JPS63261179A - Method and device for detecting state of lead-acid battery for on-vehicle sli - Google Patents

Abstract

PURPOSE:To accurately detect the degree of deterioration and charging state of a battery in a short time without reference to the kind of the battery by contrasting the relation between the differential internal resistance at the start and the means charging current within a constant time after the start with a previously found value. CONSTITUTION:When an engine is started, a power relay 4 is turned on and a large current flows to a motor 3. The current discharging current and terminal voltage are measured by an ammeter 5 and a voltmeter 6. At the same time, the battery temperature is measured by a temperature sensor 7, an arithmetic part 8 finds a reference voltage, and an arithmetic part 9 calculates the differential internal resistance of the battery from those values. The power relay 4 is turned off and a power relay 10 is turned on after the start of the engine, thereby connecting the battery to the load-charging system of a vehicle. The load-charging system detects whether or not a voltage regulator 13 reaches a set charging voltage by a set voltage attainment detector 14 and a calculation part 17 calculates a mean charging current from the time and the quantity of electricity measured by a time integrator 15 and a charging electricity quantity integrator 16. A battery state decision part 18 decides the battery state from the obtained differential internal resistance and mean charging current.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for detecting the state of charge and degree of deterioration of a lead-acid marine battery for onboard SLI while in use.

[Problems to be solved by the prior art and the invention] Lead-
A decrease in the discharge capacity of an acid battery is caused by either battery deterioration (deterioration of the electrodes) or insufficient charging. In the former case, the discharge capacity can be restored by replacing the battery with a new one, and in the latter case, by charging it.

In this way, the state of the battery is detected only after both the degree of deterioration and the state of charge of the battery are known, and appropriate measures can be taken to prevent troubles in which the engine cannot be started.

Conventionally, as a diagnostic method for automotive lead-acid batteries, the degree of deterioration is detected from the internal direct current resistance of the battery, and the state of charge is detected from the specific gravity of the electrolyte. Based on the relationship between the two, it is determined whether the battery needs to be replaced or charged. A method to do this is shown (Japanese Patent Application Laid-Open No. 56-117176).

However, in the DC internal resistance measurement method mentioned here, lead-
Since the current-voltage relationship of acid batteries is not a linear relationship, the measured internal resistance differs depending on the magnitude of the discharge current. Therefore, there is a drawback that the discharge current when measuring the internal resistance must be limited to a specific value. Furthermore, in order to detect the state of charge using the specific gravity of the electrolyte, it is necessary to modify the battery itself, such as by inserting a float that serves as a specific gravity sensor or an electrode that captures the specific gravity using an electrical signal into the battery.

It has the disadvantage of being easily affected by maintenance (water replenishment, fluid replacement) conditions.

As mentioned above, a method for accurately and easily detecting both the degree of deterioration and the state of charge of a lead-acid battery while it is mounted on a vehicle without modifying the battery has not yet been established. SUMMARY OF THE INVENTION An object of the present invention is to provide a method for detecting the degree of deterioration and state of charge of an in-vehicle SLI boat-acid battery that solves the problems of the prior art described above.

[Description of the invention]

The present invention is based on the differential internal resistance at the time of large current discharge at the time of startup of any vehicle-mounted SLR ship-acid battery, and the average charging current when the battery voltage reaches the voltage regulator set voltage within a certain period of time after startup. Search for.

A method for detecting the battery condition of a car AS+-R chartered ship-acid battery, characterized in that the state of charge and the degree of deterioration are detected by comparing the relationship between a predetermined differential internal resistance and an average charging current. It is.

However, the differential internal resistance is determined as the value (Vo-V)/I from the battery voltage (2) and the battery current (I) at the time of starting.

Here, Vo is the voltage value obtained by linearly extrapolating the relationship between ■ and ■ when a lead-acid battery is discharged for a short time at a current density of 100 to 400 mA/c+f per unit area of a single cell electrode of the battery. It is.

41 The important point of the present invention lies in the discovery that during constant voltage charging of a lead-acid battery, the charging current decreases with the upper limit of the state of charge. The present inventors investigated in detail the correlation between the average charging current and the state of charge of the battery when the voltage of the vehicle-mounted battery reaches the set voltage of the voltage regulator.

The batteries used to find this relationship were a new 55D23 battery and two used batteries that had been used for SLI for several years. The full charge capacity (5 hour rate discharge) of each battery at 25°C is 44Ah, 15Ah, and 6Ah, respectively.
It is.

