Method and system for calibrating impedance of conductive connector

Abstract

The invention discloses a method and system for calibrating impedance of a conductive connecting piece, and the method comprises the steps: determining a first type of batteries and a second type of batteries under the control of a calibration instruction for calibrating the impedance, the first type of batteries being batteries connected with the conductive connecting piece, and the second type of batteries being batteries not connected with the connecting piece; calculating a first voltage difference according to the voltage values of the first type of batteries and the second type of batteries before the fixed current is applied; calculating a second voltage difference according to the voltage values of the first type of batteries and the second type of batteries after the fixed current is applied; and calculating an impedance value according to the first voltage difference and the second voltage difference so as to obtain the impedance of the conductive connecting piece. According to the invention, the impedance can be dynamically calibrated, and the detection accuracy is improved.

Description

Technical Field

[0001] The present invention relates to the field of new energy technologies, and particularly to a method and system for calibrating the impedance of a conductive connection component. Background Art

[0002] A battery pack needs to meet certain standards before shipment. Therefore, various tests need to be carried out before shipment, such as internal resistance test, static voltage difference test, and dynamic voltage difference test. Among them, the dynamic voltage difference refers to the difference between the maximum cell voltage and the minimum cell voltage of the battery pack under charge and discharge conditions. A battery pack usually includes a plurality of small battery modules, and different small battery modules are connected by conductive connection components, and the material of the conductive connection components is usually copper or aluminum. Since the conductive connection component has a certain impedance, in the existing test methods for testing the battery pack, a fixed compensation value is generally written in advance by software. However, the impedance of the conductive connection component is affected by various factors such as the tightness of the screw and the contact area between the screw and the conductive connection component, resulting in the impedance of the conductive connection component not being fixed. Therefore, the fixed compensation value will cause the collected voltage after compensation to deviate greatly from the actual voltage of the cell, resulting in a large dynamic voltage difference and inaccurate test results, which easily makes a battery pack that originally does not meet the standard meet the standard due to inaccurate testing. Summary of the Invention

[0003] Embodiments of the present invention provide a method and system for calibrating the impedance of a conductive connection component, aiming to solve the problem that the current impedance calibration method has a large error, resulting in inaccurate test results.

[0004] In a first aspect, embodiments of the present invention provide a method for calibrating the impedance of a conductive connection component, the method comprising:

[0005] Controlled by a calibration instruction for calibrating the impedance, a first type of battery and a second type of battery are identified, wherein the first type of battery is a battery connected with a conductive connection component, and the second type of battery is a battery not connected with the connection component;

[0006] A first voltage difference is calculated according to the voltage values of the first type of battery and the second type of battery before applying a fixed current;

[0007] A second voltage difference is calculated according to the voltage values of the first type of battery and the second type of battery after applying the fixed current;

[0008] An impedance value is calculated according to the first voltage difference and the second voltage difference to obtain the impedance of the conductive connection component.

[0009] In a second aspect, embodiments of the present invention further provide a calibration system, and the system is configured with the method for calibrating the impedance of a conductive connection component as described in any one of the above.

[0010] An embodiment of the present invention provides a method and system for calibrating the impedance of a conductive connection component. The method includes: controlled by a calibration instruction for calibrating the impedance, identifying a first type of battery and a second type of battery, where the first type of battery is a battery connected with a conductive connection component, and the second type of battery is a battery not connected with the connection component; calculating a first voltage difference according to the voltage values of the first type of battery and the second type of battery before applying a fixed current; calculating a second voltage difference according to the voltage values of the first type of battery and the second type of battery after applying the fixed current; and calculating an impedance value according to the first voltage difference and the second voltage difference to obtain the impedance of the conductive connection component. The embodiment of the present invention can, when it is necessary to calibrate the impedance of a conductive connection component, identify a first type of battery and a second type of battery, then calculate the first voltage difference and the second voltage difference before and after applying a fixed current respectively, and then confirm the voltage change amount of the conductive connection component according to the first voltage difference and the second voltage difference, and further can calculate the impedance of the conductive connection component, which is convenient for subsequent detection and use and improves the accuracy of the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0012] Figure 1 is a schematic flowchart of the method for calibrating the impedance of a conductive connection component provided by an embodiment of the present invention;

