Device and method for detecting and displaying charge capacity of a battery

A method of indicating battery capacity using a plurality of switches connected in parallel with a battery, comprising the steps of:

• generating a first controlling signal, from one of said plurality of switches each comprised of complementary voltage dividers and transistors operable when a voltage existing across a first terminal and a second terminal of a battery is within a predetermined voltage range, corresponding to one of a plurality of predetermined voltage ranges, with at least one of said plurality of predetermined voltage ranges having a finite upper limit and a finite lower limit;
• generating therefrom a displaying signal representative of one of a plurality of display ranges in response to said first controlling signal with said display range corresponding to a voltage range including said voltage existing across said first terminal and said second terminal of said battery;
• and
• providing a visual indication representative of said display range in response to said displaying signal.

A battery capacity indicating device for determining a charge capacity of a battery, comprising:

• a plurality of switches each operable in a corresponding voltage range and connected in parallel to one terminal of a battery for generating a respective control signal, when a battery voltage across both terminals of the battery is within said corresponding voltage range, each of said plurality of switches comprising:
• a first transistor having a first electrode of a principle electrically conducting channel connected to said one terminal of the battery, a second electrode of said principle electrically conducting channel connected to a node, and a control electrode connected to a voltage divider;
• and
• a second transistor having a first electrode of a principle electrically conducting channel connected to a power terminal, a second electrode of said principle electrically conducting channel connected to an output terminal providing said respective control signal, and a control electrode connected to said node;
• a display unit for providing a variable visual display of the charge capacity of the battery in different discrete voltage levels;
• and
• a controller connected to said plurality of switches and said display unit, for controlling the variable visual display of the charge capacity of the battery in different discrete voltage levels in response to the respective control signals from the switches.

A battery capacity indicating device for determining a charge capacity of a battery, comprising:

• a first transistor switch operable in a first voltage range and connected in parallel to a terminal of a battery for generating a first control signal, when a battery voltage across both terminals of the battery is within said first voltage range;
• a second transistor switch operable in a second voltage range and connected in parallel to said terminal of the battery for generating a second control signal, when the battery voltage across both terminals of the battery is within said second voltage range;
• a third transistor switch operable in a third voltage range and connected in parallel to said terminal of the battery for generating a third control signal, when the battery voltage across both terminals of the battery is within said third voltage range;
• a fourth transistor switch operable in a fourth voltage range and connected in parallel to said terminal of the battery for generating a fourth control signal, when the battery voltage across both terminals of the battery is within said fourth voltage range;
• a fifth transistor switch operable in a fifth voltage range and connected in parallel to said terminal of the battery for generating a fifth control signal, when the battery voltage across both terminals of the battery is within said fifth voltage range;
• a display unit for providing a variable visual display of the charge capacity of the battery in different discrete voltage levels corresponding to each of first, second, third, fourth, and fifth voltage ranges;
• and
• a controller connected to said plurality of switches and said display unit, for controlling the variable visual display of the charge capacity of the battery in different discrete voltage levels in response to each of the first, second, third, fourth, and fifth control signals.