Lithium battery pack test circuit and test tool irrespective of positive and negative polarities

Abstract

The utility model discloses a lithium battery pack test circuit and a test tool regardless of positive and negative polarities. The lithium battery pack test circuit creatively adopts a power supply scheme of two groups of isolated power supplies, and provides stable and safe power supply for the pole test circuit of the lithium battery pack. Through the isolation power supply, the level of the test pole is successfully and effectively isolated from the battery main body, so that the safety and the accuracy of the test process are ensured. The lithium battery pack test circuit has the functions of automatically identifying and adapting to the positive and negative polarities of the lithium battery pack. No matter whether the positive pole of the lithium battery pack is upward or downward, the test tool can accurately identify and adapt, and further accurately measure key parameters such as the conduction state of the two poles with the same polarity, the working state (such as startup and dormancy) of the battery, the voltage of the battery and the like. The circuit design thoroughly abandons the step of tedious distinguishing of the positive electrode and the negative electrode in a traditional test method, integrates the performance test function of the terminal post, and is efficient and accurate.

Description

Technical Field

[0001] The utility model relates to the field of electrical property testing of lithium batteries, and particularly to a testing circuit and a testing tooling for a lithium battery pack without distinguishing positive and negative polarities. Background Art

[0002] At present, with the rapid development of technology, lithium batteries, with their high efficiency and environmental protection characteristics, have been widely integrated into the core of various electronic products and electric devices. With the continuous increase of market demand, higher requirements have been put forward for the capacity and output current of lithium batteries. Compared with lead-acid batteries of the same volume, the lithium battery pack has achieved a significant breakthrough in capacity. The capacity of products of the same volume has been increased from the original 20Ah - 50Ah to 50Ah - 200Ah.

[0003] To meet this growing demand, the design of the battery pack's pole columns has also changed. The number of pole columns has increased from one positive and one negative to two positive and two negative pole columns. This change not only improves the performance of the battery pack but also increases the complexity of the testing work, as Figure 1 shown.

[0004] In the structure of the lithium battery pack's pole columns, the two positive poles (P+) and the two negative poles (P-) are designed to be connected. If the internal connection fails during the production process or due to other factors, when a relatively large load, that is, a current output of 1C or greater, is applied, all the current will flow concentratedly to a single pole column and be transmitted to the load. This non-uniform current distribution will cause high-temperature phenomena, and in severe cases, it may even cause the softening and deformation of the plastic shell of the battery pack. Such failures will not only damage the product itself but may also lead to serious safety accidents, threatening the life and property safety of users.

[0005] Currently, the commonly used testing methods in the market, such as using a multimeter for single-sided testing or relying on testing equipment of a separate station for inspection, are extremely inefficient. This inefficient testing process not only slows down the production progress, reduces the overall production efficiency, but also significantly increases the labor cost, thereby weakening the competitiveness of the product in the market.

[0006] Therefore, it is urgent for us to explore more efficient and accurate testing methods to ensure the quality and safety of lithium battery packs during the production process, while improving production efficiency, reducing production costs, and thus enhancing the market competitiveness of the product. Summary of the Utility Model

[0007] The utility model aims to provide a testing circuit and a testing tooling for a lithium battery pack without distinguishing positive and negative polarities to solve at least one of the above problems, and the following technical solutions are given:

[0008] A lithium battery pack test circuit without distinguishing positive and negative polarities, comprising: a first connector, a second connector, a first isolated power supply, a second isolated power supply, a first switching device, a second switching device, and a controller;

[0009] The first switching device and the second switching device include a control loop and an output loop;

[0010] The first connector includes a first terminal and a second terminal, and the first terminal and the second terminal are respectively connected to the first group of same-polarity terminal posts of the lithium battery pack to be tested; the first terminal is connected to the positive pole of the first isolated power supply through a first diode; the second terminal is connected to the negative pole of the first isolated power supply through a first resistor and the control loop of the first switching device;

[0011] The second connector includes a third terminal and a fourth terminal, and the third terminal and the fourth terminal are respectively connected to the second group of same-polarity terminal posts of the lithium battery pack to be tested; the third terminal is connected to the positive pole of the second isolated power supply through a second diode; the fourth terminal is connected to the negative pole of the second isolated power supply through a second resistor and the control loop of the second switching device;

[0012] The output loop of the first switching device is connected to the controller. When the control loop of the first switching device is powered on, the output loop of the first switching device conducts, and sends a status signal indicating that the first group of same-polarity terminal posts are connected to the controller;

[0013] The output loop of the second switching device is connected to the controller. When the control loop of the second switching device is powered on, the output loop of the second switching device conducts, and sends a status signal indicating that the second group of same-polarity terminal posts are connected to the controller.