[0013] Figure 2 is a schematic flowchart of the first sub-process of the method for calibrating the impedance of a conductive connection component provided by an embodiment of the present invention;

[0014] Figure 3 is a schematic flowchart of the second sub-process of the method for calibrating the impedance of a conductive connection component provided by an embodiment of the present invention;

[0015] Figure 4 is a schematic flowchart of the third sub-process of the method for calibrating the impedance of a conductive connection component provided by an embodiment of the present invention;

[0016] Figure 5 is a schematic flowchart of the fourth sub-process of the method for calibrating the impedance of a conductive connection component provided by an embodiment of the present invention;

[0017] Figure 6 is a schematic flowchart of the fifth sub-process of the method for calibrating the impedance of a conductive connection component provided by an embodiment of the present invention;

[0018] Figure 7 is a schematic flowchart of the sixth sub-process of the method for calibrating the impedance of a conductive connection component provided by an embodiment of the present invention;

[0019] Figure 8 It is a schematic diagram of the seventh sub - process of the method for calibrating the impedance of a conductive connector provided by an embodiment of the present invention;

[0020] Figure 9 It is a schematic block diagram of a calibration system provided by an embodiment of the present invention. Detailed implementation manners

[0021] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0022] It should be understood that when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, wholes, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, operations, elements, components, and / or their combinations.

[0023] It should also be understood that the terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in this specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" are intended to include the plural forms. It should be further understood that the term "and / or" used in this specification of the present invention and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0024] Please refer to Figure 1 , Figure 1 It is a schematic flowchart of the method for calibrating the impedance of a conductive connector provided by an embodiment of the present invention. The method for calibrating the impedance of a conductive connector in an embodiment of the present invention can be applied to a calibration system to calibrate the impedance of the conductive connector in a battery pack to improve the accuracy of testing. As Figure 1 shown, the method includes steps S100 - S130.

[0025] S100, controlled by a calibration instruction for calibrating impedance, confirm the first - type battery and the second - type battery, where the first - type battery is the battery connected with a conductive connector, and the second - type battery is the battery not connected with the connector.

[0026] In an embodiment of the present invention, as Figure 9As shown, the calibration system may include a PACK and test equipment. The PACK consists of a battery pack, a BMS, a wiring harness, a housing, etc. The communication port Com, power lines P+ and P- of the PACK are connected to the test equipment. Among them, Com is used for information interaction between the BMS and the test equipment, and the power lines are connected for charging and discharging the battery pack. The calibration of the copper bus impedance needs to be carried out under charging and discharging conditions. The functions of the test equipment include communication function, charging and discharging function, display function, audible and visual alarm function, etc.

[0027] Before the batteries are assembled, they are usually screened and the batteries with similar parameters are assembled together. Then, when a certain current is given, since the parameters are similar, the internal resistances of different batteries are basically the same, and the voltages raised by the charging current or pulled down by the discharging current are also basically the same. Therefore, the voltages of all the battery cells remain basically the same during the charging and discharging process. However, if there is a conductive connection at the connection of a battery cell in a certain battery, the voltage raised by the charging current for this battery cell is U = i * (R_internal resistance + R_copper bus), resulting in overcharging of this battery cell when other battery cells are not fully charged during the charging process, and over-discharging of this battery cell when other battery cells have not completed discharging during the discharging process. As a result, the available capacity of the entire battery pack decreases and the battery life is shortened. Therefore, it is necessary to calibrate the impedance of the conductive connection to avoid the above situation.

