JP2002025631A - Battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that, in addition to an increase in the number of component items and an increase in cost, a deterioration of operability is caused if a remaining capacity display button for displaying a remaining capacity and a reset button for initializing a remaining capacity computation circuit are individually provided for a battery pack equipped with secondary batteries, a remaining capacity computation means for computing the remaining capacity of the secondary batteries from a charging/discharging current or a charging/ discharging voltage, and a display means for displaying the remaining capacity. SOLUTION: The battery pack is provided with only the remaining capacity display button that, when pressed down, causes the display means to display the remaining capacity of the secondary batteries. When the display button is pressed in accord with a prescribed pressing condition, the remaining capacity computation means is brought into its initial state, thereby making it possible to put the reset button and the display button to common use.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery pack having a function of calculating and displaying a remaining capacity of a secondary battery based on a charge / discharge current and a charge / discharge voltage applied to a charge / discharge path.

[0002]

2. Description of the Related Art A battery pack containing a chargeable / dischargeable battery is used as a power source for a portable device such as a notebook personal computer or a mobile phone, or a vehicle provided with a power assist mechanism for assisting the power of a motor. ing. In particular, a battery pack having a function of displaying the remaining capacity of a battery can easily estimate the operable time of the device. Therefore, the battery pack runs out of operation or loses data due to battery exhaustion. Such problems can be avoided, and the convenience of the user is greatly improved. As a battery pack having a function of displaying the remaining capacity, for example, there is a battery pack disclosed in JP-A-61-209371.
The remaining capacity display circuit included in the battery pack calculates and displays the remaining capacity of the battery by detecting the charge / discharge current of the battery and integrating or subtracting it.

FIG. 2 shows an example of a circuit of a battery pack incorporating the above-mentioned display means. The battery pack 1 is configured such that when the remaining capacity display button 5 is pressed, the remaining capacity of the secondary battery 2 is displayed by the light emitting diodes 5a to 5e of the display means 4. The display means 4 is connected to the remaining capacity calculating means 3 and turns on the light emitting diodes 5a to 5e corresponding to the calculated remaining capacity.

[0004] The remaining capacity calculating means 3 measures the charge / discharge current of the secondary battery 2 and / or the charge / discharge voltage of the secondary battery 2. When the remaining capacity is detected based on the charge / discharge current, the charge amount and the discharge amount are integrated from the potential difference generated at both ends of the current detection resistor inserted in the charge / discharge path and the sign thereof, and the initial discharge capacity is calculated. The remaining capacity is calculated by subtracting the amount of discharge from. In this configuration, the remaining capacity calculating means 3 is always in the operating state for the charging / discharging current, and the operating power is obtained from the secondary battery 2, so that the secondary battery 2 is turned off as much as possible. There is no.

On the other hand, when the detection is performed based on the charging / discharging voltage, the voltage of the secondary battery 2 stored in the remaining capacity calculating means 3 is compared with a voltage corresponding to a previously measured remaining capacity to calculate the remaining capacity. Has been detected. In this configuration, when the remaining capacity display button 5 is pressed, the discharge voltage of the secondary battery 2 is measured, and the remaining capacity is calculated. Become.

[0006]

As described above, in the configuration for calculating the remaining capacity from the charge / discharge current, the charge / discharge current is detected by the remaining capacity calculation means 3 and the data of the respective charge / discharge currents is integrated. Time integration method. On the other hand, the secondary battery 2
In the configuration in which the remaining capacity is calculated from the discharge voltage, the remaining capacity value is calculated based on the data on the discharge voltage and the remaining capacity stored in the remaining capacity calculating means 3. As described above, in any of the above-described configurations, since the remaining capacity calculating means 3 needs to store data relating to charging and discharging and calculate the remaining capacity, an IC with a high degree of integration is used. For this reason, the data stored in the remaining capacity calculating means 3 may be lost or erroneously stored due to static electricity to the battery pack or noise intervening in the charging / discharging path, which may result in a large detection error of the remaining capacity. Would. Therefore, as shown in FIG. 2, a reset button 6 is connected to the remaining capacity calculating means 3, and when a failure occurs in the detection state, the reset button 6 is turned on, so that the remaining capacity calculating means 3 is turned on. There has been proposed a battery pack having a function of resetting to an initial state and eliminating the effects of data disappearance or erroneous storage.

