WO2022012515A1 - Vehicle storage battery detection method and battery detection device - Google Patents

Abstract

A vehicle storage battery detection method and a battery detection device. The method comprises: determining whether there is a surface charge on a storage battery to be detected (410); if so, controlling said storage battery to discharge according to a first preset discharge condition, so as to eliminate the surface charge from said storage battery (420); and performing battery detection on said storage battery subjected to surface charge elimination, so as to obtain a detection result (430). That is, by means of determining and eliminating a surface charge, rapid and accurate battery detection is realized, such that interference of surface charge can be resisted, and the detection efficiency is high.

Description

A kind of vehicle battery detection method and battery detection equipment

This application claims the priority of the Chinese patent application filed on July 14, 2020 with the application number 202010675907.3 and the application title is "a vehicle battery testing method and battery testing equipment", the entire contents of which are incorporated by reference in this application.

technical field

The present application relates to the field of battery technology, and in particular, to a detection method and battery detection device for a vehicle battery.

Background technique

The nature and structural characteristics of the electrochemical reaction of lead-acid batteries make it easy to generate surface charges during the charging process. The open circuit voltage of batteries with surface charges will increase. This falsely high open circuit voltage is unstable and is not the current battery. the actual voltage. The falsely high open circuit voltage will affect the measurement of battery SoC, CCA and other parameters, and then affect the judgment of battery performance.

For a battery that has just been charged, such as a battery that has just been charged by an external charger, or a battery that has just been turned off in the car, there may be surface charges inside the battery. If the battery is tested immediately at this time, the measurement results will be inaccurate. Affect the judgment of battery quality.

In the process of implementing the embodiments of the present invention, the inventors of the present invention found that: at present, the conventional practice is to require the battery to stand for more than 24 hours before testing, which not only has low testing efficiency, but also cannot completely eliminate the influence of surface charge on testing results.

SUMMARY OF THE INVENTION

The main technical problem solved by the embodiments of the present invention is to provide a vehicle battery detection method and battery detection device, which can resist surface charge interference and have high detection efficiency.

In order to solve the above-mentioned technical problems, the embodiment of the present invention adopts the following technical solutions:

In order to solve the above technical problems, in a first aspect, an embodiment of the present invention provides a detection method for a vehicle battery, including:

Determine whether the battery to be tested has surface charge;

If it exists, the battery to be tested is controlled to discharge according to a first preset discharge condition, so as to eliminate the surface charge of the battery to be tested; wherein, the first preset discharge condition includes continuous discharge at a first preset discharge current discharging a first preset duration to form a discharge cycle, and repeating the discharge cycle according to the interval frequency until the second preset duration;

Perform battery testing on the battery to be tested after removing the surface charge to obtain the testing result.

In some embodiments, the first preset discharge current is greater than a current threshold, and the duration unit of the first preset duration is milliseconds (ms).

In some embodiments, the determining whether the battery to be tested has surface charge includes:

Obtain the initial voltage of the battery to be tested;

Acquiring a discharge voltage of the battery to be tested under a second preset discharge condition; wherein the second preset discharge condition includes discharging at a second preset discharge current for a third preset duration;

obtaining the open-circuit voltage of the battery to be measured after discharge;

According to the initial voltage, the discharge voltage and the open circuit voltage, it is determined whether the battery to be tested has surface charge.

In some embodiments, acquiring the discharge voltage of the battery to be tested under the second preset discharge condition includes:

Collect a plurality of first voltages discharged from the battery to be tested according to a preset first sampling rate;

The discharge voltage is determined to be a minimum value among the plurality of first voltages.

In some embodiments, the method further includes:

Obtain the battery characteristics of the battery to be tested;

The determining whether the battery to be tested has surface charge according to the initial voltage, the discharge voltage and the open-circuit voltage includes:

Determine the voltage drop of the battery to be tested according to the initial voltage and the discharge voltage;

Determine the voltage recovery parameter of the battery to be tested according to the open-circuit voltage and the discharge voltage of the battery to be tested;

According to the battery characteristic, the voltage drop, the voltage recovery parameter and the preset mapping relationship of the battery to be tested, determine whether the battery to be tested has surface charge;

The preset mapping relationship includes a corresponding relationship between battery characteristics and a voltage parameter, the voltage parameter is determined by a voltage parameter obtained from the sampling battery according to the second preset discharge condition, and the voltage parameter includes a voltage drop and a voltage parameter. Voltage recovery parameter, the sampling battery is a battery with no surface charge.

In some embodiments, the battery characteristics include at least one of rated battery capacity, battery type.

In some embodiments, the voltage recovery parameter includes at least one of a voltage recovery slope and a recovery voltage.

In some embodiments, the open-circuit voltage includes collecting a plurality of second voltages after the battery under test is discharged according to a preset second sampling rate within a preset recovery time period;

The determination of the voltage recovery parameter of the battery to be tested according to the open-circuit voltage and the discharge voltage of the battery to be tested includes at least one of the following:

determining the voltage recovery slope of the battery to be tested according to the second voltage, the discharge voltage and the recovery duration corresponding to the second voltage in the middle section of the preset recovery duration;

The recovery voltage is determined according to the maximum value of the plurality of second voltages and the discharge voltage.

In some embodiments, determining whether the battery to be tested has surface charge according to the battery characteristics, the voltage drop, the voltage recovery parameter and the preset mapping relationship of the battery to be tested includes:

determining a voltage parameter corresponding to the battery characteristic in the preset mapping relationship;

determining whether the voltage drop of the battery to be tested is greater than the voltage drop in the voltage parameter;

If yes, determine whether the voltage recovery parameter of the battery to be tested is less than the voltage recovery parameter in the voltage parameters;

If yes, determine that the battery to be tested has surface charge;

Otherwise, it is determined that the battery to be tested has no surface charge.

In some embodiments, the preset mapping relationship includes an initial voltage, a corresponding relationship between battery characteristics and voltage parameters;

The determining whether the battery to be tested has surface charge according to the battery characteristics of the battery to be tested, the voltage drop, the voltage recovery parameter and the preset mapping relationship includes:

determining the voltage parameters corresponding to the initial voltage of the battery to be tested and the battery characteristics in the preset mapping relationship;

determining whether the voltage drop of the battery to be tested is greater than the voltage drop in the voltage parameter;

If yes, determine whether the voltage recovery parameter of the battery to be tested is less than the voltage recovery parameter in the voltage parameters;

If yes, determine that the battery to be tested has surface charge;

Otherwise, it is determined that the battery to be tested has no surface charge.

In order to solve the above technical problems, in a second aspect, an embodiment of the present invention provides a battery detection device, including:

a first connection end, a second connection end, a third connection end and a fourth connection end, wherein the first connection end, the second connection end, the third connection end and the fourth connection end are respectively Used to connect the battery to be tested;

a discharge circuit, electrically connected to the battery to be tested through the first connection end and the fourth connection end, and used to trigger the battery to be tested to discharge under a preset discharge condition;

a voltage sampling circuit, which is electrically connected to the battery to be tested through the second connection terminal and the third connection terminal, and is used to detect the voltage at both ends of the battery to be tested;

A controller is electrically connected to the discharge circuit and the voltage sampling circuit, respectively, and the controller can execute the method described in the first aspect.

In some embodiments, the discharge circuit includes a switch circuit, a load, and a current sampling circuit:

The first end of the switch circuit is connected to the first connection end, the second end of the switch circuit is connected to the controller, and the third end of the switch circuit is connected to the fourth connection end through the load;

The first end of the current sampling circuit is connected to the controller, the second end of the current sampling circuit is connected to the load, and the current sampling circuit is used to detect the discharge current of the battery to be tested;

The controller is specifically used for:

The switch circuit is adjusted according to the magnitude of the discharge current detected by the current sampling circuit, so that the battery to be tested is discharged under the preset discharge condition.