[0028] During the test, the test equipment can send a calibration instruction to the BMS, and this calibration instruction contains the batteries that need to be calibrated. A battery pack can contain multiple battery cells, and some or all of the multiple battery cells can be connected to the conductive connection. Then, according to whether there is a conductive connection, the battery cells in the battery pack can be divided into the first type of battery cells and the second type of battery cells. Among them, the first type of battery cells are the battery cells connected to the conductive connection, and the second type of battery cells are the battery cells not connected to the conductive connection. It can be understood that the conductive connection can be one of a copper bus or an aluminum bus. The calibration instruction contains the batteries that need to be calibrated, that is, the first type of battery cells. Then, when the BMS obtains the calibration instruction, it can confirm the second type of battery cells according to the first type of battery cells.

[0029] For example, for a battery pack containing 24 battery cells, among them, the 6th, 12th, and 18th battery cells are the battery cells that need to have their impedance calibrated. Then, the first type of battery cells include the 6th, 12th, and 18th battery cells, and the remaining battery cells are the second type of battery cells.

[0030] S110, calculate a first voltage difference according to the voltage values of the first type of battery cells and the second type of battery cells before applying a fixed current.

[0031] In an embodiment of the present invention, after the first type of battery and the second type of battery are identified, the BMS collects the cell voltages of the first type of battery and the cell voltages of the second type of battery, and calculates a first voltage difference based on the collected cell voltages of the first type of battery and the second type of battery. The first voltage difference is a voltage change value, which is the voltage difference originally existing in the cells.

[0032] See Figure 2 , in some embodiments, such as this embodiment, the step S110 further includes steps S111 - S113.

[0033] S111, collect the cell voltages of each battery in the second type of battery, and calculate the average value of the cell voltages of the second type of battery based on the collected cell voltages to obtain a first standard value;

[0034] S112, collect the cell voltages of each battery in the first type of battery to obtain a plurality of first voltages to be calibrated;

[0035] S113, calculate a plurality of the first voltage differences based on the plurality of the first voltages to be calibrated and the first standard value.

[0036] In an embodiment of the present invention, taking a battery pack including 24 batteries as an example, and the first type of battery includes the 6th, 12th, and 18th batteries, and the remaining batteries are the second type of battery. When the calibration system is in the charging mode, the first standard value of the second type of battery collected by the BMS is 3200 mV. At the same time, the cell voltage of the 6th battery is 3199 mV, the cell voltage of the 12th battery is 3200 mV, and the cell voltage of the 18th battery is 3201 mV. Then, by calculating the differences between the first standard value and the cell voltages of the 6th, 12th, and 18th batteries respectively, we can get 3199 mV - 3200 mV = -1 mV, 3200 mV - 3200 mV = 0 mV, 3201 mV - 3200 mV = 1 mV. That is, V6 Δ1 = -1 mV, V12 Δ1 = 0 mV, V18 Δ1 = 1 mV. Among them, V6 Δ1 is the first voltage difference of the 6th battery, V12 Δ1 is the first voltage difference of the 12th battery, V18 Δ1 is the first voltage difference of the 18th battery.

[0037] S120, calculate a second voltage difference based on the voltage values of the first type of battery and the second type of battery after applying the fixed current.

[0038] In an embodiment of the present invention, after the BMS calculates the first pressure difference before applying a fixed current, it can return a response frame to the test device, enabling the test device to output a fixed current and send a current data packet to the BMS. The BMS collects the fixed current output by the test device and compares the collected fixed current with the current in the current data packet. If the difference between the two is within the error range, it is confirmed that the power line connection is okay and the output of the test device has also stabilized. Then, it collects the cell voltages of the first type of battery and the second type of battery and calculates the second pressure difference. The calculation principle of the second pressure difference is similar to that of the first pressure difference and will not be elaborated here.

[0039] See Figure 3 , in some embodiments, such as this embodiment, step S120 further includes steps S121 - S124.

[0040] S121, obtain the fixed current and use the fixed current as the output current;

[0041] S122, collect the cell voltage of each battery in the second type of battery, and calculate the average value of the cell voltages of the second type of battery based on the collected cell voltages to obtain a second standard value;

[0042] S123, collect the cell voltage of each battery in the first type of battery to obtain a plurality of second voltages to be calibrated;

[0043] S124, calculate a plurality of the second pressure differences based on the plurality of the second voltages to be calibrated and the second standard value.

