Detection method and system of echelon utilization battery pack

Abstract

The invention discloses a detection method and system for echelon utilization of a battery pack, and solves the problem that data of different types of battery packs are difficult to effectively identify during echelon utilization in the prior art, and the method comprises the following steps: setting pin ports and sampling points, and sequentially connecting the initial pin ports and the sampling points according to a sequence; voltage data and temperature data between the pin ports are collected, and pin positioning is carried out on voltage information of the series battery packs in the battery packs according to the collected data; and calibrating the collected data, sorting all the obtained voltage values, and calculating by using a difference value to obtain single voltage data of each battery in the battery pack. A battery management system of the primary battery pack is crossed, and the voltage and temperature of the single batteries in the battery pack can be quickly obtained only by using the sampling wire harness of the primary battery pack.

Description

Technical Field

[0001] The present invention relates to the technical field of cascade utilization of retired power batteries, and in particular to a detection method and system for cascade utilization battery packs. Background Art

[0002] The power battery is the "heart" of new energy vehicles and the most valuable part of the vehicle. As both the incremental and stock of new energy vehicles grow, power batteries are entering the peak period of retirement. The "retirement" of power batteries from new energy vehicles is only the first step in their life journey. At present, there are two main directions for the use of retired power batteries. When the battery capacity of new energy vehicles is between 20% and 80%, cascade utilization is the first choice. Battery detection, classification, splitting, and reorganization are first used in the field of low-speed electric vehicles, and then used in energy storage, communication base stations, street lights or power banks.

[0003] The recycling of the entire power battery pack is one of the most reasonable ways of utilization at this stage. There is no need to disassemble the battery pack. One or several battery packs can be connected in series and parallel to serve as a large UPS or peak-shaving energy storage device. One of the biggest problems facing the utilization of the entire pack is the lack of consistency in the communication protocol of the battery management system in the battery pack. Different brands of automobile OEMs have their own communication protocols. The battery management system in retired power battery packs has a variety of manufacturers, brands, and models, resulting in different pin definitions for the voltage and temperature acquisition harness interface in the battery pack connected to the battery management system, making it difficult to effectively identify and obtain the voltage and temperature data of the batteries in different types of battery packs. Summary of the invention

[0004] The purpose of the present invention is to solve the problem in the prior art that it is difficult to effectively identify data of different types of battery packs during cascade utilization, and to provide a detection method and system for cascade-utilized battery packs, which bypasses the battery management system of the original battery pack and only requires the sampling harness of the original battery pack to quickly obtain the voltage and temperature of the battery cells in the battery pack.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A method for detecting a second-life battery pack, characterized in that it comprises the following steps: Set the pin ports and sampling points, and connect the initial pin ports and sampling points in sequence; Collect voltage data and temperature data between pin ports, and perform pin positioning of the voltage information of the series-connected battery pack in the battery pack based on the collected data; The collected data is calibrated, all the acquired voltage values ​​are sorted, and the single cell voltage data of each battery in the battery pack is obtained by difference calculation.

[0006] The method of the present invention removes the battery management system in the retired power battery pack for replacement, and then plugs the data interface of the original battery pack, bypassing the battery management system of the original battery pack. Only the sampling harness of the original battery pack is needed to realize rapid acquisition of the voltage and temperature of the battery cells in different types of battery packs, and realize pin positioning of the voltage of the series battery pack in the battery pack, which has strong adaptability.

[0007] Preferably, a first pin port and a second pin port are set, and the pin ports are connected to corresponding sampling points. If the voltage value between the two pin ports is within a threshold range, the pin ports corresponding to the battery voltage point and the temperature sampling point are recorded, and the second pin port number is incremented; if the voltage value between the two pin ports is not within the threshold range, it is determined whether the resistance value between the two pin ports is within the threshold range. If so, the pin ports corresponding to the battery voltage point and the temperature sampling point are recorded, and the second pin port number is incremented; otherwise, the first pin port number is incremented; after the pin port number is incremented, the detection process is repeated.

