Battery testing device and system

Abstract

The utility model discloses a battery testing device and system, comprising a control device, a first power supply management module and a second power supply management module, the control device is respectively connected with the first power supply management module and the second power supply management module, and the first power supply management module and the second power supply management module are connected with a battery pack; the control device is used for controlling the first power management module and the second power management module to charge and discharge the battery pack, when the current demand of the battery pack is within a first range, the power supply end of the first power management module is electrically connected with the input end of the battery pack, and when the current demand of the battery pack is within a second range, the power supply end is electrically connected with the input end. The power supply end of the second power management module is electrically connected with the input end of the battery pack. According to the utility model, the testing device carries out cyclic charging and discharging testing on the battery pack, the first power supply management module and the second power supply management module are different in testing current gear, and a relatively proper current gear can be selected to test different battery packs, so that the testing result is more accurate.

Description

Technical Field

[0001] This invention relates to the field of battery testing technology, and in particular to a battery testing device and system. Background Technology

[0002] With the rapid development of portable electronic devices, electric vehicles, and energy storage systems, the demand for high-performance batteries is increasing. High-performance batteries are widely used due to their high energy density, long lifespan, and relatively low cost. However, battery performance inevitably declines over time, especially after multiple charge-discharge cycles. Therefore, accurately assessing battery cycle life is crucial for ensuring product reliability and optimizing design.

[0003] Currently, various battery cycle life testing methods exist on the market. Many existing methods rely on simplified models or assumptions that may not accurately capture the complex chemical reactions and physical changes within the battery. Therefore, test results may be inaccurate, especially in predicting long-term performance degradation. This lack of precision can lead to misjudgments of battery performance, consequently impacting product design and user safety. Utility Model Content

[0004] The purpose of this invention is to provide a battery testing device and system to solve the problem that the current levels for battery testing in the prior art are relatively fixed or all are too high, making it difficult to adapt to the testing accuracy of batteries with different capacities.

[0005] To achieve one of the above-mentioned objectives of the utility model, one embodiment of the present utility model provides a battery testing device, the device comprising: a control device, a first power management module and a second power management module, wherein the control device is connected to the first power management module and the second power management module respectively, and the first power management module and the second power management module are connected to a battery pack;

[0006] The control device is used to control the first power management module and the second power management module to charge and discharge the battery pack. When the current demand of the battery pack is within a first range, the power supply terminal of the first power management module is electrically connected to the input terminal of the battery pack. When the current demand of the battery pack is within a second range, the power supply terminal of the second power management module is electrically connected to the input terminal of the battery pack. The first range is greater than the second range.

[0007] As a further improvement of this utility model, the device further includes: the first power management module and the second power management module have multiple charging branches, and a charging switch is provided on each charging branch;

[0008] The first power management module and the second power management module are also used to detect the charging current, and the control device is also used to control the opening and closing of the charging switch to adapt to the corresponding charging current.

[0009] As a further improvement of this utility model, the device further includes: the battery testing device is configured with n testing units, and each testing unit is configured with m testing channels;

[0010] Each test unit includes a first power management module and a second power management module.

[0011] As a further improvement of this utility model, the device further includes: the first power management module includes a bidirectional buck-boost circuit, the bidirectional buck-boost circuit being coupled to the power supply and the battery pack;

[0012] The bidirectional buck-boost circuit is configured to either step down the voltage of the power supply to charge the battery pack, or step up the voltage of the battery pack to absorb electrical energy.

[0013] As a further improvement of this utility model, the device further includes: the bidirectional buck-boost circuit is connected to the battery pack through multiple first charging branches;

[0014] The first power management module further includes a first current sampling circuit, a first voltage sampling circuit, and an analog-to-digital converter. The input terminal of the first current sampling circuit is coupled to the first charging branch to collect the current on the first charging branch, and its output terminal is coupled to the analog-to-digital converter. The input terminal of the first voltage sampling circuit is coupled to the first charging branch to collect the voltage on the first charging branch, and its output terminal is coupled to the analog-to-digital converter. The analog-to-digital converter is used to convert the current information and voltage information into corresponding digital information.