After adjusting these batteries to various charging states, they are installed in the vehicle,
During 5 minutes of running (including idling), measure the average charging current when the battery voltage reaches the voltage (/regulator setting voltage), and organize the relationship between the charging status of each battery and the above average charging current. The average charging current when the battery voltage reaches the set voltage of the voltage regulator is the time during which the battery voltage reaches the set voltage of the voltage regulator within a certain period of time while the car is in use, and 2 the charge flowing at that time. Integrate the quantity of electricity and each.

This is the value obtained by dividing the integrated electrical quantity by the integration time.

As the results are shown in FIG. 1, there is a good negative correlation between the average charging current when the set voltage is reached and the state of charge of the battery. The charging state region in which the average charging current shows a good correlation when the set voltage is reached varies slightly depending on the battery temperature, but as shown in FIG. 1, the charging state may be 50 to 60% or more. However, the correlation is not uniform depending on the degree of deterioration of the battery, and the ratio of increase in the average charging current to the decrease in the state of charge is small for batteries with a small full charge capacity. In other words, the average charging current when the set voltage is reached is the battery's full charge capacity and state of charge (%) - ((remaining capacity/full charge capacity)
×100). Therefore, by adding information on the differential internal resistance, which is correlated with the remaining capacity, to the above average charging current, the full charge capacity at the time of judgment can be determined.
You can also see the charging status. Furthermore, the degree of deterioration (%) - (full charge capacity when new - full charge capacity at the time of judgment / full charge capacity when new You can ask for it.

Here, the differential internal resistance is calculated by the patent application filed by the inventors of Wood in 1983.
The value of (Vo-V)/T is determined from the battery voltage V and battery current (2) at the time of startup described in -315634.

Here, Vo is the voltage obtained by linearly extrapolating the relationship between ■ and ■ when a lead-acid battery is discharged for a short time at a current density of 100 to 400 mA/afl per unit area of a single cell electrode of the battery. It is a value. Since the value of this reference voltage Vo is affected only by the battery temperature and not by the state of charge and degree of deterioration of the battery, the value of Vo at each temperature is measured in advance with another battery of the same type.

Therefore, using each battery at the temperature, full charge capacity, and state of charge shown in Table 1, we measured the differential internal resistance during large current discharge to start the engine, and the time when the voltage regulator set voltage was reached, measured during the subsequent 5 minutes of running. The relationship between the average charging current and the average charging current is summarized in Figure 2. As seen in FIG. 2, the degree of battery deterioration is small regardless of the battery temperature.

A battery with a large capacity when fully charged has a differential internal resistance of Il+
- It is observed that for batteries that are small and in a good state of charge, the average charging current when reaching the set voltage tends to be small.

As is clear from the figure, if the differential internal resistance and the average charging current when the set voltage is reached are known, it is possible to detect both the full charge capacity and charging state of the battery.

Furthermore, if the full charge capacity is known, the degree of deterioration can also be determined.

In other words, from the relationship shown in Figure 2, the differential internal resistance measured at the time of large current discharge when starting the engine of the in-vehicle S L ■ charter acid battery of the present invention and the voltage regulator setting voltage measured for a certain period of time during running and idling stop. It is possible to detect the state of the battery (degree of deterioration, state of charge) from the average charging current at the time of arrival.

The reason why the differential internal resistance of the battery, the remaining capacity, the average charging current, the state of charge, etc. are related is not clear, but it is thought to be as follows. First, the differential internal resistance at startup, which has a good correlation with the residual capacity, is related to electrode deterioration and the first charging state, such as the resistance of the discharge reaction, the contact resistance between active materials, and the resistance of the lattice. Factors that can be treated as pure resistance contribute. This pure resistance component is considered to have a good correlation with the remaining capacity, since the contribution of this pure resistance component is greater for batteries that have progressed in deterioration and/or batteries that are in a poor state of charge.

On the other hand, when the test battery is in a fully discharged state or a state close to it, the charging current from the alternator to the battery obtains the maximum constant current output according to the alternator rotational speed. However, the alternator output and the alternator rotational speed do not have a linear relationship, and no matter how much the battery is undercharged, there is a limit value to the charging current.

Also, the discharge current varies greatly depending on the amount of load.

The larger the load, the more current is consumed. In such cases, the battery voltage often cannot reach the voltage regulator set voltage. Therefore, the charging current to the battery itself is difficult to be used as an indicator of the state of charge. On the other hand, when the battery voltage reaches the voltage regulator set voltage, that is, when charging at constant voltage, the charging current can be considered to depend only on the contribution of the factors that can be treated as pure resistances. Therefore, it seems to show a good correlation with the state of charge without being influenced by the magnitude of the load.

The method for detecting the condition of an in-vehicle SLI charter acid battery according to the present invention is to detect the current flowing in and out of the battery, the voltage of the battery, and Also, based on the battery temperature, does the test battery require charging? It is possible to know whether the degree of deterioration is large and the time for replacement is near, or whether there is no problem with either the state of charge or the degree of deterioration and the battery can be used continuously for m continuous use.

