JPH0654451A - Charge/discharge managing apparatus for battery - Google Patents

Abstract

PURPOSE:To effectively back up a power source by increasing a charging current when a residue of a battery obtained based on a charging time for charging the battery and a discharging time when it is discharged due to power interruption is smaller than a predetermined value simultaneously upon supplying power from a power source to an apparatus body. CONSTITUTION:A power source 9 charges a battery 10 through a charge controller 13 and a diode 14, and supplies power to units connected to a CPU 1 through a bus 8. When the power source 9 is interrupted, the battery 10 backs up a RAM 3 through a diode 11. A clock 4 continuously counts a time by a built-in battery, and inputs a charge/discharge starting times to a timer counter 3a of the RAM 3. The CPU 1 calculates a charge AH and a discharge AH based on accumulated time of a charging time and a discharging time from charge/ discharge starting times, and instructs an increase in a charging current to the controller 13 through an I/O port 7 if a difference becomes a predetermined value or less. Thus, the power source can be effectively backed up to improve its reliability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery charge / discharge management device for managing charge / discharge of a battery which supplies electric power to a part or the whole of a main body of a device during a power failure.

[0002]

2. Description of the Related Art For example, in an information processing apparatus or the like, a backup battery is provided for holding data stored in a volatile memory such as a RAM in the event of a power outage, such as when the information processing apparatus is powered off. The backup battery is provided to supply power to part or all of the information processing device in the event of a power failure.

However, when the remaining electric capacity of the battery is low, the power backup time is short, and therefore, the backup function such as holding the data stored in the non-volatile memory at the time of a normal power failure is sufficiently fulfilled. There is a risk that you will not be able to.

Therefore, it is necessary to know that when the remaining electric capacity of the battery becomes small, for example, one of the methods.
One that generally monitors the voltage of a battery is generally known. That is, the battery voltage drops according to the remaining capacity of the battery when the remaining capacity of the battery decreases below a predetermined capacity, so a warning is displayed on the display etc. when the voltage of the battery drops below a preset voltage. It was supposed to do.

Regarding the charging of the battery, it is necessary to know the completion of charging because the battery may be deteriorated if it is overcharged in the usual charging with a relatively large current amount. As a method therefor, there is a method of monitoring by the voltage or heat generation of the battery. Also, as a charging method that does not have to consider the deterioration of the battery due to overcharging,
Trickle charging, which charges with a small amount of current, is known.

However, the former battery charger, which monitors the voltage or heat generation of the battery, has a problem that the power supply to the battery must be cut off when the charging is completed based on the monitoring result.

Therefore, in the conventional information processing apparatus, the method of charging the battery by the latter trickle charging when the power is turned on (when there is no power failure) is generally adopted.

[0008]

For example, in an information processing apparatus, it takes a long time to charge a battery by trickle charging, so that the operating time of the information processing apparatus (time when the power is turned on) for one day is short. In this case, the amount of battery charge during that operating time cannot keep up with the amount of battery discharge at the time of power failure, and the remaining electric capacity gradually decreases, resulting in insufficient charging, and at that time, it is stored in the nonvolatile memory. There is a problem that the backup function such as holding the stored data cannot be performed.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a battery charge / discharge management device capable of reliably ensuring a part or the whole of power supply backup of the device main body by the battery at the time of power failure.

[0010]

The invention according to claim 1 is
In a battery charge / discharge management device that manages charging / discharging of a battery that supplies power to a part or the whole of the device main body at the time of power failure, a charging means for charging the battery when the power is supplied from the power supply to the device main body A charging time calculating means for calculating a charging time during which power is supplied to the apparatus main body from the discharging source, a discharging time calculating means for calculating a discharging time during which power supply is stopped from the power source to the apparatus main body, and based on the charging time and the discharging time. Remaining electric energy amount calculating means for calculating the remaining electric energy amount of the battery, and increasing the charging current amount to the battery by the charging means when the remaining electric energy amount is less than or equal to a preset minimum electric energy amount. And means for increasing the charging current amount.

