Apparatus for displaying the remaining charge of rechargeable battery
First Claim
1. An apparatus for monitoring the residual capacity of a battery comprising:
- means for detecting the output voltage of a battery and for producing a detection signal when said output voltage falls below a predetermined threshold level;
means for storing a first value;
means for accumulating the discharge of said battery to produce a second value;
first means for calculating a difference between said first and second values to produce a difference value;
means responsive to said difference value for displaying the remaining charge value of said battery;
second means responsive to said detection signal for providing said second value to said calculating means; and
means for changing either said first value or an accumulating rate of said accumulating means when said difference value is higher than a predetermined value.
1 Assignment
0 Petitions
Accused Products
Abstract
An apparatus having a rechargeable battery and a battery voltage detector which detects the output voltage of the battery to produce a detection signal when the output voltage falls below a predetermined threshold level. A controller stores a battery capacity value and accumulates the discharge of the battery to produce an accumulated capacity value. The controller also calculates a difference between the stored capacity value and the accumulated capacity value. Using the difference, a display displays the remaining charge value of the battery thereon. If the difference exceeds a predetermined value at a time the controller receives the detection signal, the controller changes the stored capacity value to a new capacity value. Alternatively, the controller may change a rate of accumulating the battery discharge.
The apparatus may have a current detector for detecting a current flowing through the battery. The controller may accumulate the battery discharge based on the detected current.
69 Citations
28 Claims
-
1. An apparatus for monitoring the residual capacity of a battery comprising:
-
means for detecting the output voltage of a battery and for producing a detection signal when said output voltage falls below a predetermined threshold level; means for storing a first value; means for accumulating the discharge of said battery to produce a second value; first means for calculating a difference between said first and second values to produce a difference value; means responsive to said difference value for displaying the remaining charge value of said battery; second means responsive to said detection signal for providing said second value to said calculating means; and means for changing either said first value or an accumulating rate of said accumulating means when said difference value is higher than a predetermined value. - View Dependent Claims (2, 3, 4, 5)
-
-
6. An apparatus for monitoring residual capacity of a battery comprising:
-
means for storing a first value; first means for producing a first detection signal when the output voltage of a battery falls below a predetermined threshold value; means for accumulating the discharge of said battery to produce an accumulated discharge value; means responsive to said first value and said accumulated value for calculating the remaining charge of said battery to produce a remaining charge value; means for displaying said remaining charge value; means responsive to said first detection signal for comparing said remaining charge value with a predetermined value to produce a change signal when said remaining charge value exceeds said predetermined value; and means responsive to said change signal for changing either said first value or an accumulating rate of said accumulating means. - View Dependent Claims (7, 8, 9, 10, 11)
-
-
12. An apparatus comprising:
-
a battery adapted to power electrical equipment; a display; means for storing a battery capacity value Cf ; means for detecting the output voltage of said battery to produce a detection signal when said output voltage falls below a predetermined threshold value; first means for calculating an accumulated discharge value A of said battery by an equation ##EQU4## where ai is a weighting constant, Ii is an operating current of said equipment and ti is a time for which said equipment operates at said current Ii ; second means for calculating a difference CR between said values Cf and A, CR =Cf -A; means responsive to said difference CR for displaying on said display the remaining charge value of said battery; means responsive to said detection signal for comparing said difference with a predetermined value Cm to produce a change signal when said difference is equal to or greater than said value Cm ; and means responsive to said change signal for replacing either said value Cf or said constant ai with a new capacity value Cf'"'"' or a new weighting constant ai'"'"'. - View Dependent Claims (13)
-
-
14. An apparatus comprising:
-
a battery adapted to provide power to electrical equipment; voltage detector means for producing a detection signal when the output voltage of said battery falls below a predetermined threshold value; means for storing a first value; means for calculating a first remaining charge value of said battery based on said first value; display means for displaying said first remaining charge value; means responsive to said detection signal for calculating a second remaining charge value of said battery based on said first value; and means for changing said first value when said second remaining charge value exceeds a predetermined value. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
-
-
25. A method of displaying a remaining charge value of a battery adapted to power electrical equipment, comprising the following steps of:
-
detecting the output voltage of said battery to produce a voltage detection signal when said output voltage falls below a predetermined threshold value; storing a first value; calculating a first remaining charge value of said battery based on said first value; displaying said first remaining charge value; responsive to said voltage detection signal, calculating a second remaining charge value of said battery based on said first value; and changing said first value when said second remaining charge value exceeds a predetermined value. - View Dependent Claims (26)
-
-
27. A method of displaying a remaining charge value of a battery adapted to power equipment, comprising the following steps of:
-
detecting the output voltage of said battery to produce a first detection signal when said output voltage falls below a predetermined threshold level; storing a first value; accumulating the discharge of said battery to produce a second value; subtracting said second value from said first value to produce a third value; responsive to said third value, displaying the remaining charge value of said battery; responsive to said first detection signal, changing either said first value or an accumulating rate at said step of accumulating when said third value exceeds a predetermined value. - View Dependent Claims (28)
-
Specification