Next, the device for detecting the battery status (state of charge, degree of deterioration) of an in-vehicle SLI chartered acid battery according to the present invention includes a calculation unit that calculates the reference voltage Vo of the battery from the battery temperature measured by the sensor, and the reference voltage vO. a calculation section that calculates the differential internal resistance R from the discharge voltage ■ and the discharge current ■, and a calculation section that calculates the average charging current from the time taken to reach the voltage regulator setting voltage and the amount of electricity Ah flowing during that time. and has.

Furthermore, the present invention is characterized by comprising a determining section that determines the state of charge and the degree of deterioration according to the relationship between the differential internal resistance R and the average charging current, which has been determined in advance for batteries of the same type, and a display section that displays the same. It's a cheat. According to this detection device, while the battery is installed in the vehicle and while the vehicle is in use, only information obtained from the battery (voltage, current, temperature) can be used to detect lead-acid marine batteries for in-vehicle SLI, without being affected by the type of battery. This makes it possible to detect the battery status (degree of deterioration and state of charge) of the battery in a short time and with high accuracy.

[Description of Embodiments] The feature of the method for detecting the state of a lead marine battery for vehicle-mounted SLI of the present invention is that the test battery can be moved in and out of the battery while the vehicle is being used, without making any modification to the battery while it is mounted on the vehicle. Does the battery under test require charging based on the current, battery voltage, and battery temperature, or is the battery under test in a state where the degree of deterioration is large and the time for replacement is near?

Or, there is no problem with either the charging state or the degree of deterioration.
This is a way to find out whether it is possible to continue using it as is. Hereinafter, embodiments of the present invention will be described using an explanatory diagram (FIG. 3) of an actual apparatus used to find the relationship shown in FIG. 2.

A power relay 4 is installed between the positive terminal 2 of the lead-acid marine battery 1 for SLI and the starter motor 3 during the engine start.
turns on and a large current flows to the starter motor. At this time, the discharge current (■) and the terminal voltage (■) are measured using an ammeter 5 and a voltmeter 6.

At the same time, the battery temperature is measured using a known temperature measurement method 1, for example, a temperature sensor 7, and the battery reference voltage V corresponding to the temperature is measured.
o is calculated by the calculation unit 8 according to the relationship between the temperature and the reference voltage (FIG. 4), which was determined in advance by the method previously published (Japanese Patent Application No. 61-302775). In the calculation unit 9, the above 1, V and V
From the oO value, the differential internal resistance R of the battery is calculated as R-(Vo-V)/
Calculate according to I2.

On the other hand, after the engine is started, the power relay 4 is turned off, and the power relay 10 is turned on instead, so that the battery is connected to the load-charging system of the vehicle.

Load - In the charging system, the electric power generated by the alternator 11 and electrical loads 1 such as ignition coils and headlamps are
If the difference with the power consumed in step 2 is positive, the battery is charged, and if it is negative, the battery is discharged.

It is designed to cover the electricity. Although the output current and output voltage of the alternator depend on the engine speed, the alternator is designed to charge the battery +J on average under normal vehicle usage conditions. In this case, charging is carried out at a constant voltage controlled by the portage l/gule 13. This voltage is the voltage at which the battery does not become overvoltage and can be used in a nearly fully charged state at all times. While the vehicle is in use in such a load-charging system, the set voltage attainment detector 14 detects whether or not the voltage regulator has reached its set voltage, and determines the time t at which the voltage has been reached.

(11) and the amount of electricity Δh flowing in the charging direction during that time are measured by the time integrator 15 and the charging amount of electricity integrator 16, respectively, and the battery voltage is Calculate the average charging current flowing through the battery while reaching the set voltage on the halterage leg. Furthermore, the battery condition determination unit 18 uses the average charging current calculated by the calculation unit 17 and the differential internal resistance (vo-
(2) The battery state (state of charge and degree of deterioration) is determined according to the relationship of the second IA previously determined for the same type of battery from /I.

The relationship of the second V is as described in the description of the invention.

Usually, it is determined using a large number of batteries whose remaining capacity and state of charge are known, but it may also be determined by sea 14 mileage. 19
This is the display section.

The state of charge of the battery changes depending on the usage state of the load and driving conditions (engine speed) while the vehicle is in use. Therefore, it is preferable to measure the average charging current at intervals of several minutes to about 10 minutes, and it is desirable to calculate the average charging current using the time taken to reach the set voltage of the voltage regulator and the amount of charging electricity measured during that period.

