JP2007080814A - Device and method for simulating battery tester using constant resistance load - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and device for simulating a battery tester using a constant resistance load such as a load tester widely used in Japan for evaluating the intensity of a battery in Japan classified based on Japanese Industrial Standards (JIS). <P>SOLUTION: The device is simulated without applying a large current load and a sure test is provided by finding usual results and utilizing an exiting data base. This method contains the estimation of a load test voltage of a battery as a function of a dynamic parameter of the measured battery, open circuit voltage, a load resistance value of a load tester, and the temperature of the battery. The bounce back voltage (BBV) of the battery is estimated. The intensity of the battery is evaluated by using the BBV, the load voltage, and battery temperature. In one example, in order to make more correct the test result of the full charged battery, the recharging result of the discharge battery is estimated without actually recharging. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to storage battery testing. More specifically, the present invention simulates a battery tester using a constant resistance load such as a Japanese load tester widely used for evaluating the strength of Japanese batteries classified based on Japanese Industrial Standards (JIS). (Simulating). The present invention simulates the device without subjecting it to a large current load, produces the usual good results, utilizes existing databases, and provides more reliable testing.

  Generally, the determination of the soundness of the battery is performed based on the evaluation standard of the battery. Japanese battery manufacturers design and manufacture batteries according to Japanese Industrial Standards (JIS). A lead acid storage battery used for the purpose of starting, lighting, and igniting an automobile is defined in JIS standard D5301. This standard defines JIS standard battery performance, test, structure and scale labeling.

  One type of battery tester in Japan is to measure the battery voltage under a resistive load and the subsequent recovery voltage to see the feasibility of service as a JIS standard battery. The tester can accommodate several ranges of battery dimensions, separated by JIS standard numbers, and multiple temperature ranges. The battery is determined to be “good”, “soon to be replaced”, “replaced” or the like according to the response.

  Since this tester is a constant load resistor that discharges the battery at a considerable rate (eg, 5 to 6 seconds at 150 amps), it is quite large and may become hot when the test is repeated. Furthermore, it takes a reasonable time to wait for the load and recovery time to complete, and the battery charge is depleted. In addition, since the tester has voltage sensing leads that are not directly connected to the battery, in order to accurately read the voltage at the battery terminal, the cable must be ohmically perfect and the current accurately known. Also, when the tester is powered from the battery being tested, the weak or discharged battery due to high load is consumed and the tester loses enough power to maintain the operation of the control circuit and is reset.

  Accordingly, it would be desirable to provide the Japanese load tester described above and other similar load testers that use test techniques that are easier to control.

  A method and apparatus for simulating a battery tester using a constant resistance load such as a widely used Japanese load tester for evaluating the strength of Japanese batteries classified based on Japanese Industrial Standards (JIS) To do.

The present invention simulates a device such as that described above without imposing a significant power load, yields common results and provides more reliable testing using an existing database. The method includes estimating a battery load test voltage as a function of measured battery dynamic parameters, open circuit voltage, load tester load resistance, and battery temperature. The battery's bounceback voltage (BBV) is also predicted. The bounceback voltage, load voltage and battery temperature are used to evaluate the strength of the battery. Furthermore, in order to make the test result of the substantially discharged battery more accurate, the result of recharging the discharged battery is predicted without actually recharging.
Furthermore, the apparatus and method of the present invention can be used for a battery outside the JIS standard by using the range of the standard CCA (Cold Cranking Amps) of each dimension category.

  The present invention provides an apparatus and method for simulating a battery tester that uses a constant resistance load, such as a Japanese load tester that evaluates the strength of Japanese batteries that are classified based on Japanese Industrial Standards (JIS). The battery tester of the present invention evaluates dynamic parameters such as conductance of a battery evaluated according to the Japanese Industrial Standard (JIS), and simulates the tester load resistance, open circuit voltage of the JIS standard battery (open circuit voltage). ) And the temperature, and a calculated value used for evaluating the strength of the JIS standard battery according to the classification of the JIS dimension classification number. Further, the tester can be used for a battery outside the JIS standard by using a reference CCA (Cold Cranking Amps) range of each dimension classification.

