor Q5 and the positive terminal of the lithium battery pack. The negative terminal of the sixteenth resistor R16 is connected in series with the positive terminal of the eighteenth resistor R18. The negative terminal of the eighteenth resistor R18 is connected to the gate of the heating control MOS transistor Q6. The negative terminals of buzzer BZ1 and warning diode D1 are connected in series with the negative terminal of the lithium battery pack, with a twentieth resistor R20.

[0010] Further optimization: The battery internal resistance test module includes an internal resistance test connection terminal, which is used to connect the internal resistance tester to the controller.

[0011] Further optimization: The battery load test module includes a load test connection terminal and a continuity unit, and the load test connection terminal is connected to a load tester; The conduction unit includes a load test control transistor Q3 and a load test control MOSFET Q4 connected together. The base of the load test control transistor Q3 is connected to the PB8 pin of the controller. The drain of the load test control MOSFET Q4 is connected to the second pin of the load test connection terminal. The collector of the load test control transistor Q3 and the source of the load test control MOSFET Q4 are both connected to the positive terminal of the lithium battery pack. The first pin of the load test connection terminal is connected to the negative terminal of the lithium battery pack.

[0012] Further optimization: A ninth resistor R9 is connected in series between the base of the load test control transistor Q3 and the PB8 pin of the controller. The two ends of the ninth resistor R9 are also connected to the positive terminals of the third capacitor C3 and the tenth resistor R10. The negative terminals of the third capacitor C3 and the tenth resistor R10, as well as the emitter of the load test control transistor Q3, are all grounded. The collector of the load test control transistor Q3 and the gate of the load test control MOS transistor Q4 are connected in series with an eleventh resistor R11 and a thirteenth resistor R13. The eleventh resistor R11 and the thirteenth resistor R13 are connected in series with the charging module with a twelfth resistor R12.

[0013] Further optimization: The high and low temperature protection function test module includes a high temperature protection test transistor Q1 and a low temperature protection test transistor Q2. The base of the high temperature protection test transistor Q1 is connected to the PA0 pin of the controller, and the base of the low temperature protection test transistor Q2 is connected to the PC3 pin of the controller. The collectors of both the high temperature protection test transistor Q1 and the low temperature protection test transistor Q2 are connected to the signal input terminal of the battery protection board inside the lithium battery pack, and the emitters of both the high temperature protection test transistor Q1 and the low temperature protection test transistor Q2 are connected to the signal output terminal of the battery protection board.

[0014] Further optimization: A first resistor R1 is connected in series between the base of the high-temperature protection test transistor Q1 and the PA0 pin of the controller. The two ends of the first resistor R1 are respectively connected to the positive terminals of the first capacitor C1 and the second resistor R2. A third resistor R3 and a seventh resistor R7 are connected in series between the negative terminals of the first capacitor C1, the negative terminals of the second resistor R2, the emitter of the high-temperature protection test transistor Q1, and the battery protection board. A fourth resistor R4 is connected in series between the base of the low-temperature protection test transistor Q2 and the PC3 pin of the controller. The two ends of the fourth resistor R4 are connected to the positive terminals of the second capacitor C2 and the fifth resistor R5, respectively. A sixth resistor R6 and an eighth resistor R8 are connected in series between the negative terminals of the second capacitor C2, the negative terminal of the fifth resistor R5, the emitter of the low-temperature protection test transistor Q2, and the battery protection board. The third resistor R3 and the sixth resistor R6 are connected together to the fifth pin of the communication terminal. The sixth pin of the communication terminal is connected to the PA1 pin of the controller. A twenty-first resistor R21 is connected in series between the sixth pin of the communication terminal and the PA1 pin of the controller.

[0015] Further optimization: The charging current detection module includes dual operational amplifiers. The INB+ pin of the dual operational amplifiers is connected to the external power supply terminal, the INB- pin of the dual operational amplifiers is connected to the charging terminal, the OUTB pin of the dual operational amplifiers is connected to the PA2 pin of the controller, and the VDD and VSS pins of the dual operational amplifiers are both connected to the output terminal of the buck module. A 23rd resistor R23 is connected in series between the INB+ pin of the dual op-amp and the external power supply terminal, and a 24th resistor R24 ​​is connected in series between the INB- pin of the dual op-amp and the charging terminal. The INB+ pin of the dual op-amp is grounded through the fifth capacitor C5 and the sixth capacitor C6 connected in series. The fifth capacitor C5 is connected in parallel with the twenty-sixth resistor R26. The INA- and OUTA pins of the dual op-amp are both connected to the positive terminal of the sixth capacitor C6. The output terminal of the step-down module is connected in series with the VSS pin of the dual op-amp, and a 28th resistor R28 and a 27th resistor R27 are connected in parallel with a 7th capacitor C7. The negative terminal of the 28th resistor R28 is connected to the INA+ pin of the dual op-amp.