If this time interval is short, it will be affected by the load electricity,
The value of the average charging current is large and unstable, causing the problem that the accurate state of charge of the battery cannot be detected.

Moreover, if this time interval is too long, it is not preferable because the battery state may not be detected during - times of vehicle use. In addition, the amount of load electricity used is large,
There may be cases where the battery voltage does not reach the voltage regulator setting voltage during the first few minutes after starting, but in this case, it is sufficient to use the value when it is recognized that the setting voltage has been reached in the second and subsequent integral data.

On the other hand, the battery voltage is voltage legif -1/- evening setting -1
6. There are several methods of detecting whether a constant voltage has been reached, and for example, a method of measuring the field current of the field coil of the alternator may be used.

(Example) In order to demonstrate the effectiveness of the battery state detection method for in-vehicle S L l chartered acid batteries of the present invention, a plurality of test batteries (55D23 type to N540ZΔ type) with unknown capacity reduction degree and unknown state of charge were used. Using a car equipped with the system shown in Figure 3, a 5-minute running experiment was conducted using each battery. Table 2 shows the measured differential internal resistance at startup and the average charging current when the voltage regulator set voltage was reached for 5 minutes after startup. Based on the differential internal resistance value obtained in each experiment and the average charging current value when the set voltage was reached, the state of charge and fully charged capacity of the test battery were estimated from FIG. 2 and are shown in Table 2. Further, after the experiment, the test batteries were discharged and charged at a constant current rate for 5 hours, and the remaining capacity and capacity at full charge were measured, and the values are also shown in Table 2.

The value determined by the detection method of the present invention is not significantly different from the state of charge value based on the measured capacity after the experiment.

The effectiveness of the method for detecting the battery status of an on-vehicle SLI ship-acid battery according to the present invention has been demonstrated.

Margin below----1-----------□----
−−−−−−−−−−−−−1−−7/′

[Brief explanation of the drawing]

Figure 1 shows the relationship between the battery charging state and the average charging current when reaching the Hortage I/regulator set voltage, and Figure 2 shows the relationship between the average charging current when reaching the voltage regulator set voltage and the differential internal resistance ( (Vo-
V)/II, Figure 3 is an example of the test circuit, Figure 4
The figure shows the temperature dependence of the reference voltage Vo for determining the differential internal resistance. ■...Lead-acid battery, 7...Temperature sensor 8...
- Arithmetic unit, 90. - Arithmetic unit 13... Voltage regulator 17... Calculation unit, 18... Judgment unit 19...
Display section

Claims (3)

[Claims] (1) Determine the differential internal resistance of any vehicle-mounted lead-acid battery for SLI when discharging a large current when the engine is started, and the average charging current when the battery voltage reaches the voltage regulator setting voltage within a certain period of time after startup, and determine the predetermined value. An in-vehicle S is characterized in that the state of charge and the degree of deterioration are detected by comparing the relationship between the differential internal resistance and the average charging current.
A method for detecting the battery condition of a lead-acid battery for LI. (However, the differential internal resistance is determined from the battery voltage V and battery current I at startup as the value (Vo-V)/I. Here, V
o is 10 per unit area of a single cell electrode of a lead-acid battery.
This is the reference voltage value obtained when I = 0 by linearly extrapolating the relationship between V and I when discharging for a short time at a current density of 0 to 400 mA/cm^2) (2) The predetermined relationship between the differential internal resistance and the average charging current is calculated by using a variety of in-vehicle SLI lead-acid batteries whose state of charge and degree of deterioration are known, and which is determined by the differential during large current discharge at startup. The lead-acid for in-vehicle SLI according to claim (1), wherein the battery voltage is determined by measuring the internal resistance and the average charging current when the voltage regulator reaches the set voltage within a certain period of time after starting. A method to detect the battery status (state of charge and degree of deterioration) of a battery. (3) A calculation unit that calculates the battery reference voltage Vo from the battery temperature measured by the sensor, a calculation unit that calculates the differential internal resistance R from the reference voltage Vo, discharge voltage V, and discharge current I, and a calculation unit that calculates the differential internal resistance R from the reference voltage Vo, the discharge voltage V, and the discharge current I, and the calculation unit that calculates the battery reference voltage Vo from the battery temperature measured by the sensor. It has a calculation unit that calculates the average charging current @A@ from the time h during which the battery is running and the amount of electricity Ah that has flowed during that time, and further calculates the average charging current @A@ from the differential internal resistance R and the average charging current @A@ for the same type of battery in advance. A battery state (state of charge and degree of deterioration) detection device for a lead-acid battery for automotive SLI, comprising a determination section that determines the state of charge and degree of deterioration according to the established relationship between the two, and a display section that displays the same. .