A lithium battery sensitivity testing method and system

Abstract

The present invention belongs to the technical field of lithium battery testing, and discloses a lithium battery sensitivity testing method and system, the method comprising: connecting a data acquisition interface to a lithium battery through a test line, collecting characteristic data of the lithium battery, and sending the characteristic data to a main processor; the main processor analyzes the initial state of the lithium battery according to the characteristic data of the lithium battery, and tests the sensitivity of the lithium battery based on the initial state of the lithium battery to obtain the characteristic data of the lithium battery in a stable state; calculates the temperature range in combination with the characteristic data in the stable state, establishes a functional relationship between the characteristics of the lithium battery according to the calculation result of the temperature range, and analyzes the functional relationship to obtain the sensitivity test result of the lithium battery. The present invention covers more comprehensive conditions, can be used to determine battery performance parameters, and helps to reduce the impact of temperature changes on the battery during the battery production process, thereby improving the battery's pass rate, safety and parameter accuracy.

Description

Technical Field

[0001] With the vigorous development of the new energy industry, lithium batteries, as core energy storage components, have a performance stability and reliability that is directly related to the operating efficiency and safety of the entire system. However, existing technologies often focus on the capacity, cycle life, and charge and discharge efficiency of lithium batteries. Temperature, as a factor that can affect batteries in many ways, does not have a mature test method to characterize the impact of temperature on lithium batteries.

[0002] There is no doubt that temperature has an impact on batteries. In the current battery research and development, verification, and production process, all battery manufacturers will control the temperature throughout the process. However, so far there is no exact parameter to characterize the relationship and degree of influence between temperature and batteries. Specifically, battery manufacturers deal with the impact of temperature by controlling the ambient temperature during the battery production process. However, batteries of different models, capacities, and manufacturing processes are affected by temperature in different ways, so there is no way to control the ambient temperature standard. Only empirical values ​​can be used, and effective problem analysis and testing cannot be performed when problems arise.

[0003] In addition, the control of ambient temperature cannot be guaranteed to be within a fixed fluctuation range. It is affected by weather, equipment efficiency and other factors, so the impact on the battery is not as controllable as expected. At the same time, when relevant personnel encounter related problems, they usually manually test the temperature and open circuit voltage separately. However, manual testing is difficult to control the consistency of test conditions, manual contact stability performance is low, test instrument accuracy is low, test cycle is long, lack of appropriate calculation algorithms, and the inability to visualize results, which requires the consumption of professional human resources for data statistics and analysis.

[0004] The present invention relates to the technical field of lithium battery testing, and in particular to a lithium battery sensitivity testing method and system. Background Art

[0005] Therefore, how to provide a lithium battery sensitivity testing method and system is a problem that needs to be solved urgently. Summary of the invention

[0006] The embodiment of the present invention provides a lithium battery sensitivity testing method and system to solve the problem in the prior art that the influence relationship between temperature and battery cannot be characterized.

[0007] In order to have a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not a general review, nor is it intended to identify key / important components or to describe the scope of protection of these embodiments. Its only purpose is to present some concepts in a simple form as a prelude to the detailed description that follows.

[0008] According to a first aspect of an embodiment of the present invention, a lithium battery sensitivity testing method is provided.

[0009] In one embodiment, the lithium battery sensitivity testing method includes:

[0010] Connect the data acquisition interface to the lithium battery through the test line, collect characteristic data of the lithium battery, and send the characteristic data to the main processor;

[0011] The main processor analyzes the initial state of the lithium battery according to the characteristic data of the lithium battery, and tests the sensitivity of the lithium battery based on the initial state of the lithium battery to obtain the characteristic data of the lithium battery in a stable state;

[0012] The temperature range is calculated in combination with the characteristic data in the stable state, and the functional relationship between the lithium battery characteristics is established according to the temperature range calculation results. The functional relationship is analyzed to obtain the lithium battery sensitivity test results.

[0013] In one embodiment, connecting the data acquisition interface to the lithium battery through a test line, collecting characteristic data of the lithium battery, and sending the characteristic data to the main processor includes:

[0014] Connect the temperature acquisition interface and the voltage acquisition interface to the lithium battery through the test line to obtain the temperature acquisition signal and the voltage acquisition signal of the lithium battery;

[0015] The temperature acquisition signal is sent to the temperature acquisition module for processing to obtain the temperature data of the lithium battery; the voltage acquisition signal is sent to the voltage acquisition module for processing to obtain the voltage data of the lithium battery;

[0016] The temperature data and voltage data of the lithium battery are sent to the main processor.

