JP2000295778A - Battery life determining method and apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a method for easily determining life of a battery. SOLUTION: The method comprises a full-charge determining process S11 to determine whether a battery is in the full-charge condition or not, a measuring process S15, S16 to start S12 discharge of the battery when it is in the full-charge condition and to measure a discharge voltage and a discharge current when a constant time has passed from the start of discharge and a range determining process S17 to determine whether the discharge current measured in the measuring process is within the life determining range or not. Moreover, a determining data acquiring means S17 for obtaining life determining data corresponding to a discharge current when the discharge current is determined to be within the life determining range in the range determining process and a battery life determining process S20 for comparing a discharge voltage and life determining data measured in the measuring process and determining the battery life when the discharge voltage is smaller than the life determining data are also comprised.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery life judging method and apparatus for judging the life of a battery in use, for example, in a power supply device using a battery.

[0002]

2. Description of the Related Art Batteries are used in various fields and environments such as for starters of automobiles, uninterruptible power supplies, and solar power generation systems, and play a large role as electric power for each. Therefore, knowing the life of a battery is very important in each field.

[0003] However, the life of a battery is greatly affected by conditions such as a use temperature, a use period, a charge voltage, and the number of times of discharge, and therefore is not constant, and it is not easy to judge it.

As a method of determining the life of a battery, there is known a method of determining the life by measuring an internal resistance that increases at the end of the life of the battery or when a failure occurs.

However, in the battery life determining method using the internal resistance, it is necessary to collect in advance data of a change in the internal resistance over a long period of time from the new state of the battery to the end of its life.

Therefore, as a battery life determining method that does not require such data collection, a battery life determining method using a discharge voltage has been proposed. This is a method of actually discharging a battery under a constant load for a long time to determine the life, measuring the discharge voltage, and determining the life based on the measurement result. Show.

First, in step S101, discharging of the battery is started, and at that time, measurement of the discharging time is also started. Next, in step S102, it is determined whether the discharge voltage VB is higher than the discharge end voltage VE. If it is higher, proceed to step S103; if it is lower, step S103
Proceed to 105.

In step S105, a process for determining the life (such as external output) is performed, and the process proceeds to step S104, in which the discharge is terminated and the process is terminated. When the process proceeds to step S103, it is determined whether the discharge time is longer than the determination time TE (backup time). If it is longer, the process proceeds to step S104, where the discharge of the battery is terminated, and the process is terminated. If it is shorter, the process returns to step S102, and the comparison of the battery voltage is repeated. In other words, when the discharge voltage is lower than the discharge end voltage within the determination time, the life is determined.

[0009]

However, in the case of the above-mentioned conventional battery life determining method using a discharge voltage, only the actual backup time (the time required for the backup operation performed after the life determination) in the discharge state of a constant current is obtained. Since the life is determined by discharging the battery, the battery is discharged for a long time. Therefore, it takes a long time to charge the battery thereafter, which causes not only a system using the battery to be unusable for a long time, but also a problem that the battery is brought one step closer to the end of its life due to the long-time discharge.

The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a battery life judging method that can easily judge the life of a battery. Another object of the present invention is to provide a battery life determining device that can easily determine the life of a battery and output battery replacement information at an appropriate time.

[0011]

According to a first aspect of the present invention, there is provided a battery life determining method for determining whether a battery is in a fully charged state. A measuring step of starting discharging of the battery when the battery is in a fully charged state, and measuring a discharge voltage and a discharge current when a predetermined time has elapsed from the start of the discharging; and A range determining step of determining whether or not the discharged discharge current is within a life determinable range, and when the discharge current is determined to be within a life determinable range in the range determining step, the discharge current Judgment data acquisition means for acquiring corresponding life judgment data, comparing the magnitude of the discharge voltage measured in the measuring step with the life judgment data, and when the discharge voltage is smaller than the life judgment data Is to have a battery life judging process judges that battery life.

According to a second aspect of the invention, there is provided a battery life determining method for determining whether or not a battery is fully charged, and determining whether or not the battery is fully charged. A first measuring step of measuring a discharge current when a first time elapses from the start of the discharge as a first discharge current, and determining that the first discharge current has a life determinable range. A first range determination step of determining whether the first discharge current is within a life-determinable range in the first range determination step. A second measuring step of measuring a discharge voltage when a second time has elapsed from the time and measuring a discharge current after the second time has elapsed as a second discharge current; Is within the life determination range A second range determination step, and when it is determined in the second range determination step that the second discharge current is within the life determinable range, the average value of the first and second discharge currents is determined. The average value calculation step to be determined, the determination data obtaining step to obtain life determination data corresponding to the average value, and comparing the magnitudes of the discharge voltage and the life determination data measured in the second measurement step, A battery life judging step of judging the battery life when the discharge voltage is smaller than the life judgment data.

According to a third aspect of the present invention, there is provided a battery life determining method for determining whether or not a battery is fully charged, and determining whether the battery is fully charged when the battery is fully charged. A temperature measuring step of measuring the temperature of the environment, a temperature range determining step of determining whether or not the temperature measured in the temperature measuring step falls within a life determinable range, and a temperature determined in the temperature range determining step. When the battery life is within the life determinable range, the battery starts discharging, and a measuring step of measuring a discharging voltage and a discharging current when a predetermined time has elapsed from the start of the discharging; and A current range determination step of determining whether the measured discharge current is within the life determinable range, and that the discharge current is determined to be within the life determinable range in the current range determination step. Determining data obtaining means for obtaining life determination data corresponding to the discharge current and the temperature; comparing the magnitude of the discharge voltage measured in the measurement step with the life determination data; A battery life determining step of determining that the battery life has elapsed when the value is smaller than the determination data.