[0015] As a further improvement of this utility model, the device further includes: the second power management module includes a signal conditioning circuit and an operational amplifier circuit, the output terminal of the signal conditioning circuit is coupled to the operational amplifier circuit, the output terminal of the operational amplifier circuit is used to couple to the battery pack, the input terminal of the signal conditioning circuit is coupled to a current source and a voltage source, and the output terminal of the signal conditioning circuit outputs current and voltage.

[0016] As a further improvement of this utility model, the device further includes: the output terminal of the operational amplifier circuit is used to connect to the battery pack through multiple second charging branches;

[0017] The second power management module further includes a second current sampling circuit and a second voltage sampling circuit. The input terminal of the second current sampling circuit is coupled to the second charging branch to collect the current in the second charging branch, and the second voltage sampling circuit is coupled to the second charging branch to collect the voltage in the second charging branch.

[0018] The output terminals of the second current sampling circuit and the second voltage sampling circuit are both coupled to the signal conditioning circuit, which is used to adjust the output current and the output voltage.

[0019] To achieve one of the above-mentioned objectives, one embodiment of this utility model also provides a battery testing system, the system including industrial control equipment, communication equipment, and a battery testing device as described in any of the above embodiments; the industrial control equipment is connected to the communication equipment via a switch, the communication equipment is used to communicate with the battery pack via network signals, and the industrial control equipment is also connected to the battery testing device via a switch.

[0020] As a further improvement of this utility model, the system further includes: the control device includes a main controller and a processor, the main controller is electrically connected to the processor, and the processor is electrically connected to the first power management module and the second power management module;

[0021] The main controller is used to process control signals sent by industrial control equipment; the processor is used to control and adjust the output current and voltage of the first power management module or the second power management module.

[0022] As a further improvement of this utility model, the system further includes: the processor is also used to receive the current and voltage of the battery pack collected by the first power management module and the second power management module.

[0023] Compared with the prior art, the present invention has the following advantages: the testing device has a first power management module and a second power management module to perform cyclic charge and discharge tests on the battery pack. The first power management module and the second power management module test different current levels, so a more suitable current level can be selected to test different battery packs, making the test results more accurate. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the system framework of the battery testing system according to one embodiment of the present invention.

[0025] Figure 2 This is a schematic diagram of the system framework of a battery testing device according to one embodiment of the present invention.

[0026] Figure 3 This is a schematic diagram of the system framework of the first power management module in one embodiment of this utility model.

[0027] Figure 4 This is a schematic diagram of the system framework of the second power management module in one embodiment of this utility model.

[0028] Figure 5 This is a schematic diagram of the circuit structure of the second power management module in one embodiment of this utility model. Detailed Implementation

[0029] The present invention will now be described in detail with reference to the specific embodiments shown in the accompanying drawings. However, these embodiments do not limit the present invention, and any structural, methodological, or functional modifications made by those skilled in the art based on these embodiments are included within the protection scope of the present invention.

[0030] This invention provides a battery testing system for charging and discharging battery packs, detecting the battery pack's operational information during the charging and discharging process to determine battery performance. Specifically, the battery testing system selects a suitable accuracy for charging and discharging the battery pack based on its capacity, detecting charging and discharging parameters during the process to determine its performance.

[0031] In one embodiment, the battery pack includes a battery and a charge / discharge module. In a specific embodiment, the battery is a lithium battery. The battery testing system is capable of testing lithium batteries and accurately assessing their cycle life based on their parameters.

[0032] like Figure 1 As shown, in this embodiment, the battery testing system includes industrial control equipment 1, battery testing device 2, and communication equipment 4.

[0033] Industrial control equipment 1 includes a control unit and a display. The control unit is used to control the battery testing device 2 to test the battery pack, and it is also used to detect the operating information of the battery pack. The display is used to show the operating information and other information required by the operators.

[0034] The battery pack's operating information includes battery capacity, current voltage, current current, and current power.

[0035] The display interface triggers commands, enabling the controller to operate the battery testing device 2 in single-channel or multi-channel mode. It also allows selection of different charge / discharge curves or parameters, real-time display of the current status of each channel, saving real-time battery charge / discharge data, plotting actual charge / discharge curves, and configurable register reading. Configurable charge / discharge modes include: CC (constant current), CV (constant voltage), CCCV (constant current to constant voltage), CP (constant power), and CR (constant resistance).