In some embodiments, the switch circuit includes a MOS transistor and a first operational amplifier;

The non-inverting input terminal of the first operational amplifier is connected to the controller, the inverting input terminal of the first operational amplifier is connected to the source of the MOS transistor, and the output terminal of the first operational amplifier is connected to the MOS transistor The gate of the MOS transistor is connected to the first terminal of the load, and the drain of the MOS transistor is connected to the first connection terminal.

In some embodiments, the discharge circuit further includes a diode, a first end of the diode is connected to the first connection end, and a second end of the diode is connected to the drain of the MOS transistor.

In some embodiments, the current sampling circuit includes a second operational amplifier, the non-inverting input terminal of the second operational amplifier is connected to the first terminal of the load, and the inverting input terminal of the second operational amplifier is connected to the The second end of the load, the output end of the second operational amplifier is connected to the controller.

In some embodiments, the voltage sampling circuit includes:

The third operational amplifier, the non-inverting input terminal of the third operational amplifier is connected to the second connection terminal, the inverting input terminal of the third operational amplifier is connected to the third connection terminal, and the output of the third operational amplifier connected to the controller.

Beneficial effects of the embodiments of the present invention: Different from the situation in the prior art, the vehicle battery detection method and battery detection device provided by the embodiments of the present invention determine whether there is surface charge in the battery to be tested, and if so, control the battery to be tested. The battery under test is discharged according to the first preset discharge condition to eliminate the surface charge of the battery under test, and the battery under test after the surface charge has been eliminated is subjected to battery detection to obtain a detection result. That is, by judging and eliminating the surface charge, fast and accurate battery detection can be realized, and the interference of the surface charge can be resisted, and the detection efficiency is high.

Description of drawings

One or more embodiments are exemplified by the pictures in the corresponding drawings, and these exemplifications do not constitute limitations of the embodiments, and elements with the same reference numerals in the drawings are denoted as similar elements, Unless otherwise stated, the figures in the accompanying drawings do not constitute a scale limitation.

1 is a schematic diagram of a circuit structure of a battery detection system according to an embodiment of the present invention;

2 is a schematic flowchart of a method for detecting a vehicle battery according to an embodiment of the present invention;

Fig. 3 is a sub-flow schematic diagram of step 410 in the method shown in Fig. 2;

Fig. 4 is a sub-flow schematic diagram of step 413 in the method shown in Fig. 3;

Fig. 5 is a sub-flow schematic diagram of step 417 in the method shown in Fig. 3;

FIG. 6 is a schematic diagram of a sub-flow of step 4172 in the method shown in FIG. 5;

FIG. 7 is a schematic diagram of a sub-flow of step 4173 in the method shown in FIG. 5;

Fig. 8 is another sub-flow diagram of step 4173 in the method shown in Fig. 5;

9 is a schematic diagram of a circuit structure of a battery detection device provided by an embodiment of the present invention;

10 is a schematic diagram of the circuit structure of the discharge circuit and the voltage sampling circuit shown in FIG. 9;

FIG. 11 is a schematic diagram of circuit connection of a battery detection device according to an embodiment of the present invention.

detailed description

The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the inventive concept. These all belong to the protection scope of the present invention.

In order to make the purpose, technical solutions and advantages of the present application more clearly understood, the present application will be described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application.

It should be noted that, if there is no conflict, various features in the embodiments of the present invention may be combined with each other, which are all within the protection scope of the present application. In addition, although the functional modules are divided in the schematic diagram of the device, and the logical sequence is shown in the flowchart, in some cases, the modules in the device may be divided differently, or the sequence shown in the flowchart may be performed. or the described steps. In addition, the words "first", "second" and "third" used herein do not limit the data and execution order, but only distinguish the same or similar items with substantially the same function and effect.

Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the technical field of the present invention. The terms used in the description of the present invention in this specification are only for the purpose of describing specific embodiments, and are not used to limit the present invention. As used in this specification, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

Please refer to FIG. 1 , which is a schematic diagram of a circuit structure of a battery detection system according to an embodiment of the present invention. As shown in FIG. 1 , the battery testing system 300 includes a battery 200 and a testing device 100 . The testing device 100 is electrically connected to the battery 200 for measuring electrical parameters of the battery 200 .

The storage battery 200 is a device that directly converts chemical energy into electrical energy and realizes recharging through a reversible chemical reaction. That is, during charging, external electrical energy is used to regenerate internal active substances, and electrical energy is stored as chemical energy. Again the chemical energy is converted into electrical output. However, the electrochemical reaction of the battery is relatively slow, and the lead sulfate cannot be quickly converted into lead and lead dioxide during the charging process. This sluggish electrochemical reaction causes most of the charging activity to occur on the plate, resulting in an increase in the external state of charge, forming an artificially high open circuit voltage, which is unstable and not the current real voltage of the battery. That is, the battery has surface charge. When the battery has surface charge, it will affect the measurement of battery SoC, CCA and other parameters, and then affect the judgment of battery performance. Therefore, it is necessary to ensure that there is no surface charge on the storage battery 200 before testing.

The detection device 100 is electrically connected to the battery 200 , for example, the positive and negative electrodes of the battery 200 can be connected through a Kelvin connector 201 . The detection device 100 is used to measure the electrical parameters of the battery 200 . The electrical parameters include basic parameters such as voltage and current, and may also include parameters derived from voltage and current, such as parameters such as SOC and CCA. The detection device 100 obtains the electrical parameters, and combines with a preset algorithm to first determine whether the battery 200 has surface charge, remove the surface charge of the battery 200 with surface charge, and then perform battery detection.

An embodiment of the present invention provides a method for detecting vehicle power storage applied to the detection device 100. The method can be executed by the detection device 100. Please refer to FIG. 2. The method 400 includes:

Step 410 : Determine whether the battery to be tested has surface charge, and if so, go to Step 420 .

Step 420: Control the battery to be tested to discharge according to the first preset discharge condition, so as to eliminate the surface charge of the battery to be tested.

Step 430: Perform a battery test on the battery to be tested after the surface charge has been eliminated to obtain a test result.

First, in step 410, the surface charge is detected, and it can be determined whether there is surface charge according to the electrical parameters of the battery to be tested.

In order to eliminate the surface charge of the battery to be tested, in step 420, the battery to be tested is controlled to discharge according to a first preset discharge condition. Wherein, the first preset discharge condition includes continuously discharging with a first preset discharge current for a first preset duration to form a discharge cycle, and repeating the discharge cycle according to an interval frequency until a second preset duration. For example, take 100A continuous discharge for 100ms as a discharge cycle, repeat the discharge cycle at 1s intervals, and stop the cycle discharge until 5min, or take 120A continuous discharge for 200ms as a discharge cycle, repeat the discharge cycle at 2s intervals, and cycle discharge until 6min. By intermittently discharging a large current for a certain period of time, the surface charge accumulated on the electrode plate of the battery to be tested can be quickly eliminated, so that subsequent discharge can reflect the real condition of the battery to be tested.

In some embodiments, the first preset discharge current is greater than a current threshold, and the current threshold may be set according to the rated parameters of the battery to be tested, by presetting the corresponding relationship between the rated parameters and the current threshold, and combining the rated parameters to determine the the current threshold. For example, when the rated battery capacity of the battery to be tested is larger, the more surface charges it has, a larger current threshold can be used, so that the battery to be tested can run at a first pre-charge greater than the current threshold. By setting the discharge current to discharge, that is, by discharging with a large current, the surface charge can be quickly eliminated, and the discharge time can also be saved, that is, the second preset time period can be shortened or the interval time can be increased.