According to a fourth aspect of the invention, there is provided a battery life determining method for determining whether or not a battery is fully charged, and determining whether the battery is fully charged when the battery is fully charged. A temperature measuring step of measuring the temperature of the environment, a temperature range determining step of determining whether or not the temperature measured in the temperature measuring step falls within a life determinable range, and a temperature determined in the temperature range determining step. When the battery life falls within the life determinable range, the battery discharge is started, and a discharge current when a first time has elapsed from the start of the discharge is measured as a first discharge current.
And a first current range determination step of determining whether the first discharge current is within a life determination range,
When it is determined in the first current range determination step that the first discharge current is within the life determinable range, a discharge voltage is measured when a second time has elapsed from the start of the discharge. A second measuring step of measuring a discharge current at the time when the second time has elapsed as a second discharge current, and a second step of determining whether the second discharge current is within a life determinable range. The current value determination step and the second current range determination step, when it is determined that the second discharge current is within the life determinable range, the average value of the first and second discharge current Calculating an average value, determining data obtaining means for obtaining life determining data corresponding to the average value and the temperature, and comparing the magnitude of the discharge voltage measured in the second measuring step with the life determining data. And the discharge voltage is based on the life determination data. It is to have a battery life judging process judges that battery life is smaller.

According to a fifth aspect of the invention, there is provided a battery life determining apparatus for determining whether or not a battery is fully charged, and determining whether the battery is fully charged when the battery is fully charged. Measurement means for measuring a discharge voltage and a discharge current when a predetermined time has elapsed from the start of the discharge, and whether the discharge current measured by the measurement means is within a life determinable range. A range determining unit that determines whether the discharge current is within the life determinable range by the range determining unit, and a determination data obtaining unit that obtains life determining data corresponding to the discharge current; A battery life judgment procedure for comparing the magnitude of the discharge voltage measured by the measuring means with the life judgment data, and judging the battery life when the discharge voltage is smaller than the life judgment data. Lies in that it has a door.

According to a sixth aspect of the present invention, there is provided a battery life determining apparatus, comprising: a full charge determining means for determining whether a battery is fully charged; and a battery when the battery is fully charged. And a first measuring means for measuring a discharge current when a first time elapses from the start of the discharge as a first discharge current, and wherein the first discharge current is within a life determinable range. A first range determining means for determining whether the first discharge current is within the range of a service life, and a start of the discharge when the first range current is determined to be within a life determinable range. A second measuring means for measuring a discharge voltage when a second time has elapsed from the time and measuring a discharge current at the time when the second time has elapsed as a second discharge current; Is within the life determination range When the second range determining means and the second range determining means determine that the second discharge current is within the life determinable range, the average value of the first and second discharge currents is calculated. The calculated average value calculating means, the judgment data obtaining means for obtaining the life judgment data corresponding to the average value, and comparing the magnitude of the discharge voltage measured by the second measuring means with the life judgment data, Battery life determining means for determining that the battery life has elapsed when the discharge voltage is smaller than the life determination data.

According to a seventh aspect of the present invention, there is provided a battery life determining apparatus for determining whether or not a battery is fully charged, and determining whether the battery is fully charged when the battery is fully charged. Temperature measuring means for measuring the temperature of the environment, temperature range determining means for determining whether or not the temperature measured by the temperature measuring means falls within a life determinable range, and a temperature determined by the temperature range determining means. Measuring means for measuring a discharge voltage and a discharge current when a predetermined time has elapsed from the start of the discharge when the battery life is within the life determinable range; and Current range determining means for determining whether the measured discharge current is within the life determinable range, and when the discharge current is determined to be within the life determinable range by the current range determining means. A determination data acquisition unit that acquires life determination data corresponding to the discharge current and the temperature; and compares the magnitude of the discharge voltage measured by the measurement unit with the life determination data, and determines that the discharge voltage is equal to the lifetime. Battery life determining means for determining that the battery life has elapsed when the value is smaller than the determination data.

The battery life determining apparatus according to the present invention is characterized in that a full charge determining means for determining whether or not the battery is fully charged, and the battery when the battery is fully charged. Temperature measuring means for measuring the temperature of the environment, temperature range determining means for determining whether or not the temperature measured by the temperature measuring means falls within a life determinable range, and a temperature determined by the temperature range determining means. When the battery life falls within the life determinable range, the battery discharge is started, and a discharge current when a first time has elapsed from the start of the discharge is measured as a first discharge current.
Measuring means, and first current range determining means for determining whether the first discharge current is within a life determinable range,
When the first current range determination means determines that the first discharge current is within the life determinable range, a discharge voltage is measured when a second time has elapsed from the start of the discharge. A second measuring means for measuring a discharge current at the lapse of the second time as a second discharge current; and a second determining means for determining whether or not the second discharge current is within a life determinable range. When the second current range determining means determines that the second discharge current is within the life determinable range, the average value of the first and second discharge currents is determined. Average value calculation means to be obtained, determination data obtaining means for obtaining life determination data corresponding to the average value and the temperature, and comparison between the discharge voltage measured by the second measuring means and the life determination data. And the discharge voltage is based on the life determination data. It is to have a determining battery life judging means and battery life when small.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 is a flowchart showing a battery life determining method according to a first embodiment of the present invention. FIG. 2 is a flowchart for realizing the battery life determining method shown in FIG. It is a block diagram showing composition of a battery life judging device.

