Dual-mode fuel gauge for display in battery-powered equipment

An apparatus comprising:

• a smart battery comprising a battery having a terminal voltage and a current charge capacity, means for acquiring a first value representing the current charge capacity of said battery, and means for acquiring a second value representing the terminal voltage of said battery;
• a display panel;
• and
• a processor for controlling said display panel to display a gauge comprising an indicator representing said first value in a charge depletion mode or an indicator representing said second value in a voltage mode,
• wherein said processor comprises means for switching from said charge depletion mode to said voltage mode when said terminal voltage reaches a predetermined threshold.

An apparatus comprising:

• a smart battery having a current charge capacity and a terminal voltage;
• a display panel;
• and
• a computer programmed to perform the steps of controlling said display panel to display a gauge comprising an indicator representing said current charge capacity of said smart battery in a charge depletion mode or an indicator representing said terminal voltage of said smart battery in a voltage mode, and switching from said charge depletion mode to said voltage mode when said terminal voltage reaches a predetermined threshold.

A method of displaying a gauge representing the state of a battery, comprising the steps of:

• calculating electronic data representing a gauge comprising an indicator representing a current charge capacity of the battery in a charge depletion mode or an indicator representing a terminal voltage of the battery in a voltage mode;
• displaying said electronic data on a display panel;
• and
• switching from said charge depletion mode to said voltage mode when said terminal voltage reaches a predetermined threshold.

A method of displaying a gauge representing the state of a battery, comprising the steps of:

• calculating electronic data representing a gauge comprising an indicator representing a current charge capacity of the battery in a charge depletion mode or an indicator representing a terminal voltage of the battery in a voltage mode;
• displaying said electronic data on a display panel;
• and
• scaling a portion of the width of said gauge to a difference between a predetermined voltage threshold and a predetermined shutdown voltage.

An apparatus comprising:

• a smart battery having a current charge capacity and a terminal voltage;
• a display panel;
• and
• a computer programmed to perform the steps of controlling said display panel to display a gauge comprising an indicator representing said current charge capacity of said smart battery in a charge depletion mode or an indicator representing said terminal voltage of said smart battery in a voltage mode, and scaling a portion of the width of said gauge to a difference between a predetermined voltage threshold and a predetermined shutdown voltage.