According to a second aspect of the present invention, there is provided a battery charge / discharge management device for managing charge / discharge of a battery for supplying electric power to part or the whole of the main body of the device during a power failure.
Charging means for charging the battery when power is supplied from the power source to the device body, charging time calculation means for calculating the charging time during which power is supplied from the power source to the device body, and power supply from the power source to the device body are stopped. And a discharge time calculating means for calculating the discharge time, a residual electric energy amount calculating means for calculating the remaining electric energy amount of the battery based on the charging time and the discharge time, and the remaining electric energy amount is preset. Charging time calculating means for calculating a charging time required for the battery to recover to a predetermined electric energy amount equal to or higher than the minimum electric energy amount based on the remaining electric energy amount when the electric energy amount is equal to or lower than the minimum electric energy amount; A power supply stop prohibition means for prohibiting stop of power supply from the power supply to the main body of the apparatus until the predetermined charging time has elapsed is also provided. It is.

[0012]

According to the first aspect of the invention, the battery is charged by the charging means when the power is supplied from the power source to the main body of the apparatus, and the battery is discharged during a power failure of the main body of the apparatus to partially or entirely. Supply power to.

The charging time and discharging time are calculated by the charging time calculating means and the discharging time calculating means, and the remaining electric energy amount of the battery is calculated by the remaining electric energy amount calculating means based on the charging time and discharging time. .

The charging current amount increasing means increases the charging current amount to the battery by the charging means when the calculated remaining electric energy amount is equal to or less than the preset minimum electric energy amount.

In the invention corresponding to claim 2, the charging time and the discharging time are calculated by the charging time calculating means and the discharging time calculating means, and the remaining electric energy amount calculating means is
The remaining amount of electric energy of the battery is calculated based on the charging time and the discharging time.

When the calculated remaining electric energy amount is equal to or less than the preset minimum electric energy amount by the charging time calculation means, the battery is determined to have a predetermined electric power amount equal to or more than the minimum electric energy amount based on the remaining electric energy amount. The charging time required to recover the amount of electric energy is calculated, and the power supply stop prohibiting means prohibits the stop of the power supply from the power source to the apparatus main body until the charging time elapses.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. Note that this embodiment applies the present invention to a general information processing apparatus, and FIG. 1 is a block diagram showing a basic circuit configuration of this information processing apparatus. Reference numeral 1 denotes a CPU (cen-tral processing unit) that constitutes the main body of the control unit, a ROM (read only memory) 2 in which program data for processing performed by the CPU 1 is stored, and various types used when the CPU 1 performs processing. A RAM (random access memo) in which a memory area is formed and a timer counter 3a for counting a set time is formed.
ry) 3, RTC (real time cloc) that outputs time data
k) 4, a display controller 6 that controls a display device 5 that displays messages and data, and an I / O (input / output) that inputs signals output from various peripheral devices and outputs signals to various peripheral devices Port 7 is system bus 8
It is connected to the CPU 1 via. Although not shown, the CPU 1 is also connected to other peripheral devices.

Power is supplied from the power supply unit 9 to each of the above circuits.

The RTC 4 has a built-in battery,
The time can be measured even when the power supply from the power supply unit 9 is stopped (during a power failure). In the case of a power failure, the RAM 3 also has a power supply backup battery 10
The electric power is supplied through the diode 11 and the stored data is stored and held.

The battery 10 is connected to the power supply unit 9 via a charging current supply line 12 as a charging means, and the charging current supply line 12 controls the amount of charging current to the battery 10. A charging control unit 13 is inserted, and a second diode 14 is inserted in the charging current supply line 12 from the charging control unit 13 toward the battery 10. When power is supplied from the power supply unit 9 to the apparatus main body, a charging current is supplied from the power supply unit 9 to the battery 10 via the charging current supply line 12.

Further, the two output terminals of the I / O port 7 are connected to the power supply unit 9 and the charging control unit 13, and the power supply unit 9 is supplied with a power-on signal for continuing power supply. Is output, and a switching signal for switching the charging current amount of the battery 10 is output to the charging control unit 13.

The battery 10 has a capacity of 500 mA · h as a power source backup capacity, and its charging efficiency is 60%. At the time of power failure of the apparatus main body, a discharge current of 2 mA is supplied from the battery 10 to a backup circuit such as the RAM 3, and when the apparatus main body is supplied with power from the power supply section 9, the power supply section 9 is used. A charging current of 25 mA is usually supplied.

FIG. 2A shows a flow of processing at the time of power-on performed by the CPU 1.