[0008] Preferably, the first pin port and the first sampling point are connected, and the second pin port and the second sampling point are connected. If the voltage value between the two pin ports is within the threshold range, the pin ports corresponding to the battery voltage point and the temperature sampling point are recorded, and the second pin port number is incremented. If the voltage value between the two pin ports is not within the threshold range, the sampling points corresponding to the two pin ports are exchanged, and the voltage value between the two pin ports is collected again. If it is still not within the threshold range, it is determined whether the resistance value between the two pin ports is within the threshold range.

[0009] Preferably, before the next sampling period starts, the gate positions of all valid voltage sampling points and temperature points are recorded, and at the beginning of the next sampling period, data collection is performed according to the recorded gate positions.

[0010] Preferably, the minimum voltage value is the single cell voltage of the first battery, the second to last voltage value is the series voltage of the first battery and the second battery, and the maximum voltage value is the series voltage of all battery cells in the battery pack. By calculating the difference, the single cell voltage of each battery in the battery pack is obtained in turn.

[0011] Preferably, the first pin port is connected to the first sampling point, and the second pin port is connected to the second sampling point. If the voltage value between the two pin ports is within a threshold range, the first pin port is recorded as the negative electrode of the N battery, the second pin port is the positive electrode of the N battery, and N is the number of the first pin port.

[0012] A detection system for a second-life battery pack includes: a gating circuit and an isolation circuit, wherein the gating circuit is connected to an interface unit, a sampling point is provided between the gating circuit and the isolation circuit, the isolation amplifier is also connected to a control switch, the output end of the isolation amplifier is connected to an analog-to-digital converter, and the analog-to-digital converter is connected to a main control module.

[0013] Preferably, the gating circuit comprises a gating chip and an optocoupler, the output end of the optocoupler is respectively connected to the interface unit and the sampling point, and the input end of the optocoupler is respectively connected to the power supply and the gating chip.

[0014] Preferably, the power port of the isolation amplifier is connected to a first control switch, the control switch is connected to a power supply unit, and a second sampling point is provided between the gating circuit and the power port of the isolation amplifier; the input port of the isolation amplifier is connected to a second control switch, the second control switch is connected to an analog-to-digital converter, a first sampling point is provided between the gating circuit and the input port of the isolation amplifier, and the feedback port of the isolation amplifier is connected to the analog-to-digital converter.

[0015] Preferably, the gating chip comprises n optocouplers, the output ends of n / 2 optocouplers are connected to the first sampling point, the output ends of n / 2 optocouplers are connected to the second sampling point, and the output end of each optocoupler is connected to the same pin port in the interface unit.

[0016] Therefore, the present invention has the following beneficial effects: by removing the battery management system in the retired power battery pack for replacement, and then plugging the data interface of the original battery pack, bypassing the battery management system of the original battery pack, only the sampling harness of the original battery pack is needed to realize the rapid acquisition of the voltage and temperature of the battery cells in different types of battery packs, and realize the pin positioning of the voltage of the series battery pack in the battery pack, which has strong adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a flowchart of the overall steps of the detection method for the second-use battery pack in Example 1.

[0018] Figure 2 Schematic diagram of the architecture of the detection system for the recycled battery pack in Example 3.

[0019] Figure 3 Schematic diagram of the circuit structure of the gating circuit in the third embodiment.

[0020] Figure 4 Schematic diagram of the circuit structure of the gating circuit in the fourth embodiment.

[0021] In the figure: 1. interface unit; 2. selection circuit; 3. second sampling point; 4. first sampling point; 5. first control switch; 6. second control switch; 7. isolation module; 8. digital-to-analog converter; 9. power supply voltage; 10. main control module. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments: Embodiment 1: This embodiment provides a detection method for a second-life battery pack, such as Figure 1 As shown, the operation process is as follows: Step 1, set the pin port and the sampling point, and connect the initial pin port and the sampling point in sequence; Step 2, collect the voltage data and temperature data between the pin ports, and perform pin positioning on the series battery pack voltage information in the battery pack according to the collected data; Step 3, calibrate the collected data, sort all the acquired voltage values, and use the difference calculation to obtain the single cell voltage data of each battery in the battery pack.

[0023] Figure 1 In the figure, Um,n represents the voltage between the two pins; Rm,n represents the resistance value measured between the two pins. The corresponding temperature value can be obtained by looking up the table; 0-100 is the effective value range of the voltage measured by the two sampling points. If it exceeds this range, the measured value is considered to be invalid.

