Patent ID: 7418356

Claim:
A method of estimating a usable battery capacity for a mobile device, comprising: measuring one or more operating condition of the mobile device; measuring a present loaded battery voltage of the mobile device; determining a present unloaded battery voltage based on the present loaded battery voltage and the one or more operating condition, wherein the present unloaded battery voltage represents a battery voltage in a completely unloaded condition; determining a present battery capacity using the present unloaded battery voltage; determining a loaded operational threshold voltage of the mobile device, the loaded operational threshold voltage being a battery voltage below which an operation of the mobile device is shut off, and at least one operation of the mobile device remains operable; determining an unloaded operational threshold voltage of the mobile device based on the loaded operational threshold voltage and the one or more operating condition; determining an operational threshold capacity using the unloaded operational threshold voltage; estimating the usable battery capacity based on the present battery capacity and the operational threshold capacity; and storing the usable battery capacity estimation in a computer-readable medium; wherein the usable battery capacity is estimated as a function of time.