First, the time data output from the RTC 4 is read and the time data is stored in the RAM 3 as the charging start time. Here, the discharge time is calculated from the charge stop time and the charge start time already stored in the RAM 3, and the current battery 10 is calculated from the discharge time and the remaining electric capacity value already stored in the RAM 3. The remaining electric capacity value (electrical energy amount value) is calculated (remaining electric energy calculation means), and the remaining electric capacity value is stored in the RAM 3.

Next, it is judged whether or not the remaining electric capacitance value is less than or equal to a preset minimum electric capacitance value of 100 mA · h (minimum electric energy amount value), and the remaining electric capacitance value is 10 mA.
If it is not 0 mA · h or less, the power-on process is ended. The set value of 100 mA · h can be freely set by software, for example, 15
It can be set as 0 mA or 200 mA · h.

The remaining capacitance value is 100 mA · h.
If it is the following, the charging current is increased by the charging control unit 13 based on the remaining electric capacity value, and the battery 10
The charging time required to restore the electric capacity of 100 mA · h to 100 mA · h is calculated. (Charging time calculating means) Here, the stop count value of the timer counter 3a is set based on this charging time, and the charging control unit 13 is set through the I / O port 7.
A charging current switching signal is output to (charging current amount increasing means) to increase the charging current from the normal 25 mA to 50 mA, which is doubled. Further, a power-on signal is output to the power supply unit 9 via the I / O port 7, and the timer counter 3a starts counting.

Then, the charge flag formed in the RAM 3 is set to 1 and the power-on process is terminated.

When the power-on process is completed, the CPU 1 carries out a normal process.

FIG. 2B shows the flow of the interrupt processing which the CPU 1 periodically performs.

First, 1 is set in the charging flag formed in the RAM 3.
Is set, and if 1 is not set in the charging flag, the interrupt processing is ended.

If the charge flag is set to 1, it is determined whether the count value of the timer counter 3a at this time is equal to or greater than the preset stop count value.
If the count value of the timer counter 3a is not equal to or more than the stop count value, this interrupt processing is ended.

If the count value of the timer counter 3a is equal to or greater than the stop count value, the output of the charging current switching signal output from the I / O port 7 to the charging control unit 13 is stopped (power supply stop prohibition). Means), and set the charge flag to 0. Furthermore, the remaining electric capacity value of the battery 10 is set to 1
Stored in RAM3 as 00mA · h, and I / O port 7
The output of the power-on signal output from the power supply unit 9 is stopped, the time data output from the RTC 4 is read, and the time data is stored in the RAM 3 as the charging start time. Then, this interrupt processing is ended.

FIG. 3 shows a flow of processing when the CPU 1 is turned off.

First, it is determined whether or not the charge flag is set to 1. If the charge flag is not set to 1, the time data output from the RTC 4 is read,
The time data is stored in the RAM 3 as the charging stop time. Here, the charging time is calculated from the charging start time and the charging stop time already stored in the RAM 3, and the remaining electric capacity value of the battery 10 is calculated from the calculated charging time (calculation of remaining electric energy amount). Means) and stores the remaining electric capacitance value in the RAM 3. Then, this power-off processing is ended.

If the charge flag is set to 1, it is determined whether the count value of the timer counter 3a at this time is greater than or equal to the preset stop count value.
If the count value of the timer counter 3a is not more than the stop count value, until the count value of the timer counter 3a becomes more than the stop count value, the display unit 5 shows "charging time is insufficient" or "charging is insufficient". Is displayed.

When the count value of the timer counter 3a exceeds the stop count value, the switching signal output from the I / O port 7 to the charging control unit 13 is stopped and the charging flag is set to 0. Further, the remaining electric capacity value of the battery 10 is stored in the RAM 3 as 100 mA · h,
The output of the power-on signal output from the I / O port 7 to the power supply unit 9 is stopped (power supply stop prohibition means), and the RTC
RAM3 by reading the time data output from
Then, the time data is stored as the charging start time. Then, this power-off processing is ended.

In this embodiment having such a configuration, when the power switch (not shown) of the information processing apparatus is turned on, the power supply from the power supply unit 9 to the main body of the information processing apparatus is started and the power supply is turned on. From the time when the power supply from the unit 9 is stopped (discharge time) and the remaining electric capacity (electric energy amount) value already stored in the RAM 3, the remaining electric capacity value of the battery 10 when the power is turned on is calculated. It is calculated and stored in the RAM 3.