First, referring to FIG. 2, the battery life determining device includes a charger 1 for charging a battery 4 and a load device 8.
A voltage detecting means 5 for detecting a discharge voltage of the battery 4 connected to the battery 4, a current detecting means 7 for detecting a discharge current of the battery 4,
The battery charging / discharging unit includes a switch 2 for connecting / disconnecting the battery 4 and the charger 1 and a switch 6 for connecting / disconnecting the battery 4 and the load device 8.

The detection results of the voltage detecting means 5 and the current detecting means 7 of the battery charging / discharging section are supplied to the life judging section 9 via the A / D converter 20. The life determining unit 9 determines the RO in which the life determining data table is recorded.
M10, a RAM 11 in which the detection results of the voltage detection means 5 and the current detection means 7 converted into digital values by the A / D converter 20 are stored, and a predetermined life determination voltage Vh (described later) and recorded in the RAM 11. Discharge voltage Vs
(To be described later).
Then, the life determination result 13 which is the output of the arithmetic unit 12
Is output to the outside.

Next, prior to a specific description of the battery life determining method of the present embodiment realized using the battery life determining apparatus having the above-described configuration, the battery life determining method of the present embodiment such as the definition of the life in the present embodiment will be described. An outline of the method will be described with reference to FIGS.

In this embodiment, the life is defined as the battery 4
Is defined as when the capacity of the battery reaches 50% of the initial state. As an example, FIG. 3 shows the discharge voltage characteristics when the battery 4 in the initial state (new) is discharged at a constant current from the fully charged state. The characteristic curve shown in the figure is a curve that is gentle at first and sharply falls in the latter half.

Here, the discharge end voltage of the battery 4 is Ve
When the battery 4 starts discharging,
Ve is reached after an hour. Therefore, it is possible to discharge for one hour in the initial state. Therefore, the capacity that can be discharged for one hour in the initial state is set to the capacity 10 of the battery 4.
0%. Further, when the time from the start of discharging to reaching Ve after using the battery 4 for a long time is 30 minutes (half of an hour), the capacity of the battery 4 is changed to the initial state. 50% of half compared to
It turns out that. Therefore, at this time, the life has been reached.

The end-of-discharge voltage Ve is a threshold voltage set to prevent the battery 4 from being over-discharged. Discharge below this voltage is not performed to protect the battery 4. Further, Te in FIG. 3 is the time from the start of the discharge to the end of discharge voltage Ve, and Th is half the time of Te.

Next, the discharge voltage characteristics until the end of the life will be described. The discharge voltage characteristics of a battery are specific to the battery, and the discharge voltage characteristics of the same type of battery are not affected by the capacity (Ah) of the battery. Further, this discharge voltage characteristic is characterized in that it is always on the same curve from the initial state (new) to the end of its life. In other words, the curve of the discharge voltage characteristic of the battery after long-term use always appears on the curve of the discharge voltage characteristic in the initial state. These points will be described with reference to FIG.

Immediately after discharging, the battery from the initial state to a capacity reduction of 10% starts discharging from the voltage Vs (stable voltage after discharging) at the leftmost point in the curve shown in FIG. 3, and discharges according to this curve. . Next, when the battery has been used for a certain period and the capacity has decreased by 20% compared to the initial capacity, the battery immediately after discharging has a capacity of 0.2 [h] in the curve of FIG.
ow], and discharge is performed according to this curve.

Further, when the battery is used for a certain period and the capacity is reduced by 40% as compared with the initial capacity, the battery immediately after discharging has a voltage of 0.4 [hour] in the curve shown in FIG. Discharge starts and discharges according to this curve. That is, as the use becomes longer, Vs moves to the right on the curve in FIG.

Based on the above definition of the life and the discharge voltage characteristic of the battery, the battery life judgment method according to the present embodiment is as follows.

From the discharge voltage characteristics of an initial state (new) of a certain battery, the time until the discharge end voltage Ve is reached is determined. Next, the discharge voltage Vs immediately after the battery discharge at the time of the capacity 50%, which is determined as the life of the battery, is the discharge voltage Vh at the time Th, which is half the discharge time Te shown in FIG.
Becomes

Thus, the life of the battery can be determined by comparing the discharge voltage Vs immediately after the discharge with the discharge voltage Vh during the discharge time Th. That is, when Vs becomes smaller than Vh (Vs <Vh), the life is determined. Here, Vh is defined as a life determination voltage.

Next, the voltage Vs immediately after the battery is used for determining the life will be described with reference to FIG. FIG. 4 is an enlarged view of a discharge voltage characteristic immediately after discharge. It is known that it takes several seconds for the voltage Vs immediately after the discharge used for the life determination to stabilize. Thus, it is assumed that the fully charged battery 4 in FIG. 4 starts discharging at time T0.
Thereafter, the discharge voltage has a sharply falling curve, and the time T1
After the lapse of time, a stable and almost linear discharge voltage curve is obtained. This indicates that the discharge voltage of the battery is not stable between time T0 and T1.