[0036] The industrial control device 1 is connected to the communication device 4 via the switch 3. The communication device 4 is used to communicate with the battery pack via network signals. The industrial control device 1 is also connected to the battery testing device 2 via the switch 3. The battery testing device 2 is connected to the battery pack.

[0037] Switch 3 is responsible for data exchange between industrial control equipment 1 and battery testing device 2. Switch 3 is also responsible for data exchange between industrial control equipment 1 and battery pack.

[0038] Switch 3 is responsible for transmitting data signals from industrial control equipment 1 to battery testing device 2, thereby controlling the operation of battery testing device 2. Industrial control equipment 1 can also collect data from the battery pack through switch 3. Specifically, communication device 4 is a communication box.

[0039] In this way, communication device 4 can achieve long-distance data interaction and support data transmission over longer distances, thereby increasing the flexibility and adaptability of test setup, avoiding signal interference problems in complex environments, and providing more reliable and stable data transmission.

[0040] In one embodiment of this utility model, such as Figure 2 As shown, a battery testing device 2 is provided. The battery testing device 2 includes a control device, a first power management module 21 and a second power management module 22, which are connected to the battery pack.

[0041] The control device is used to control the first power management module 21 and the second power management module 22 to charge and discharge the battery pack. When the current demand of the battery pack is within a first range, the power supply terminal of the first power management module 21 is electrically connected to the input terminal of the battery pack. When the current demand of the battery pack is within a second range, the power supply terminal of the second power management module 22 is electrically connected to the input terminal of the battery pack. The first range is greater than the second range.

[0042] The power supply terminals of the first power management module 21 and the second power management module 22 represent the current and voltage output terminals of the first power management module 21 and the second power management module 22. The first power management module 21 and the second power management module 22 can output current and voltage to supply the battery pack.

[0043] The minimum current value of the first power management module 21 is greater than the maximum current value of the second power management module 22.

[0044] In one embodiment of the battery testing system, the control device includes a main controller 23 and a processor 24, wherein the main controller 23 is electrically connected to the processor 24, and the processor 24 is electrically connected to the first power management module 21 and the second power management module 22.

[0045] In the battery testing system, the main controller 23 is communicatively connected to the switch 3.

[0046] The main controller 23 is used to receive and process control signals sent by the industrial control equipment 1 and instruct the processor 24 to operate; the processor 24 is used to control and adjust the output current and voltage of the first power management module 21 or the second power management module 22. The processor 24 is also used to receive the current and voltage of the battery pack collected by the first power management module 21 and the second power management module 22.

[0047] In the battery testing system, the control signals issued by the industrial control equipment 1 include selecting either the first power management module 21 or the second power management module 22 to operate, or selecting both the first power management module 21 and the second power management module 22 to operate simultaneously. It also includes selecting the current level of the first power management module 21 and the current level of the second power management module 22 to output current for charging the battery pack.

[0048] In other embodiments, the control signals issued by the industrial control equipment 1 may also include other instruction commands, such as controlling the operation of other circuits in the battery testing device 2. These other circuits may be sampling circuits, protection circuits, etc., which will not be specifically described here.

[0049] In one embodiment, the processor 24 is a digital signal processor. The processor 24 can control the first power management module 21 and the second power management module 22 to output current at specific levels via digital signals.

[0050] In one embodiment of the present invention, the processor 24 is further configured to receive the current and voltage of the battery pack and provide feedback to adjust the first power management module 21; the processor 24 is also configured to receive the current and voltage of the battery pack and provide feedback to adjust the second power management module 22.

[0051] In this way, the processor 24 can adjust the output of the first power management module 21 and the second power management module 22 according to the current and voltage feedback of the battery pack, so that the current and voltage of the battery pack are kept within a stable set range.

[0052] In one embodiment of the battery testing device 2, the first power management module 21 and the second power management module 22 have multiple charging branches, and a charging switch is provided on each charging branch.

[0053] When the charging switch is closed, the corresponding charging branch is activated, charging the battery pack.

[0054] It should be noted that different charging circuits provide different levels of current.