[0016] Further optimization: The battery voltage detection module includes a 33rd resistor R33 and a 15th capacitor C15 arranged in parallel. The negative terminal of the 33rd resistor R33 is connected in series with the positive terminal of the lithium battery pack by a 32nd resistor R32, and is connected in series with the negative terminal of the lithium battery pack by a 34th resistor R34. The negative terminal of the 15th capacitor C15 is connected to the negative terminal of the lithium battery pack.

[0017] The present invention adopts the above technical solution and has the following beneficial effects: After the lithium battery pack is connected to the present invention, the performance of the lithium battery pack at the time of leaving the factory can be scientifically and comprehensively tested to ensure the stability of the lithium battery pack after it is assembled into the photovoltaic module, thereby solving the problem that it is difficult to guarantee the operational stability of the lithium battery pack because it is impossible to scientifically test it at the time of leaving the factory. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the overall structure in an embodiment of the present utility model; Figure 2 This is a schematic diagram of the controller structure in an embodiment of the present invention; Figure 3 This is a schematic diagram of the step-down module in an embodiment of this utility model; Figure 4 This is a schematic diagram of the battery load testing module in an embodiment of the present invention; Figure 5 This is a schematic diagram of the high and low temperature protection function test module in an embodiment of this utility model; Figure 6 This is a schematic diagram of the charging and heating function test module in an embodiment of this utility model; Figure 7 This is a schematic diagram of the charging current detection module in an embodiment of the present invention; Figure 8 This is a schematic diagram of the battery voltage detection module in an embodiment of this utility model.

[0020] The components include: 1. Lithium battery pack; 101. Battery protection board; 102. Charging module; 2. Battery detection board; 201. Charging terminal; 202. Communication terminal; 203. Discharge terminal; 204. External power supply terminal; 3. External DC power supply; 4. Controller; 5. Display screen; 501. Screen terminal; 6. Step-down module; 601. Switching chip; 602. Voltage regulator; 7. Battery internal resistance test module; 701. Internal resistance test connection terminal; 702. Internal resistance tester; 8. Battery load test module; 801. Load test connection terminal; 802. Conductivity unit; 803. Load tester; 9. High and low temperature protection function test module; 10. Heating function test module; 11. Charging current detection module; 1101. Dual operational amplifier; 12. Battery voltage detection module. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] like Figures 1-7 As shown, a photovoltaic lithium battery testing device includes a battery testing board 2 for testing a lithium battery pack 1.

[0023] In this embodiment, lithium battery pack 1 is the lithium battery used in the photovoltaic tracking system.

[0024] The battery detection board 2 is connected to the charging cable, communication cable and discharge cable of the lithium battery pack 1 through the charging terminal 201, communication terminal 202 and discharge terminal 203 respectively. The battery detection board 2 is also connected to an external DC power supply 3 through the external power supply terminal 204.

[0025] In this embodiment, the external DC power supply 3 can be an adjustable DC power supply that is available on the market.

[0026] In this embodiment, the external DC power supply 3 is connected to the battery detection board 2 through the external power supply terminal 204, and supplies power to the lithium battery pack 1 through the charging terminal 201.

[0027] like Figure 1 As shown, the battery testing board 2 is equipped with a controller 4, a display screen 5, a step-down module 6, a battery internal resistance testing module 7, and a battery load testing module 8.

[0028] In this embodiment, the controller 4 can be a commercially available microcontroller, such as the STM32F103RBT6 microcontroller provided by STMicroelectronics.

[0029] Furthermore, the controller 4 is powered by an external DC power supply 3.

[0030] In this embodiment, the display screen 5 can be a commercially available model, such as the TJC4857X543 serial port screen provided by Shenzhen Taojingchi Electronics Co., Ltd.

[0031] In this embodiment, the display screen 5 is connected to the controller 4 via the screen terminal 501. The display screen 5 can control the start and stop of each module of this utility model and the execution of various detection tasks. The progress and results of each detection task are displayed on the display screen 5 in real time.

[0032] Preferably, the battery internal resistance test module 7 and the battery load test module 8 are both connected to the controller 4, the external DC power supply 3 is connected to the input terminal of the step-down module 6 through the external power supply terminal 204, and the output terminal of the step-down module 6 is connected to the display screen 5 and the controller 4.

[0033] Preferably, the battery testing board 2 is also equipped with a high and low temperature protection function test module 9, a heating function test module 10, a charging current detection module 11, and a battery voltage detection module 12. The high and low temperature protection function test module 9, the heating function test module 10, the charging current detection module 11, and the battery voltage detection module 12 are all connected between the controller 4 and the lithium battery pack 1.

[0034] In this embodiment, the present invention can test or detect various performance aspects of the lithium battery pack 1, such as high and low temperature protection, charging function, heating element and temperature control switch, as well as data such as charging current, voltage and discharge voltage. This enables scientific detection of the state of the lithium battery pack 1 itself, and solves the problem that it is difficult to ensure the operational stability of the lithium battery pack 1 because it cannot be scientifically tested at the factory. This ensures the operational stability of the lithium battery pack 1 after it is assembled onto the photovoltaic module.