Further, in the time integrating method for detecting the remaining capacity by integrating the charging / discharging current, the detection accuracy is reduced due to repeated charging / discharging or a memory effect. Therefore, when the refresh charge / discharge is completed, the reset button 6
Is turned on, and the detection value of the remaining capacity in the remaining capacity calculation means 3 is set to the fully charged state, whereby the detection accuracy can be returned to the initial state.

As described above, the reset button 6 initializes the remaining capacity calculating means in order to reduce external factors such as static electricity and noise, and to reduce the detection error due to the charge / discharge current detection and the memory effect. . The reset button 6 is provided on the surface of the housing of the battery pack, and resets the remaining capacity calculating means 3 when the user of the battery pack turns on.
Further, a remaining capacity display button 5 for turning on the display means 4 is provided on the surface of the housing of the battery pack, and the light emitting diodes 5a to 5e are turned on when the user turns on. Therefore, it is necessary to provide two buttons, a reset button and a remaining capacity display button, on the housing of the battery pack, which leads to an increase in cost as the number of components increases.

In the battery pack provided with the above two types of buttons, it is necessary for the user to select a button according to the purpose and press it. However, since these buttons are provided at positions where they will not be accidentally pressed when the device is used, their installation positions are necessarily restricted, and they are provided close to each other on the surface of the pack housing. For this reason, in a situation where it is difficult to confirm the type of the button, such as under darkness, there is a possibility that the user may mistakenly press the button. For example, if the user presses the reset button by mistake in spite of pressing the button to check the remaining capacity, the calculated value of the remaining capacity is reset, and the necessary value is required during the discharge of the secondary battery. Initialization is performed. There is also a problem in operability such that the wrong pressing of the button causes deterioration of the detection accuracy of the remaining capacity value.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a battery pack which does not cause an increase in cost and has excellent operability when confirming a remaining capacity or performing a reset.

[0011]

In order to achieve the above object, a battery pack according to the present invention comprises a secondary battery, detecting means for detecting a charge / discharge current and / or charge / discharge voltage of the secondary battery, A charge / discharge current value calculated from the charge / discharge voltage value, a remaining capacity calculation means for calculating the remaining capacity of the secondary battery, and a display means for displaying the calculated remaining capacity value. The battery pack has a remaining capacity display button for displaying the remaining capacity of the secondary battery on the display means when pressed, and when the remaining capacity display button is pressed so as to meet a predetermined pressing condition. The button for resetting the remaining capacity calculating means to the initial state, and a button for displaying the remaining capacity of the secondary battery on the display means, and a button for resetting the remaining capacity calculating means to the initial state are the same. The feature is that it is composed of buttons.

[0012] According to the above configuration, the function of displaying the remaining capacity of the secondary battery in the remaining capacity display and the remaining capacity calculating means when the remaining capacity data is lost, erroneously stored, or a detection error increases. In a battery pack having a function of initializing, a switch mechanism for operating these functions is provided for one button, and a function to be operated by pressing the button so as to match a predetermined pressing condition is selected. It becomes possible. For this reason, it is not necessary to separately provide a button having a switch mechanism for operating each function, so that the number of components can be reduced and the cost can be minimized. At the same time, by sharing the buttons, the area required for installation is halved compared to the case where each button is provided on the housing, and the degree of freedom in designing the battery pack shape is greatly improved.

Further, the present invention sets a pressing condition of the button corresponding to each of the above functions, and selects a function to be operated according to a pressing pattern of the user. That is, the function for displaying the remaining capacity and the function for initializing the remaining capacity calculating means are distinguished by changing the time or the number of times the button is pressed. For this reason, the probability that the user presses the button incorrectly is greatly reduced.