[0044] In an embodiment of the present invention, taking the previous example as an example, if the fixed current is 20A, that is, the current value in the current data packet sent by the test device is 20A, and the input current received by the BMS is also 20A. Then, the actual input current is collected. If the difference between the actual input current and 20A is within the error range, it is considered that the power line connection is okay and the output of the test device has also stabilized. For example, if the error is 1%, when the actual input current is between 19.8A - 20.2A, it is considered a normal output. After applying the fixed current, if the average value of the cell voltages of the second type of battery is 3250mV, the cell voltage of the 6th section is 3299mV, the cell voltage of the 12th section is 3300mV, and the cell voltage of the 18th section is 3291mV, then V6 Δ2 = 49mV, V12 Δ2 = 50mV, V18 Δ2 = 41mV.

[0045] S130, calculate an impedance value based on the first pressure difference and the second pressure difference to obtain the impedance of the conductive connection.

[0046] In the embodiments of the present invention, after obtaining the first pressure difference, the second pressure difference, and the current value of the fixed current, the impedance of the conductive connection member of each battery in the first type of battery can be calculated according to the resistance calculation formula. Finally, the obtained impedance is stored, for example, stored in Flash, to avoid data loss caused by the power failure of the BMS.

[0047] See Figure 4 , in some embodiments, such as in this embodiment, step S130 further includes steps S131 - S132.

[0048] S131, obtaining the current value of the fixed current to obtain a first current value;

[0049] S132, calculating the difference between the second pressure difference and the first pressure difference to obtain a first difference;

[0050] S133, calculating the impedance value according to the first current value and the first difference.

[0051] In the embodiments of the present invention, taking the previous example as an example, the first current value is 20A, V6 Δ1 = -1mV, V12 Δ1 = 0mV, V18 Δ1 = 1mV, V6 Δ2 = 49mV, V12 Δ2 = 50mV, V18 Δ2 = 41mV, then V6 Δ2 - V6 Δ1 = 50mV, V12 Δ2 - V12 Δ1 = 50mV, V18 Δ2 - V18 Δ1 = 40mV, then the impedance of the conductive connection members of the 6th battery and the 12th battery is both 50mV / 20A = 2.5mR ， The impedance of the conductive connection member of the 18th battery is 2.0mR.

[0052] The above example is the calibration process when the calibration system is in the charging mode. In the discharging mode, the calibration process is similar to that in the charging mode, which is illustrated as follows. In the discharging mode, the fixed current value is 20A. Before applying the fixed current, the average value of the cell voltages of the second type of battery is 3200mV, the cell voltage of the 6th battery is 3199mV, the cell voltage of the 12th battery is 3200mV, and the cell voltage of the 18th battery is 3201mV, then V6 Δ1 = -1mV, V12 Δ1 = 0mV, V18 Δ1= 1 mV. After applying a fixed current, the average voltage of the battery cells of the second type of battery is 3150 mV. The voltage of the battery cell of the 6th battery is 3099 mV, the voltage of the battery cell of the 12th battery is 3100 mV, and the voltage of the battery cell of the 18th battery is 3111 mV. Then V6 Δ2 = -49 mV, V12 Δ2 = -50 mV, V18 Δ2 = -39 mV. Then the impedance of the 6th battery is (-51 mV - (-1 mV)) / -20 A = 2.5 mΩ, the impedance of the 12th battery is (-50 mV - 0 mV) / -20 A = 2.5 mΩ, and the impedance of the 18th battery is (-39 mV - 1 mV) / -20 A = 2.0 mΩ.

[0053] See Figure 5 , in some embodiments, such as this embodiment, the method for calibrating the impedance of the conductive connection member further includes steps S140 - S160.

[0054] S140, confirm whether the impedance value meets the first preset requirement;

[0055] S150, if the impedance value meets the first preset requirement, then return the information of successful calibration;

[0056] S160, if the impedance value does not meet the first preset requirement, then return the information of failed calibration.