[0017] In one embodiment, sending the temperature acquisition signal to the temperature acquisition module for processing to obtain the temperature data of the lithium battery includes:

[0018] The temperature sensor is connected to the temperature acquisition module. After receiving the temperature acquisition signal, the temperature acquisition module uses the operational amplifier U91A channel to connect the temperature acquisition signal to the chip U90 through the resistor R589 as a voltage reference signal;

[0019] The voltage reference signal is divided by voltage R577 and resistor R578 in turn, and then connected to the non-inverting input terminal of the operational amplifier U91B channel;

[0020] If the temperature of the lithium battery changes, the potential difference signals at both ends of the temperature sensor that change synchronously with the temperature of the lithium battery are respectively connected to the differential input terminals of the chip U90, and the chip U90 is used to convert the potential difference signals into digital signals to obtain the temperature data of the lithium battery.

[0021] In one embodiment, the step of sending the voltage acquisition signal to a voltage acquisition module for processing to obtain the voltage data of the lithium battery includes:

[0022] After receiving the voltage acquisition signal, the voltage acquisition module sends the positive and negative voltage signals of the lithium battery to the chip U69 for signal buffering and signal isolation processing;

[0023] The positive and negative voltage signals after signal processing are respectively connected to the chip U70 to form a differential amplifier circuit, and the positive and negative voltage signals are differentially amplified to obtain a differential signal;

[0024] The differential signal is sent to chip U72 and chip U73 in turn for calculation, and after the calculation is completed, the output signals of chip U72 and chip U73 are connected to chip U12 for digital signal conversion to obtain the voltage data of the lithium battery.

[0025] In one embodiment, the main processor analyzing the initial state of the lithium battery according to the characteristic data of the lithium battery includes:

[0026] Analyze the standing time of lithium battery charging and discharging based on the characteristic data of lithium battery, and determine the polarization state of lithium battery according to the standing time;

[0027] The charge and discharge state of the lithium battery is analyzed based on the characteristic data of the lithium battery, and the charge state of the lithium battery is determined according to the charge and discharge state.

[0028] In one embodiment, the testing of the sensitivity of the lithium battery based on the initial state of the lithium battery to obtain characteristic data of the lithium battery in a stable state includes:

[0029] After the initial state of the lithium battery is determined, the temperature of the lithium battery is tested, and the stable condition of the lithium battery temperature is judged during the lithium battery temperature test;

[0030] If the temperature fluctuation of the lithium battery within the preset time period is greater than the preset threshold, it means that the temperature of the lithium battery has not reached the stable condition, and the initial state of the lithium battery is re-analyzed; if the temperature fluctuation of the lithium battery within the preset time period is less than the preset threshold, it means that the temperature of the lithium battery has reached the stable condition, and the stable condition of the lithium battery voltage is judged.

[0031] In one embodiment, determining the stability condition of the lithium battery voltage includes:

[0032] If the lithium battery voltage fluctuation within the preset time period is greater than the preset threshold, it means that the lithium battery voltage has not reached the stable condition, and the initial state of the lithium battery is re-analyzed;

[0033] If the lithium battery voltage fluctuation within the preset time period is less than the preset threshold, it means that the lithium battery voltage reaches a stable condition.

[0034] In one embodiment, the step of calculating the temperature range in combination with the characteristic data in the stable state, establishing a functional relationship between the lithium battery characteristics according to the temperature range calculation result, and analyzing the functional relationship to obtain the lithium battery sensitivity test result includes:

[0035] Combined with the characteristic data in the stable state, the open circuit voltage change value of the lithium battery is calculated within a preset range, and a temperature range is generated based on the open circuit voltage change value;

[0036] It is determined whether the temperature within the temperature range has been tested, and a functional relationship between the lithium battery temperature and the lithium battery voltage is established based on the test results of the temperature range, and the lithium battery sensitivity test results are obtained based on the functional relationship.

[0037] In one embodiment, the step of determining whether the temperature within the temperature range has been tested, and establishing a functional relationship between the lithium battery temperature and the lithium battery voltage based on the test results of the temperature range, and obtaining the lithium battery sensitivity test results based on the functional relationship includes:

[0038] If the temperature within the temperature range is not fully tested, change the lithium battery temperature and re-perform the lithium battery temperature test;

[0039] If the temperature within the temperature range is fully tested, a coordinate system is established with the lithium battery temperature as the horizontal axis and the lithium battery voltage as the vertical axis, and a function is fitted with the lithium battery temperature as the independent variable to obtain a functional relationship. The functional relationship and the coordinate system are analyzed to obtain the lithium battery sensitivity test results.

[0040] According to a second aspect of an embodiment of the present invention, a lithium battery sensitivity testing system is provided.

[0041] In one embodiment, the lithium battery sensitivity testing system comprises:

[0042] A data acquisition module is used to connect the data acquisition interface to the lithium battery through a test line, collect characteristic data of the lithium battery, and send the characteristic data to the main processor;

[0043] A sensitivity test module is used for the main processor to analyze the initial state of the lithium battery according to the characteristic data of the lithium battery, and to test the sensitivity of the lithium battery based on the initial state of the lithium battery to obtain the characteristic data of the lithium battery in a stable state;

[0044] The sensitivity result analysis module is used to calculate the temperature range in combination with the characteristic data in the stable state, establish the functional relationship between the lithium battery characteristics according to the temperature range calculation results, and analyze the functional relationship to obtain the lithium battery sensitivity test results.