[0024] The detection method for the recycled battery pack provided in the present embodiment is to remove the battery management system in the retired power battery pack for replacement, and then plug the data interface of the original battery pack into the original battery pack, bypassing the battery management system of the original battery pack. Only the sampling harness of the original battery pack is needed to realize the rapid acquisition of the voltage and temperature of the battery cells in different types of battery packs, and realize the pin positioning of the voltage of the series battery pack in the battery pack, which has strong adaptability.

[0025] The following further illustrates the technical solution and technical effects of the present invention through specific examples and specific application scenarios. The following examples are explanations of the present invention and the present invention is not limited to the following examples.

[0026] Step 1: Set the pin ports and sampling points, and connect the initial pin ports and sampling points in sequence.

[0027] Set the first pin port number to 1, the second pin port number to 1, connect the first pin port to the first sampling point, and connect the second pin port to the second sampling point.

[0028] Step 2: Collect the voltage data and temperature data between the pin ports, and locate the pins of the series battery pack voltage information in the battery pack based on the collected data.

[0029] (1) Collect the voltage data between the first pin port and the second pin port. If the voltage value between the two pin ports is within the threshold range (in this embodiment, the voltage value between the first pin port and the second pin port is between 0-100V), record the pin port corresponding to the battery voltage point and the temperature sampling point, and determine whether the second pin port number reaches the pin port maximum number minus 1. If so, execute the third step. Otherwise, the second pin port number is incremented, the first pin port number remains unchanged, and the detection process is repeated. In this embodiment, the first pin port is recorded as the negative electrode of battery #N, and the second pin port is recorded as the positive electrode of battery #N.

[0030] (2) If the voltage value between the two pin ports is not within the threshold range, the sampling points corresponding to the two pin ports are exchanged, that is, the first sampling point is connected to the second pin port, and the second sampling point is connected to the first pin port, and the voltage value between the two pin ports is collected again. If the voltage value between the two pin ports is within the threshold range, the pin ports corresponding to the battery voltage point and the temperature sampling point are recorded, and it is determined whether the number of the second pin port reaches the maximum number of the pin port minus 1. If so, the third step is executed. Otherwise, the number of the second pin port is incremented, the number of the first pin port remains unchanged, and the detection process is repeated.

[0031] (3) If the voltage value between the two pin ports is still not within the threshold range after the sampling points corresponding to the two pin ports are exchanged, the resistance value between the two pin ports is collected to determine whether the resistance value between the two pin ports is within the threshold range. If so, the resistance value is recorded, and the temperature value of the sampling point is obtained according to the temperature corresponding resistance table lookup method. It is determined whether the second pin port number reaches the maximum pin port number at this time. If so, the third step is executed, otherwise the second pin port number is incremented, the first pin port number remains unchanged, and the detection process is repeated. If the resistance value between the two pin ports is not within the threshold range, the first pin port number is incremented, the second pin port number remains unchanged, and the detection process is repeated.

[0032] The temperature-resistance lookup table method uses the thermistor temperature and resistance comparison table to find the temperature corresponding to the resistance in the table according to the detected resistance. For example, if the measured resistance is 22.783 ohms, the corresponding temperature is 24 degrees Celsius; 15.699 ohms corresponds to 35 degrees Celsius; each temperature point will have a corresponding resistance value.

[0033] It should be noted that, because two measurement points are required to measure the voltage of a battery, the first pin port is one of the measurement points, and then the other measurement point, the second pin port, is first assigned the same value as the first pin port, and the next step is to let the second pin port increment its pin number.

[0034] Step 3: Calibrate the collected data, sort all the acquired voltage values, and use the difference calculation to obtain the single cell voltage data of each battery in the battery pack.

[0035] The acquired data information is calibrated and recorded, and finally all the acquired voltage values ​​are sorted. The minimum voltage value is the voltage of the #1 battery cell, the second-to-last voltage value is the series voltage of the #1 and #2 battery cells, the third-to-last voltage value is the series voltage of the #1, #2 and #3 battery cells, and so on. The data of all single cell voltages can be obtained by taking the difference method.

[0036] After the current sampling cycle ends, the selection positions of all valid voltage sampling points and temperature sampling points are recorded, so that the selection circuit can be switched directly when the voltage is sampled next time. The next sampling cycle begins, and the voltage and temperature data are collected according to the recorded selection channels.