The first preset duration is the duration of discharge in one discharge cycle. When the first preset discharge current is relatively large, the first preset duration may be relatively short. In some embodiments, the duration unit of the first preset duration is milliseconds (ms), that is, the millisecond level, for example, it may be 100ms, 150ms, or 200ms. In one discharge cycle, the discharge time is short, which can prevent the battery to be tested from generating a large amount of heat, so that no additional heat dissipation device is required during the detection process.

The second preset duration is the total time of intermittent discharge, and its magnitude is related to the actual rated battery capacity. The larger the rated battery capacity, the longer the second preset duration. Therefore, it can be set according to the rated battery capacity of the battery to be tested. On the other hand, if the first preset discharge current is large and/or the interval frequency is small, the second preset duration can be shortened, and if the first preset discharge current is small and/or the interval frequency is large, it needs to be extended the second preset duration. It is worth noting that the interval frequency should be determined in combination with the heat generated during the discharge process of the battery under test, and the interval frequency should be reasonably set so that a small amount of heat is generated when the battery under test is discharged for a single time, which does not affect subsequent detection.

Thus, by continuously discharging the first preset discharge current for a first preset duration to form a discharge cycle, and repeating the discharge cycle according to the interval frequency until the second preset duration, the first preset discharge current, The first preset duration, the interval frequency and the second preset duration can quickly and effectively eliminate the surface charge of the battery to be tested, with less heat generation and high efficiency, without affecting subsequent detection.

After the surface charge of the battery to be tested is eliminated, in step 430, battery detection is performed on the battery to be tested to obtain a detection result. The battery detection refers to collecting electrical parameters of the battery to be tested, including basic parameters such as voltage and current, to obtain detection results, such as state of charge SOC, CCA or state of health, etc., that is, the battery The inspection includes all inspection items in the battery maintenance process. In some embodiments, before the detection, the battery characteristics of the battery to be tested, such as the type of the battery to be tested, rated CCA, rated voltage, etc., need to be input to the detection device 100 to facilitate the acquisition of detection results.

The battery detection is not affected by the surface charge, which improves the battery detection accuracy, and can perform the detection in real time without waiting for the battery to stabilize for a long time.

In this embodiment, it is determined whether the battery to be tested has surface charge, and if so, the battery to be tested is controlled to discharge according to the first preset discharge condition, so as to eliminate the surface charge of the battery to be tested. The battery to be tested after being charged is tested for the battery to obtain the test result. That is, by judging and eliminating the surface charge, fast and accurate battery detection can be realized, and the interference of the surface charge can be resisted, and the detection efficiency is high.

In order to quickly and accurately determine whether the battery to be tested has surface charge, in some embodiments, referring to FIG. 3 , the step 410 specifically includes:

Step 411: Obtain the initial voltage of the battery to be tested.

The initial voltage is the static voltage staticV at both ends of the battery to be tested before discharge, which can be obtained by detecting the voltages at both ends of the positive and negative electrodes when the battery to be tested is in open circuit before discharge (ie, static state). It can be understood that the initial voltage is the open-circuit voltage at both ends collected when the battery to be tested is in a cooling state, so as to avoid the influence of the heat generated by the battery on the initial voltage, thereby making the initial voltage more accurate.

Step 413: Acquire the discharge voltage of the battery to be tested under the second preset discharge condition.

The discharge voltage is the voltage between the positive and negative terminals of the battery to be tested collected during the process of discharging the battery to be tested under the second preset discharge condition.

Wherein, the second preset discharge condition includes discharging with a second preset discharge current for a third preset time period.

The second preset discharge current can be set according to the rated parameter of the battery to be tested, for example, by presetting the corresponding relationship between the rated parameter and the second preset discharge current, combined with the rated parameter, to determine the second preset discharge current. In some embodiments, the second preset discharge current may be determined according to the rated current of the battery to be tested, for example, the preset discharge current is less than the rated current and accounts for a preset percentage of the rated current. If the rated current is relatively high, the preset percentage can be reduced to reduce the heat generated by the discharge of the battery under test. It can be understood that the second preset discharge current can also be manually set according to historical experience values. For example, the preset discharge current is a large current such as 30A, 40A, or 50A. Different currents have different anti-noise capabilities. Noise needs to be set by yourself.

In addition, in order to stabilize the second preset discharge current to a preset value, a preset value of the second preset discharge current is set in the detection device 100, and the preset value of the second preset discharge current is The current-voltage signal relationship table in the detection device 100 outputs a voltage signal to control the discharge current of the battery under test to be equal to the second preset discharge current, that is, the relationship between the detection device 100 and the battery under test 200. The current of the discharge loop is equal to the second preset discharge current.

The third preset duration refers to the duration during which the battery to be tested is discharged at the second preset discharge current. The second preset discharge current is a large current, and the third preset duration is short. In some embodiments, the third preset duration is in the millisecond level, such as 50ms, 100ms, 150ms, 200ms, or 500ms. In order to prevent the collection of the discharge voltage from being disturbed by the start-up of the battery to be tested, in some embodiments, the third preset duration is greater than or equal to 50 ms, so that after the battery to be tested is discharged stably, the The above-mentioned discharge voltage is collected, and no error will be caused by the short discharge time. In addition, the discharge time lasts for milliseconds. On the one hand, it saves the detection time, and can quickly determine whether the battery to be tested has surface charge, which improves the detection efficiency. On the other hand, the short discharge time can avoid the occurrence of the battery to be tested. A large amount of heat, so that no additional heat sinks are required during the detection process.

In order to make the discharge voltage more accurate and suitable, in some embodiments, referring to FIG. 4 , the step 413 specifically includes:

Step 4131: Collect a plurality of first voltages discharged from the battery under test according to a preset first sampling rate.

Step 4132: Determine that the discharge voltage is the minimum value among the plurality of first voltages.

The plurality of first voltages are obtained by sampling the discharge voltages in a third preset time period during which the battery under test is discharged at a first sampling rate. For example, within a third preset duration of 50ms when the battery to be tested is discharged, 50 first voltages are collected at a first sampling rate of 1ms, and the minimum value minV1 of the 50 first voltages is used as the discharge voltage. It can be understood that determining the discharge voltage to be the minimum value among the plurality of first voltages is to facilitate subsequent evaluation of the voltage recovery of the battery to be tested, so as to prevent abnormally large discharge voltages from causing voltage recovery. The situation interferes and affects judgment.

Specifically, the third preset duration is accumulated by means of a timer, and when the discharge time of the battery to be tested reaches the third preset duration, the timer reaches a set stop threshold and triggers the The battery under test stops discharging. During the third preset time period, that is, during the discharge process of the battery to be tested, counting is performed at the preset first sampling rate by means of a counter, for example, the number of samplings is performed once every the preset first sampling rate. , until the counter reaches the stop threshold set in the timer, stop sampling. In some embodiments, before starting the timer and the counter, the method further includes: initializing the detection device 100 .

In this embodiment, by collecting a plurality of first voltages within a third preset time period of discharge of the battery to be tested, and using the minimum value of the plurality of first voltages as the discharge voltage, it is convenient for subsequent accurate Evaluate the voltage recovery situation of the battery to be tested, so as to prevent abnormally large discharge voltage from interfering with the voltage recovery situation and affecting judgment.

Step 415: Obtain the open circuit voltage of the battery to be tested after discharge.

The open circuit voltage is the voltage across the positive and negative terminals of the battery to be tested collected after the battery to be tested is discharged under the second preset discharge condition. It can be understood that, in some embodiments, the open-circuit voltage may be collected at a preset second sampling rate within a preset recovery period after the discharge is stopped, that is, the open-circuit voltage is included in the preset recovery period. A plurality of second voltages after the battery under test is discharged are collected according to the preset second sampling rate within a time period. For example, within 500ms (preset recovery time) after the battery to be tested stops discharging, 50 pieces of the second voltage are collected at a second sampling rate of 10ms. It is worth noting that, in order to meet the characteristics of voltage recovery after battery discharge, the preset recovery time can be greater than or equal to 100ms, so that the battery to be tested has sufficient recovery time, the preset recovery time should be less than 1min, In order to prevent the collected second voltages (open circuit voltages) as voltages after excessive recovery, the open circuit voltages are more accurate.