  FIG. 1 is a simplified block diagram of a battery test circuit 16 according to one embodiment of the present invention. In FIG. 1, the device 16 is connected to a battery 12 having a positive terminal 22 and a negative terminal 24. The battery 12 may be a JIS standard battery or a non-JIS standard battery such as a CCA standard battery.

  In the preferred embodiment, circuit 16 is one of the US patents obtained by Dr. Champlin and Midtronics, Inc., including exceptions and additions as described below. Operates with one or more of the battery test methods described.

The circuit 16 operates in accordance with one embodiment of the present invention and includes the conductance (G) of the battery 12, the open circuit voltage (OCV) between the terminals 22, 24 of the battery 12, and the bounceback voltage of the battery 12 ( A change in voltage from when the battery is released from the load until a certain time (for example, 3 seconds) elapses is measured. The circuit 16 includes a current source 50, a differential amplifier 52, an A / D converter 54, and a microprocessor 56. Amplifier 52 is capacitively coupled to battery 12 via capacitors C ₁ and C ₂ . The amplifier 52 has an output connected to the input of the A / D converter 54. The microprocessor 56 is connected to the system clock 58, the memory 60, and the A / D converter 54. Microprocessor 56 can also receive input from input devices 66, 68. Further, the microprocessor 56 is also connected to an output device 72.

In operation, the current source 50 is controlled by the microprocessor 56 to supply the current I in the direction indicated by the arrow in FIG. In one embodiment, this is a square wave or pulse. The differential amplifier 52 is connected to the terminals 22 and 24 of the battery 12 via the capacitors C ₁ and C ₂ , respectively, and provides an output related to the voltage potential difference between the terminals 22 and 24. In one preferred embodiment, amplifier 52 has a high input impedance. Circuit 16 includes a differential amplifier 70 having inverting and non-inverting inputs connected to terminals 24 and 22, respectively. Amplifier 70 is connected to measure the OCV of battery 12 between terminals 22 and 24. The output of the amplifier 70 is supplied to the A / D converter 54, and the voltage between the terminals 22 and 24 is measured by the microprocessor 56.

  The circuit 16 is connected to the battery 12 by a four-point connection technique known as Kelvin connection. With this Kelvin connection, the current I is injected into the battery 12 via the first pair of terminals, and the voltage V between the terminals 22, 24 is measured by the second pair of connections. Since the current flowing through amplifier 52 is negligible, the voltage drop across the input to amplifier 52 is substantially the same as the voltage drop across terminals 22, 24 of battery 12. The output of the differential amplifier 52 is converted to digital form and provided to the microprocessor 56. The microprocessor 56 operates at the frequency determined by the system clock 58 according to the instructions of the program stored in the memory 60.

Microprocessor 56 measures the conductance of battery 12 by applying current pulse I using current source 50. The microprocessor 56 uses the amplifier 52 and the A / D converter 54 to measure the change in battery voltage due to the current pulse I. The value of the current I generated by the current source 50 is known and stored in the memory 60. The microprocessor 56 calculates the conductance of the battery 12 using the following equation.

Conductance = G = ΔI / ΔV (Formula 1)

  Here, ΔI represents a change in current flowing through the battery 12 by the current source 50, and ΔV represents a change in battery voltage due to the applied current ΔI. In one preferred embodiment of the present invention, the temperature of the battery 12 is input from the input device 66 by, for example, a tester user. In another embodiment, the circuit 16 includes a temperature sensor 74 coupled to the microprocessor 56 that is thermally coupled to the battery 12 to measure the temperature of the battery 12 and to provide a measurement of the battery temperature. Provided to the microprocessor 56. In one embodiment, the temperature of the battery is measured using an infrared signal from outside the battery. The microprocessor 56 can also use other input information provided by the operator from the input device 66, for example. This information includes the specific type of battery, position, time, operator name, battery dimension number, battery temperature, and the like.

