Method for accurate battery run time estimation utilizing adaptive offset values

Abstract

A disclosed method comprises adaptive offset values in an open-circuit voltage lookup table, a temperature lookup table, and an age lookup table, and then determining a present charge of the battery utilizing an open-circuit voltage of the battery and a temperature of the battery, determining a low-voltage-alarm charge of the battery utilizing a discharge current of the battery and an age of the battery, and utilizing the present charge and the low-voltage-alarm charge to estimate the run time of the battery. Utilizing the open-circuit voltage, temperature, and age comprises looking up a present battery capacity, temperature coefficient, and ageing coefficient in lookup tables, and adjusting the present battery capacity, temperature coefficient, and ageing coefficient by the respective offset values adaptive to the battery. Estimating the run time of the battery comprises, in one embodiment, dividing the difference of the present charge and the low-voltage-alarm charge by the discharge current.

Dependencies are inferred from the claim text.