[0057] In the embodiment of the present invention, the first preset requirement may be a preset interval. When the impedance value is within the preset interval, it indicates successful calibration, and then the information of successful calibration can be returned to the test device. When the impedance value is outside the preset interval, it indicates failed calibration, and then the information of failed calibration can be returned to the test device, facilitating the staff to understand the calibration situation through the test device.

[0058] See Figure 6 , in some embodiments, such as this embodiment, step S140 further includes steps S141 - S143.

[0059] S141, respectively obtain the impedance value, the preset lower limit value, and the preset upper limit value;

[0060] S142, if the impedance value is greater than or equal to the preset lower limit value and less than or equal to the preset upper limit value, then confirm that the impedance value meets the first preset requirement;

[0061] S143, if the impedance value is less than the preset lower limit value or greater than the preset upper limit value, then confirm that the impedance value does not meet the first preset requirement.

[0062] In an embodiment of the present invention, the preset range may include a preset lower limit value and a preset upper limit value. When the impedance value is greater than or equal to the preset lower limit value and less than or equal to the preset upper limit value, it indicates that the impedance value meets the first preset requirement. When the impedance value is less than the preset lower limit value or greater than the preset upper limit value, it indicates that the impedance value does not meet the first preset requirement.

[0063] For example, the preset lower limit value may be 1 mR, and the preset upper limit value may be 4 mR. Then, when the impedance value is greater than or equal to 1 mR and less than or equal to 4 mR, it meets the first preset requirement. When the impedance value is less than 1 mR or greater than 4 mR, it does not meet the first preset requirement.

[0064] See Figure 7 , in some embodiments, such as this embodiment, the method for calibrating the impedance of the conductive connection member further includes steps S170 - S180.

[0065] S170, calculate the acquisition voltage and the impedance voltage of each battery in the first type of battery;

[0066] S180, calculate the compensation voltage of each battery in the first type of battery according to the acquisition voltage and the impedance voltage.

[0067] In an embodiment of the present invention, after applying a fixed current, if the average value of the cell voltages of the second type of battery is 3250 mV, the cell voltage of the 6th cell is 3299 mV, the cell voltage of the 12th cell is 3300 mV, and the cell voltage of the 18th cell is 3291 mV, and the impedances of the conductive connection members of the 6th battery, the 12th battery, and the 18th battery are all 2.5 mR. Among them, 3299 mV, 3300 mV, and 3291 mV are all acquisition voltages. Then, calculate the impedance voltage according to the impedance, and then calculate the difference between the acquisition voltage and the impedance voltage to obtain the compensation voltage.

[0068] See Figure 8 , in some embodiments, such as this embodiment, step S170 further includes steps S171 - S172.

[0069] S171, obtain the impedance value of each battery in the first type of battery and the first current value corresponding to the fixed current;

[0070] S172, calculate the compensation voltage of each battery in the first type of battery according to the impedance value and the first current value.

[0071] In the embodiment of the present invention, the impedance of the conductive connectors of the 6th battery and the 12th battery is 2.5 mR, and the impedance of the conductive connector of the 18th battery is 2.0 mR. Then, the impedance voltages of the 6th battery and the 12th battery are both 20 A * 2.5 mR = 50 mV, the impedance voltage of the 18th battery is 40 mV, the compensation voltage of the 6th battery is 3299 mV - 50 mV = 3249 mV, the compensation voltage of the 12th battery is 3300 mV - 50 mV = 3250 mV, and the compensation voltage of the 18th battery is 3291 mV - 40 mV = 3251 mV.

[0072] The present invention also provides a calibration system, which is configured with the method for calibrating the impedance of the conductive connector in any one of the above embodiments.

[0073] The charging method and system for multi-battery packs disclosed by the present invention can, when it is necessary to calibrate the impedance of the conductive connector, identify the first type of battery and the second type of battery, then calculate the first pressure difference and the second pressure difference before and after applying a fixed current respectively, and then confirm the voltage change amount of the conductive connector according to the first pressure difference and the second pressure difference, so as to calculate the impedance of the conductive connector, which is convenient for subsequent detection and use and improves the accuracy of the test.