In this embodiment, by collecting a plurality of second voltages after the battery under test is discharged, the open circuit voltage includes a plurality of second voltages, which is beneficial for subsequent accurate evaluation of the voltage recovery of the battery under test.

Step 417: According to the initial voltage, the discharge voltage and the open circuit voltage, determine whether the battery to be tested has surface charge.

According to the initial voltage, the discharge voltage and the open-circuit voltage, the discharge condition and voltage recovery condition of the battery to be tested can be determined. Since the battery with surface charge has an artificially high open-circuit voltage, its discharge and voltage recovery will be different from those of the battery without surface charge. Therefore, according to the discharge and voltage recovery of the battery under test, the Whether the battery to be tested has surface charge. That is, whether there is a surface charge is determined from the two aspects of the discharge condition and the voltage recovery condition, which makes the judgment more accurate and reduces misjudgments and missed judgments.

In some embodiments, the method 410 further includes:

Step 412: Acquire the battery characteristics of the battery to be tested.

The battery characteristics refer to the unique properties of the battery, such as factory parameters, rated parameters (such as rated voltage) of the battery, and the like. In some embodiments, the battery characteristics include at least one of rated battery capacity, battery type. For example, when the battery feature includes a battery type, the battery feature may be an AGM-type battery, an EFB-type battery, or a Flooded-type battery. When the battery characteristic includes a rated battery capacity, the rated battery capacity may be a capacity interval or a capacity representative value, such as 150Ah, 140Ah, 130Ah, 120Ah, and the like. When the battery characteristics include battery type and rated battery capacity, the battery characteristics are the combination of the battery type and the rated battery capacity, for example, 150Ah, 140Ah, 130Ah, 120Ah AGM type batteries, and so on. specific properties of .

Based on the battery characteristics, in some embodiments, referring to FIG. 5 , the step 417 specifically includes:

Step 4171: Determine the voltage drop of the battery under test according to the initial voltage and the discharge voltage.

The voltage drop deltaV of the battery to be tested is the difference between the initial voltage staticV and the discharge voltage. It can be understood that, the discharge voltage may be the minimum value minV1 among the above-mentioned multiple first voltages, that is, deltaV=staticV−minV1, so that the maximum voltage drop deltaV can be obtained.

Step 4172: Determine the voltage recovery parameter of the battery to be tested according to the open circuit voltage and the discharge voltage of the battery to be tested.

The voltage recovery parameter is a parameter representing the voltage recovery condition of the battery after discharge, such as the speed of voltage recovery and the degree of voltage recovery. According to the open-circuit voltage (voltage at both ends after discharge) and the discharge voltage of the battery to be measured, the speed of voltage recovery and the degree of voltage recovery (voltage recovery parameter) of the battery to be measured can be determined.

In some embodiments, the voltage recovery parameter includes at least one of a voltage recovery slope and a recovery voltage. That is, the voltage recovery slope of the battery after discharge can be used to represent the voltage recovery situation of the battery. In this embodiment, the voltage recovery situation after the battery discharge is characterized by the speed of the voltage recovery. The recovery voltage can also be used to characterize the voltage recovery after the battery is discharged. In this embodiment, the voltage recovery after the battery is discharged is represented by the degree of voltage recovery. It can be understood that, in some embodiments, the voltage recovery slope and the recovery voltage can also be used to simultaneously characterize the voltage recovery after the battery is discharged.

In order to determine the voltage recovery slope and/or the recovery voltage, in some embodiments, referring to FIG. 6 , the step 4172 includes at least one of the following steps 41721 and 41722:

Step 41721: Determine the voltage recovery slope of the battery to be tested according to the second voltage, the discharge voltage and the recovery duration corresponding to the second voltage in the middle section of the preset recovery duration.

The second voltage located in the middle section of the preset recovery period refers to a voltage across both ends that is collected after the discharge of the battery to be tested stops and is located in the middle section of the preset recovery period. The middle section of the preset recovery duration refers to the time period after the recovery for a certain period of time to the end of the recovery. The recovery time period corresponding to the second voltage refers to the time difference between the time when the second voltage is collected and the time when the discharge is terminated.

For example, when the preset recovery period is 500ms, the second voltage may be selected within a period of 20%-80% of the preset recovery period to determine the voltage recovery slope. For example, taking the second voltage corresponding to 100ms after the discharge is stopped, the difference between the second voltage and the discharge voltage when the voltage recovery slope s is 100ms is longer than the recovery time (100ms) corresponding to the second voltage, that is, the voltage recovery Slope s=(second voltage at 100ms-discharge voltage minV1)/100. It can be understood that the range of the middle section can also be 30%-70%, and the specific range can be determined according to the actual discharge situation. It can be determined that the battery is in the voltage recovery period within the middle section.

In this embodiment, by taking the second voltage in the middle section and calculating the recovery slope, it can be further determined that the second voltage is the voltage in the voltage recovery period, so that the recovery slope is more accurate, and the recovery slope is avoided due to the voltage recovery period. Error caused by unstable voltage recovery of the front and rear segments.

Step 41722: Determine the recovery voltage according to the maximum value of the plurality of second voltages and the discharge voltage.

The recovery voltage refers to the recovery value relative to the discharge voltage after the discharge ends, that is, the difference between the voltage after the discharge and the discharge voltage. The difference between the maximum value maxV2 of the plurality of second voltages and the discharge voltage is used as the recovery voltage to characterize the degree of recovery of the voltage. It can be understood that, in order to make the recovery voltage more accurate, the discharge voltage is the minimum value minV1 among the plurality of first voltages, and the maximum recovery voltage maxV can be obtained, that is, maxV=(maxV2-minV1). It can be understood that, according to the battery voltage recovery feature, within the preset recovery time period, as the recovery time increases, the second voltage is also larger, so that the maximum value maxV2 among the plurality of second voltages can be is the second voltage when the preset recovery duration is cut off, for example, when the preset recovery duration is 500ms, the maxV2 is the second voltage at 500ms.

In this embodiment, taking the maximum value of the plurality of second voltages and calculating the recovery voltage can make the recovery voltage more accurate, so as to prevent errors caused by different battery voltage recovery rhythms. For example, some batteries recover quickly in the early stage of recovery and slow in the later stage of recovery. Some batteries may recover slowly in the early stage of recovery and fast in the later stage of recovery. If the second voltage corresponding to a certain recovery time is taken, it will bring errors and cannot The voltage recovery of the battery can be truly reflected, and the maximum value maxV2 among the plurality of second voltages is used to avoid this error and to accurately reflect the voltage recovery of the battery.

Step 4173: Determine whether the battery to be tested has surface charge according to the battery characteristics, the voltage drop, the voltage recovery parameter and the preset mapping relationship of the battery to be tested.

Wherein, the preset mapping relationship is established in advance, and the preset mapping relationship includes a corresponding relationship between battery characteristics and voltage parameters, and the voltage parameters are determined by voltage parameters obtained from the sampling battery according to the preset discharge conditions , the voltage parameters include voltage drop and voltage recovery parameters, and the sampling battery is a battery without surface charge.

In the preset mapping relationship, each battery feature has a corresponding relationship with a voltage parameter. For example, when the battery feature includes a rated battery capacity, batteries with rated battery capacities such as 150Ah, 140Ah, 130Ah, and 120Ah have corresponding voltage parameters. Therefore, when the battery characteristics of the battery to be tested are determined, and the battery characteristics corresponding to the battery characteristics of the battery to be tested are searched in the preset mapping relationship, corresponding voltage parameters can be obtained.