[0014] Further, the first switching device and the second switching device are optocouplers.

[0015] Further, an overcurrent protection device is provided between the first connector and the first diode; an overcurrent protection device is provided between the first connector and the first resistor; an overcurrent protection device is provided between the second connector and the second diode; an overcurrent protection device is provided between the second connector and the second resistor.

[0016] Further, the overcurrent protection device is a PTC temperature fuse.

[0017] Further, the isolated power supply includes a four-terminal isolated DC-DC module.

[0018] Further, it further includes a non-polarity voltage sampling circuit, which includes a bridge rectifier circuit and a voltage dividing circuit. Two input terminals of the bridge rectifier circuit are respectively connected to a certain terminal of the first connector and a certain terminal of the second connector; two output terminals of the bridge rectifier circuit are connected to an input terminal of the voltage dividing circuit, and an output terminal of the voltage dividing circuit outputs a voltage sampling signal and sends it directly or indirectly to the controller.

[0019] Further, an ADC module is integrated inside the controller, and the output terminal of the voltage dividing circuit outputs a voltage sampling signal and sends it directly to the ADC module of the controller.

[0020] A test tooling applies the lithium battery pack test circuit without distinguishing positive and negative polarities as described above.

[0021] Further, it further includes a USB interface, which is used for communicating with a host computer.

[0022] Further, it further includes a serial interface, which is used for connecting peripherals, and the peripherals include a barcode scanner.

[0023] The utility model achieves the following technical effects:

[0024] This lithium battery pack test circuit innovatively adopts a two-group isolated power supply scheme to provide a stable and safe power supply for the pole column test circuit of the lithium battery pack. Through the isolated power supply, the level of the test pole column is effectively isolated from the battery body, thus ensuring the safety and accuracy of the test process.

[0025] This lithium battery pack test circuit has the function of automatically identifying and adapting to the positive and negative polarities of the lithium battery pack. Whether the positive pole column of the lithium battery pack is facing up or down, this test tooling can accurately identify and adapt to it, and then accurately measure key parameters such as the conduction state of two like-polarity pole columns, the working state of the battery (such as power on, sleep), and the voltage of the battery.

[0026] This lithium battery pack test circuit adopts an innovative circuit design, completely abandoning the cumbersome steps of distinguishing positive and negative polarities in traditional test methods, and integrating the performance test function of the end post. This design not only realizes the efficient and accurate test of the lithium battery pack, but also fully considers the special properties of the lithium battery, thus ensuring the safety and stability during the test process, and providing a more professional and reliable solution for the test of the lithium battery pack. Description of the Drawings

[0027] Figure 1 It is a top view schematic diagram of the lithium battery pack to be tested;

[0028] Figure 2It is the block diagram of the lithium battery testing system of the present utility model;

[0029] Figure 3 It is the circuit diagram of the isolated power supply of the present utility model;

[0030] Figure 4 It is the non-polarity connectivity detection and voltage acquisition module of the present utility model;

[0031] Figure 5 It is the controller and its peripheral circuits of the present utility model. Detailed implementation manners

[0032] To further illustrate the embodiments, the present utility model provides accompanying drawings. These drawings are part of the disclosure of the present utility model, which are mainly used to illustrate the embodiments and can be combined with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, those of ordinary skill in the art should be able to understand other possible implementation manners and the advantages of the present utility model. The components in the drawings are not drawn to scale, and similar component symbols are usually used to represent similar components.

[0033] The present utility model will be further described below in conjunction with the accompanying drawings and specific implementation manners.

[0034] As Figures 2 to 5 shown, the present utility model discloses a lithium battery pack testing tool without distinguishing between positive and negative polarities, which is composed of test connectors 201, 202, non-polarity voltage acquisition module 203, isolated power supplies 205, 506, ADC module 204, MCU 207 and other modules.

[0035] The two terminals 2011, 2012 of the test connector 201 are respectively connected to the first group of same-polarity terminal posts of the lithium battery pack 10, such as the power supply positive terminal posts 101, 102. The two terminals 2021, 2022 of the test connector 202 are respectively connected to the other group of same-polarity terminal posts of the lithium battery pack 10, such as the power supply negative terminal posts 103, 104.