[0045] The technical solution provided by the embodiment of the present invention may have the following beneficial effects:

[0046] 1. The lithium battery sensitivity testing method provided by the present invention can effectively combine the charge state and polarization state of the battery, and can obtain applicable compensation coefficients under different states. It has wide adaptability. The present invention covers more comprehensive conditions and can be used to determine battery performance parameters. It helps to reduce the impact of temperature changes on the battery during the battery production process, thereby improving the battery's pass rate, safety and parameter accuracy.

[0047] 2. The lithium battery sensitivity testing method provided by the present invention further enhances the reliability and accuracy of the test results by improving the test accuracy, thereby avoiding a long testing process, saving time costs and reducing the risk of cargo backlogs. In addition, data visualization is achieved through algorithm program control, which significantly reduces the cost of manual testing and calculation, making the entire testing process more efficient.

[0048] 3. The present invention can be used to compensate for the battery open circuit voltage affected by temperature in various situations by analyzing the sensitivity coefficient between temperature and battery open circuit voltage. It is specifically used to test the relationship between battery open circuit voltage and temperature change, and test battery characteristics through a fixed algorithm, thereby improving the test precision, accuracy and test result resolution. At the same time, the test time will also be shortened accordingly, thereby improving the battery performance safety factor and the accuracy of performance parameters.

[0049] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0051] Figure 1 is a flow chart of a lithium battery sensitivity testing method according to an exemplary embodiment;

[0052] Figure 2 is a principle block diagram of a lithium battery sensitivity testing system according to an exemplary embodiment;

[0053] Figure 3 is a schematic diagram of a temperature acquisition module in a lithium battery sensitivity testing method according to an exemplary embodiment;

[0054] Figure 4 This is one of the principle diagrams of a voltage acquisition module in a lithium battery sensitivity testing method according to an exemplary embodiment;

[0055] Figure 5 is a second schematic diagram of a voltage acquisition module in a lithium battery sensitivity testing method according to an exemplary embodiment;

[0056] Figure 6 This is a third schematic diagram of a voltage acquisition module in a lithium battery sensitivity testing method according to an exemplary embodiment;

[0057] Figure 7 is a schematic diagram of a data acquisition module in a lithium battery sensitivity testing system according to an exemplary embodiment;

[0058] Figure 8 The present invention is a schematic diagram of a connector in a temperature acquisition module in a lithium battery sensitivity testing system according to an exemplary embodiment. DETAILED DESCRIPTION

[0059] The following description and accompanying drawings fully illustrate the specific embodiments of this article so that those skilled in the art can practice them. The parts and features of some embodiments can be included in or replace the parts and features of other embodiments. Herein, the terms "first", "second", etc. are only used to distinguish one element from another element, without requiring or implying any actual relationship or order between these elements. In fact, the first element can also be called the second element, and vice versa. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that the structure, device or equipment including a series of elements not only include those elements, but also include other elements that are not clearly listed, or also include elements inherent to such structure, device or equipment. In the absence of more restrictions, the elements defined by the sentence "comprise one..." do not exclude the existence of other identical elements in the structure, device or equipment including the elements. Each embodiment is described in a progressive manner herein, and each embodiment focuses on the differences from other embodiments, and the same similar parts between the embodiments can be referred to each other.

[0060] The terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. in this document indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing this document and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description of this document, unless otherwise specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a mechanical connection or an electrical connection, it can also be the internal communication of two elements, it can be a direct connection, or it can be an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0061] As used herein, the term "plurality" means two or more than two, unless otherwise specified.

[0062] In this document, the character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B means: A or B.

[0063] In this article, the term "and / or" is a description of the association relationship between objects, indicating that three relationships may exist. For example, A and / or B means: A or B, or, A and B.

[0064] It should be understood that, although the various steps in the flow chart are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear description in this article, the execution of these steps is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the figure may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these sub-steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.

[0065] Each module in the device or system of the present application can be implemented in whole or in part by software, hardware, or a combination thereof. The above modules can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute operations corresponding to the above modules.

[0066] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0067] Figure 1An embodiment of a lithium battery sensitivity testing method of the present invention is shown.

[0068] In this optional embodiment, the lithium battery sensitivity testing method includes:

[0069] Step S101, connecting the data acquisition interface to the lithium battery through the test line, collecting characteristic data of the lithium battery, and sending the characteristic data to the main processor;

[0070] Step S103, the main processor analyzes the initial state of the lithium battery according to the characteristic data of the lithium battery, and tests the sensitivity of the lithium battery based on the initial state of the lithium battery to obtain characteristic data of the lithium battery in a stable state;

[0071] Step S105, calculating the temperature range in combination with the characteristic data in the stable state, establishing a functional relationship between the lithium battery characteristics according to the temperature range calculation result, and analyzing the functional relationship to obtain the lithium battery sensitivity test result.