The voltage parameter is determined by a voltage parameter obtained by the sampling battery according to the preset discharge condition, the voltage parameter includes a voltage drop and a voltage recovery parameter, and the sampling battery is a battery without surface charge. The sampling battery has no surface charge, and its voltage parameter can be used as a reference for judgment. It can be understood that, before collecting the voltage parameter of the sampling battery, the operation of eliminating the surface charge can be performed on the sampling battery, so as to ensure that the sampling battery does not have surface charge, so that the voltage parameter can be judged. reference.

When constructing the preset mapping relationship, the sampling battery is classified according to the battery characteristics, and the initial voltage, discharge voltage, and open-circuit voltage after discharge of the sampling battery can be obtained according to steps 411 to 415 , and according to steps 4171 and 415 4172. Calculate the voltage parameters (voltage drop and voltage recovery parameters) of the sampling battery, and record the voltage parameters of the sampling battery in the preset mapping relationship.

Therefore, in the mapped relationship, after obtaining the voltage parameters (voltage drop and voltage recovery parameters) corresponding to the battery characteristics of the battery to be tested, the voltage drop and voltage recovery parameters of the battery to be tested can be compared with the corresponding voltage drop and voltage recovery parameters. The voltage drop and voltage recovery parameters are compared and analyzed to determine whether the battery to be tested has surface charge.

In this embodiment, for each battery feature, according to the voltage drop of the battery to be tested, the voltage recovery parameter and the voltage drop and voltage recovery parameter of the corresponding sampling battery without surface charge, it can be quickly and accurately Determine whether the battery under test has surface charge.

Specifically, in some embodiments, referring to FIG. 7 , the step 4173 further includes:

Step 41731a: Determine the voltage parameters corresponding to the battery characteristics in the preset mapping relationship.

Through the matching of battery characteristics, the voltage parameters corresponding to the battery characteristics of the battery to be tested are found in the preset mapping relationship, and the voltage parameters include voltage drop and voltage recovery parameters. Corresponding voltage drop and voltage recovery parameters.

Step 41732a: Determine whether the voltage drop of the battery to be tested is greater than the voltage drop in the voltage parameter, and if so, go to Step 41733a.

Step 41733a: determine whether the voltage recovery parameter of the battery to be tested is smaller than the voltage recovery parameter in the voltage parameters, if yes, perform step 41734a, otherwise, perform step 41735a.

Step 41734a: It is then determined that the battery to be tested has surface charge.

Step 41735a: It is determined that the battery to be tested has no surface charge.

If the voltage drop of the battery to be tested is greater than the voltage drop in the voltage parameter, it means that the battery to be tested has a relatively high initial voltage, which may be an artificially high initial voltage. Judgment is to determine whether the voltage recovery parameter of the battery to be tested is smaller than the voltage recovery parameter in the voltage parameters. If the voltage recovery parameter of the battery under test is smaller than the voltage recovery parameter in the voltage parameters, that is, the voltage recovery slope is smaller than the voltage recovery slope of the corresponding sampling battery, it means that the voltage recovery of the battery under test is slow and/or, the recovery If the voltage is lower than the recovery voltage of the corresponding sampling battery, it indicates that the voltage recovery degree is low, so that it can be determined that the battery to be tested has surface charge; otherwise, it is determined that the battery to be tested has no surface charge.

In this embodiment, the voltage drop and voltage recovery parameters of the battery to be tested are determined by controlling the battery to be tested to discharge under preset discharge conditions, and then, according to the battery characteristics, voltage drop, and voltage of the battery to be tested By restoring the parameters and the preset mapping relationship, it is possible to quickly and accurately determine whether the battery to be tested has surface charge, which is beneficial to the accuracy of the later detection of the battery. That is, whether there is a surface charge is determined from the two aspects of the discharge condition and the voltage recovery condition, which makes the judgment more accurate and reduces misjudgments and missed judgments.

In order to make the preset mapping relationship more accurate, considering the influence of the initial voltage of the battery on the voltage parameter, in some embodiments, the preset mapping relationship includes the corresponding relationship between the initial voltage, battery characteristics and voltage parameters. As shown in Table 1, which shows a method of the preset mapping relationship, sampling batteries are selected at intervals of 10Ah, the rated voltage of the sampling batteries is 12V, and within the range of the test voltage 8V-13.1V, Take 0.5V as an interval to select the test voltage, under a test voltage, according to steps 411-415, measure the initial voltage, discharge voltage and open-circuit voltage under the test voltage, according to steps 4171 and 4172, calculate and obtain the voltage parameter ( Voltage drop deltaV, voltage recovery slope s and recovery voltage maxV) and recorded. For example, for a sampling battery with a battery characteristic of 150Ah, first discharge it to 8V, according to steps 411 to 415, measure the initial voltage, discharge voltage and open circuit voltage under the test voltage, according to steps 4171 and 4172, calculate and obtain the voltage parameters ( Voltage drop deltaV, voltage recovery slope s and recovery voltage maxV) and record, and then perform constant current charging, so that the sampling battery voltage rises to the next test voltage (for example, 8.5V), repeat the above operation immediately, and record the test voltage. Voltage parameters (voltage drop deltaV, voltage recovery slope s and recovery voltage maxV). By analogy, for different battery characteristics, the establishment of the preset mapping relationship is completed in the same manner as described above.

Table 1 Default mapping relationship

It is worth noting that the interval can also be other values, such as 0.3V, 0.4V, or 0.6V, etc., which can be artificially set according to actual experience. The test voltage range may also be other interval values, such as 20V-25V, etc., which may be determined according to the rated voltage of the sampling battery.

It should be noted that, in the preset mapping relationship, the voltage recovery parameter only needs to include at least one of the voltage recovery slope s and the recovery voltage maxV, and the preset mapping relationship in Table 1 is only an exemplary illustration.

In this embodiment, referring to FIG. 8 , the step 4173 specifically includes:

Step 41731b: Determine the voltage parameters corresponding to the initial voltage of the battery to be tested and the battery characteristics in the preset mapping relationship.

By matching the initial voltage and the battery characteristics, the voltage parameters corresponding to the initial voltage and the battery characteristics are found in the preset mapping relationship. For example, if the initial voltage of the battery to be tested is 12.3V and the rated capacity of the battery is 150Ah, the initial voltage of 12.3V is positioned to the voltage range [12.0, 12.5), that is, the third row in Table 1, the rated capacity of the battery is 150Ah Locate to columns 5-7 in Table 1, where the corresponding voltage parameters (deltaV0, s0, maxV0) are recorded in sequence in columns 5-7 in the table.

Step 41732b: Determine whether the voltage drop of the battery to be tested is greater than the voltage drop in the voltage parameter, and if so, go to Step 4733b.

Step 41733b: determine whether the voltage recovery parameter of the battery to be tested is smaller than the voltage recovery parameter in the voltage parameters, if yes, execute step 41734b, otherwise, execute step 41735b.

Step 41734b: determine that the battery to be tested has surface charge.

Step 41735b: It is determined that the battery to be tested has no surface charge.

If the voltage drop of the battery to be tested is greater than the voltage drop in the voltage parameter, it means that the battery to be tested has a relatively high initial voltage, which may be an artificially high initial voltage. Judgment is to determine whether the voltage recovery parameter of the battery to be tested is smaller than the voltage recovery parameter in the voltage parameters. If the voltage recovery parameter of the battery under test is smaller than the voltage recovery parameter in the voltage parameters, that is, the voltage recovery slope is smaller than the voltage recovery slope of the corresponding sampling battery, it means that the voltage recovery of the battery under test is slow and/or, the recovery If the voltage is lower than the recovery voltage of the corresponding sampling battery, it indicates that the voltage recovery degree is low, so that it can be determined that the battery to be tested has surface charge; otherwise, it is determined that the battery to be tested has no surface charge.