[0035] like Figures 1-3 As shown, the step-down module 6 includes a switching chip 601 connected to an external DC power supply 3. The VIN and N / OFF pins of the switching chip 601 are respectively connected to the positive and negative terminals of the external DC power supply 3. An eighth capacitor C8 and a ninth capacitor C9 are also connected in parallel between the positive and negative terminals of the external DC power supply 3. The OUT pin of the switching chip 601 is connected to a first inductor L1. The two ends of the first inductor L1 are respectively connected to the positive terminal of the freewheeling diode D3 and the positive terminal of the tenth capacitor C10. The FB pin of the switching chip 601 is also connected to the positive terminal of the tenth capacitor C10. The negative terminals of the freewheeling diode D3 and the tenth capacitor C10 are also connected to the negative terminal of the external DC power supply 3. The GND pin of the switching chip 601 is grounded.

[0036] In this embodiment, the switch chip 601 can be a commercially available step-down switch chip, such as the LM2596 series step-down switch chip provided by Texas Instruments.

[0037] The switching chip 601 controls the charging and discharging process of the first inductor L1 by periodically turning it on and off, thereby realizing voltage step-down conversion and converting the DC voltage output by the external DC power supply 3 into a 5V DC voltage.

[0038] The working principle of using step-down module 6 to convert the DC voltage output from external DC power supply 3 to 5V DC voltage is as follows: When the switching chip 601 is turned on, the DC voltage output by the external DC power supply 3 supplies power to the first inductor L1 through the turned-on switching chip 601. The first inductor L1 begins to store energy. At this time, the current of the first inductor L1 gradually increases, and the voltage polarity at both ends is positive on the left and negative on the right. Meanwhile, the eighth capacitor C8 and the ninth capacitor C9 continuously provide a stable input voltage to the circuit and filter the input voltage; At this time, the freewheeling diode D3 is cut off due to the reverse voltage.

[0039] When the switching chip 601 is turned off, since the current in the first inductor L1 cannot change abruptly, the first inductor L1 will generate an induced electromotive force in the same direction as the original current (negative on the left and positive on the right) to maintain the continued flow of current. At this time, the freewheeling diode D3 is turned on, and the first inductor L1 discharges to the load and the tenth capacitor C10 through the freewheeling diode D3. The energy stored in the first inductor L1 is released to provide power to the load and charge the tenth capacitor C10 at the same time.

[0040] The tenth capacitor, C10, absorbs current fluctuations and stabilizes the output voltage to 5V.

[0041] Preferably, the step-down module 6 further includes a voltage regulator 602. The IN pin and H pin of the voltage regulator 602 are both connected to the OUT pin of the switching chip 601. The IN pin of the voltage regulator 602 is also connected to the twenty-third capacitor C23. The Vout pin of the voltage regulator 602 is connected to the twenty-fourth capacitor C24 and the twenty-fifth capacitor C25 arranged in parallel. The negative terminals of the twenty-third capacitor C23, the twenty-fourth capacitor C24 and the twenty-fifth capacitor C25, as well as the GND pin of the voltage regulator 602, are all grounded.

[0042] In this embodiment, the voltage regulator 602 can be a commercially available linear voltage regulator, which can convert the input 5V DC voltage into a stable output 3.3V DC voltage.

[0043] like Figure 1 As shown, the battery internal resistance test module 7 includes an internal resistance test connection terminal 701, which is used to connect the internal resistance tester 702 to the controller 4.

[0044] In this embodiment, the internal resistance tester 702 can be a commercially available model, such as the IT5100 series internal resistance tester provided by ITECH Electronics (Nanjing) Co., Ltd.

[0045] like Figure 1 , Figure 2 and Figure 4 As shown in the figure, the battery load test module 8 includes a load test connection terminal 801 and a conduction unit 802, and the load test connection terminal 801 is connected to a load tester 803.

[0046] In this embodiment, the load tester 803 can be a commercially available model, such as the FT6301A single-channel programmable DC electronic load tester provided by Shenzhen Degong Electronics Technology Co., Ltd.

[0047] Preferably, the conduction unit 802 includes a load test control transistor Q3 and a load test control MOSFET Q4 connected together. The base of the load test control transistor Q3 is connected to the PB8 pin of the controller 4, the drain of the load test control MOSFET Q4 is connected to the second pin of the load test connection terminal 801, and the collector of the load test control transistor Q3, the source of the load test control MOSFET Q4, and the first pin of the load test connection terminal 801 are all connected to the charging module 102 inside the lithium battery pack 1.

[0048] Preferably, a ninth resistor R9 is connected in series between the base of the load test control transistor Q3 and the PB8 pin of the controller 4. The two ends of the ninth resistor R9 are also connected to the positive terminals of the third capacitor C3 and the tenth resistor R10. The negative terminals of the third capacitor C3 and the tenth resistor R10, as well as the emitter of the load test control transistor Q3, are all grounded.