[0037] The selection position refers to the number value of the first pin port and the number value of the second pin port corresponding to the effective voltage value or temperature value, so as to facilitate direct and fast sampling at the next sampling.

[0038] The detection method of the battery pack for cascade utilization provided in this embodiment can solve the problem that the battery management system in the retired power battery pack has different manufacturers, brands, and models, resulting in different pin definitions of the voltage and temperature acquisition harness interface in the battery pack connected to the battery management system, making it difficult to effectively identify. It can realize the acquisition of voltage and temperature data of batteries in different types of battery packs.

[0039] Embodiment 2: This embodiment provides a detection method for a second-use battery pack, which is brought into a specific application scenario and combined with specific detection data to implement the detection method for a second-use battery pack in Embodiment 1.

[0040] In this embodiment, it is assumed that the maximum pin number Nmax=12.

[0041] First, set the first pin port number to 1, the second pin port number to 1, then set the second pin port number +1, now the second pin port number is 2, and start detection.

[0042] Connect the first pin port No. 1 and the second pin port No. 2, collect the voltage between the two pin ports, the voltage collected in this embodiment is 3.342V, within the threshold range of 0-100V, record the voltage, and record the positive and negative poles, at this time, record the first pin port No. 1 as the negative pole of battery #1, and the second pin port No. 2 as the positive pole of battery #2. At this time, the second pin port number does not reach the maximum pin port number, the second pin port number increases, and is the second pin port No. 3. Connect the first pin port No. 1 to the first sampling point, the second pin port No. 2 to the second sampling point, and detect the voltage between the two pin ports again. At this time, the voltage collected between the two pin ports is -6.679V, which is not within the threshold range of 0-100V, so the sampling points connected by the two pin ports are exchanged, that is, the first pin port No. 1 is connected to the second sampling point, and the second pin port No. 2 is connected to the first sampling point, and the voltage between the two pin ports is detected again. At this time, the voltage collected between the two pin ports is 6.679V, within the threshold range of 0-100V, record the voltage, and record the positive and negative poles. By analogy, the voltage data collected in the battery pack is as follows: All the voltage values ​​obtained are sorted, and statistics are performed based on the above data to obtain the following table: Voltage 1 Voltage 2 Voltage 3 Voltage 4 Voltage 5 Voltage 6 Voltage 7 Voltage 8 Voltage 9 Voltage 10 Voltage 11 33.404 30.059 26.722 23.380 20.039 16.700 13.363 10.023 6.679 3.342 3.341 m,n m,n m,n m,n m,n m,n m,n m,n m,n n,m m,n 11,1 12,1 9,1 10,1 7,1 8,1 5,1 6,1 3,1 1,2 4,1 Based on the above table, according to the minimum voltage value, the voltage of the #1 battery cell, the second-to-last voltage value is the voltage of the #1 battery cell and the #2 battery cell in series, the third-to-last voltage value is the voltage of the #1, #2 and #3 battery cells in series, and so on. The data of all cell voltages are obtained by taking the difference method.

[0043] Therefore, it can be obtained that: the voltage of battery cell #1 is 3.341V, the voltage of battery cell #2 is 0V, the voltage of battery cell #3 is 3.337V, the voltage of battery cell #4 is 3.344V, the voltage of battery cell #5 is 3.34V, the voltage of battery cell #6 is 3.337V, the voltage of battery cell #7 is 3.339V, the voltage of battery cell #8 is 3341V, the voltage of battery cell #9 is 3.342V, the voltage of battery cell #10 is 3.337V, and the voltage of battery cell #11 is 3.345V.

[0044] The final calculated data is shown in the following table: This sampling cycle ends and the next sampling cycle begins.

[0045] Embodiment three: This embodiment provides a detection system for a second-use battery pack, which is used to implement a detection method for a second-use battery pack in the first embodiment.