[0055] The first power management module 21 and the second power management module 22 are also used to detect the charging current on the charging branch. The control device is also used to control the opening and closing of the charging switch to adapt to the corresponding charging current. Specifically, the control device conducts the corresponding charging branch according to the magnitude of the detected charging current. For example, if the charging current is 15A, the first charging branch of the first power management module 21 is used to charge the battery pack, and the first charging branch of the first power management module 21 corresponds to the 15A level; when the charging current gradually decreases to 1.5A, the second charging branch of the first power management module 21 is switched on to charge the battery pack, and the second charging branch of the first power management module 21 corresponds to the 1.5A level; if the charging current continues to decrease and the first power management module 21 has been adjusted to the minimum level, the control device switches to control the first charging branch of the second power management module 22 to charge the battery pack, and so on.

[0056] In one embodiment, the lowest current value of the lowest setting of the first power management module 21 is greater than the highest current value of the highest setting of the second power management module 22. Of course, in other embodiments, the lowest setting of the first power management module 21 may partially overlap with the highest setting of the second power management module 22.

[0057] In one embodiment, the first power management module 21 and the second power management module 22 output a single current level. That is, both the first power management module 21 and the second power management module 22 have only one current level, and the output current of the first power management module 21 is greater than the output current of the second power management module 22.

[0058] In one embodiment, the first power management module 21 is a digital power management module, and the second power management module 22 is an analog power management module. In this embodiment, the digital power management module controls the current output using digital signals, and the analog power management module controls the current output using analog signals.

[0059] The aforementioned current ranges can be either current ranges or specific current values. For example, the first power management module 21 has a current range of 0-15A and a current range of 0-1.5A. The second power management module 22 has a current range of 0-200mA, a current range of 0-10mA, and a current range of 0-200uA.

[0060] In this way, a more suitable current value can be selected to test different battery packs, making the test accuracy more precise, avoiding errors in the test results that could lead to misjudgments, and ensuring that each test yields results that are closest to the true value.

[0061] If the accuracy is set to 0.02% of the full range, meaning all current values ​​in the 15A range have an accuracy of 0.02% * 15A = 3mA. Since the accuracy of 15A is 3mA, the accuracy of 2A is also 3mA. This results in excessively high accuracy, so the range will be switched, for example, switching from 1.5A to the 1.5A range. The accuracy of the 1.5A range is also 0.02%, which is 0.3mA, and so on.

[0062] For example, a large-capacity battery such as 10000mAh only needs 15A or 1.5A, but a 30mAh battery needs 200mA, 10mA or 200uA. Therefore, sampling resistors with different ranges are required to meet the accuracy needs of customers under different current requirements.

[0063] In one embodiment of this utility model, the battery testing device 2 is configured with n testing units, each testing unit is configured with m testing channels; each testing unit includes a first power management module 21 and a second power management module 22, and each testing channel is used to connect to the battery pack.

[0064] Each test unit can form a charge / discharge test system with an independent battery pack. Similarly, each test channel can also form a charge / discharge test system with an independent battery pack. Thus, m test channels can connect to m battery packs, and with n test units, n*m battery packs can be connected. The industrial control equipment 1 can simultaneously test n*m battery packs, which can be of the same type or different types. Each independent channel can be configured with individual charge / discharge parameters, greatly improving testing efficiency and equipment utilization. Furthermore, the first power management module 21 and the second power management module 22 in each test unit can collect operating information from one or more battery packs within the corresponding test unit. This includes collecting the battery pack's current and voltage, and obtaining information such as battery capacity and power.

[0065] like Figure 3 As shown, in one embodiment of this utility model, the first power management module 21 includes a bidirectional buck-boost circuit 211, which is coupled to the power supply and the battery pack.

[0066] The bidirectional buck-boost circuit 211 operates primarily based on switching power supply conversion technology. It includes both boost and buck functions. The bidirectional buck-boost circuit 211 is configured to either step down the power supply voltage to charge the battery pack, or step up the battery pack voltage to absorb electrical energy.