[0049] Preferably, an eleventh resistor R11 and a thirteenth resistor R13 are connected in series between the collector of the load test control transistor Q3 and the gate of the load test control MOS transistor Q4, and a twelfth resistor R12 is connected in series between the eleventh resistor R11 and the thirteenth resistor R13 and the charging module 102.

[0050] The principle of using the battery load test module 8 to perform high-load battery testing on the lithium battery pack 1 is as follows: First, the PB8 pin of controller 4 outputs a high level. After the high-level signal enters the battery load test module 8, it is limited by the ninth resistor R9 and filtered by the third capacitor C3, and then drives the load test control transistor Q3. The second step is that after the base of the load test control transistor Q3 receives a positive bias voltage, it is turned on and its collector is pulled low. After the voltage division / current limiting of the eleventh resistor R11, the twelfth resistor R12 and the thirteenth resistor R13, the load test control MOSFET Q4 is turned on so that the entire circuit is connected and the lithium battery pack 1 will discharge at a high current. The third step is to test the high current output capability of the lithium battery pack 1 by the load tester 803. The load tester 803 can determine the high load capability of the lithium battery pack 1 based on the voltage fluctuation and current stability at both ends of the lithium battery pack 1. Fourth step, the PB8 pin of controller 4 outputs a low level, which turns off the load test control transistor Q3 and turns off the load test control MOSFET Q4, thereby disconnecting the load and stopping the discharge. The fifth step is to calculate the actual capacity of lithium battery pack 1 based on the discharge current, battery voltage, and discharge time of the load tester 803.

[0051] like Figure 1 , Figure 2 and Figure 5 As shown, the high and low temperature protection function test module 9 includes a high temperature protection test transistor Q1 and a low temperature protection test transistor Q2. The base of the high temperature protection test transistor Q1 is connected to the PA0 pin of the controller 4, and the base of the low temperature protection test transistor Q2 is connected to the PC3 pin of the controller 4. The collectors of both the high temperature protection test transistor Q1 and the low temperature protection test transistor Q2 are connected to the signal input terminal of the battery protection board 101 inside the lithium battery pack 1, and the emitters of both the high temperature protection test transistor Q1 and the low temperature protection test transistor Q2 are connected to the signal output terminal of the battery protection board 101.

[0052] In this embodiment, the battery protection board 101 has a built-in high and low temperature detection circuit. The voltage changes due to the resistance change of the set thermistor. The chip on the battery protection board 101 determines the battery temperature by detecting the corresponding voltage.

[0053] In this embodiment, the high and low temperature protection function test module 9 of this utility model simulates the function of high and low temperature by changing the voltage of its high and low temperature detection circuit.

[0054] Preferably, a first resistor R1 is connected in series between the base of the high-temperature protection test transistor Q1 and the PA0 pin of the controller 4. The two ends of the first resistor R1 are respectively connected to the positive terminals of the first capacitor C1 and the second resistor R2. A third resistor R3 and a seventh resistor R7 are connected in series between the negative terminals of the first capacitor C1, the negative terminals of the second resistor R2, and the emitter of the high-temperature protection test transistor Q1 and the battery protection board 101.

[0055] Preferably, a fourth resistor R4 is connected in series between the base of the low-temperature protection test transistor Q2 and the PC3 pin of the controller 4. The two ends of the fourth resistor R4 are respectively connected to the positive terminals of the second capacitor C2 and the fifth resistor R5. A sixth resistor R6 and an eighth resistor R8 are connected in series between the negative terminals of the second capacitor C2, the negative terminal of the fifth resistor R5, the emitter of the low-temperature protection test transistor Q2, and the battery protection board 101.

[0056] Preferably, the third resistor R3 and the sixth resistor R6 are connected together to the fifth pin of the communication terminal 202, the sixth pin of the communication terminal 202 is connected to the PA1 pin of the controller 4, and a twenty-first resistor R21 is connected in series between the sixth pin of the communication terminal 202 and the PA1 pin of the controller 4.

[0057] The procedure for testing the high-temperature protection function of the battery protection board 101 using the high and low temperature protection function test module 9 is as follows: First, select the option to perform high temperature protection function test on display screen 5. Display screen 5 sends a command to controller 4 to start the high temperature protection function test. The second step is that after receiving the instruction, the controller 4 sends out a level signal through the PA0 pin. After the level signal enters the high and low temperature protection function test module 9, it turns on the high temperature protection test transistor Q1 and supplies a voltage that simulates the high temperature of the battery into the battery protection board 101 of the lithium battery pack 1. Third, the chip on the battery protection board 101 detects this voltage and mistakenly believes that the temperature of the lithium battery pack 1 exceeds the threshold. The battery protection board 101 can then cut off the discharge circuit of the lithium battery pack 1.