From this, it is assumed that the stable voltage V1 after the lapse of the time T1 from the start of the discharge is used as Vs used for the life determination in this embodiment. However, if the battery discharge rate is low (1 [C])
(Less than) tens of seconds or more in some cases (for example, C / 3 means full capacity discharge in 3 hours). It is not preferable to perform discharge for several tens of seconds or more to determine the life, and the discharge must be suppressed to several seconds. That is, if the discharge time is long, the capacity of the battery that can be discharged decreases, and the charging time also increases. For this reason, when an actual backup operation occurs after the life determination, the original backup operation cannot be sufficiently performed. For this reason, it is not preferable to perform discharge for several tens of seconds or more to determine the life.

Therefore, in the life determination according to the present embodiment,
Life determination is performed only when the discharge rate is 1 [C] or more. In this case, the time until stabilization is within T1 = 5 seconds. Further, the determination of the life of the battery in a system that does not cause any trouble even if the discharge is performed for several tens of seconds or more is not limited to this.

Next, the life determining method according to the present embodiment will be specifically described with reference to the flowchart of FIG.

When the life is judged, since the changeover switch 2 is initially turned on and the changeover switch 6 is turned off, the battery 4 whose life is to be judged is determined.
Is separated from the load device 8 and is in a charged state. The changeover switches 2 and 6 are operated by the life determining unit 9.

The life determination is started by making a full charge determination of the battery 4 in step S11 of FIG. The full charge determination is made based on whether or not the voltage measured by the voltage detection means 5 is equal to or higher than a certain voltage. Specifically, after the measured voltage is recorded in the RAM 11, it is compared with the full charge determination voltage previously recorded in the ROM 10 by the calculator 12. If the voltage of the battery 4 is equal to or higher than the full charge determination voltage, it is determined that the battery is fully charged.

Here, when the full charge is not detected, the life judgment is not performed. This is to fix the state of the battery 4 whose life is to be determined to a fully charged state so that the life is determined in a constant state at all times.

If a full charge is detected in step S11, the process proceeds to step S12. In this embodiment, the full charge determination voltage recorded in the ROM 10 used here is set to 13.65 [V].
If there is a difference in the charging environment and the number of batteries, it can be changed.

In step S12, discharging of the battery 4 is started. The discharge is started by turning off the changeover switch 2 and turning on the changeover switch 6.

Next, in step S13, the discharge current Is after a lapse of time T2 from the start of discharge is measured. The measurement of the discharge current Is is performed by the current detection means 7. The measured discharge current Is is recorded in the RAM 11. This T2 is a time between T0 and T1 in FIG. 4, and T2 = 1 second. The reason for using the discharge current after the lapse of time T2 is that the discharge current is not stable immediately after the discharge. Since the value of the time T2 changes depending on the type of the battery 4, the value can be changed.

Next, it is determined whether or not the discharge current Is measured in step S14 is within the life determinable range. If the discharge rate of the battery 4 is low, it may take several tens of seconds or more to reach a stable discharge voltage. As described above, it is not preferable to perform discharge for several tens of seconds or more for the purpose of determining the life. Therefore, the discharge must be suppressed to several seconds. Therefore, the discharge current Is stored in the RAM 11 in this step is compared with the life determinable current stored in the ROM 10 by the computing unit 12, and if it is within the possible range, the process proceeds to step S15. Does not judge the life.

In step S15, the discharge time T1
At this time, the discharge voltage Vs of the battery 4 is measured. The measurement is performed by the voltage detecting means 5. Measured discharge voltage V
s is stored in the RAM 11.

Next, in step S16, the discharge current Ie after a lapse of time T1 from the start of the discharge is measured. The measurement of the discharge current Ie is performed by the current detection means 7.
The measured discharge current Ie is stored in the RAM 11.
Here, the reason why the discharge current is measured over two times T1 and T2 is that when the load fluctuates during the discharge time T1 and the discharge current is out of the life judgment, the battery 4 is measured.
This is because the life determination is not performed. Also, the discharge current Ie
After the measurement is completed, the changeover switch 6 is turned off and the changeover switch 2 is turned on to end the discharge of the battery 4.

Next, in step S17, it is determined whether or not the measured discharge current Ie falls within the life determinable range. Therefore, the discharge current Ie stored in the RAM 11 is compared with the life determinable current stored in the ROM 10 in advance by the computing unit 12, and if it is within the possible range, the process proceeds to step S18. Not performed.

Next, in step S18, the RAM 11
And the average current Ec of the discharge currents Is and Ie stored in the RAM 11 is stored in the RAM 11.

Next, in step S19, the RAM 11
The life determination data Vh is obtained from the life determination data table stored in the ROM 10 in advance by the average current Ec stored in the ROM 10.

Here, the life judgment data table recorded in the ROM 10 will be described. In the above description of the life determination method, in order to determine the life determination voltage Vh,
First, the time Te until the discharge end voltage Ve is reached must be determined from the discharge voltage characteristics of a new battery in a fully charged state during constant current discharge. Then, the discharge voltage at the time Th, which is half of Ve, becomes the life determination voltage Vh. Here, Te changes when the value of the discharge current changes (FIG. 6).
reference). That is, when the value of the discharge current changes, Te, T
h and Vh change.

Actually, when the life is determined, the life must be determined in accordance with the discharge current of the battery 4 connected to the variable load device 8, so that Vh at various discharge current values is required. Come. Therefore, the data of the life determination voltage Vh at each discharge current value is collected in advance, and RO as a data table corresponding to the discharge current.
It is stored in M10. As a result, the life determination voltage Vh corresponding to the discharge current value can be obtained from the average current Ec stored in the ROM 10.