For example, in the example of step 41731b, compare the voltage drop deltaV0 of the battery under test with the corresponding deltaV, and when deltaV0<deltaV, compare the voltage recovery slope s0 of the battery under test with the corresponding s , and/or, compare the recovery voltage maxV0 of the battery to be tested with the corresponding maxV, if s0<s and/or maxV0<maxV, then determine that the battery to be tested has surface charge, otherwise, determine that the battery to be tested has surface charge The battery to be tested has no surface charge.

In this embodiment, the voltage drop and voltage recovery parameters of the battery to be tested are determined by controlling the battery to be tested to discharge under preset discharge conditions, and then, according to the battery characteristics, initial voltage, voltage of the battery to be tested Drop, voltage recovery parameters and preset mapping relationship can quickly and accurately determine whether the battery to be tested has surface charge, which is beneficial to the accuracy of the later detection of the battery. That is, based on the characteristics of the battery and the initial voltage, it is determined from the two aspects of the discharge condition and the voltage recovery condition whether there is a surface charge, which makes the judgment more accurate and reduces misjudgments and missed judgments.

In the detection method of the vehicle battery in the embodiment of the present invention, the surface charge of the battery to be tested is detected and eliminated, and then the battery is detected. Therefore, it is applicable to any suitable detection device that can detect and eliminate surface charges, for example, the battery detection device in the following embodiments of the present invention.

Please refer to FIG. 9 , which is a schematic diagram of a circuit structure of a battery detection device according to an embodiment of the present invention. As shown in FIG. 9 , the battery detection device 100 is electrically connected to the battery to be tested 200 , and the battery detection device 100 includes a discharge circuit 10 , a voltage sampling circuit 20 and a controller 30 .

As shown in FIG. 10 , the battery detection device 100 includes a first connection end 101 , a second connection end 102 , a third connection end 103 and a fourth connection end 104 , the first connection end 101 , the second connection end 101 , the second connection end 104 The terminal 102 , the third connection terminal 103 and the fourth connection terminal 104 are respectively used to connect the battery to be tested. In this embodiment, the first connection end 101 and the second connection end 102 are both electrically connected to the positive electrode of the battery under test 200 , and the third connection end 103 and the fourth connection end 104 are both electrically connected It is electrically connected to the negative electrode of the battery to be tested 200 . In some embodiments, the first connection end 101 , the second connection end 102 , the third connection end 103 and the fourth connection end 104 can also be Kelvin connectors, that is, the battery testing device 100 passes through the Kelvin connectors. The connector electrically connects the battery under test 200 , which can eliminate wiring, and eliminate resistance generated by contact connection when current flows through the positive or negative electrode of the battery under test 100 .

For the above-mentioned discharge circuit 10, the battery under test 200 is electrically connected through the first connection end 101 and the fourth connection end 104, so as to trigger the battery under test 200 to discharge. When the discharge circuit 10 is in an on state, the discharge circuit 10 and the battery to be tested 200 form a discharge loop, triggering the battery to be tested 100 to discharge.

In some of the embodiments, please refer to FIG. 10 , the discharge circuit 10 includes a switch circuit 11 , a load 12 and a current sampling circuit 13 .

The first end of the switch circuit 11 is connected to the first connection end 104 , the second end of the switch circuit 11 is connected to the controller 30 , and the third end of the switch circuit 11 is connected to the controller 30 through the load 12 . The fourth connection terminal 104 is used to close or open the discharge circuit between the switch circuit 11, the load 12 and the battery to be tested 200 according to the voltage signal sent by the controller 30, and to adjust the The degree of conduction of the discharge circuit.

The first end of the current sampling circuit 13 is connected to the controller 30 , the second end of the current sampling circuit 13 is connected to the load 12 , and the current sampling circuit 13 is used to detect the switch circuit 11 and the load 12 The current in the discharge loop formed with the battery to be tested 200 is the discharge current of the battery to be tested 200 .

The controller 30 adjusts the switch circuit 11 according to the magnitude of the discharge current detected by the current sampling circuit 20, so that the battery to be tested 200 is discharged under the second preset discharge condition, wherein the first The two preset discharge conditions include discharging the battery under test 200 for a third preset time period according to a second preset discharge current.

In some embodiments, please refer to FIG. 11 , the switch circuit 11 includes a MOS transistor Q and a first operational amplifier U1 , and the non-inverting input end of the first operational amplifier U1 is connected to the controller 30 (the DAC port of the microcontroller U4 ) ), the inverting input terminal of the first operational amplifier U1 is connected to the source of the MOS transistor Q, the output terminal of the first operational amplifier U1 is connected to the gate of the MOS transistor Q, the The source is connected to the first terminal of the load 12 , and the drain of the MOS transistor Q is connected to the first connection terminal 101 . The second end of the load 12 is connected to the fourth connection end 104 , and the fourth connection end 104 is electrically connected to the negative electrode of the battery under test 200 .

When the MOS transistor Q is disconnected, the voltage of the first terminal of the load 12 and the source voltage of the MOS transistor Q are both the negative voltage of the battery to be tested 200, that is, the first operation The negative voltage is input to the inverting input terminal of the amplifier U1. When the controller 30 sends a first voltage signal to the non-inverting input terminal of the first operational amplifier U1, the first operational amplifier U1 processes the first voltage signal and the negative voltage, and outputs a first The driving signal is sent to the gate of the MOS transistor Q, so that a voltage difference VGS is formed between the gate and the source of the MOS transistor Q. Wherein, the magnitude of the first driving signal is related to the magnitude of the first voltage signal. By adjusting the first voltage signal, the first driving signal is further adjusted, so that when the voltage difference VGS is greater than the turn-on voltage of the MOS transistor Q, the MOS transistor Q is turned on, and the discharge loop generates a current , that is, the battery under test 200 starts to discharge.

When the MOS transistor Q is turned on, the discharge current flows through the load 12 , and the voltage of the first end of the load 12 increases, that is, the voltage of the first end of the load 12 is equivalent to the voltage of the load 12 . The voltage drop value of the load 12 is sent to the inverting input terminal of the first operational amplifier U1 as a voltage drop signal. Due to the negative feedback effect of the first operational amplifier U1, after processing the first voltage signal and the voltage drop signal, the first operational amplifier U1 will output a stable second driving signal to the The gate of the MOS transistor Q. Under the action of the stable second driving signal, the conduction degree of the MOS transistor Q is certain, and the internal resistance of the channel of the MOS transistor Q is stable, so that the discharge current in the discharge loop can be ensured to be stable. In addition, the magnitude of the second driving signal is related to the magnitude of the first voltage signal sent by the controller 30, so that by adjusting the first voltage signal sent by the controller 30, the stability of the corresponding magnitude can be obtained. The discharge current is obtained, that is, the second preset discharge current is obtained.

In some embodiments, the load 12 includes a resistor, a first terminal of the resistor is electrically connected to the source of the MOS transistor Q, and a second terminal of the resistor is electrically connected to the fourth connection terminal 104 . The resistance value of the resistor can be set according to the actual situation, for example, the resistance value of the resistor is 10 mΩ, so that the discharge current of the battery to be tested 200 can be a large current.

In some embodiments, the current sampling circuit 13 includes a second operational amplifier U2, the non-inverting input terminal of the second operational amplifier U2 is connected to the first terminal of the load 12, and the inverting phase of the second operational amplifier U2 The input terminal is connected to the second terminal of the load 12, and the output terminal of the second operational amplifier U2 is connected to the controller. Therefore, the voltage of the first terminal of the load 12 is input to the non-inverting terminal of the second operational amplifier U2, and the voltage of the second terminal of the load 12 is input to the inverting terminal of the second operational amplifier U2. After processing by the operational amplifier U2, the voltage across the load 12 is obtained and sent to the controller 30, and the controller 30 can determine the flow through the The current of the load 12 is the discharge current in the discharge circuit.