[0058] If the buzzer BZ1 stops beeping at this time, it indicates that the discharge circuit of lithium battery pack 1 has been cut off, that is, the over-temperature protection mechanism of lithium battery pack 1 is triggered normally, and the high temperature protection function of lithium battery pack 1 is effective.

[0059] The procedure for testing the low-temperature protection function of the battery protection board 101 using the high and low temperature protection function test module 9 is as follows: First, select the option to perform low temperature protection function test on display screen 5. Display screen 5 sends a command to controller 4 to start the low temperature protection function test. The second step is that after receiving the instruction, the controller 4 sends out a level signal through the PC3 pin. After the level signal enters the high and low temperature protection function test module 9, it turns on the low temperature protection test transistor Q2 and supplies a voltage that simulates the low temperature of the battery into the battery protection board 101 of the lithium battery pack 1. Third, the chip on the battery protection board 101 detects this voltage and mistakenly believes that the temperature of the lithium battery pack 1 is below the threshold. The battery protection board 101 can then cut off the discharge circuit of the lithium battery pack 1.

[0060] If the buzzer BZ1 stops beeping at this time, it indicates that the discharge circuit of lithium battery pack 1 has been cut off, that is, the low temperature protection mechanism of lithium battery pack 1 is triggered normally, and the low temperature protection function of lithium battery pack 1 is effective.

[0061] like Figure 1 , Figure 2 and Figure 6 As shown, the heating function test module 10 includes a control unit and a detection unit.

[0062] Preferably, the control unit includes a heating control transistor Q5, a heating control MOSFET Q6, and a buzzer BZ1 connected in sequence. The base of the heating control transistor Q5 is connected to the PB9 pin of the controller 4. The emitter of the heating control transistor Q5 and the source of the heating control MOSFET Q6 are both connected to the positive terminal of the lithium battery pack 1. The collector of the heating control transistor Q5 and the buzzer BZ1 are both connected to the negative terminal of the lithium battery pack 1.

[0063] Preferably, the detection unit includes an alarm diode D1 and a Zener diode D2. The negative terminal of the alarm diode D1 is connected to the negative terminal of the lithium battery pack 1, and the positive terminal of the alarm diode D1 is connected to the positive terminal of the Zener diode D2. A nineteenth resistor R19 is connected in series between the positive terminals of the alarm diode D1 and the positive terminals of the Zener diode D2. The negative terminal of the Zener diode D2 is connected to the drain of the heating control MOSFET Q6.

[0064] Preferably, a fourteenth resistor R14 is connected in series between the base of the heating control transistor Q5 and the PB9 pin of the controller 4. The two ends of the fourteenth resistor R14 are connected to the positive terminals of the fourth capacitor C4 and the fifteenth resistor R15, respectively. The negative terminals of the fourth capacitor C4 and the fifteenth resistor R15 are both connected to the negative terminal of the lithium battery pack 1. A sixteenth resistor R16 and a seventeenth resistor R17 are connected in series between the collector of the heating control transistor Q5 and the positive terminal of the lithium battery pack 1. The negative terminal of the sixteenth resistor R16 is connected in series with the positive terminal of the eighteenth resistor R18. The negative terminal of the eighteenth resistor R18 is connected to the gate of the heating control MOS transistor Q6.

[0065] Preferably, the negative terminal of the buzzer BZ1 and the negative terminal of the warning diode D1 are connected in series with the negative terminal of the lithium battery pack 1 by a twentieth resistor R20.

[0066] The procedure for testing the heating element and temperature control switch inside the lithium battery pack 1 using the heating function test module 10 is as follows: First, connect the main output line of lithium battery pack 1 to the discharge terminal 203; The second step is to control the heating element test to start on display screen 5. Display screen 5 sends a command to controller 4 to start the heating element test. Third, the controller 4, which receives the instruction, sends a level signal through the PB9 pin. This level signal is input to the base of the heating control transistor Q5 and turns it on. After it turns on, the output voltage of the lithium battery pack 1 is applied to the gate of the heating control MOSFET Q6, which turns on the heating control MOSFET Q6, thereby energizing the heating element to generate heat. Fourth, if the buzzer BZ1 continues to beep during the test, it means that the discharge circuit of lithium battery pack 1 is conducting normally. If the buzzer BZ1 continues to sound and the warning diode D1 is off, it can be determined that the driving circuit and power components of the heating element are functioning normally. If the buzzer BZ1 does not sound, it indicates that the discharge function of lithium battery pack 1 is abnormal or there is a short circuit in the heating element or temperature control. If the warning diode D1 lights up, it indicates that the heating element and the temperature control switch have broken the circuit, causing the voltage across the positive and negative terminals of the battery pack 1 to rise sharply, which breaks down the Zener diode D2 and causes the warning diode D1 to light up.