[0046] Specific: like Figure 2 As shown, a detection system for a second-use battery pack includes: an interface unit 1, a gating circuit 2, a first sampling point 4, a first sampling point 3, a first control switch 5, a second control switch 6, an isolation circuit 7, a digital-to-analog converter 9, a power supply module 9 and a main control module 10, the interface unit is connected to the gating circuit, the gating circuit is respectively connected to the first sampling point and the second sampling point, the second sampling point is connected to the power port of the isolation module, the first sampling point is connected to the input port of the isolation module, the second control switch is connected to the input port of the isolation module, the first control switch is connected to the power port of the isolation module, the first control switch is connected to the power supply module, and the feedback port of the isolation module is connected to the analog-to-digital converter.

[0047] In this embodiment, the interface unit is provided with a plurality of pin ports for connecting to the battery pack.

[0048] The isolation module uses an isolation amplifier, the power port of the isolation amplifier is connected to the first control switch, the first sampling point is set between the gating circuit and the power port of the isolation amplifier, the input port of the isolation amplifier is connected to the second control switch, the second sampling point is set between the gating circuit and the input port of the isolation amplifier, and the feedback port of the isolation amplifier is connected to the analog-to-digital converter. Because the power supply and ground of the battery management system need to be isolated from the negative and positive electrodes of the battery, an isolation amplifier is used to remove common-mode interference.

[0049] The digital converter converts analog signals into digital signals. The control switch can be turned on or off by the main control module, thus realizing the power supply of the power supply module and data collection.

[0050] The main control module is used to execute Figure 1 The control logic of the flowchart shown in the figure, and the data storage function of the result generated by the logic, the main control module includes a main chip, and the main chip can also have multiple options.

[0051] Among them, the gating circuit is a basic circuit that can be realized by optocoupler control, or a gating chip or a transistor. Because providing one will not limit other basic circuits, one of them is provided as an example in this embodiment.

[0052] like Figure 3As shown, the gating circuit includes a gating chip and 8 optocoupler isolation switches, the collectors of the photosensitive triodes of the 8 optocoupler isolation switches (the positive pole of the output signal) are all connected to the interface unit, wherein each group of two optocoupler isolation switches are connected to the same pin port in the interface unit, the emitter of the photosensitive triode of one optocoupler isolation switch (the negative pole of the output signal) is connected to the first sampling point, and the emitter of the photosensitive triode of another optocoupler isolation switch is connected to the second sampling point. The positive poles of the light-emitting diodes of the 8 optocoupler isolation switches (the input end of the input signal) are all connected to the power supply, and the negative poles of the light-emitting diodes of the 8 optocoupler isolation switches are all connected to the gating chip and controlled by the gating chip.

[0053] The new battery pack needs to be equipped with a battery management system. The voltage of each series-connected battery in the battery pack needs to be connected to the battery management system through a sampling harness. During the cascade utilization of batteries retired from new energy vehicles, the pin definition of the original sampling harness cannot be obtained. If manual disassembly is performed, a large amount of man-hour costs will be increased. Therefore, the detection system for cascade utilization battery packs provided in this embodiment is to solve this problem. The steps for detecting a battery pack using a cascade utilization battery pack detection system provided in this embodiment are as follows: Step (1): insert the collection harness port of the original battery pack into the battery management system interface suitable for cascade utilization of the present invention.

[0054] Step (2): Set N=1, M=N, and the maximum pin number Nmax=constant.

[0055] A battery pack may be composed of dozens or more than a hundred battery cells connected in series. In order to collect the voltage value of each battery cell, the number of pins will be increased accordingly. It also includes the wiring harness and corresponding pins required by the temperature sensor. Therefore, the maximum pin port number here refers to the total number of pins of the battery pack's collection harness.

[0056] Step (3): Set the value of M to M+1. Because two measurement points are required to measure the voltage of a battery, N is one of the measurement points. Then the other measurement point M is assigned the same value as N. In the next step, let M increment by one pin number.

[0057] Step (4): The gating circuit will follow the order ( Figure 1 In the order shown in ), select pin port N to connect to the first sampling point and pin port M to connect to the second sampling point.

[0058] Step (5): Data collection.

[0059] The following situations may occur: (5.1) If pin N corresponds to the battery negative pole voltage sampling point, and pin M corresponds to the battery positive pole voltage sampling point, the voltage value can be read out in the main chip program through the isolation amplifier to analog-to-digital converter, and pin N is marked as #N battery negative pole and pin M is marked as #N battery positive pole.

