Fractional depletion estimation for battery condition metrics

A method of evaluating an energy state comprising:

• collecting, at a sampling interval, samples of a measure of current discharged from at least one cell powering an electric load during a discharge event;
• sorting the collected samples into bins so as to group the collected samples based upon sample value;
• integrating, for each bin, the samples in that bin to create a use estimate based on a number of samples sorted into the bin, a value associated with the bin, and the sampling interval;
• determining, for each bin, a fractional depletion contribution of the at least one cell based on the use estimate and an expected value for that bin;
• and
• generating a depletion estimate associated with the state of the at least one cell based upon an accumulation of the fractional depletion contributions.

A system that evaluates a state of a battery, the system comprising:

• a sensor communicatively coupled to a battery that is powering an electric load, the sensor operative to collect samples, each sample representing a measure of current discharged from the battery during a discharge event;
• bins stored in a memory and accessible by a processor;
• wherein the processor is programmed to:
• sort the collected samples into bins so as to group the collected samples based upon sample value;
• integrate, for each bin, the samples in that bin to create a battery use estimate based on a number of samples sorted into the bin, a value associated with the bin, and the sampling interval;
• determine, for each bin, a fractional depletion contribution of the battery based on the battery use estimate and an expected value for that bin;
• and
• generate a depletion estimate associated with the state of the battery based upon an accumulation of the fractional depletion contributions.

A system that evaluates an energy state, the system comprising:

• a sensor communicatively coupled to at least one cell that is powering an electric load, the sensor operative to collect samples, each sample representing a measure of current discharged from the at least one cell during a discharge event;
• bins stored in a memory and accessible by a processor;
• wherein the processor is programmed to:
• sort the collected samples into bins so as to group the collected samples based upon sample value;
• create a battery use estimate based upon samples sorted into their corresponding bins;
• and
• determine a fractional depletion of the battery for each bin, each fractional depletion being a quotient that is computed by dividing an expected value for that bin by the battery use estimate for that bin.