Next, in step S20, the life determining voltage Vh obtained in step S19 is compared with Vs stored in the RAM 11 by the computing unit 12. And
If Vs is less than Vh, it is determined that the life has expired, and if Vs is not less than Vh, it is determined that the life has not expired.

If it is determined that the life has expired, step S21 is performed.
, The life determining unit 9 notifies the outside that the battery 4 has reached the end of its life.

The discharge current may be detected only by Ie. However, by detecting Is and Ie, it is possible to reduce the amount of discharge of the battery 4 and determine whether the life can be determined as soon as possible. (At time T2).

As described above, in the present embodiment, the battery is discharged for a certain period of time (time until the discharge voltage is stabilized: 5 seconds) in a power supply device using the battery, and the discharge voltage of the battery after the short-time discharge is performed. And the discharge current to determine the life of the battery. This allows the battery life to be determined without collecting data on the change in internal resistance over a long period of time from the new state of the battery to the end of its life as in the related art, and without discharging the battery for a long time. can do.

(Second Embodiment) In the first embodiment,
The average value Ec of the discharge currents Is and Ie is obtained, and the life determination voltage Vh is obtained from the Ec from the data table. In the present embodiment, the average value Ec is obtained in the configuration of the first embodiment. Instead, the life determination voltage Vh is obtained from the data table from Ie. FIG. 7 shows a flowchart thereof.

When the life is determined, the changeover switch 2 is initially turned on and the changeover switch 6 is turned off, so that the battery 4 is disconnected from the load device 8 and is in a charged state.

First, in step S31, the battery 4
The processing is started by making a full charge determination of (step S11 in FIG. 1). If the voltage of the battery 4 is equal to or higher than the full charge determination voltage, it is determined that the battery is fully charged. Here, when the full charge is not detected, the life determination is not performed. When full charge is detected in step S31, the process proceeds to step S32 (corresponding to step S12 in FIG. 1), and discharging of the battery 4 is started. The discharge is started by turning off the changeover switch 2 and turning on the changeover switch 6.

Next, step S33 (step S33 in FIG. 1)
15), the discharge voltage Vs of the battery 4 during the discharge time T1 is measured. The measured discharge voltage Vs is RA
It is stored in M11.

Subsequently, step S34 (step S34 in FIG. 1)
(Corresponding to 16), the discharge current Ie after a lapse of time T1 from the start of discharge is measured by the current detection means 7.
The measured discharge current Ie is stored in the RAM 11.
After the measurement of the discharge current Ie, the changeover switch 6 is turned off and the changeover switch 2 is turned on to end the discharge of the battery 4.

Next, step S35 (step S35 in FIG. 1)
17), it is determined whether or not the measured discharge current Ie is within the life determinable range. Therefore, the discharge current Ie stored in the RAM 11 and RO
The computing unit 12 compares the life-determinable current stored in advance in M10 with the computing unit 12. If it is within the possible range, the process proceeds to step S36.

Next, in step S36, the RAM 11
The life determination voltage Vh is obtained from the life determination data table stored in the ROM 10 in advance from the discharge current Ie stored in the ROM.

Next, step S37 (step S37 in FIG. 1)
(Corresponding to 20), the arithmetic unit 12 compares the importance determination voltage Vh acquired in step S36 with Vs stored in the RAM 11. If Vs is less than Vh, it is determined that the life has expired. If Vs is not less than Vh, it is determined that the life has not expired.

If it is determined that the life has expired, step S38
In (corresponding to step S21 in FIG. 1), the life determination unit 9 notifies the outside that the battery 4 has reached the end of its life.

In this embodiment, the same effects as in the first embodiment can be obtained.

(Third Embodiment) FIG. 8 is a flowchart showing a battery life judging method according to a third embodiment of the present invention. FIG. 9 is a flowchart showing a battery life judging device according to the third embodiment of the present invention. FIG. 3 is a block diagram illustrating a configuration.

In the present embodiment, the life judgment is performed by adding a temperature parameter to the life judgment method described in the first embodiment. As shown in FIG.
The temperature detecting means 30 is added in the configuration of FIG.

The discharge voltage characteristics of a battery vary greatly depending on the temperature of the environment in which it is used (see FIG. 10). As shown in the figure, the curve shifts to the upper right when the temperature increases, and shifts to the lower left when the temperature decreases. As a result, the time Te until the discharge end time Ve changes, as a result, the half time Th of Te also changes, and the life determination voltage Vh changes depending on the temperature. For this reason, it is necessary to perform a life determination with temperature correction. For example, 25 [° C]
When Vh is set and the life is determined without considering the temperature, the life may be determined in the environment of 5 ° C. even though the battery has not reached its life. This correction method is performed by selecting the life determination voltage Vh based on the discharge current and the temperature in the life determination data table used in the first embodiment.

When the life is judged, the changeover switch 2 is initially turned on and the changeover switch 6 is turned off, so that the battery 4 is disconnected from the load device 8 and is in a charged state. This changeover switch is operated by the life determining unit 9.

The life determination is started by making a full charge determination of the battery 4 in step S41 of FIG. 8 as in step S11 of FIG. If full charge is detected in step S41, the process proceeds to step S42,
An environment temperature Tmp for determining the life of the battery 4 is measured. The measurement is performed by the temperature detecting means 30 in FIG. 9, and the temperature Tmp is stored in the RAM 11.

In step S43, it is determined whether or not the temperature Tmp stored in the RAM 11 falls within the life determinable range. This determination is made by comparing the temperature Tmp stored in the RAM 11 with the life determinable range temperature recorded in the ROM 10 by the computing unit 12.