[0060] (5.2) If pin N corresponds to the positive voltage sampling point of the battery, and pin M corresponds to the negative voltage sampling point of the battery, it cannot be read in the main chip program through the isolation amplifier to the analog-to-digital converter; then, the main chip controls the selection circuit to collect the voltage in reverse: pin N corresponds to sampling point 2, and pin M corresponds to sampling point 1 for voltage collection. If the battery cell voltage is within a reasonable value range, the battery sampling point position corresponding to the pin port will be recorded.

[0061] (5.3) If pins N and M correspond to the two ends of the temperature sensor, and the main chip controls the two control switches to turn on, the temperature value of the sampling point can be obtained by measuring the voltage across the temperature sensor and performing a temperature-corresponding resistance table lookup method.

[0062] (5.4) If the values ​​collected in the above three cases are not within the reasonable value range, the pin number N is increased by 1 and returns to step (3).

[0063] Each time a sampling point is recorded, the N value and the M value need to be recorded, and then the M or N value is changed according to the result before proceeding to the next step.

[0064] Step (6): Calibrate and record the acquired data information and repeat step (3).

[0065] Step (7): Finally, all the obtained voltage values ​​are sorted. The minimum voltage value is the voltage of the #1 battery cell, the second-to-last voltage value is the series voltage of the #1 and #2 battery cells, the third-to-last voltage value is the series voltage of the #1, #2 and #3 battery cells, and so on. The data of all cell voltages can be obtained by taking the difference method.

[0066] Step (8): Record the gating positions of all valid voltage sampling points and temperature sampling points, so that the gating circuit can be switched directly when the voltage is sampled next time. The gating position refers to the corresponding N value and M value when the valid voltage value or temperature value is obtained, so that the next time the sampling is done directly and quickly.

[0067] Step (9): Start the next sampling cycle and collect voltage and temperature data according to the recorded selection channels. When the end command is received, the process ends.

[0068] Embodiment 4: This embodiment provides a detection system for a second-use battery pack, and further optimizes the gating circuit based on the third embodiment.

[0069] like Figure 4 As shown, in this embodiment, the gating circuit includes a gating chip, 8 optocoupler isolation switches U133-U141 and 7 diode groups D122-D128, the positive electrodes of the light-emitting diodes of the optocoupler isolation switches U133, U135, U138 and U140 are all connected to one end of a resistor R106, and the other end of the resistor R106 is connected to a power supply; the positive electrodes of the light-emitting diodes of the optocoupler isolation switches U134, U137, U139 and U141 are all connected to one end of a resistor R107, and the other end of the resistor R107 is connected to a power supply.

[0070] The cathode of the light-emitting diode of the optocoupler isolation switch U133 is connected to the first end of the diode group D122, the second end of the diode group D122 is connected to the cathode of the light-emitting diode of the optocoupler isolation switch U134, the third end of the diode group D122 is connected to the first end of the diode group D123, the second end of the diode group D123 is connected to the cathode of the light-emitting diode of the optocoupler isolation switch U135, the third end of the diode group D123 is connected to the first end of the diode group D124, and so on. At the same time, the first end of the diode group D122, the third end of the diode group D122, the third end of the diode group D123, the third end of the diode group D124, the third end of the diode group D125, the third end of the diode group D126, the third end of the diode group D127, and the third end of the diode group D128 are connected to the Y port of the selection chip.

[0071] The gating chip uses a chip of model SN74HC138-Q1, and the optocoupler isolation switch uses a switch of model TLP172.

[0072] The diode group includes a first diode and a second diode, the anode of the first diode is connected to the anode of the second diode, the anode of the first diode is the second end of the diode group, the cathode of the first diode is the first end of the diode group, and the cathode of the second diode is the second end of the diode group. The diode group is used to prevent reverse current.

[0073] The detection system for the recycled battery pack provided in this embodiment bypasses the battery management system of the original battery pack and only needs to use the sampling harness of the original battery pack to quickly obtain the voltage and temperature of the battery cells in the battery pack, and can prevent backflow to ensure the stable operation of the circuit.

[0074] The above-described embodiment is only a preferred solution of the present invention and does not limit the present invention in any form. There are other variations and modifications without exceeding the technical solution described in the claims.