  Under the control of the microprocessor 56, the battery tester 16 estimates the load voltage of the battery 12 as a function of battery conductance G (Equation 1), OCV, simulated tester load resistance, and battery temperature. Further, the battery tester 16 predicts the bounceback voltage of the battery as described above. The microprocessor 56 of the battery tester 16 uses the bounceback voltage, the load voltage, and the battery temperature to evaluate the strength of the battery according to the classification of the JIS dimension classification number. Derivation of an example of an algorithm used by the battery tester 16 to estimate the bounceback voltage and load voltage of the battery 12 will be described in detail below. The algorithm shown below is derived from the analysis of a general Japanese battery load tester.

Analysis of Japanese load tester In Japanese load tester, the user needs to input the size and temperature of the battery after connecting the cable clamp to the battery. When the user presses the start button, the tester applies a load to the battery for 5 to 6 seconds, and then records the load voltage (LV). The tester then makes a judgment on the battery by looking at the bounceback voltage or the recovery voltage after 2.5 seconds.

  As described above, the user enters the dimensions of the battery. Specifically, 10-stage size categories (0 to 9) in which the cranking power width gradually increases are input to the battery. However, each section is strictly associated with various JIS battery numbers printed on the tester. Table 1 below shows the range of various dimension categories.

  As described above, the user inputs the temperature in addition to the dimension category. The temperature is input by the user in four categories (see Table 2).

  If the battery supplies enough voltage to operate the tester while it is under load, the tester can test a battery that has dropped to 11.5 volts (V), which is reported as low voltage after recovery. To do. If the voltage actually becomes very low, the load tester will only reset and report nothing.

  The basic relationship between dimensional categories (0-9) and temperature (° C.) for this type of tester has the following relationship:

For good voltage (Vg volts):

Vg = 8.8 + 0.1 × GroupSize + 0.02 × TempC (Formula 2)

Here, GroupSize = battery size category (above Table 1), TempC = battery temperature in the battery (above Table 2).

When replacing voltage (Vr volts):

Vr = Vg−0.3 (Formula 3)

However, since the battery may be accompanied by discharge or other problems, the measured recovery voltage or bounceback voltage (BBV) is evaluated and combined with the dimensional criteria and temperature to produce the following results (see below) (See Table 3).

Example of Battery Tester Algorithm According to the Present Invention As described above, the battery tester of the present invention predicts load voltage (LV) using measured values of battery OCV, conductance, and temperature (measured or input by the user). By functioning.
In order to predict the load voltage in volts, the following relationship is used:

LV = Vact−I × R (Formula 4)

Here, Vact = activation voltage, I = load current, and R = battery resistance.

Vact = K1 × OCV ² + K2 × OCV + K3 × TempC-K4 (Formula 5)

Here, K1, K2, K3 and K4 are constants, and their values are selected based on the type of battery tester to be simulated.

The conductance (G) of the battery is measured using Equation 1 as described above. The resistance of the battery is estimated by the following equation using the conductance measured at 100 Hz.

R = K5 / G + K6 (Formula 6)

Here, K5 and K6 are constants. However, since the Japanese tester uses a constant load resistance, the current varies depending on the resistance of the battery. Therefore, the load current needs to be estimated first.
This can be done using the following relationship:

I = Vact / (R + R1) (Formula 7)

Here, R1 is the resistance of the load tester estimated in ohms.

  In general, the load has been found to vary between 110-160 amps. If it is below 110 amps, the load tester is reset. Therefore, the load voltage can be estimated and used for battery strength evaluation.

Furthermore, it has been found that the recovery voltage or bounceback voltage (BBV) can be estimated by a quadratic equation using the open circuit voltage and temperature.

BBV = K7 × OCV + K8 × OCV−K9 + K10 × (TempC−K11)
(Formula 8)

Here, K7, K8, K9, K10 and K11 are constants.

  Therefore, by using these calculations (Equations 1 and 4 to 8), it is possible to predict a value obtained by a Japanese load tester without applying a high load.