[0072] In this optional embodiment, connecting the data acquisition interface to the lithium battery through a test line, collecting characteristic data of the lithium battery, and sending the characteristic data to the main processor includes:

[0073] The temperature acquisition interface and the voltage acquisition interface are respectively connected to the lithium battery through the test line to obtain the temperature acquisition signal and the voltage acquisition signal of the lithium battery; the temperature acquisition signal is sent to the temperature acquisition module for processing to obtain the temperature data of the lithium battery; the voltage acquisition signal is sent to the voltage acquisition module for processing to obtain the voltage data of the lithium battery; the temperature data and the voltage data of the lithium battery are sent to the main processor.

[0074] In this optional embodiment, sending the temperature acquisition signal to the temperature acquisition module for processing to obtain the temperature data of the lithium battery includes:

[0075] The temperature sensor is connected to the temperature acquisition module. After receiving the temperature acquisition signal, the temperature acquisition module uses the operational amplifier U91A channel to connect the temperature acquisition signal to the chip U90 through the resistor R589 as a voltage reference signal; the voltage reference signal is divided by the voltage R577 and the resistor R578 in turn, and then connected to the same-direction input terminal of the operational amplifier U91B channel; if the temperature of the lithium battery changes, the potential difference signals at both ends of the temperature sensor that change synchronously with the temperature of the lithium battery are respectively connected to the differential input terminals of the chip U90, and the potential difference signal is converted into a digital signal using the chip U90 to obtain the temperature data of the lithium battery.

[0076] In this alternative embodiment, if Figure 3 and Figure 8As shown, the temperature acquisition module includes a diode D57, a capacitor C579, a resistor R588, a diode D61, a capacitor C651, a chip U91 (chip U91 is a dual-channel operational amplifier, including U91A channel and U91B channel), a resistor R591, a capacitor C652, a resistor R577, a resistor R578, a capacitor C649, a capacitor C648, a capacitor C650, a chip U90, a capacitor C653, a capacitor C654, a capacitor C655, a resistor R592, a resistor R593, a resistor R594, a resistor R595, a diode D58, a diode D59, a resistor R596 and a connector P4.

[0077] The functions of the diodes (D57, D58, D59, and D61) include:

[0078] The forward voltage drop of a diode changes with temperature. Diodes (such as D57) can be used as temperature sensing elements, and some diodes (such as D58, D59, and D61) are used for input protection to prevent overvoltage or reverse voltage from damaging subsequent circuits.

[0079] The functions of operational amplifier U91 (dual channel: U91A and U91B) include:

[0080] The operational amplifier is the core processing unit of the temperature signal. Its main function is to amplify the output signal of the diode through the feedback network (such as R588, R591), ensure that the signal is strong enough for subsequent processing, and adjust the reference level of the initial signal through appropriate bias (provided by the resistor and capacitor combination network).

[0081] The resistors (such as R588 and R591) in the resistors (R577, R578, R588, R591, R592, R593, R594, R595, and R596) provide a reasonable voltage bias for the input of the op amp, so that the temperature signal is within the input range of the op amp. The resistors (such as R591 and R592) and the op amp form a feedback network, which determines the gain characteristics of the op amp, thereby adjusting the amplification factor of the signal.

[0082] Among the capacitors (C579, C651, C652, C649, C648, C650, C653, C654, C655), capacitors (such as C579 and C652) can filter out high-frequency noise in the circuit to ensure signal purity. Some capacitors (such as C651 and C653) are used for signal coupling or isolation of DC components to extract AC signals corresponding to temperature changes. At the same time, capacitors (such as C648 and C650) in the feedback network can improve the stability of the operational amplifier and prevent high-frequency self-excitation.

[0083] Chip U90 is another operational amplifier or signal processing module, which is used to further process the signal output by U91, to select different temperature channels, and to further adjust the temperature signal output by U91 to enhance the linearity or resolution of the system.

[0084] Specifically, the principles of the temperature acquisition module include: connecting the temperature test interface at the P4-3 / 4 end and the P4-5 / 6 end respectively, and the test line connected to the temperature test interface has a temperature sensor PT1000 at the end connected to the product under test (its function can be regarded as a variable resistor that changes linearly with temperature).

[0085] Chip U91 is a dual-channel operational amplifier. Channel U91A is used as a voltage follower to isolate the voltage excitation 5V_1 signal to ensure power supply stability.

[0086] The output of the U91A channel is connected to the third pin of the chip U90 through resistor R589 as the voltage reference of the AD sampling chip, and is connected to the same-direction input terminal of the U91B channel after voltage division through resistors R577 and R578.