In some embodiments, the discharge circuit 10 further includes a diode D1, a first end of the diode D1 is connected to the first connection end 101, and a second end of the diode D1 is connected to the The drain of the MOS transistor Q, the diode D1 is used to prevent the discharge current from flowing back into the battery under test 200 . When the first connection terminal 101 is connected to the positive electrode of the battery to be tested 200, the anode of the diode D1 is connected to the first connection terminal 101, and the cathode of the diode D1 is connected to the MOS transistor The drain of Q uses the unidirectional conductivity of the diode D1, so that in the discharge circuit, the discharge current always flows from the positive electrode of the battery to be tested 200 through the MOS transistor Q and the load 12, and finally flows back to The negative electrode of the battery to be tested 200 prevents current from flowing backwards and burns the battery to be tested 200 .

For the above-mentioned voltage sampling circuit 20 , the battery under test 200 is electrically connected through the second connection end 102 and the third connection end 103 for detecting the voltage across the battery under test 200 . When the discharge circuit 10 is in the disconnected state, the voltage at both ends of the battery under test 200 collected by the voltage sampling circuit 20 is an open-circuit voltage; when the discharge circuit 10 is in the connected state, the battery under test is in the open state. 200 is discharged, and the voltage at both ends of the battery to be tested 200 collected by the voltage sampling circuit 20 is the discharge voltage.

In some embodiments, the voltage sampling circuit 20 includes a third operational amplifier U3, the non-inverting input terminal of the third operational amplifier U3 is connected to the second connection terminal 102, and the inverting input terminal of the third operational amplifier U3 The terminal is connected to the third connection terminal 103 , and the output terminal of the third operational amplifier U3 is connected to the controller 30 . In this embodiment, the second connection end 102 is connected to the positive electrode of the battery to be tested 200 , and the third connection end 103 is connected to the negative electrode of the battery to be tested 200 , then the third operational amplifier U3 collects the The voltage is the voltage across the battery 200 to be tested.

The above-mentioned controller 30 is electrically connected to the discharge circuit 10 and the voltage sampling circuit 20, respectively, and the controller 30 is configured to execute the method for detecting a vehicle battery in any of the above-mentioned method embodiments.

As shown in FIG. 11 , the controller 30 includes a single-chip microcomputer U4, which can be 51 series, Arduino series, STM32 series, etc. The single-chip microcomputer U4 includes a DAC port, an ADC1 port, and an ADC2 port. The DAC port of the single-chip microcomputer U4 is electrically connected to the non-inverting input terminal of the first operational amplifier U1, the ADC1 port of the single-chip microcomputer U4 is electrically connected to the output terminal of the second operational amplifier U2, and the ADC2 port of the single-chip microcomputer U4 is electrically connected to the third operational amplifier. The output terminal of the amplifier U3 is electrically connected.

In other embodiments, the controller 30 may also be a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), an ARM (Acorn RISC Machine) or other Programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination of these components; can also be any conventional processor, controller, microcontroller, or state machine; can also be implemented as a combination of computing devices, For example, a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors combined with a DSP core, or any other such configuration.

To sum up, the working process of the battery detection device 100 is as follows:

(1) When the discharge circuit 10 is disconnected and the battery to be tested 200 is not discharged, the third operational amplifier U3 performs signal processing on the voltage at both ends of the battery to be tested 200 to obtain the battery to be tested 200 initial voltage.

(2) The DAC port of the single-chip microcomputer U4 outputs the first voltage signal to the non-inverting input terminal of the first operational amplifier U1, and the source voltage of the MOS transistor Q is input to the inverting input terminal of the first operational amplifier U1. , the source voltage of the MOS transistor Q is the negative electrode voltage of the battery to be tested 200 . The first operational amplifier U1 performs signal processing on the first voltage signal input at the non-inverting input terminal and the negative voltage input at the inverting input terminal to obtain a first driving signal, the magnitude of which is the same as that of the first voltage. the size of the signal. The first driving signal acts on the gate of the MOS transistor Q, so that a voltage difference VGS is formed between the gate and the source of the MOS transistor Q. By adjusting the voltage signal, the first driving signal is further adjusted, so that when the voltage difference VGS is greater than or equal to the turn-on voltage of the MOS transistor Q, the MOS transistor Q is turned on, and the discharge loop generates a current , that is, the battery under test 200 starts to discharge.

When the MOS transistor Q is turned on, the discharge current flows through the load 12 , and the voltage of the first end of the load 12 increases, that is, the voltage of the first end of the load 12 is equivalent to the voltage of the load 12 . The voltage drop value of the load 12 is sent to the inverting input terminal of the first operational amplifier U1 as a voltage drop signal. Due to the negative feedback effect of the first operational amplifier U1, after processing the voltage signal and the voltage drop signal, the first operational amplifier U1 will output a stable second driving signal to the MOS transistor Q's gate. Under the action of the stable second drive signal, the battery to be tested 200 is discharged with a stable discharge current, wherein the magnitude of the discharge current is related to the magnitude of the second drive signal, and further, the discharge current The magnitude of is related to the first voltage signal input by the controller 30 . Therefore, by adjusting the first voltage signal, the battery to be tested 200 can be discharged for a third preset time period according to the second preset discharge current.

When the battery under test 200 is discharged at the second preset discharge current, the battery under test 200 generates a discharge voltage. The third operational amplifier U3 performs signal processing on the discharge voltage to obtain the discharge voltage, and sends the discharge voltage to the ADC2 port of the microcontroller U4.

When the discharge time reaches the third preset duration, stop outputting the voltage signal or adjust the voltage signal, so that the voltage difference VGS between the gate and the source of the MOS transistor Q is smaller than the MOS transistor Q The turn-on voltage of the MOS transistor Q is turned off, and the discharge circuit of the battery under test 200 is cut off, and the battery under test 200 stops discharging.

(3) After the battery under test 200 stops discharging, the third operational amplifier U3 performs signal processing on the voltage across the battery under test 200 to obtain the open circuit voltage of the battery under test 200 after discharge.

(4) The single-chip microcomputer U4 determines whether the battery to be tested has surface charge according to the initial voltage, the discharge voltage and the open-circuit voltage.

(5) If there is, the DAC port of the single-chip microcomputer U4 outputs a second voltage signal to the first operational amplifier U1, and referring to step (2), a corresponding third driving signal is generated, so that the MOS transistor is turned on , the second voltage signal is adjusted to output a stable fourth drive signal, so that the battery to be tested 200 continues to discharge for a first preset duration at a stable first preset discharge current.

(6) Repeat the step (5) according to the interval frequency until the second preset time period, thereby eliminating the surface charge of the battery to be tested.

(7) The single-chip microcomputer U4 controls the discharge circuit and the voltage sampling circuit to detect the battery to be tested to obtain a detection result.

The battery detection device further includes a memory, or a memory is integrated in the controller, and the memory is a non-volatile computer-readable storage medium, which can be used to store non-volatile software programs, non-volatile computer Programs and modules are executed, such as program instructions corresponding to the method for detecting a vehicle battery in the embodiment of the present invention. The controller executes various functional applications and data processing of the battery detection device by running the non-volatile software programs and instructions stored in the memory, ie, implements the vehicle battery detection method in the method embodiment.

The battery detection device can execute the method provided by the embodiment of the present invention, for example, the detection method of the vehicle battery in FIG. 2 to FIG. 8 , and has functional modules and beneficial effects corresponding to the execution method. For technical details not described in detail in this embodiment, reference may be made to the method provided by the embodiment of the present invention.

It should be noted that, in this embodiment, the execution device for determining whether the battery to be tested has surface charge is integrated into the electrical measurement detection device. It can be understood that the detection of the battery to be tested can also be performed by other detection devices.