The remaining capacitance value is the minimum capacitance value 1
If it is less than 00mA · h (minimum electric energy value),
The charging time to recover to 100 mA · h at the charging current of 50 mA is calculated, and this charging time is counted by the timer counter 3a.
Is set to. In addition, the charging current switching signal is output to the charging control unit 13 so that the charging current to the battery 10 becomes 2
While being increased from 5 mA to 50 mA, the power-on signal is output to the power supply unit 9, and the power supply from the power supply unit 9 to this information processing apparatus main body is maintained regardless of the power switch.

When the charging time set by the timer counter 3a is counted before the power switch is turned off, the output of the switching signal output to the charging control unit 13 is stopped and the charging current to the battery 10 is reduced. Is normal 25
When the current becomes mA, the output of the power-on signal output to the power supply unit 9 is stopped and the power switch is turned off, so that the power supply to the information processing apparatus main body is stopped.

If the timer counter 3a has not yet counted the charging time when the power switch is turned off, the power supply from the power supply unit 9 to the information processing apparatus main body is related to the power switch. It is retained as it is. When the time elapses in this state and the charging time in which the timer counter 3a is set is counted,
The output of the switching signal output to the charging control unit 13 is stopped, the output of the power-on signal output to the power supply unit 9 is stopped, and the power supply to the information processing apparatus main body is stopped.

At this time, the remaining electric capacity value of the battery 10 is stored in the RAM 3 as 100 mA · h.

When the power supply is stopped by the normal power switch, the time (charging time) during which the charging current is 25 mA from the power supply unit 9 to the battery 10 and the remaining electricity already stored in the RAM 3 are stored. From the capacity value, the remaining 10 electric capacity values of the battery when the power supply is stopped are calculated and stored in the RAM 3.

For example, assuming that the battery 10 is initially charged to the maximum electric capacity, when the power switch of the apparatus main body is turned on for 150 hours, the remaining electric capacity value of the battery 10 at this time is It is calculated that 500 mA · h− (2 mA × 150 h) = 200 mA · h, and the electric capacity value of 200 mA · h is RAM3.
Memorized in. At this time, the power-on signal and the charging current switching signal are not output, and the normal charging current 2
The battery 10 is charged at 5 mA.

When the power switch is turned off four hours after it is turned on, the remaining capacitance value of the battery 10 at this time is calculated as 200 mA · h + (0.6 × 25 mA × 4 h) = 260 mA · h. , This electric capacity value 260mA · h is RAM3
Memorized in.

100 hours later, when the power switch is turned on again, the remaining electric capacity value of the battery 10 at this time is calculated as 260 mA · h- (2 mA × 100 h) = 60 mA · h, and this electric capacity is calculated. The value is stored in RAM3.
At this time, the remaining electric capacity value 60 of the battery 10
Since 100 mA ・ h is less than 100 mA ・ h, 100 mA ・ h
The charging time until it recovers to (100-60) mA · h / (50 mA × 0.6) = 1.33 h is calculated, and the count corresponding to this time is set in the timer counter 3 a.

Therefore, the switching signal of the charging current and the power-on signal continue to be output until 1.33 h has elapsed.

Therefore, even if the power switch is turned off before 1.33 h has elapsed, the power supply signal does not stop the power supply from the power supply unit 9 to the main body of the apparatus, so that the battery 10 has an electric capacity of 100 mA · h. The power supply from the power supply unit 9 to the main body of the apparatus is stopped after the power is restored. That is, since the battery 10 is always secured with an electric capacity of 100 mA · h or more at the start of backup, as can be seen from the following equation, the backup of 50 hours is guaranteed for about 2 days. 100 mA · h / 2 mA = 50 h As described above, according to the present embodiment, the power supply unit 9 that holds the power supply to the apparatus main body by the power-on signal and the charging current supply that supplies the charging current from the power supply unit 9 to the battery 10. A charging control unit 13 which is inserted in the line 12 and increases the charging current to the battery 10 by a switching signal of the charging current and a timer counter 3a are provided, and the remaining battery 10 is determined based on the discharging time and the charging time of the battery 10. Calculate the electric capacity value of this, and the remaining electric capacity value is 100 mA · h
In the following cases, the power-on signal and the charging current switching signal are output, and the electric capacity value of the battery 10 is 100.
The charging time required to recover to mA · h is calculated and set in the timer counter 3a, and when the timer counter 3a counts the set charging time, the output of the power-on signal and the charging current switching signal is stopped. As a result, when the remaining electric capacity of the battery 10 is small, the charging current amount to the battery 10 can be increased to shorten the charging time, and moreover, the electric power from the power supply unit 9 can reach 100 mA · h. Since the supply is not stopped, the power supply backup of the battery 10 to the circuit such as the RAM that needs the power supply backup can be surely guaranteed at the time of power failure.