If it is determined that the life is within the life determinable range,
Proceed to step S44. If it is determined that the value is out of the range, the life is not determined. The determination of the life determinable range is performed when the temperature is extremely low or extremely high because the discharge voltage characteristics of the battery 4 change significantly and accurate life determination cannot be performed. In the present embodiment, the life determination range is set to be 0 ° C. or more and 40 ° C. or less, but this range can be changed based on the performance of the battery 4.

In the next step S44, discharging of the battery 4 is started. The discharge is started by turning off the changeover switch 2 and turning on the changeover switch 6.

In the next step S45, similarly to step S13 in FIG. 1, the discharge current Is after a lapse of time T2 from the start of the discharge is measured, and in the next step S46, the discharge current Is in FIG.
As in step S14, it is determined whether the measured discharge current Is falls within the life determinable range.

In step S47, similarly to step S15 of FIG. 1, the discharge voltage Vs of the battery 4 during the discharge time T1 is measured.

In the following step S48, the discharge current Ie is measured after a lapse of time T1 from the start of the discharge in the same manner as in step S16 of FIG. After the measurement of the discharge current Ie, the changeover switch 6 is turned off and the changeover switch 2 is turned on to end the discharge of the battery 4.

In the next step S49, similarly to step S17 in FIG. 1, it is determined whether or not the measured discharge current Ie falls within the life determinable range. Therefore, R
The discharge current Ie stored in the AM 11 and the ROM 10
And the life-determinable current stored in advance in
If it is within the feasible range, the process proceeds to step S50, and if it is outside the feasible range, the life is not determined.

Further, in step S50, the average current Ec of the discharge currents Is and Ie stored in the RAM 11 is obtained as in step S18 of FIG.
To memorize.

Next, in step S51, the average current Ec and the temperature Tmp stored in the RAM 11 are used to calculate R
The life judgment data Vh is obtained from the life judgment data table stored in the OM 10.

Here, the life determination data table recorded in the ROM 10 will be described. In the above description of the life determination method, the life determination data Vh is determined by first obtaining a time Te until the discharge end voltage Ve is reached from the discharge voltage characteristic of the fully charged new battery 4 at the time of constant current discharge. There must be. Then, the discharge voltage at the time of Th which is half of this Ve becomes the life determination voltage Vh. Here, this Te changes when the values of the discharge current and the temperature change (see FIGS. 6 and 10). That is, when the values of the discharge current and the temperature change, Te, Th, and Vh change. Actually, when the life is determined, the life must be determined according to the discharge current of the battery 4 connected to the variable load device 8 instead of the environment where the temperature is constant. That is, Vh at various discharge current and temperature values is required. Therefore, the values of the life determination voltage Vh at each temperature corresponding to each discharge current value are collected in advance and stored in the ROM 10 as a data table corresponding to the discharge current and temperature (see FIG. 5). Thus, the life determination voltage Vh corresponding to the discharge current value can be obtained from the average current Ec and the temperature Tmp stored in the ROM 10.

Next, in step S 52, the life determining voltage Vh obtained in step S 51 is compared with Vs stored in the RAM 11 by the arithmetic unit 12. And
If Vs is less than Vh, it is determined that the life has expired, and if Vs is not less than Vh, it is determined that the life has not expired.

If it is determined that the life has expired, the process proceeds to step S53.
, The life determining unit 9 notifies the outside that the battery 4 has reached the end of its life.

As described above, in the present embodiment, the battery is discharged for a certain period of time (time until the discharge voltage is stabilized: 5 seconds) in a power supply device using the battery, and the discharge voltage of the battery after the short-time discharge is performed. And the life of the battery is determined from the discharge current and the temperature. Thus, the life of the battery can be easily determined even when the temperature or the discharge current changes.

(Fourth Embodiment) In the third embodiment,
The average value Ec of the discharge currents Is and Ie is obtained, and the life determination voltage Vh is obtained from the data table based on the average value Ec and the temperature Tmp. However, in the present embodiment, in the configuration of the third embodiment, Without finding the average value Ec,
The life determination data Vh is obtained from the data table based on the discharge current Ie and the temperature Tmp. FIG.
FIG. 1 shows the flowchart.

In the present embodiment, the battery life is determined according to FIG.
In step S61, the process is started by making a full charge determination of the battery 4 as in step S11 of FIG.

If full charge is detected in step S61, the process proceeds to step S62, and step S4 in FIG.
2, the temperature T of the environment in which the life of the battery 4 is determined.
Measure mp. The measurement is performed by the temperature detecting means 30 in FIG. 9, and the temperature Tmp is stored in the RAM 11.

In step S63, step S4 in FIG.
Similarly to 3, it is determined whether or not the temperature Tmp stored in the RAM 11 is within the life determinable range. This determination is based on the temperature Tmp and the RO stored in the RAM 11.
Computation is performed by the computing unit 12 with the life determinable range temperature recorded in M10. When it is determined that the life is within the life determinable range, the process proceeds to step S64. If it is determined that the value is out of the range, the life is not determined.

In the next step S64, discharging of the battery 4 is started. The discharge is started by turning off the changeover switch 2 and turning on the changeover switch 6.

In the following step S65, the discharge voltage Vs of the battery 4 during the discharge time T1 is measured as in step S15 in FIG. 1, and in step S66, after the discharge is started in the same manner as in step S16 in FIG. The discharge current Ie after the elapse of the time T1 is measured and stored in the RAM 11. After the measurement of the discharge current Ie, the changeover switch 6 is turned off and the changeover switch 2 is turned on to end the discharge of the battery 4.