  FIG. 2 is a flowchart 100 illustrating the steps of a method for programming a battery tester 16 in accordance with one embodiment of the present invention. As shown in flowchart 100, at step 102, a mathematical relationship is established for estimating load voltage from battery conductance, temperature, and OCV (Equations 1 and 4-7 above). At step 104, a mathematical relationship is established for estimating the bounceback voltage of the battery (Equation 8). In step 106, these mathematical relationships are programmed into the memory 60 of the battery tester 16. At this time, the battery tester 16 estimates the load voltage and bounceback voltage of the battery, and evaluates the strength of the battery according to the classification of the JIS dimension classification number using the estimated bounceback voltage, load voltage, and battery temperature. Ready.

  FIG. 3 is a flowchart 150 illustrating the steps of a method for testing a battery according to one embodiment of the invention. In step 152, the battery dynamic parameters are measured. In step 154, the open circuit voltage of the battery is obtained. In step 156, the temperature of the battery is obtained. In step 157, the load resistance value of the tester is set. This is a predetermined load resistance value suitable for the load tester to be simulated. At step 158, the battery load voltage is estimated as a function of the measured battery dynamic parameters, battery open voltage, load resistance and battery temperature. At step 160, the battery bounceback voltage is predicted. In step 162, the strength of the battery is evaluated according to the classification of the JIS dimension classification number using the bounceback voltage, the load voltage, and the battery temperature. It is possible to perform the steps shown in the flowchart of FIG. 3 using different techniques, while maintaining substantially similar functionality, without departing from the scope and spirit of the present invention, some of which are described above. ing.

  Furthermore, since no load is applied from the tester of the present invention, the tester can perform determination even in an area to be reset if it is a standard load tester, which is an improvement over the standard load tester. In particular, if the bounceback voltage is 11.5V or higher and the load voltage is very low (<7V), it is certain that the battery will be a factor of “bad / replacement”. If the bounceback voltage is less than 11.5V, the OCV is greater than 11V, and the load voltage is estimated to be less than Vr, the decision is postponed and the battery is placed in the “charge and retest” category. In addition, the tester can detect a battery that can be shorted by finding an important conductance if the OCV is below 11V. These are placed in the category “Bad / Replaced”. If the voltage is very low and there is little conductance, the battery is placed in the “charge and retest” category. Improved and more specific comparisons and results are shown in Table 4 below.

  While the above example embodiments according to the present invention relate to load voltage estimation based on battery conductance measurements, dynamic parameters other than battery conductance may be used without departing from the spirit and scope of the present invention. It is. Examples of other dynamic parameters include dynamic resistance, admittance, impedance, reactance, susceptance, or combinations thereof. In a preferred embodiment of the present invention, the battery tester 16 is relatively small and portable.

  The above-described embodiment according to the present invention is mainly described with respect to the simulation of a Japanese load tester. However, the significance of the present invention is not necessarily imitating a Japanese tester, but generally imitating any tester using a constant resistance load. In general, to simulate a tester using a constant resistance load, (1) measure how much current flows from the battery (Equation 7 above), and (2) how much voltage the battery has under such load. (Equation 4 above), there is a two-step process. Many prior art algorithms assume that the voltage is predicted by defining the load current.

Additional Embodiments The above-described electronic battery tester embodiment can simulate a load tester commonly used in the Japanese battery test market. As mentioned above, these battery tester embodiments can replicate load test results very well without the actual load.

  In both the load tester and the simulated load tester embodiments described above, the test results can be adversely affected if the battery is substantially discharged. Therefore, in the embodiment described further below with respect to FIG. 4, the load test simulator embodiment described above is modified so that the result after recharging can be predicted without actually recharging the discharged battery. Has been.

  This change is made by using a function to compensate the battery conductance based on the open circuit voltage and temperature of the battery (f (OCV, Temp)). Since discharged batteries typically have a low conductance value, this function predicts a conductance value that has been raised to the conductance value of a fully charged battery. Connected to the voltage of a fully charged battery (which in some embodiments is about 12.8V), this predicted value produces a predicted value of the load voltage when fully charged: Put in the above algorithm. The recovery or bounceback voltage is then calculated using the full charge parameters. As these two voltages pass sequentially through the battery category criteria, the battery can be determined to be good after being properly recharged.