[0067] The bidirectional buck-boost circuit 211 can convert high voltage to low voltage and vice versa. In this embodiment, the high voltage is converted to low voltage to charge the battery pack, and the remaining energy of the battery pack can also be converted to high voltage for storage via the bidirectional buck-boost circuit 211. This allows the remaining energy of the battery pack to be recovered for use by other devices.

[0068] Specifically, the bidirectional buck-boost circuit 211 includes a bidirectional DC-DC converter and a bidirectional AC-DC power supply.

[0069] The bidirectional DC-DC converter employs a bidirectional Buck-Boost converter topology, enabling efficient DC power conversion and bidirectional flow. The bidirectional AC-DC power supply can be used to charge battery packs or as a load to feed energy back into the grid from discharging battery packs.

[0070] In one embodiment, the processor 24 includes a PID controller (i.e., a proportional-integral-derivative controller). The PID controller calculates the proportional (P), integral (I), and derivative (D) values ​​of the system deviation to obtain a control quantity and applies it to the controlled object, so that the system output gradually approaches the set value.

[0071] In the bidirectional buck-boost circuit 211, the main function of the PID controller is to adjust the input voltage or current of the circuit in order to control the output voltage or current to stabilize near the set value.

[0072] When the output voltage or current of the bidirectional buck-boost circuit 211 deviates from the set value, the proportional element of the PID controller will directly adjust the control signal according to the magnitude of the deviation. The larger the deviation, the more the control signal is adjusted to speed up the system response; the smaller the deviation, the less the control signal is adjusted to avoid excessive system oscillation.

[0073] Furthermore, the output terminal of the bidirectional buck-boost circuit 211 is connected to the battery pack through multiple first charging branches. The first charging branches are wire connections that connect the bidirectional buck-boost circuit 211 and the battery pack for transmitting current and voltage.

[0074] The first charging branch is also used for current and voltage sampling. Specifically, at least one resistor is provided in the first charging branch.

[0075] In other embodiments, the output terminal of the bidirectional buck-boost circuit 211 has multiple first charging branches between it and the battery pack, each branch having a different level of resistance, thus forming a bidirectional buck-boost circuit 211 that outputs different current levels.

[0076] The first power management module 21 further includes a first current sampling circuit 212, a first voltage sampling circuit 213, and an analog-to-digital converter 214. The input terminal of the first current sampling circuit 212 is coupled to the first charging branch to collect the current in the first charging branch, and its output terminal is coupled to the analog-to-digital converter 214; the input terminal of the first voltage sampling circuit 213 is coupled to the first charging branch to collect the voltage in the first charging branch, and its output terminal is coupled to the analog-to-digital converter 214; the analog-to-digital converter 214 is configured to convert the current information and voltage information into corresponding digital information.

[0077] The analog-to-digital converter 214 outputs the corresponding digital information to the processor 24 for the processor 24 to make judgments and adjust the bidirectional buck-boost circuit 211 accordingly.

[0078] In one embodiment, both the first current sampling circuit 212 and the first voltage sampling circuit 213 include operational amplifiers. The input of the operational amplifier is used to detect the current and voltage on the first charging branch, and the output is then sent to the analog-to-digital converter 214 for analog-to-digital conversion after amplification by the operational amplifier.

[0079] like Figure 4 As shown, in one embodiment of this utility model, the second power management module 22 includes a signal conditioning circuit 221 and an operational amplifier circuit 222. The output terminal of the signal conditioning circuit 221 is coupled to the operational amplifier circuit 222, and the output terminal of the operational amplifier circuit 222 is used to couple to the battery pack. The input terminal of the signal conditioning circuit 221 is coupled to a current source and a voltage source, and the output terminal of the signal conditioning circuit outputs current and voltage.

[0080] In one embodiment, the operational amplifier circuit 222 includes a power operational amplifier.

[0081] The output of the operational amplifier circuit 222 is used to connect to the battery pack through multiple second charging branches. These second charging branches are used for current and voltage sampling. Specifically, each second charging branch contains at least one resistor.

[0082] In other embodiments, the operational amplifier circuit 222 has multiple second charging branches between itself and the battery pack, each branch having a different level of resistance, thus enabling the operational amplifier circuit 222 to output different current levels.