[0067] like Figure 1 , Figure 2 and Figure 7 As shown, the charging current detection module 11 includes a dual operational amplifier 1101. The INB+ pin of the dual operational amplifier 1101 is connected to the external power supply terminal 204, the INB- pin of the dual operational amplifier 1101 is connected to the charging terminal 201, the OUTB pin of the dual operational amplifier 1101 is connected to the PA2 pin of the controller 4, and the VDD pin and VSS pin of the dual operational amplifier 1101 are both connected to the output terminal of the step-down module 6.

[0068] Preferably, a 23rd resistor R23 is connected in series between the INB+ pin of the dual op-amp 1101 and the external power supply terminal 204, and a 24th resistor R24 ​​is connected in series between the INB- pin of the dual op-amp 1101 and the charging terminal 201.

[0069] Preferably, the INB+ pin of the dual op-amp 1101 is grounded through a fifth capacitor C5 and a sixth capacitor C6 connected in series. The fifth capacitor C5 is connected in parallel with a twenty-sixth resistor R26. The INA- and OUTA pins of the dual op-amp 1101 are both connected to the positive terminal of the sixth capacitor C6.

[0070] Preferably, a 28th resistor R28 and a 27th resistor R27 are connected in series between the output terminal of the step-down module 6 and the VSS pin of the dual op-amp 1101. A 7th capacitor C7 is connected in parallel between the 28th resistor R28 and the 27th resistor R27. The negative terminal of the 28th resistor R28 is connected to the INA+ pin of the dual op-amp 1101.

[0071] The procedure for testing the charging function of lithium battery pack 1 using charging current detection module 11 is as follows: The first step is to set the output voltage of the external DC power supply 3; The second step is to connect the charging cable of the lithium battery pack 1 to the charging terminal 201 and use the DC power output from the external DC power supply 3 to power the lithium battery pack 1. The third step is to use the charging current detection module 11 to detect the real-time charging current of the lithium battery pack 1 and display it on the display screen 5. If the detected charging current parameter is stable in the range of 400mA-600mA, it is determined that the charging circuit function of the lithium battery pack 1 is normal. Fourth, if the controller 4 detects that the voltage at both ends of the lithium battery pack 1 reaches the preset voltage threshold, and the output current of the external DC power supply 3 jumps from a stable value to 0mA, the display screen 5 will show "Overcharge protection triggered". This indicates that the threshold judgment and actuator of the charging protection board inside the lithium battery pack 1 are normal and the overcharge protection function is effective.

[0072] like Figure 1 , Figure 2 and Figure 8 As shown, the battery voltage detection module 12 includes a 33rd resistor R33 and a 15th capacitor C15 connected in parallel. The negative terminal of the 33rd resistor R33 is connected in series with the positive terminal of the lithium battery pack 1 by a 32nd resistor R32, and a 34th resistor R34 is connected in series with the negative terminal of the lithium battery pack 1 by a 34th resistor R34. The negative terminal of the 15th capacitor C15 is connected to the negative terminal of the lithium battery pack 1.

[0073] In this embodiment, the battery voltage detection module 12 is configured to directly detect the voltage at both ends of the lithium battery pack 1 and transmit it to the display screen 5 through the controller 4, so that the voltage of the lithium battery pack 1 is displayed on the display screen 5 in real time.

[0074] The steps for performing performance testing on lithium battery pack 1 using this invention are as follows: First, adjust the output voltage of the external DC power supply 3 (no further adjustment is needed), and connect the external DC power supply 3 to the battery detection board 2 through the external power supply terminal 204.

[0075] In the second step, the charging cable of the lithium battery pack 1 is connected to the corresponding position of the battery detection board 2 through the charging terminal 201. The charging current of the lithium battery pack 1 is monitored by the current detection module 11, and the monitoring data can be displayed in real time on the display screen 5.

[0076] The third step is to determine whether the charging current of lithium battery pack 1 is normal by measuring the magnitude of the charging current. After lithium battery pack 1 is fully charged, the charging circuit of lithium battery pack 1 will automatically stop. The presence or absence of current at this time will be combined with the magnitude of voltage to determine whether the overcharge protection function of lithium battery pack 1 is normal.

[0077] Fourth step: After the charging function test is completed, remove the charging cable of lithium battery pack 1.

[0078] Fifth step, connect the signal cable of lithium battery pack 1 to the corresponding position of battery detection board 2 through communication terminal 202, and connect the discharge cable of lithium battery pack 1 to the corresponding position of battery detection board 2 through discharge terminal 203. Read the real-time data of internal temperature and battery voltage of lithium battery pack 1 through the monitoring interface of display screen 5. If the displayed temperature value matches the temperature of the test environment, it indicates that the NTC temperature sensor built into the lithium battery pack 1 is working properly and the battery voltage is within the preset threshold range, indicating that the battery voltage is normal.

[0079] Fifth step: Start the high and low temperature protection function test through the display screen 5, and use the high and low temperature protection function test module 9 to test the high temperature protection function and low temperature protection function on the battery protection board 101.