[0036] When performing the connectivity test on the same-polarity terminal posts, the test connector 201 draws power from the isolated power supply 205 and tests the connectivity of the power supply positive terminal posts 101, 102, and the test result is sent to the MCU 207. At the same time, the test connector 202 draws power from the isolated power supply 206 and tests the connectivity of the power supply positive terminal posts 103 / 104; the test result is sent to the MCU 207.

[0037] When performing the voltage detection on the lithium battery pack, power is drawn from the terminal posts of the lithium battery pack through the test connectors 201 and 202, and the voltage detection data is sent to the MCU 207 through the non-polarity voltage acquisition module 203 and the ADC module 204.

[0038] The specific circuits for detecting the connectivity of the same-polarity terminal posts and the voltage of the lithium battery pack are as Figures 3 to 5 shown.

[0039] In Figure 3 it, the specific circuits of the isolated power supplies 205 / 206 are given. The isolated power supplies 205 / 206 respectively include a four-terminal isolated DC-DC module U3, U4, and output the isolated power supplies +5PB / GPB and +5PA / GPA.

[0040] In Figure 4 it, the circuit for detecting the connectivity of the same-polarity terminal posts is given. The terminal P1 (terminal 2011) of the connector JP2 (test connector 201) is connected to the positive pole +5PA of the isolated power supply after passing through the fuse PT2 and the diode D1; the terminal P2 (terminal 2012) of the connector JP2 is connected to the negative pole GPA of the isolated power supply after passing through the fuse PT3, the resistor R19, and the control circuit of the optocoupler DP1. One end of the output circuit of the optocoupler DP2 is grounded, and the other end is connected to the power supply +3.3V through the resistor R20, and outputs the connectivity detection signal PA_EN. Similarly, the terminal P3 (terminal 2021) of the connector JP3 (test connector 202) is connected to the positive pole +5PB of the isolated power supply after passing through the fuse PT4 and the diode D3; the terminal P4 (terminal 2022) of the connector JP3 is connected to the negative pole GPB of the isolated power supply after passing through the fuse PT5, the resistor R21, and the control circuit of the optocoupler DP2. One end of the output circuit of the optocoupler DP2 is grounded, and the other end is connected to the power supply +3.3V through the resistor R22, and outputs the connectivity detection signal PB_EN.

[0041] When performing the connectivity test of the same-polarity terminal posts, the isolated power supplies U3, U4 start to supply power. At this time, if the terminals P1, P2 are connected, there is current passing through the control circuit of the optocoupler DP1, the output end of the optocoupler DP1 is closed, and the connectivity detection signal PA_EN outputs a low level, indicating that the same-polarity terminal posts connected by the connector JP2 are connected; if the terminals P3, P4 are connected, there is current passing through the control circuit of the optocoupler DP2, the output end of the optocoupler DP2 is closed, and the connectivity detection signal PB_EN outputs a low level, indicating that the same-polarity terminal posts connected by the connector JP3 are connected.

[0042] In Figure 4 it, the circuit for detecting the voltage of the lithium battery pack is given. The circuit for detecting the voltage of the lithium battery pack shares the connectors JP2, JP3 with the circuit for detecting the connectivity of the same-polarity terminal posts. The battery voltages PA, PB are respectively converted into a voltage signal EB+ through a bridge rectifier circuit, and the voltage signal EB+ is output to the MCU through a voltage division circuit as A_BT1, and is processed by the ADC module (ADC module 204) inside the MCU, and the voltage value of the battery can be obtained.

[0043] Among them, the bridge rectifier circuit is composed of diodes D1, D2, D3, and D4. The voltage division circuit is composed of devices such as R14, R15, and R16.

[0044] As Figure 2 shown, in this test tooling, communication interfaces such as USB interface 211 and serial port are set to communicate with the host computer 30, receive operation instructions from the host computer 30 and upload detection data, and support peripherals such as barcode scanner 209. This test tooling is also provided with operation guidance and warning devices such as buzzer 208 and indicator light 210.

[0045] This lithium battery pack test circuit innovatively adopts a two-group isolated power supply scheme to provide a stable and safe power supply for the pole column test circuit of the lithium battery pack. Through the isolated power supply, the level of the test pole column is effectively isolated from the battery body, thus ensuring the safety and accuracy of the test process.

[0046] This lithium battery pack test circuit has the function of automatically identifying and adapting to the positive and negative polarities of the lithium battery pack. Whether the positive pole column of the lithium battery pack is facing up or down, this test tooling can accurately identify and adapt, and then accurately measure key parameters such as the conduction state of two like-polarity pole columns, the working state of the battery (such as power on, sleep), and the voltage of the battery.