Further, in this embodiment, since the minimum electric capacitance value can be freely set, it is 150 mA · h or 200 mA.
By changing the setting such as h, the power source backup time of the battery 10 can be changed to a long time such as 3 days or 4 days.

In this embodiment, the charging current amount is switched in two steps by the charging current switching signal, but the present invention is not limited to this. The charging current amount may be made variable in a plurality of steps according to the capacitance value, and the charging current switching signal may not be output. That is, when the remaining capacitance value is 100 mA · h or less, the charging time is calculated as 25 mA without increasing the charging current amount, the charging time is set in the timer counter 3a, and only the power-on signal is output. It is a thing.

The above-mentioned remaining capacitance value is 60 mA · h
In the above example, (100-60) mA · h / (25mA × 0.6) = 2.66h is calculated, and the timer counter 3a is set to a count corresponding to 2.66h.

In this embodiment, when the remaining electric capacity value is 100 mA · h or less, the electric capacity value is 100 mA.
-The charging time until the battery was recovered to h was calculated, but the present invention is not limited to this.
For example, the charging time required to recover up to 150 mA · h may be calculated.

[0052]

As described above in detail, according to the present invention,
It is possible to provide a battery charge / discharge management device capable of reliably ensuring a power backup of a part or the whole of the device main body by the battery at the time of power failure.

[Brief description of drawings]

FIG. 1 is a diagram showing a circuit configuration of a main part of an embodiment of the present invention.

FIG. 2 is a diagram showing a flow of power-on processing and interrupt processing of the embodiment.

FIG. 3 is a diagram showing a flow of processing when the power is off in the embodiment.

[Explanation of symbols]

1 ... CPU, 3 ... RAM, 3a ... Timer counter, 4 ...
RTC, 5 ... indicator, 7 ... I / O port, 9 ... power supply section,
10 ... Battery, 12 ... Charging current supply line, 13 ...
Charge control unit.

Claims (2)

[Claims] 1. A battery charge / discharge management device for managing charging / discharging of a battery that supplies power to a part or the whole of the device body during a power outage, wherein the battery is charged when power is supplied from a power source to the device body. And a charging time calculating means for calculating a charging time during which power is supplied from the power source to the apparatus body, and a discharging time for calculating a discharging time during which power supply is stopped from the power source to the apparatus body. A calculating means, a remaining electric energy amount calculating means for calculating the remaining electric energy amount of the battery based on the charging time and the discharging time, and the remaining electric energy amount is equal to or less than a preset minimum electric energy amount. And a charging current amount increasing means for increasing the charging current amount to the battery by the charging means. Lee's charge / discharge management device. 2. A battery charge / discharge management device for managing charging / discharging of a battery that supplies power to part or the whole of the device body during a power failure, wherein the battery is charged when power is supplied from a power source to the device body. And a charging time calculating means for calculating a charging time during which power is supplied from the power source to the apparatus body, and a discharging time for calculating a discharging time during which power supply is stopped from the power source to the apparatus body. A calculating means, a remaining electric energy amount calculating means for calculating the remaining electric energy amount of the battery based on the charging time and the discharging time, and the remaining electric energy amount is equal to or less than a preset minimum electric energy amount. Sometimes the battery recovers to a predetermined amount of electrical energy above the minimum amount of electrical energy based on the remaining amount of electrical energy A charging time calculating means for calculating a charging time required for charging and a power supply stop prohibiting means for prohibiting stop of power supply from the power source to the apparatus main body until the calculated charging time elapses. A battery charge / discharge management device characterized in that