[0080] The sixth step is to connect the internal resistance tester 702 to the internal resistance test connection terminal 701 and use the internal resistance tester 702 to test the internal resistance of the lithium battery pack 1. If the value of the DC internal resistance of the lithium battery pack 1 displayed by the internal resistance tester 702 is ≤200mΩ, it can be determined that the internal cells of the lithium battery pack 1 have good consistency and the internal resistance parameters meet the design standards.

[0081] The sixth step is to start the heating function test through the display screen 5 and test the heating element and temperature control switch inside the lithium battery pack 1 through the heating function test module 10.

[0082] Step 7: Start the load test via display screen 5. Controller 4 controls the on / off state of load test connection terminal 801. Load tester 803 is connected to the circuit, which can then test the high current output capability and battery capacity of lithium battery pack 1.

[0083] Step 8: When the discharge voltage of lithium battery pack 1 drops to a predetermined threshold, the battery protection board 101 activates the protection function. When the voltage drops sharply to below 5V, lithium battery pack 1 stops discharging, thus determining that the over-discharge function of lithium battery pack 1 is normal.

[0084] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A testing device for photovoltaic lithium batteries, comprising a battery testing board (2) for testing lithium battery packs (1), characterized in that, The battery detection board (2) is connected to the charging cable, communication cable and discharge cable of the lithium battery pack (1) through the charging terminal (201), communication terminal (202) and discharge terminal (203) respectively. The battery detection board (2) is also connected to an external DC power supply (3) through the external power supply terminal (204). The battery testing board (2) is equipped with a controller (4), a display screen (5), a step-down module (6), a battery internal resistance test module (7), and a battery load test module (8). The battery internal resistance test module (7) and the battery load test module (8) are both connected to the controller (4). An external DC power supply (3) is connected to the input terminal of the step-down module (6) through an external power supply terminal (204). The output terminal of the step-down module (6) is connected to the display screen (5) and the controller (4). The battery test board (2) is also equipped with a high and low temperature protection function test module (9), a heating function test module (10), a charging current detection module (11) and a battery voltage detection module (12). The high and low temperature protection function test module (9), the heating function test module (10), the charging current detection module (11) and the battery voltage detection module (12) are all connected between the controller (4) and the lithium battery pack (1).

2. The photovoltaic lithium battery testing device according to claim 1, characterized in that, The heating function test module (10) includes a control unit and a detection unit; The control unit includes a heating control transistor Q5, a heating control MOSFET Q6, and a buzzer BZ1 connected in sequence. The base of the heating control transistor Q5 is connected to the PB9 pin of the controller (4). The emitter of the heating control transistor Q5 and the source of the heating control MOSFET Q6 are both connected to the positive terminal of the lithium battery pack (1). The collector of the heating control transistor Q5 and the buzzer BZ1 are both connected to the negative terminal of the lithium battery pack (1). The detection unit includes an alarm diode D1 and a Zener diode D2. The negative terminal of the alarm diode D1 is connected to the negative terminal of the lithium battery pack (1), and the positive terminal of the alarm diode D1 is connected to the positive terminal of the Zener diode D2. A nineteenth resistor R19 is connected in series between the positive terminal of the alarm diode D1 and the positive terminal of the Zener diode D2. The negative terminal of the Zener diode D2 is connected to the drain of the heating control MOS transistor Q6.

3. The photovoltaic lithium battery testing device according to claim 2, characterized in that, The base of the heating control transistor Q5 is connected in series with the PB9 pin of the controller (4) by a fourteenth resistor R14. The two ends of the fourteenth resistor R14 are connected to the positive terminals of the fourth capacitor C4 and the fifteenth resistor R15, respectively. The negative terminals of the fourth capacitor C4 and the fifteenth resistor R15 are both connected to the negative terminal of the lithium battery pack (1). The collector of the heating control transistor Q5 is connected in series with the positive terminal of the lithium battery pack (1) by a sixteenth resistor R16 and a seventeenth resistor R17. The negative terminal of the sixteenth resistor R16 is connected in series with the positive terminal of the eighteenth resistor R18. The negative terminal of the eighteenth resistor R18 is connected to the gate of the heating control MOS transistor Q6. The negative terminals of buzzer BZ1 and warning diode D1 are connected in series with the negative terminal of lithium battery pack (1) by a twentieth resistor R20.

4. The photovoltaic lithium battery testing device according to claim 1, characterized in that, The battery internal resistance test module (7) includes an internal resistance test connection terminal (701), which is used to connect the internal resistance tester (702) to the controller (4).

5. A testing device for photovoltaic lithium batteries according to claim 4, characterized in that, The battery load test module (8) includes a load test connection terminal (801) and a conduction unit. The load test connection terminal (801) is connected to a load tester (802). The conduction unit includes a load test control transistor Q3 and a load test control MOSFET Q4 connected together. The base of the load test control transistor Q3 is connected to the PB8 pin of the controller (4). The drain of the load test control MOSFET Q4 is connected to the second pin of the load test connection terminal (801). The collector of the load test control transistor Q3 and the source of the load test control MOSFET Q4 are both connected to the positive terminal of the lithium battery pack (1). The first pin of the load test connection terminal (801) is connected to the negative terminal of the lithium battery pack (1).