[0087] The U91B channel is a common-mode amplifier, and the common-mode input terminal is the voltage obtained by dividing the resistors R577 and R578, so the voltage of the resistor R594 is fixed. Since the resistance value of the resistor R594 is fixed, the current at the output of the U19B channel is constant. At the same time, since the temperature sensor connected between the P4-3 / 4 terminal and the P4-5 / 6 terminal can be equivalent to a variable resistor, when the temperature changes, the resistance value between the P4-3 / 4 terminal and the P4-5 / 6 terminal also changes, resulting in a change in the potential difference between the P4-3 / 4 terminal and the P4-5 / 6 terminal.

[0088] Connect the P4-3 / 4 and P4-5 / 6 terminals to the chip U90, the inverting terminal and the non-inverting terminal of the CS1238 differential input respectively to convert the analog quantity to the digital quantity. The CS1238 exchanges information with the main control chip to complete the temperature data collection.

[0089] In this optional embodiment, the step of sending the voltage acquisition signal to the voltage acquisition module for processing to obtain the voltage data of the lithium battery includes:

[0090] After receiving the voltage acquisition signal, the voltage acquisition module sends the positive and negative voltage signals of the lithium battery to chip U69 for signal buffering and signal isolation processing respectively; the positive and negative voltage signals after signal processing are respectively connected to chip U70 to form a differential amplifier circuit, and the positive and negative voltage signals are differentially amplified to obtain a differential signal; the differential signal is sent to chip U72 and chip U73 in turn for calculation, and after the calculation is completed, the output signals of chip U72 and chip U73 are connected to chip U12 for digital signal conversion to obtain the voltage data of the lithium battery.

[0091] In this alternative embodiment, if Figure 4-Figure 6 As shown, the voltage acquisition module includes a resistor R27, a capacitor C59, a capacitor C58, a capacitor C50, a capacitor C51, a capacitor C52, a capacitor C53, a capacitor C61, a passive crystal oscillator Y1, a capacitor C62, a resistor R38, a resistor R39, a chip U12 (for example Figure 4 1-12 in the figure represent the first to twelfth pins of chip U12, and the same is true for the other components), capacitor C54, capacitor C55, capacitor C56, capacitor C57, resistor R42, capacitor C109, resistor R526, resistor R528, chip U73 (chip U73 is a dual-channel operational amplifier, including channel U73A and channel U73B), resistor R525, capacitor C89, capacitor C90, resistor R527, chip U72 (chip U72 is a dual-channel operational amplifier, including chip U72A and chip U72B), resistor R524, capacitor C84, capacitor C85, resistor R523, resistor R520, resistor R517, resistor R518, resistor R519, resistor R521, resistor R522, diode D44, diode D45, resistor R516, diode D46, diode D47 , diode D48, capacitor C81, chip U71 (chip U71 is a dual-channel operational amplifier, including U71A channel and U71B channel), capacitor C83, capacitor C76, resistor R72, resistor R73, resistor R515, resistor R70, resistor R68, capacitor C68, chip U70 (chip U70 is a dual-channel operational amplifier, including U70A channel and U70B channel), capacitor C69, resistor R67, resistor R59, resistor R63, resistor R66, (chip U69 is a dual-channel operational amplifier, including U69A channel and U69B channel), capacitor C66, capacitor C67, capacitor C64, common-mode inductor FL1, capacitor C65, resistor R57, capacitor C60, capacitor C63, inductor L15, capacitor C48, capacitor C610, capacitor C49, resistor R58 and inductor L17.

[0092] It should be noted that resistors (R27, R38, R39, R525, R524, R523, R520, R517, R518, R519, R521, R522, R516, R515, R526, R527, R528, R72, R73, R70, R68, R67, R59, R63, R66, R57, R58) are used to divide the voltage of the input signal, reduce the input voltage to a range suitable for chip processing, adjust the signal amplitude or limit the current.

[0093] Capacitors (C59, C58, C50, C51, C52, C53, C61, C62, C54, C55, C56, C57, C109, C89, C90, C84, C85, C81, C83, C76, C68, C69, C66, C67, C64, C65, C60, C63, C48, C49, C610) are used to filter out high-frequency noise in the input signal and stabilize the input signal; eliminate interference fluctuations in the power supply and stabilize the voltage.

[0094] The passive crystal oscillator (Y1) is used to generate a precise reference frequency and provide a clock signal to support the operation or synchronization of certain chips.

[0095] Chips U70 (U70A, U70B), U71 (U71A, U71B), U72 (U72A, U72B), U73 (U73A, U73B), and U69 (U69A, U69B) are dual-channel operational amplifiers used for signal amplification and buffering, adapting to the input requirements of voltage sensors and subsequent processing circuits; and they work with external resistors and capacitors to achieve signal processing functions such as integration, differentiation, and filtering.