In the next step S67, similarly to step S17 in FIG. 1, it is determined whether or not the measured discharge current Ie falls within the range in which the life can be determined. Therefore, R
The discharge current Ie stored in the AM 11 and the ROM 10
And the life-determinable current stored in advance in
If it is within the feasible range, the process proceeds to step S68.

Next, in step S68, the RO current is calculated based on the discharge current Ie and the temperature Tmp recorded in the RAM 11.
The life judgment voltage Vh is obtained from the life judgment data table stored in M10.

In step S69, the computing unit 12 compares the life determination voltage Vh obtained in step S68 with Vs stored in the RAM 11. If Vs is less than Vh, it is determined that the life has elapsed, and Vs is Vh.
In the above case, it is determined that the life has not expired.

If it is determined that the life has expired, step S70
, The life determining unit 9 notifies the outside that the battery 4 has reached the end of its life.

In the fourth embodiment, the same effects as in the third embodiment can be obtained.

[0094]

As described above in detail, according to the battery life judging method according to the first and second aspects of the present invention, the life judging voltage Vh can be obtained only from the charging voltage characteristic in the fully charged state. It does not collect data on changes in internal resistance over a long period of time from the new state of the battery to the end of its life as in the prior art, and does not discharge the battery over a long period of time. Finally, the battery life can be determined.

According to the battery life judging method according to the third and fourth aspects of the invention, the same effects as those of the first and second aspects of the invention can be obtained, and the life of the battery can be maintained even when the temperature changes. Can be easily determined.

According to the battery life judging device according to the fifth and sixth aspects, the same effects as those of the first and second aspects of the invention can be obtained, and the battery replacement information is output at an appropriate time. Can be.

According to the battery life judging device according to the seventh and eighth aspects, the same effects as those of the third and fourth aspects can be obtained, and the battery replacement information is output at an appropriate time. Can be.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating a battery life determining method according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a battery life determining device for realizing the battery life determining method shown in FIG.

FIG. 3 is a diagram showing discharge voltage characteristics when a battery in an initial state (new) is discharged at a constant current from a fully charged state.

FIG. 4 is an enlarged view of a discharge voltage characteristic immediately after discharge.

FIG. 5 is a life determination voltage Vh stored in a RAM 10;
FIG. 4 is a diagram showing a data table of FIG.

FIG. 6 is a diagram of a discharge voltage characteristic of a battery depending on a difference in discharge current.

FIG. 7 is a flowchart illustrating a battery life determining method according to a second embodiment of the present invention.

FIG. 8 is a flowchart illustrating a battery life determining method according to a third embodiment of the present invention.

FIG. 9 is a block diagram showing a configuration of a battery life determining device according to a third embodiment of the present invention.

FIG. 10 is a graph showing a discharge voltage characteristic of a battery depending on a difference in temperature.

FIG. 11 is a flowchart illustrating a battery life determining method according to a fourth embodiment of the present invention.

FIG. 12 is a flowchart showing a conventional battery life determining method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Charger 2 Changeover switch 4 Battery 5 Voltage detection means 6 Changeover switch 7 Current detection means 8 Load device 9 Life determination unit 10 ROM 11 RAM 12 Computing unit 20 A / D converter 30 Temperature detection unit

Claims (8)