Further, in the battery pack of the present invention, the pressing condition of the button is set according to the frequency of use of each function. The function of displaying the remaining capacity is activated every time the user checks the remaining capacity of the battery, and the use frequency increases. On the other hand, the function of initializing the remaining capacity calculation means operates in a state where the accuracy of detection of the remaining capacity is deteriorated due to erroneous storage or erasure of data stored in the circuit, or repeated charge / discharge or a memory effect. Therefore, the frequency of use is smaller than the frequency of displaying the remaining capacity. Therefore, it is set so that the function of displaying the remaining capacity is operated in a state where the button is simply pressed, and the remaining capacity calculating means is operated only when the pressing pattern of the button matches the conditions such as the predetermined time and the number of times. By setting, the operation of the function of displaying the remaining capacity that is frequently used is prioritized. By setting the button pressing method according to the frequency of use of each function in this way,
Unnecessary functions are not erroneously operated, and functions frequently used are preferentially operated, so that operability of each function is also improved.

The pressing condition of the button for activating the function which is used less frequently can be differentiated from the pressing condition for activating the function which is used frequently by the time and the number of times the button is pressed. The battery pack according to the present invention is configured such that when the remaining capacity display button is pressed, the remaining capacity of the battery is displayed on the display means, and the remaining capacity calculating means continuously presses the remaining capacity display button. The remaining time is measured, and when the pressing time is equal to or longer than the set time, the remaining capacity calculating means is set to the initial state, so that the button pressing method giving priority to the display of the remaining capacity can be provided. Similarly, the remaining capacity calculation means counts the number of times the remaining capacity display button is pressed within the set time, and sets the remaining capacity calculation means to the initial state when the remaining capacity display button is pressed more than the set number of times within the set time. It is good also as composition. Further, instead of the button pressing time and the number of times, the stroke of pressing the button is changed, and the remaining capacity calculating means is reset when the button is pressed inside the housing surface of the battery pack, It is possible to perform a similar function. Also, by initializing the remaining capacity calculating means, setting a new pressing condition different from the pressing condition of the remaining capacity display, and adopting a configuration in which a new function such as refresh charge / discharge operates when the condition is met. The remaining capacity display button can have three or more functions.

[0016]

Embodiments of the present invention will be described below with reference to the accompanying drawings to provide an understanding of the present invention.
The embodiment described below is an example embodying the present invention, and does not limit the technical scope of the present invention.

The battery pack according to the present embodiment has a configuration in which the remaining capacity of the secondary battery is indicated by a plurality of light emitting diodes. FIG. 1 is a block diagram showing the configuration of the battery pack. The components having the same functions as those of the above-described conventional example are denoted by the same reference numerals.

In FIG. 1, a battery pack 1 has a built-in rechargeable battery 2 and a remaining capacity calculating means 3, and a remaining capacity display button 5 and a light emitting diode 5 constituting a display means 4 are provided on the surface of the housing.
a to 5e are arranged. The display means 4 is connected to the remaining capacity calculating means 3 and turns on the light emitting diodes 5a to 5e corresponding to the calculated remaining capacity. Further, the display means 4 suppresses the consumption of the secondary battery 2 by turning off the light emitting diode not only when the battery pack is charged or left, but also in a use state in which the battery pack is connected.

The remaining capacity display button 5 has two functions, that is, a function of turning on the light emitting diode for displaying the remaining capacity and a function of initializing the remaining capacity calculating means. A configuration is adopted in which judgment is made based on the pressed time. Hereinafter, two functions selected according to the button pressing condition will be described.

When the remaining capacity display button 5 is pressed, the display means 4
Turns on the light emitting diodes 5a to 5e to display the remaining capacity. Remaining capacity calculating means 3 in the present embodiment
Measures the charging / discharging current to the secondary battery 2. The detection of the remaining capacity of the secondary battery 2 is performed by integrating the charge amount and the discharge amount from the potential difference generated between both ends of the current detection resistor inserted in the charge / discharge path and the sign thereof, and subtracting the discharge amount from the initial discharge capacity. Thus, the remaining capacity is calculated. In this configuration,
The remaining capacity calculation means 3 is always in the operating state for the charge / discharge current,
Since the operating power is obtained from the secondary battery 2, the secondary battery 2 is not turned off as long as the secondary battery 2 can be discharged. On the other hand, the light emitting diodes 5a to 5e are turned on only when the remaining capacity is displayed as described above, and the display unit 4 turns on the light emitting diodes for a predetermined time, for example, several seconds, and then turns them off. .