[0096] Diodes (D44, D45, D46, D47, D48) are used for overvoltage protection of input signals to prevent the signal from exceeding the voltage range allowed by the operational amplifier or acquisition module and to avoid damage to the circuit caused by reverse current flow; inductor components (FL1, L15, L17) are used to filter out high-frequency noise (EMI filtering), suppress spike interference, and protect the stability of the circuit.

[0097] Specifically, the principles of the voltage acquisition module include: connecting inductor L15 and inductor L17 to the high voltage end and loop end of the voltage test interface, the positive and negative poles of the battery under test, respectively, filtering the common mode interference through the common mode inductor FL1, and the positive voltage signal and the negative voltage signal pass through two independent amplification circuits of chip U69 respectively to buffer and isolate the signals; connecting the positive and negative voltage signals to the same direction end and the reverse direction end of the A channel op amp of chip U70 to form a differential amplifier circuit, and the chip output is connected to the fifth pin of chip U70 after voltage division by resistors R68 and R70, and the A channel output of chip U70 is included in the same direction end input of the B channel of chip U70 to form a voltage follower, and the differential amplified signal of the positive and negative signals is connected to the U71A channel through the seventh pin of chip U70.

[0098] Chip U72 and chip U73 form an addition circuit and a subtraction circuit, and their outputs are respectively connected to the differential input terminals of the AD conversion chip U12 to perform analog-to-digital conversion of the data. The AD chip finally sends the processed data to the main control chip to complete the voltage data collection.

[0099] In this optional embodiment, the main processor analyzing the initial state of the lithium battery according to the characteristic data of the lithium battery includes:

[0100] The standing time of the lithium battery charge and discharge is analyzed based on the characteristic data of the lithium battery, and the polarization state of the lithium battery is determined according to the standing time; the charge and discharge state of the lithium battery is analyzed based on the characteristic data of the lithium battery, and the charge state of the lithium battery is determined according to the charge and discharge state.

[0101] In this optional embodiment, the lithium battery sensitivity is tested based on the initial state of the lithium battery to obtain characteristic data of the lithium battery in a stable state, including:

[0102] After the initial state of the lithium battery is determined, the lithium battery temperature is tested, and the stability condition of the lithium battery temperature is judged during the lithium battery temperature test; if the lithium battery temperature fluctuation within the preset time period is greater than the preset threshold, it means that the lithium battery temperature has not reached the stable condition, and the initial state of the lithium battery is re-analyzed; if the lithium battery temperature fluctuation within the preset time period is less than the preset threshold, it means that the lithium battery temperature has reached the stable condition, and the stability condition of the lithium battery voltage is judged.

[0103] In this optional embodiment, the determining of the stability condition of the lithium battery voltage includes:

[0104] If the lithium battery voltage fluctuation within the preset time period is greater than the preset threshold, it means that the lithium battery voltage has not reached the stable condition, and the initial state of the lithium battery is re-analyzed; if the lithium battery voltage fluctuation within the preset time period is less than the preset threshold, it means that the lithium battery voltage has reached the stable condition.

[0105] In this optional embodiment, the temperature range is calculated in combination with the characteristic data in the stable state, a functional relationship between the lithium battery characteristics is established according to the temperature range calculation result, and the functional relationship is analyzed to obtain the lithium battery sensitivity test result, which includes:

[0106] Combined with the characteristic data in the stable state, the open circuit voltage change value of the lithium battery is calculated within the preset range, and a temperature range is generated based on the open circuit voltage change value; it is determined whether the temperature within the temperature range has been tested, and a functional relationship between the lithium battery temperature and the lithium battery voltage is established based on the test results of the temperature range, and the lithium battery sensitivity test results are obtained based on the functional relationship.

[0107] In this optional embodiment, the step of determining whether the temperature within the temperature range has been tested, and establishing a functional relationship between the lithium battery temperature and the lithium battery voltage based on the test results of the temperature range, and obtaining the lithium battery sensitivity test results based on the functional relationship includes:

[0108] If the temperature within the temperature range has not been fully tested, change the lithium battery temperature and re-execute the lithium battery temperature test; if the temperature within the temperature range has been fully tested, use the lithium battery temperature as the horizontal axis and the lithium battery voltage as the vertical axis to establish a coordinate system, and use the lithium battery temperature as the independent variable to perform function fitting to obtain the function relationship, analyze the function relationship and the coordinate system to obtain the lithium battery sensitivity test results.

[0109] In order to facilitate understanding of the above technical solution of the present invention, the lithium battery sensitivity testing method provided by the present invention is described in detail below.

[0110] In this optional embodiment, the lithium battery sensitivity testing method includes:

[0111] Before starting the test, determine the polarization state of the battery by the rest time since the last charge / discharge;

[0112] Determine the state of charge of the battery under test by the percentage of charge / discharge capacity to total capacity;

[0113] After the battery status is determined, the test begins;

[0114] First, the temperature is tested, and then the temperature test value is judged; the temperature stability judgment condition: the temperature fluctuation within (X) time is less than (Y), and X and Y are open to setting permissions according to different temperature requirements;

[0115] If the temperature reaches the stable condition, proceed to the next step. If the temperature does not reach the stable condition, repeat the previous step.