Claims

1. A method for detecting a second-life battery pack, characterized in that: include: Set the pin ports and sampling points, and connect the initial pin ports and sampling points in sequence; Collect voltage data and temperature data between pin ports, and perform pin positioning of the voltage information of the series-connected battery pack in the battery pack based on the collected data; The collected data is calibrated, all the acquired voltage values ​​are sorted, and the single cell voltage data of each battery in the battery pack is obtained by difference calculation.

2. A detection method for a second-life battery pack according to claim 1, characterized in that: A first pin port and a second pin port are set, and the pin ports are connected to corresponding sampling points. If the voltage value between the two pin ports is within a threshold range, the pin ports corresponding to the battery voltage point and the temperature sampling point are recorded, and the second pin port number is incremented; if the voltage value between the two pin ports is not within the threshold range, it is determined whether the resistance value between the two pin ports is within the threshold range. If so, the pin ports corresponding to the battery voltage point and the temperature sampling point are recorded, and the second pin port number is incremented; otherwise, the first pin port number is incremented; after the pin port number is incremented, the detection process is repeated.

3. A detection method for a second-life battery pack according to claim 2, characterized in that: Connect the first pin port and the first sampling point, connect the second pin port and the second sampling point, if the voltage value between the two pin ports is within the threshold range, record the pin ports corresponding to the battery voltage point and the temperature sampling point, and increase the number of the second pin port; if the voltage value between the two pin ports is not within the threshold range, exchange the sampling points corresponding to the two pin ports, collect the voltage value between the two pin ports again, if it is still not within the threshold range, determine whether the resistance value between the two pin ports is within the threshold range.

4. A method for detecting a second-life battery pack according to claim 1, 2 or 3, characterized in that: Before the next sampling period starts, the strobe positions of all valid voltage sampling points and temperature points are recorded, and at the beginning of the next sampling period, data is collected according to the recorded strobe positions.

5. A method for detecting a second-life battery pack according to claim 1, 2 or 3, characterized in that: The minimum voltage value is the single cell voltage of the first battery, the second-to-last voltage value is the series voltage of the first battery and the second battery, and the maximum voltage value is the series voltage of all battery cells in the battery pack. By calculating the difference, the single cell voltage of each battery in the battery pack is obtained in turn.

6. A method for detecting a second-life battery pack according to claim 2 or 3, characterized in that: Connect the first pin port and the first sampling point, connect the second pin port and the second sampling point. If the voltage value between the two pin ports is within the threshold range, record that the first pin port is the negative electrode of the N battery, the second pin port is the positive electrode of the N battery, and N is the number of the first pin port.

7. A detection system for a second-life battery pack, using a detection method for a second-life battery pack according to any one of claims 1 to 6, characterized in that: include: A gating circuit and an isolation circuit, wherein the gating circuit is connected to an interface unit, a sampling point is provided between the gating circuit and the isolation circuit, the isolation amplifier is also connected to a control switch, the output end of the isolation amplifier is connected to an analog-to-digital converter, and the analog-to-digital converter is connected to a main control module.

8. The detection system for a second-life battery pack according to claim 7, characterized in that: The gating circuit includes a gating chip and an optocoupler isolating switch, wherein the output end of the optocoupler isolating switch is respectively connected to the interface unit and the sampling point, and the input end of the optocoupler isolating switch is respectively connected to the power supply and the gating chip.

9. A detection system for a second-life battery pack according to claim 7 or 8, characterized in that: The power port of the isolation amplifier is connected to a first control switch, the first control switch is connected to a power supply unit, and a second sampling point is provided between the gating circuit and the power port of the isolation amplifier; the input port of the isolation amplifier is connected to a second control switch, the second control switch is connected to an analog-to-digital converter, a first sampling point is provided between the gating circuit and the input port of the isolation amplifier, and the feedback port of the isolation amplifier is connected to the analog-to-digital converter.

10. A method for detecting a second-life battery pack according to claim 9, characterized in that: The gating circuit includes n optocoupler isolation switches, the output ends of n / 2 optocoupler isolation switches are connected to the first sampling point, the output ends of n / 2 optocoupler isolation switches are connected to the second sampling point, and the output end of each optocoupler isolation switch is connected to the same pin port in the interface unit.

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