6. A testing device for photovoltaic lithium batteries according to claim 5, characterized in that, The base of the load test control transistor Q3 is connected in series with the PB8 pin of the controller (4) by a ninth resistor R9. The two ends of the ninth resistor R9 are also connected to the positive terminals of the third capacitor C3 and the tenth resistor R10. The negative terminals of the third capacitor C3 and the tenth resistor R10, as well as the emitter of the load test control transistor Q3, are all grounded. The collector of the load test control transistor Q3 and the gate of the load test control MOS transistor Q4 are connected in series with an eleventh resistor R11 and a thirteenth resistor R13. The eleventh resistor R11 and the thirteenth resistor R13 are connected in series with the charging module (102) with a twelfth resistor R12.

7. A testing device for photovoltaic lithium batteries according to claim 1, characterized in that, The high and low temperature protection function test module (9) includes a high temperature protection test transistor Q1 and a low temperature protection test transistor Q2. The base of the high temperature protection test transistor Q1 is connected to the PA0 pin of the controller (4), and the base of the low temperature protection test transistor Q2 is connected to the PC3 pin of the controller (4). The collectors of both the high temperature protection test transistor Q1 and the low temperature protection test transistor Q2 are connected to the signal input terminal of the battery protection board (101) inside the lithium battery pack (1). The emitters of both the high temperature protection test transistor Q1 and the low temperature protection test transistor Q2 are connected to the signal output terminal of the battery protection board (101).

8. A testing device for photovoltaic lithium batteries according to claim 7, characterized in that, The base of the high-temperature protection test transistor Q1 is connected in series with the PA0 pin of the controller (4) and a first resistor R1 is connected in series. The two ends of the first resistor R1 are connected to the positive terminals of the first capacitor C1 and the second resistor R2 respectively. The negative terminals of the first capacitor C1, the negative terminals of the second resistor R2, and the emitter of the high-temperature protection test transistor Q1 are connected in series with the battery protection board (101) and a third resistor R3 and a seventh resistor R7. The base of the low-temperature protection test transistor Q2 is connected in series with the PC3 pin of the controller (4) by a fourth resistor R4. The two ends of the fourth resistor R4 are connected to the positive terminals of the second capacitor C2 and the fifth resistor R5, respectively. The negative terminals of the second capacitor C2, the fifth resistor R5, and the emitter of the low-temperature protection test transistor Q2 are connected in series with the battery protection board (101) by a sixth resistor R6 and an eighth resistor R8. The third resistor R3 and the sixth resistor R6 are connected together to the fifth pin of the communication terminal (202). The sixth pin of the communication terminal (202) is connected to the PA1 pin of the controller (4). The twenty-first resistor R21 is connected in series between the sixth pin of the communication terminal (202) and the PA1 pin of the controller (4).

9. A testing device for photovoltaic lithium batteries according to claim 1, characterized in that, The charging current detection module (11) includes a dual operational amplifier (1101). The INB+ pin of the dual operational amplifier (1101) is connected to the external power supply terminal (204), the INB- pin of the dual operational amplifier (1101) is connected to the charging terminal (201), the OUTB pin of the dual operational amplifier (1101) is connected to the PA2 pin of the controller (4), and the VDD pin and VSS pin of the dual operational amplifier (1101) are both connected to the output terminal of the step-down module (6). The INB+ pin of the dual op-amp (1101) is connected in series with the external power supply terminal (204) and the twenty-third resistor R23 is connected in series with the INB- pin of the dual op-amp (1101) and the charging terminal (201) and the twenty-fourth resistor R24. The INB+ pin of the dual op-amp (1101) is grounded through the fifth capacitor C5 and the sixth capacitor C6 connected in series. The fifth capacitor C5 is connected in parallel with the twenty-sixth resistor R26. The INA- and OUTA pins of the dual op-amp (1101) are both connected to the positive terminal of the sixth capacitor C6. The output terminal of the step-down module (6) is connected in series with the VSS pin of the dual op-amp (1101) by a 28th resistor R28 and a 27th resistor R27. The 28th resistor R28 and the 27th resistor R27 are connected in parallel with a 7th capacitor C7. The negative terminal of the 28th resistor R28 is connected to the INA+ pin of the dual op-amp (1101).

10. A testing device for photovoltaic lithium batteries according to claim 1, characterized in that, The battery voltage detection module (12) includes a 33rd resistor R33 and a 15th capacitor C15 connected in parallel. The negative terminal of the 33rd resistor R33 is connected in series with the positive terminal of the lithium battery pack (1) by a 32nd resistor R32, and the negative terminal of the 33rd resistor R33 is connected in series with the negative terminal of the lithium battery pack (1) by a 34th resistor R34. The negative terminal of the 15th capacitor C15 is connected to the negative terminal of the lithium battery pack (1).

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