[0047] In specific applications, optocouplers OP1 and OP2 can also use switching devices such as relays with isolated control circuits and output circuits.

[0048] In specific applications, PA can be connected to any terminal of connector JP2, and PB can be connected to any terminal of connector JP3.

[0049] Fuses PT2 - PT5 are preferred optional settings. In specific applications, fuses PT2 - PT5 are preferably PTC thermal fuses to provide recoverable overcurrent protection.

[0050] To sum up, this lithium battery pack test circuit adopts an innovative circuit design, completely abandoning the cumbersome steps of distinguishing positive and negative poles in traditional test methods, and integrating the performance test function of the end post. This design not only realizes the efficient and accurate test of the lithium battery pack, but also fully considers the special properties of the lithium battery, thus ensuring the safety and stability during the test process, and providing a more professional and reliable solution for the test of the lithium battery pack.

[0051] This innovative design plays an important role in the production process and provides strong support for quality control. Through the test tooling of this patent, we can timely discover and solve possible problems in the production process of the lithium battery pack, thus ensuring that the quality and performance of the product reach the best state.

[0052] Although the present utility model is specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes can be made to the present utility model in terms of form and details without departing from the spirit and scope of the present utility model defined by the appended claims, and all such changes are within the protection scope of the present utility model.

Claims

1. A lithium battery pack test circuit without distinguishing between positive and negative polarities, characterized in that: Including: A first connector, a second connector, a first isolated power supply, a second isolated power supply, a first switching device, a second switching device, and a controller; The first switching device and the second switching device include a control loop and an output loop; The first connector includes a first terminal and a second terminal, and the first terminal and the second terminal are respectively connected to the first group of like-polarity terminal posts of the lithium battery pack to be tested; the first terminal is connected to the positive pole of the first isolated power supply through a first diode; the second terminal is connected to the negative pole of the first isolated power supply through a first resistor and the control loop of the first switching device; The second connector includes a third terminal and a fourth terminal, and the third terminal and the fourth terminal are respectively connected to the second group of like-polarity terminal posts of the lithium battery pack to be tested; the third terminal is connected to the positive pole of the second isolated power supply through a second diode; the fourth terminal is connected to the negative pole of the second isolated power supply through a second resistor and the control loop of the second switching device; The output loop of the first switching device is connected to the controller. When the control loop of the first switching device is powered on, the output loop of the first switching device conducts, and sends a status signal indicating that the first group of like-polarity terminal posts are connected to the controller; The output loop of the second switching device is connected to the controller. When the control loop of the second switching device is powered on, the output loop of the second switching device conducts, and sends a status signal indicating that the second group of like-polarity terminal posts are connected to the controller.

2. The test circuit for a lithium battery pack without positive and negative polarity as described in claim 1, wherein: The first switching device and the second switching device are optocouplers.

3. The non-polarity lithium battery pack test circuit according to claim 1, wherein: An overcurrent protection device is provided between the first connector and the first diode; an overcurrent protection device is provided between the first connector and the first resistor; an overcurrent protection device is provided between the second connector and the second diode; an overcurrent protection device is provided between the second connector and the second resistor.

4. The non-polarity lithium battery pack test circuit according to claim 3, wherein: The overcurrent protection device is a PTC thermal fuse.

5. The non-polarity lithium battery pack test circuit according to claim 1, wherein: The isolated power supply includes a four-terminal isolated DC-DC module.

6. The non-polarity lithium battery pack test circuit according to claim 1, wherein: It further includes a non-polar voltage sampling circuit, and the non-polar voltage sampling circuit includes a bridge rectifier circuit and a voltage dividing circuit. The two input terminals of the bridge rectifier circuit are respectively connected to a certain terminal of the first connector and a certain terminal of the second connector; the two output terminals of the bridge rectifier circuit are connected to the input terminal of the voltage dividing circuit, and the output terminal of the voltage dividing circuit outputs a voltage sampling signal and sends it directly or indirectly to the controller.

7. The non-polarity lithium battery pack test circuit according to claim 6, characterized in that: An ADC module is integrated inside the controller, and the output terminal of the voltage dividing circuit outputs a voltage sampling signal and sends it directly to the ADC module of the controller.

8. A test tooling, characterized in that: The non-polar lithium battery pack test circuit according to any one of claims 1-7 is applied.

9. The test tooling according to claim 8, characterized in that: It further includes a USB interface, and the USB interface is used for communicating with a host computer.

10. The test tooling according to claim 8, wherein: It further includes a serial interface, and the serial interface is used for connecting peripherals, and the peripherals include a barcode scanner.

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