[0083] The second power management module 22 further includes a second current sampling circuit 223 and a second voltage sampling circuit 224. The input terminal of the second current sampling circuit 223 is coupled to the second charging branch to collect the current in the second charging branch, and the second voltage sampling circuit 224 is coupled to the second charging branch to collect the voltage in the second charging branch.

[0084] In one embodiment, both the second current sampling circuit 223 and the second voltage sampling circuit 224 include operational amplifiers, and the input terminals of the operational amplifiers collect current and voltage through resistors set on the second charging branch.

[0085] The output terminals of the second current sampling circuit 223 and the second voltage sampling circuit 224 are both coupled to the signal conditioning circuit 221, which is used to adjust the output current and output voltage.

[0086] The signal conditioning circuit 221 adjusts both voltage and current, specifically increasing or decreasing the output voltage and current. This adjustment adapts to changes at the battery terminal. When the battery terminal changes, the current is adjusted to keep the output voltage constant, or the voltage is adjusted to keep the output current constant, or both current and voltage are adjusted to simultaneously increase or decrease the current and voltage. This system offers diverse control modes and allows for flexible coordination.

[0087] The signal conditioning circuit 221 is configured to receive a set current Ia and a set voltage Va, and output corresponding current and voltage based on the set current Ia and set voltage Va. This ensures that the output current and output voltage are related to the set current Ia and set voltage Va.

[0088] Here, the current Ia is set to the value of the current source, and the voltage Va is set to the value of the voltage source.

[0089] This invention allows the output current and output voltage to change accordingly by adjusting the values ​​of the set current Ia and the set voltage Va.

[0090] The above implementation method ensures that the current supplied to the battery pack remains stable, or the voltage supplied to the battery pack remains stable. It also allows for rapid detection and adjustment when changes occur at the battery pack.

[0091] The signal conditioning circuit 221 is configured to adjust the output current to achieve constant current output and adjust the output voltage to achieve constant voltage output based on the current value (output current) and voltage value (output voltage) on the second charging branch.

[0092] The constant current output means that a constant current is output, and the constant voltage output means that a constant voltage is output.

[0093] For example, when the control device controls the second power management module 22 to charge the battery pack, it charges based on a set current Ia and a set voltage Va. Specifically, during the charging process, the signal conditioning circuit 221 changes from a constant current output to a constant voltage output. In the initial stage of charging, the battery pack is charged with a constant current, and the voltage at the battery pack terminals increases continuously as charging progresses. When the voltage reaches the set voltage Va, the voltage stops changing, and the current at the battery pack terminals gradually decreases.

[0094] like Figure 5 As shown, in one embodiment, the signal conditioning circuit 221 includes a first operational amplifier A1 and a second operational amplifier A2. The first input terminal of the first operational amplifier A1 receives a set current Ia, the second input terminal of the first operational amplifier A1 receives the output current fed back by the second current sampling circuit 223, and the output terminal of the first operational amplifier A1 is coupled to the operational amplifier circuit 222.

[0095] The first input terminal of the second operational amplifier A2 receives a set voltage Va, the second input terminal of the second operational amplifier A2 receives the output voltage fed back by the second voltage sampling circuit 224, and the output terminal of the second operational amplifier A2 is coupled to the first input terminal of the first operational amplifier A1 through a first switch branch and a second switch branch connected in parallel.

[0096] The first operational amplifier A1 and the second operational amplifier A2 compare the feedback current and voltage with the set current and voltage, thereby making the output voltage approach or equal to the set voltage and the output current approach or equal to the set current. This ensures that the signal conditioning circuit 221 can output stable current and voltage.

[0097] When the output voltage is less than the set voltage Va, the first switch branch is turned on, and the signal conditioning circuit 221 controls the operational amplifier circuit 222 to output a constant current related to the set current Ia value. When the output voltage reaches the set voltage Va, the second switch branch is turned on, and the signal conditioning circuit 221 controls the operational amplifier circuit 222 to output a constant voltage related to the set voltage Va value.

[0098] Thus, during the initial operation of the signal conditioning circuit 221, a constant current output is maintained, and the output voltage is gradually increased. When the output voltage increases to the set voltage Va, the second switch K2 branch is turned on to perform constant voltage output.