[0074] It should be noted that those skilled in the art can clearly understand that the specific implementation processes of the above calibration system and each unit can refer to the corresponding descriptions in the foregoing method embodiments. For the sake of convenience and brevity of description, they will not be repeated here.

[0075] In the above embodiments, the descriptions of each embodiment have their own focuses. For the parts not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0076] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, provided that these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

[0077] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A method for calibrating the impedance of a conductive connection, characterized in that: The method comprises: Controlled by a calibration instruction for calibrating impedance, identifying a first type of battery and a second type of battery, wherein the first type of battery is a battery connected with a conductive connector, and the second type of battery is a battery not connected with the connector; Calculating a first voltage difference according to voltage values ​​of the first type of battery and the second type of battery before applying a fixed current; Calculating a second voltage difference according to voltage values ​​of the first type of battery and the second type of battery after the fixed current is applied; An impedance value is calculated according to the first pressure difference and the second pressure difference to obtain the impedance of the conductive connection.

2. The method according to claim 1, characterized in that The step of calculating the first voltage difference according to the voltage values ​​of the first type of battery and the second type of battery before applying the fixed current comprises: collecting a cell voltage of each battery in the second type of batteries, and calculating an average value of the cell voltages of the second type of batteries according to the collected cell voltages to obtain a first standard value; Collecting the cell voltage of each battery in the first type of batteries to obtain a plurality of first voltages to be calibrated; A plurality of first pressure differences are calculated according to a plurality of first voltages to be calibrated and the first standard value.

3. The method according to claim 1, characterized in that The step of calculating the second voltage difference according to the voltage values ​​of the first type battery and the second type battery after applying the fixed current comprises: Obtaining the fixed current and using the fixed current as the output current; collecting a cell voltage of each battery in the second type of batteries, and calculating an average value of the cell voltages of the second type of batteries according to the collected cell voltages to obtain a second standard value; Collecting the cell voltage of each battery in the first type of batteries to obtain a plurality of second voltages to be calibrated; A plurality of second voltage differences are calculated according to a plurality of the second voltages to be calibrated and the second standard value.

4. The method according to claim 1, characterized in that The step of calculating the impedance value according to the first pressure difference and the second pressure difference comprises: Acquiring a current value of the fixed current to obtain a first current value; calculating a difference between the second pressure difference and the first pressure difference to obtain a first difference; The impedance value is calculated according to the first current value and the first difference.

5. The method according to claim 1, characterized in that The method further comprises: confirming whether the impedance value meets the first preset requirement; If the impedance value meets the first preset requirement, information indicating successful calibration is returned.

6. The method according to claim 5, characterized in that After the step of confirming whether the impedance value meets the first preset requirement, the method further includes: If the impedance value does not meet the first preset requirement, a calibration failure message is returned.

7. The method according to claim 5, characterized in that The step of confirming whether the impedance value meets the first preset requirement includes: Respectively obtaining the impedance value, the preset lower limit value, and the preset upper limit value; If the impedance value is greater than or equal to the preset lower limit value and less than or equal to the preset upper limit value, then confirming that the impedance value meets the first preset requirement; If the impedance value is less than the preset lower limit value or greater than the preset upper limit value, it is confirmed that the impedance value does not meet the first preset requirement.

8. The method according to claim 1, characterized in that The method further comprises: Calculating the collected voltage and the impedance voltage of each battery in the first type of batteries; The compensation voltage of each battery in the first type of batteries is calculated according to the collected voltage and the impedance voltage.

9. The method according to claim 8, characterized in that The step of calculating the impedance voltage of each battery in the first type of battery comprises: Obtaining an impedance value of each battery in the first type of batteries and a first current value corresponding to the fixed current; The compensation voltage of each battery in the first type of batteries is calculated according to the impedance value and the first current value.

10. A calibration system, characterized in that: The calibration system is configured with the method for calibrating the impedance of a conductive connection as claimed in any one of claims 1 to 9.

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