[0116] After the temperature reaches a stable state, the voltage is judged to be stable. Voltage stability judgment condition: voltage fluctuation within (X) time is less than (Y), and X and Y are open to setting permissions according to different voltage requirements;

[0117] If the voltage reaches the stable condition, proceed to the next step. If the voltage does not reach the stable condition, repeat the previous step.

[0118] Record the temperature and voltage data when it is finally determined to be stable;

[0119] After the data is recorded, determine the temperature range. For example, if you want to calculate the open circuit voltage change value within the range of 0-50℃, you can select the step temperature according to the accuracy of the external temperature source. For example, set it to 0 degrees for the first test, change the temperature to 1 degree after the test, test again, and then change it to 2 degrees... Continue testing until 50 degrees to obtain a complete curve corresponding to temperature and open circuit voltage;

[0120] If the test is not completed within the temperature range, change the battery temperature and perform the temperature test again;

[0121] If all temperatures within the temperature range have been tested and data recorded, the recorded data will be processed;

[0122] The processing method includes: using temperature as the horizontal coordinate and voltage as the vertical coordinate to establish a coordinate system, using temperature as the independent variable to perform function fitting based on the data, and finally obtaining the function of OCV=f(t); outputting the function relationship and the coordinate system established by the data as the test result;

[0123] End the test.

[0124] Figure 2 An embodiment of a lithium battery sensitivity testing system of the present invention is shown.

[0125] In this optional embodiment, the lithium battery sensitivity testing system includes:

[0126] The data acquisition module 201 is used to connect the data acquisition interface to the lithium battery through the test line, collect characteristic data of the lithium battery, and send the characteristic data to the main processor;

[0127] A sensitivity test module 203 is used for the main processor to analyze the initial state of the lithium battery according to the characteristic data of the lithium battery, and to test the sensitivity of the lithium battery based on the initial state of the lithium battery to obtain the characteristic data of the lithium battery in a stable state;

[0128] The sensitivity result analysis module 205 is used to calculate the temperature range of the characteristic data in a stable state, establish a functional relationship between the lithium battery characteristics according to the temperature range calculation result, and analyze the functional relationship to obtain the lithium battery sensitivity test result.

[0129] In order to facilitate understanding of the above technical solution of the present invention, the lithium battery sensitivity testing system provided by the present invention is described in detail below.

[0130] In one embodiment, Figure 7 As shown, the temperature acquisition interface is connected to a special temperature test line and connected to the battery under test;

[0131] The voltage acquisition interface is connected to a special voltage test line, which is connected to the lithium battery under test (equivalent to a lithium battery);

[0132] The temperature signal tested by the temperature acquisition interface is transmitted to the temperature acquisition module and processed into a digital signal;

[0133] The voltage signal tested by the voltage acquisition interface is transmitted to the voltage acquisition module and processed into a digital signal;

[0134] After receiving the data from the temperature acquisition module and the voltage acquisition module, the main processor performs calculation and processing;

[0135] The main processor sends the processed calculation results to the host computer or other data terminal required by the user for storage.

[0136] The present invention is not limited to the structures which have been described above and shown in the drawings, and various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A lithium battery sensitivity testing method, characterized in that: The method includes: Connect the data acquisition interface to the lithium battery through the test line, collect characteristic data of the lithium battery, and send the characteristic data to the main processor; The main processor analyzes the initial state of the lithium battery according to the characteristic data of the lithium battery, and tests the sensitivity of the lithium battery based on the initial state of the lithium battery to obtain the characteristic data of the lithium battery in a stable state; The temperature range is calculated in combination with the characteristic data in the stable state, and the functional relationship between the lithium battery characteristics is established according to the temperature range calculation results, and the functional relationship is analyzed to obtain the lithium battery sensitivity test results; The step of connecting the data acquisition interface to the lithium battery through a test line, collecting characteristic data of the lithium battery, and sending the characteristic data to the main processor includes: Connect the temperature acquisition interface and the voltage acquisition interface to the lithium battery through the test line to obtain the temperature acquisition signal and the voltage acquisition signal of the lithium battery; The temperature acquisition signal is sent to the temperature acquisition module for processing to obtain the temperature data of the lithium battery; the voltage acquisition signal is sent to the voltage acquisition module for processing to obtain the voltage data of the lithium battery; Sending the temperature data and voltage data of the lithium battery to the main processor; The main processor analyzes the initial state of the lithium battery according to the characteristic data of the lithium battery, including: Analyze the standing time of lithium battery charging and discharging based on the characteristic data of lithium battery, and determine the polarization state of lithium battery according to the standing time; Analyze the charge and discharge state of the lithium battery based on the characteristic data of the lithium battery, and determine the charge state of the lithium battery according to the charge and discharge state; The lithium battery sensitivity is tested based on the initial state of the lithium battery to obtain characteristic data of the lithium battery in a stable state, including: After the initial state of the lithium battery is determined, the temperature of the lithium battery is tested, and the stable condition of the lithium battery temperature is judged during the lithium battery temperature test; If the temperature fluctuation of the lithium battery within the preset time period is greater than the preset threshold, it means that the temperature of the lithium battery has not reached the stable condition, and the initial state of the lithium battery is re-analyzed; if the temperature fluctuation of the lithium battery within the preset time period is less than the preset threshold, it means that the temperature of the lithium battery has reached the stable condition, and the stable condition of the lithium battery voltage is judged; The calculation of the temperature range in combination with the characteristic data in the stable state, establishing a functional relationship between the lithium battery characteristics according to the temperature range calculation result, and analyzing the functional relationship to obtain the lithium battery sensitivity test result includes: Combined with the characteristic data in the stable state, the open circuit voltage change value of the lithium battery is calculated within a preset range, and a temperature range is generated based on the open circuit voltage change value; It is determined whether the temperature within the temperature range has been tested, and a functional relationship between the lithium battery temperature and the lithium battery voltage is established based on the test results of the temperature range, and the lithium battery sensitivity test results are obtained based on the functional relationship.