[0099] The first switching branch includes a first diode D1 and a first switch K1. The cathode of the first diode D1 is coupled to the output terminal of the second operational amplifier A2, and the anode of the first diode D1 is coupled to the first input terminal of the first operational amplifier A1 through the first switch K1.

[0100] When the first switch K1 is closed, the first switch branch is turned on. At this time, the output terminal of the second operational amplifier A2 cannot output voltage to the second operational amplifier 12. The signal conditioning circuit 1 continuously outputs a stable current, thereby increasing the voltage value at the output terminal, so that the output voltage gradually increases.

[0101] The second switch branch includes a second diode D2 and a second switch K2. The anode of the second diode D2 is coupled to the output terminal of the second operational amplifier A2, and the cathode of the second diode D2 is coupled to the first input terminal of the first operational amplifier A1 through the second switch K2.

[0102] When the output voltage reaches the set voltage Va, the second switch K2 closes and the second switch branch is turned on. At this time, the output terminal of the second operational amplifier A2 outputs the value of the set voltage Va to the first operational amplifier A1, and the signal conditioning circuit 221 outputs a constant voltage.

[0103] Furthermore, a first resistor R1 and a first capacitor C1 are connected in series between the second input terminal and the output terminal of the second operational amplifier A2; a second resistor R2 and a second capacitor C2 are connected in series between the second input terminal and the output terminal of the first operational amplifier A1.

[0104] The first resistor R1 and the first capacitor C1, which are connected in series, as well as the second resistor R2 and the second capacitor C2, which are connected in series, are used to filter and eliminate noise, and improve gain.

[0105] In one embodiment of this invention, in the second current sampling circuit 223, the first and second input terminals of the operational amplifier are respectively connected to the two ends of a resistor in the second charging branch through a third resistor R3 and a fourth resistor R4. This operational amplifier is a high-input-impedance, high-gain instrumentation amplifier, capable of detecting minute voltage differences and ensuring the stability and accuracy of the current output.

[0106] A third capacitor C3 is connected in series between the first and second input terminals of the operational amplifier, and an eighth resistor R8 is connected between the third and fourth input terminals. The eighth resistor R8 is used to configure the gain of the operational amplifier. The third capacitor C3 and the eighth resistor R8 also ensure the stability of the current sampling signal.

[0107] The output of the operational amplifier in the second current sampling circuit 22 is connected to the second input of the first operational amplifier A1 through the fifth resistor R5. The main function of the fifth resistor R5 is to limit the current, and it also helps to reduce the noise of the output signal.

[0108] In one embodiment of this invention, in the second voltage sampling circuit 224, the output terminal of the operational amplifier is connected to the second input terminal of the second operational amplifier A2 via a sixth resistor R6. This operational amplifier, acting as a voltage follower, primarily provides high input impedance and low output impedance to ensure that the voltage feedback signal is not affected by the load. The sixth resistor R6 primarily limits current and also helps reduce noise in the feedback voltage signal.

[0109] In operational amplifier circuit 222, the output terminal of the operational amplifier is connected to the resistor on the second charging branch through the seventh resistor R7, and the first input terminal of the operational amplifier is connected to the output terminal of the first operational amplifier A1 through the ninth resistor R9. This operational amplifier is a high-gain power operational amplifier, and its supply voltage is both positive and negative to improve its dynamic range, thereby ensuring that it can both output and sink current.

[0110] It should be noted that when the operational amplifier circuit 222 absorbs current (absorbs electrical energy, i.e., controls the battery pack to discharge), the signal conditioning circuit 221 switches from constant voltage output to constant current output. That is, the battery pack discharges according to the set voltage Va, and as the output current increases, when the set current Ia is reached, the signal conditioning circuit 221 switches to constant current output.

[0111] The first input terminal of the first operational amplifier A1 receives the set current Ia through the tenth resistor R10. The ninth resistor R9, the tenth resistor R10, the first operational amplifier A1, the second resistor R2, and the second capacitor C2 constitute a current loop conditioning circuit. This circuit can effectively eliminate static errors caused by voltage and current feedback, automatically adjust to cope with load changes and temperature drift, and quickly respond to input changes to maintain stable output voltage and current.

