US 5,596,260 A · Apparatus and method for determining a charge of a battery

Abstract

In an electronic device powered by a battery, a method of determining a charge of the battery. Initially, a discharge curve specifying the battery's voltage as a function of time is determined. This discharge curve is calibrated according to actual measurements. Next, a battery state model is established. The battery state model is comprised of a number of discrete charge states. The probability of the actual battery's charge for a particular charge state is specified by the battery state model for each of the charge states. The battery's voltage is periodically measured. Based on the measured voltage and the discharge curve, a voltage probability distribution is computed. The battery discharge model is updated by applying Bayes theorem to the old discharge model and the voltage probability distribution. The charge of the battery based on a mean value of the battery discharge model is then displayed.

Claims14

Dependent claims

In an electronic device powered by a battery, a method of analyzing a voltage signal to determine a charge of said battery for display on a display device, said method comprising the steps of:

determining a discharge curve corresponding to said battery, said discharge curve specifying voltage of said battery as a function of a state of charge of said battery;
calibrating said discharge curve;
formulating a battery state model, said model specifying probabilities of an actual charge of said battery for a plurality of possible battery capacities;
periodically obtaining the voltage signal by measuring a voltage of said battery;
updating said battery state model according to said voltage signal and said discharge curve by applying Bayes theorem;
normalizing said battery state model;
displaying on said display device a representation of said charge of said battery based on a mean value of said battery state model.

4 more elements

In an electronic device having a charge storage device, a method of analyzing a voltage signal to determine a charge of said charge storing device for display on a display device, said method comprising the steps of:

defining a plurality of discrete intervals of charge ranging from no charge to full charge of said charge storing device;
establishing a probabilistic model of said charge storing device by establishing a probability for each of said discrete intervals of an actual charge corresponding to that particular discrete interval;
establishing a discharge curve specifying voltage of said charge storage device as a function of a state of charge of said charge storing device;
periodically obtaining the voltage signal by measuring a voltage of said charge storage device;
determining a probabilistic distribution of said charge storage device based on said voltage;
updating said probabilistic model by applying Bayes theorem to said probabilistic distribution;
displaying on said display device a representation of said charge of said charge storing device based on a mean of said probabilities.

4 more elements

Dependencies are inferred from the claim text.

Apparatus and method for determining a charge of a battery

Life of this patent

Apparatus and method for determining a charge of a battery

Life of this patent

Abstract

Claims14