The display means 4 comprises five light emitting diodes 5a to 5a.
5e is connected. The remaining capacity calculating means 3 turns on all the light emitting diodes 5a to 5e when the battery is fully charged. One light emitting diode 5a to 5e is turned off every time 20% of the battery capacity is discharged, and the user of the device determines the remaining capacity of the secondary battery 2 by checking the lighting number of the light emitting diodes 5a to 5e. I can judge. For example, in a state where the two light emitting diodes 5a to 5e are turned on, the number of the secondary batteries is 80 to
About 60% discharged and the remaining capacity is 20-40
%. When one light emitting diode is lit,
Rechargeable battery is 80% or more discharged, remaining capacity is 20%
Indicates that:

When the remaining capacity display button 5 is pressed, the remaining capacity calculation means 3 measures the time during which the button is pressed, and a predetermined number of times is pressed within a predetermined time, or a predetermined pattern is set. Then, the remaining capacity calculating means 3 determines that the user does not display the remaining capacity but needs to initialize the remaining capacity calculating means 3, and initializes the data. Such initialization is effective when the remaining capacity calculation means 3 erroneously stores or erases the charge / discharge data due to noise or the like, or when the error in the detected value of the remaining capacity becomes large.

As an example of the pressing condition of the remaining capacity display button 5, the following condition is set. Remaining capacity display button 5
Is turned off in less than three seconds after being turned on, the remaining capacity calculating means 3 is set so that the display means 4 is turned on. Further, when the remaining capacity display button 5 is continuously turned on for 3 seconds or more, and after the off state for less than 2 seconds, it is turned on again and turned off in less than 3 seconds, the remaining capacity calculation means 3 is initialized. Set to In this way, a relatively simple pressing condition is set for the display of the remaining capacity that is frequently used,
By setting a complicated pressing condition for a function with low frequency, it is possible to prevent a function that is not required by the user from operating.

In this embodiment, the remaining capacity display button 5 is a push button switch. However, it is needless to say that other types of switches or components having a switch function can be used instead of the buttons. In addition, it is easy to incorporate a switch function into a stopper for fixing to the tool body. Furthermore, although the description has been given using a battery pack in which the remaining capacity is displayed by a light emitting diode as an example, a configuration using a display device in the battery pack, or sending remaining capacity data to a main unit to which the battery pack is attached, and It is also possible to implement a configuration in which the remaining capacity is displayed.

[0025]

As described above, according to the present invention, a switch mechanism for operating the function of displaying the remaining capacity of the secondary battery in the remaining capacity display and the function of initializing the remaining capacity calculation means is provided by one button. With this arrangement, the number of parts can be reduced, the cost can be minimized, and at the same time, a malfunction due to an incorrect button press can be prevented, and its industrial value is great.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a battery pack according to an embodiment.

FIG. 2 is a block diagram showing a configuration of a conventional battery pack.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Battery pack 2 Secondary battery 3 Remaining capacity calculating means 5a-5e Light emitting diode 5 Remaining capacity display button

Claims (1)

[Claims] 1. A secondary battery, a detecting means for detecting a charge / discharge current and / or a charge / discharge voltage of the secondary battery, and a remaining charge of the secondary battery based on the detected charge / discharge current value and charge / discharge voltage value. A battery pack comprising: a remaining capacity calculating means for calculating a capacity; and a display means for displaying the calculated remaining capacity value, further comprising: Equipped with a remaining capacity display button to display the remaining capacity,
A battery pack characterized in that when the remaining capacity display button is pressed so as to meet a predetermined pressing condition, the remaining capacity calculating means is reset to an initial state.