[0112] Thus, the connection using the current-limiting resistor makes the circuit operation safer and more reliable. See the appendix for details. Figure 5 As shown.

[0113] It should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0114] The detailed descriptions listed above are merely specific descriptions of feasible implementations of this utility model, and are not intended to limit the scope of protection of this utility model. All equivalent implementations or modifications made without departing from the spirit of this utility model should be included within the scope of protection of this utility model.

Claims

1. A battery testing device, characterized in that, include: The system includes a control device, a first power management module, and a second power management module. The control device is connected to the first power management module and the second power management module, and the first power management module and the second power management module are connected to the battery pack. The control device is used to control the first power management module and the second power management module to charge and discharge the battery pack. When the current demand of the battery pack is within a first range, the power supply terminal of the first power management module is electrically connected to the input terminal of the battery pack. When the current demand of the battery pack is within a second range, the power supply terminal of the second power management module is electrically connected to the input terminal of the battery pack. The first range is greater than the second range.

2. The battery testing apparatus according to claim 1, characterized in that, The first power management module and the second power management module have multiple charging branches, and each charging branch is equipped with a charging switch. The first power management module and the second power management module are also used to detect the charging current, and the control device is also used to control the opening and closing of the charging switch to adapt to the corresponding charging current.

3. The battery testing apparatus according to claim 1, characterized in that, The battery testing device is configured with n testing units, and each testing unit is configured with m testing channels; Each test unit includes a first power management module and a second power management module.

4. The battery testing apparatus according to claim 1, characterized in that, The first power management module includes a bidirectional buck-boost circuit, which is coupled to the power supply and the battery pack; The bidirectional buck-boost circuit is configured to either step down the voltage of the power supply to charge the battery pack, or step up the voltage of the battery pack to absorb electrical energy.

5. The battery testing apparatus according to claim 4, characterized in that, The bidirectional buck-boost circuit is connected to the battery pack through multiple first charging branches; The first power management module further includes a first current sampling circuit, a first voltage sampling circuit, and an analog-to-digital converter. The input terminal of the first current sampling circuit is coupled to the first charging branch to collect the current in the first charging branch, and its output terminal is coupled to the analog-to-digital converter. The input terminal of the first voltage sampling circuit is coupled to the first charging branch to collect the voltage on the first charging branch, and its output terminal is coupled to the analog-to-digital converter. The analog-to-digital converter is used to convert current and voltage information into corresponding digital information.

6. The battery testing apparatus according to claim 1, characterized in that, The second power management module includes a signal conditioning circuit and an operational amplifier circuit. The output terminal of the signal conditioning circuit is coupled to the operational amplifier circuit, and the output terminal of the operational amplifier circuit is used to couple to the battery pack. The input terminal of the signal conditioning circuit is coupled to a current source and a voltage source, and the output terminal of the signal conditioning circuit outputs current and voltage.

7. The battery testing apparatus according to claim 6, characterized in that, The output of the operational amplifier circuit is used to connect to the battery pack through multiple second charging branches; The second power management module further includes a second current sampling circuit and a second voltage sampling circuit. The input terminal of the second current sampling circuit is coupled to the second charging branch to collect the current in the second charging branch, and the second voltage sampling circuit is coupled to the second charging branch to collect the voltage in the second charging branch. The output terminals of the second current sampling circuit and the second voltage sampling circuit are both coupled to the signal conditioning circuit, which is used to adjust the output current and the output voltage.

8. A battery testing system, characterized in that, The device includes industrial control equipment, communication equipment, and a battery testing device as described in any one of claims 1-7; the industrial control equipment is connected to the communication equipment via a switch, the communication equipment is used to communicate with the battery pack via network signals, and the industrial control equipment is also connected to the battery testing device via a switch.

9. The battery testing system according to claim 8, characterized in that, The control device includes a main controller and a processor. The main controller is electrically connected to the processor, and the processor is electrically connected to the first power management module and the second power management module. The main controller is used to process control signals sent by industrial control equipment; the processor is used to control and adjust the output current and voltage of the first power management module or the second power management module.

10. The battery testing system according to claim 9, characterized in that, The processor is also used to receive the current and voltage of the battery pack collected by the first power management module and the second power management module.

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