From the description of the above embodiments, those of ordinary skill in the art can clearly understand that each embodiment can be implemented by means of software plus a general hardware platform, and certainly can also be implemented by hardware. Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium, and the program is During execution, it may include the processes of the embodiments of the above-mentioned methods. Wherein, the storage medium may be a magnetic disk, an optical disk, a read-only memory (Read-Only Memory, ROM) or a random access memory (Random Access Memory, RAM) or the like.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; under the idea of the present invention, the technical features in the above embodiments or different embodiments can also be combined, The steps may be carried out in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity; although the invention has been The skilled person should understand that it is still possible to modify the technical solutions recorded in the foregoing embodiments, or to perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the implementation of the present invention. scope of technical solutions.

Claims (16)

1. A detection method for a vehicle battery, comprising:

   Determine whether the battery to be tested has surface charge;

   If it exists, the battery to be tested is controlled to discharge according to a first preset discharge condition, so as to eliminate the surface charge of the battery to be tested; wherein, the first preset discharge condition includes continuous discharge at a first preset discharge current discharging a first preset duration to form a discharge cycle, and repeating the discharge cycle according to the interval frequency until the second preset duration;

   Perform battery testing on the battery to be tested after removing the surface charge to obtain the testing result.
2. The method according to claim 1, wherein the first preset discharge current is greater than a current threshold, and the unit of the first preset duration is milliseconds (ms).
3. The method according to claim 1 or 2, wherein the determining whether the battery to be tested has surface charge comprises:

   Obtain the initial voltage of the battery to be tested;

   Acquiring a discharge voltage of the battery to be tested under a second preset discharge condition; wherein the second preset discharge condition includes discharging at a second preset discharge current for a third preset duration;

   obtaining the open-circuit voltage of the battery to be measured after discharge;

   According to the initial voltage, the discharge voltage and the open circuit voltage, it is determined whether the battery to be tested has surface charge.
4. The method according to claim 3, wherein the acquiring the discharge voltage of the battery to be tested under the second preset discharge condition comprises:

   Collect a plurality of first voltages discharged from the battery to be tested according to a preset first sampling rate;

   The discharge voltage is determined to be a minimum value among the plurality of first voltages.
5. The method according to claim 3, wherein the method further comprises:

   Obtain the battery characteristics of the battery to be tested;

   The determining whether the battery to be tested has surface charge according to the initial voltage, the discharge voltage and the open-circuit voltage includes:

   Determine the voltage drop of the battery to be tested according to the initial voltage and the discharge voltage;

   Determine the voltage recovery parameter of the battery to be tested according to the open-circuit voltage and the discharge voltage of the battery to be tested;

   According to the battery characteristic, the voltage drop, the voltage recovery parameter and the preset mapping relationship of the battery to be tested, determine whether the battery to be tested has surface charge;

   The preset mapping relationship includes a corresponding relationship between battery characteristics and a voltage parameter, the voltage parameter is determined by a voltage parameter obtained from the sampling battery according to the second preset discharge condition, and the voltage parameter includes a voltage drop and a voltage parameter. Voltage recovery parameter, the sampling battery is a battery with no surface charge.
6. The method of claim 5, wherein the battery characteristics include at least one of a rated battery capacity and a battery type.
7. The method of claim 5, wherein the voltage recovery parameter comprises at least one of a voltage recovery slope and a recovery voltage.
8. The method according to claim 7, wherein the open-circuit voltage comprises collecting a plurality of second voltages after the battery under test is discharged according to a preset second sampling rate within a preset recovery period;

   The determination of the voltage recovery parameter of the battery to be tested according to the open-circuit voltage and the discharge voltage of the battery to be tested includes at least one of the following:

   determining the voltage recovery slope of the battery to be tested according to the second voltage, the discharge voltage and the recovery duration corresponding to the second voltage in the middle section of the preset recovery duration;

   The recovery voltage is determined according to the maximum value of the plurality of second voltages and the discharge voltage.
9. The method according to any one of claims 5-8, wherein the determining the Whether the battery to be tested has surface charge, including:

   determining a voltage parameter corresponding to the battery feature in the preset mapping relationship;

   determining whether the voltage drop of the battery to be tested is greater than the voltage drop in the voltage parameter;

   If yes, determine whether the voltage recovery parameter of the battery to be tested is less than the voltage recovery parameter in the voltage parameters;

   If yes, determine that the battery to be tested has surface charge;

   Otherwise, it is determined that the battery to be tested has no surface charge.
10. The method according to any one of claims 5-8, wherein the preset mapping relationship includes a corresponding relationship between an initial voltage, a battery characteristic and a voltage parameter;

    The determining whether the battery to be tested has surface charge according to the battery characteristics of the battery to be tested, the voltage drop, the voltage recovery parameter and the preset mapping relationship includes:

    determining the voltage parameters corresponding to the initial voltage of the battery to be tested and the battery characteristics in the preset mapping relationship;

    determining whether the voltage drop of the battery to be tested is greater than the voltage drop in the voltage parameter;

    If yes, determine whether the voltage recovery parameter of the battery to be tested is less than the voltage recovery parameter in the voltage parameters;

    If yes, determine that the battery to be tested has surface charge;

    Otherwise, it is determined that the battery to be tested has no surface charge.
11. A battery detection device, characterized in that it includes:

    a first connection end, a second connection end, a third connection end and a fourth connection end, wherein the first connection end, the second connection end, the third connection end and the fourth connection end are respectively Used to connect the battery to be tested;

    a discharge circuit, electrically connected to the battery to be tested through the first connection end and the fourth connection end, and used to trigger the battery to be tested to discharge under a preset discharge condition;

    a voltage sampling circuit, which is electrically connected to the battery to be tested through the second connection terminal and the third connection terminal, and is used to detect the voltage at both ends of the battery to be tested;

    A controller is electrically connected to the discharge circuit and the voltage sampling circuit respectively, and the controller can execute the method of any one of claims 1-10.
12. The battery detection device according to claim 11, wherein the discharge circuit comprises a switch circuit, a load and a current sampling circuit:

    The first end of the switch circuit is connected to the first connection end, the second end of the switch circuit is connected to the controller, and the third end of the switch circuit is connected to the fourth connection end through the load;

    The first end of the current sampling circuit is connected to the controller, the second end of the current sampling circuit is connected to the load, and the current sampling circuit is used to detect the discharge current of the battery to be tested;

    The controller is specifically used for:

    The switch circuit is adjusted according to the magnitude of the discharge current detected by the current sampling circuit, so that the battery to be tested is discharged under the preset discharge condition.
13. The battery detection device according to claim 12, wherein the switch circuit comprises a MOS transistor and a first operational amplifier;

    The non-inverting input terminal of the first operational amplifier is connected to the controller, the inverting input terminal of the first operational amplifier is connected to the source of the MOS transistor, and the output terminal of the first operational amplifier is connected to the MOS transistor The gate of the MOS transistor is connected to the first terminal of the load, and the drain of the MOS transistor is connected to the first connection terminal.
14. The battery testing device according to claim 13, wherein the discharge circuit further comprises a diode, a first end of the diode is connected to the first connection end, and a second end of the diode is connected to the first connection end the drain of the MOS transistor.
15. The battery detection device according to any one of claims 12-14, wherein the current sampling circuit comprises a second operational amplifier, and a non-inverting input end of the second operational amplifier is connected to the first end of the load, The inverting input terminal of the second operational amplifier is connected to the second terminal of the load, and the output terminal of the second operational amplifier is connected to the controller.
16. The battery detection device according to any one of claims 11-14, wherein the voltage sampling circuit comprises:

    The third operational amplifier, the non-inverting input terminal of the third operational amplifier is connected to the second connection terminal, the inverting input terminal of the third operational amplifier is connected to the third connection terminal, and the output of the third operational amplifier connected to the controller.

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