[Claims] 1. A full charge determining step of determining whether a battery is in a fully charged state, and starting discharging of the battery when the battery is in a fully charged state, and for a predetermined time from the start of the discharging. A measurement step of measuring a discharge voltage and a discharge current when the elapsed time, a range determination step of determining whether or not the discharge current measured in the measurement step is within a life determination range, and the range determination step. When the discharge current is determined to be within the life determinable range, a determination data obtaining unit that obtains life determination data corresponding to the discharge current, a discharge voltage measured in the measurement step and the life determination data A battery life judging step of judging the battery life when the discharge voltage is smaller than the life judgment data. 2. A full charge determining step of determining whether the battery is in a fully charged state; and starting discharging of the battery when the battery is in a fully charged state; Measuring the discharge current when the time has elapsed as the first discharge current.
Measuring step; determining whether the first discharge current is within a life determinable range; and determining whether the first discharge current has a life in the first range determination step. When it is determined that the discharge voltage is within the allowable range, a discharge voltage when a second time has elapsed from the start of the discharge is measured, and the discharge current after the second time has elapsed is measured as a second discharge current. A second measurement step of measuring the second discharge current, a second range determination step of determining whether or not the second discharge current is within a life determinable range, and a second range determination step of determining the second discharge current in the second range determination step. An average value calculating step of obtaining an average value of the first and second discharge currents when it is determined that the discharge current is within the life determinable range; and a determination of obtaining life determination data corresponding to the average value. A data acquisition step, and a discharge measured in the second measurement step Comparing the magnitude of the pressure and the lifetime determination data, battery life judging process, characterized in that the discharge voltage and a battery life judging process judges that battery life is smaller than the lifetime determination data. 3. A full charge determining step of determining whether the battery is in a fully charged state; a temperature measuring step of measuring a temperature of the battery environment when the battery is in a fully charged state; A temperature range determining step of determining whether or not the temperature measured in the step is within the life determinable range; and, if the temperature determined in the temperature range determining step is within the life determinable range, A battery discharging start, a measuring step of measuring a discharging voltage and a discharging current when a certain period of time has elapsed from the start of the discharging, and whether the discharging current measured in the measuring step is within a life determinable range. A current range determining step of determining whether or not the discharge current is within a life determinable range in the current range determining step; and life determining data corresponding to the discharge current and the temperature. Determining data obtaining means for obtaining, battery life determination for comparing the magnitude of the discharge voltage measured in the measurement step with the life determination data, and determining that the battery life is reached when the discharge voltage is smaller than the life determination data And a battery life determining method. 4. A full charge determining step of determining whether the battery is in a fully charged state; a temperature measuring step of measuring a temperature of the battery environment when the battery is in a fully charged state; A temperature range determining step of determining whether or not the temperature measured in the step is within the life determinable range; and, if the temperature determined in the temperature range determining step is within the life determinable range, A first measuring step of starting discharge of the battery and measuring a discharge current when a first time has elapsed from the start of the discharge as a first discharge current; and determining that the first discharge current has a life span. A first current range determination step of determining whether or not the first discharge current is within a range; and when the first discharge current is determined to be within a life determination range in the first current range determination step, Second from the beginning of the discharge A second measuring step of measuring the discharge voltage when the time has elapsed and measuring the discharge current at the time when the second time has elapsed as a second discharge current; A second current range determining step of determining whether or not the second discharge current is within a range; and when it is determined in the second current range determining step that the second discharge current is within a life determinable range, First
And an average value calculating step of obtaining an average value of the second discharge current; determining data obtaining means for obtaining life determining data corresponding to the average value and the temperature; and a discharge voltage measured in the second measuring step. A battery life determining step of comparing the magnitude of the battery life determination data with the battery life determination data, and determining that the battery life has elapsed when the discharge voltage is smaller than the life determination data. 5. A full-charge determining means for determining whether or not the battery is in a fully charged state, and starting discharging the battery when the battery is in a fully charged state, and for a predetermined time from the start of the discharging. Measuring means for measuring a discharge voltage and a discharge current when elapses, a range determining means for determining whether or not the discharge current measured by the measuring means is within a life determinable range, and the range determining means When it is determined that the discharge current is within the life determinable range, a determination data obtaining unit that obtains life determination data corresponding to the discharge current, a discharge voltage measured by the measuring unit and the life determination data And a battery life determining unit that determines the battery life when the discharge voltage is smaller than the life determination data. 6. A full-charge determining means for determining whether or not the battery is in a fully charged state, and starting discharging of the battery when the battery is in a fully charged state; Measuring the discharge current when the time has elapsed as the first discharge current.
Measuring means; first range determining means for determining whether or not the first discharge current is within a life-determinable range; and the first range current determining the life of the first discharge current by the first range determining means. When it is determined that the discharge voltage is within the allowable range, a discharge voltage when a second time has elapsed from the start of the discharge is measured, and the discharge current after the second time has elapsed is determined by a second discharge current. A second measuring means for measuring the second discharge current, a second range judging means for judging whether or not the second discharge current is within a life judging range; Means for calculating an average value of the first and second discharge currents when it is determined that the discharge current is within the life-determinable range; and determination for obtaining life-determination data corresponding to the average value. Data acquisition means, and discharge measured by the second measurement means Wherein the pressure life size of the decision data to compare the battery life determining apparatus characterized by having a battery life judging means judges that the battery life when the discharge voltage is smaller than the lifetime determination data. 7. A full charge determination unit for determining whether the battery is in a fully charged state, a temperature measurement unit for measuring a temperature of the battery environment when the battery is in a fully charged state, and the temperature measurement Temperature range determining means for determining whether or not the temperature measured by the means is within the life determinable range; and, when the temperature determined by the temperature range determining means is within the life determinable range, Measuring means for starting discharging of the battery and measuring a discharging voltage and a discharging current when a predetermined time has elapsed from the start of the discharging, and whether the discharging current measured by the measuring means is within a life determinable range. Current range determining means for determining whether or not the discharge current is within the life determinable range by the current range determining means; life determination data corresponding to the discharge current and the temperature; Determining data obtaining means for obtaining, and comparing the magnitude of the discharge voltage measured by the measuring means with the life determining data, and determining the battery life when the discharge voltage is smaller than the life determining data. Means for determining battery life. 8. A full charge determination unit for determining whether the battery is fully charged, a temperature measurement unit for measuring a temperature of the battery environment when the battery is fully charged, and the temperature measurement Temperature range determining means for determining whether or not the temperature measured by the means is within the life determinable range; and, when the temperature determined by the temperature range determining means is within the life determinable range, First measuring means for starting discharge of a battery and measuring a discharge current when a first time has elapsed from the start of the discharge as a first discharge current; and determining that the first discharge current has a lifetime. First current range determining means for determining whether or not the first discharge current is within a range; and when the first current range determining means determines that the first discharge current is within a life determinable range, Second from the beginning of the discharge A second measuring means for measuring a discharge voltage when the second time has elapsed, and measuring a discharge current after the second time has elapsed as a second discharge current; A second current range determining means for determining whether or not the second discharge current is within a range; and when the second discharge current is determined to be within a life determinable range by the second current range determining means, First
And average value calculating means for obtaining an average value of the second discharge current; determining data obtaining means for obtaining life determining data corresponding to the average value and the temperature; and a discharge voltage measured by the second measuring means. And a battery life determining unit for comparing the magnitude of the battery life determination data with the battery life determination data, and determining that the battery life has elapsed when the discharge voltage is smaller than the life determination data.