2. A lithium battery sensitivity testing method according to claim 1, characterized in that: The step of sending the temperature acquisition signal to the temperature acquisition module for processing to obtain the temperature data of the lithium battery includes: The temperature sensor is connected to the temperature acquisition module. After receiving the temperature acquisition signal, the temperature acquisition module uses the operational amplifier U91A channel to connect the temperature acquisition signal to the chip U90 through the resistor R589 as a voltage reference signal; The voltage reference signal is divided by resistors R577 and R578 in turn, and then connected to the same-direction input terminal of the operational amplifier U91B channel; If the temperature of the lithium battery changes, the potential difference signals at both ends of the temperature sensor that change synchronously with the temperature of the lithium battery are respectively connected to the differential input terminals of the chip U90, and the chip U90 is used to convert the potential difference signals into digital signals to obtain the temperature data of the lithium battery.

3. A lithium battery sensitivity testing method according to claim 2, characterized in that: The step of sending the voltage acquisition signal to the voltage acquisition module for processing to obtain the voltage data of the lithium battery includes: After receiving the voltage acquisition signal, the voltage acquisition module sends the positive and negative voltage signals of the lithium battery to the chip U69 for signal buffering and signal isolation processing; The positive and negative voltage signals after signal processing are respectively connected to the chip U70 to form a differential amplifier circuit, and the positive and negative voltage signals are differentially amplified to obtain a differential signal; The differential signal is sent to chip U72 and chip U73 in turn for calculation, and after the calculation is completed, the output signals of chip U72 and chip U73 are connected to chip U12 for digital signal conversion to obtain the voltage data of the lithium battery.

4. A lithium battery sensitivity testing method according to claim 3, characterized in that: The determining of the stability condition of the lithium battery voltage includes: If the lithium battery voltage fluctuation within the preset time period is greater than the preset threshold, it means that the lithium battery voltage has not reached the stable condition, and the initial state of the lithium battery is re-analyzed; If the lithium battery voltage fluctuation within the preset time period is less than the preset threshold, it means that the lithium battery voltage reaches a stable condition.

5. A lithium battery sensitivity testing method according to claim 4, characterized in that: The determining whether the temperature within the temperature range has been tested and establishing a functional relationship between the lithium battery temperature and the lithium battery voltage based on the test results of the temperature range, and obtaining the lithium battery sensitivity test results based on the functional relationship include: If the temperature within the temperature range is not fully tested, change the lithium battery temperature and re-perform the lithium battery temperature test; If the temperature within the temperature range is fully tested, a coordinate system is established with the lithium battery temperature as the horizontal axis and the lithium battery voltage as the vertical axis, and a function is fitted with the lithium battery temperature as the independent variable to obtain a functional relationship. The functional relationship and the coordinate system are analyzed to obtain the lithium battery sensitivity test results.

6. A lithium battery sensitivity testing system, used to implement the lithium battery sensitivity testing method according to any one of claims 1 to 5, characterized in that: The system includes: A data acquisition module is used to connect the data acquisition interface to the lithium battery through a test line, collect characteristic data of the lithium battery, and send the characteristic data to the main processor; A sensitivity test module is used for the main processor to analyze the initial state of the lithium battery according to the characteristic data of the lithium battery, and to test the sensitivity of the lithium battery based on the initial state of the lithium battery to obtain the characteristic data of the lithium battery in a stable state; The sensitivity result analysis module is used to calculate the temperature range in combination with the characteristic data in the stable state, establish the functional relationship between the lithium battery characteristics according to the temperature range calculation results, and analyze the functional relationship to obtain the lithium battery sensitivity test results.

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