  FIG. 4 is a flowchart 400 of a load tester simulation method with discharge compensation according to an embodiment of the present invention. In step 402, the dynamic parameters of the battery are measured. In step 404, the open circuit voltage of the battery is acquired. In step 406, the temperature of the battery is obtained. At step 410, the battery full charge dynamic parameters and the full charge OCV are estimated. In step 412, the battery load voltage is estimated as a function of the estimated charged battery dynamic parameters, the charged battery open voltage, the tester load resistance, and the battery temperature. Thereafter, in step 414, the battery's full charge bounceback voltage is predicted. At step 416, the battery strength is evaluated using the fully charged bounceback voltage and the second load voltage.

  The foregoing embodiment described in connection with FIG. 4 can be performed using a battery tester similar to that shown in FIG. However, to implement the embodiment of FIG. 4, the microprocessor 56 is configured to operate with programming instructions stored in memory 60, which are modified to implement the method of FIG. ing.

  Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.

FIG. 2 is a simplified schematic diagram illustrating a battery test circuit according to the present invention. FIG. 6 is a simplified block diagram illustrating the steps of a method for programming a battery tester according to the present invention. FIG. 4 is a simplified block diagram illustrating the steps of a method for testing a battery according to the present invention. 3 is a flowchart of a load tester simulation method with discharge compensation according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 12 ... Battery, 16 ... Battery test circuit, 22 ... Positive terminal, 24 ... Negative terminal, 50 ... Current source, 52 ... Differential amplifier, 54 ... A / D converter, 56 ... Micro Processor 58 58 System clock 60 Memory 68 66 Input device 70 Amplifier 72 Output device 74 Thermally coupleable to battery 12 Microprocessor 56 Combined, C ₁ , C ₂ ... capacitor

Claims (8)

A method for testing a battery using a battery evaluation standard,
(A) measuring a dynamic parameter of the battery;
(B) obtaining an open circuit voltage of the battery;
(C) obtaining the temperature of the battery;
(D) setting a predetermined load resistance value;
(E) estimating a fully charged dynamic parameter and a fully charged open voltage of the battery;
(F) estimating the load voltage of the battery as a function of the estimated dynamic parameters of the charged battery, the open voltage of the charged battery, the load resistance value and the battery temperature;
(G) predicting a bounceback voltage of the fully charged battery;
(H) evaluating the strength of the battery using the fully charged bounceback voltage and the load voltage.   The method of claim 1, wherein the setting of the predetermined load resistance value in step (d) includes setting an appropriate load resistance value for the simulated load tester.   The method of claim 1, wherein measuring the dynamic parameter in step (a) comprises measuring a battery response to an applied current pulse.   The method of claim 1, wherein the measured battery dynamic parameter value is battery conductance.   The method of claim 1, wherein the measured dynamic parameter value of the battery is a resistance value of the battery. An electronic battery tester,
A positive connector configured to couple to the positive terminal of the battery;
A negative connector configured to couple to the negative terminal of the battery;
A voltage sensor configured to measure an open voltage of the battery; an input configured to obtain a temperature of the battery;
A battery test circuit,
The battery test circuit
(A) measuring the dynamic parameters of the battery using the first and second connectors;
(B) estimating the fully charged dynamic parameters and fully charged open voltage of the battery;
(C) estimating the load voltage of the battery as a function of the estimated dynamic parameters of the charged battery, the open voltage of the charged battery, the load resistance value and the battery temperature;
(D) predicting the full charge bounceback voltage of the battery;
(D) An electronic battery tester configured to evaluate the strength of the battery using the fully charged bounceback voltage and the load voltage.   The apparatus of claim 6, wherein the input is configured to obtain the battery temperature from a user.   The apparatus of claim 6, wherein the input is configured to obtain the battery temperature from a temperature sensor.

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