Systems and methods for determining battery state of charge
AssigneeCirrus Logic, Inc.
InventorsYandong Zhang, John L. Melanson
Life of this patent
Estimating the term…
Abstract
A method for estimating a battery state of charge may include determining a first estimated state of charge and a first estimated accuracy of the state of charge using a first estimation approach, determining a second estimated state of charge and a second estimated accuracy of the state of charge using a second estimation approach, and estimating the battery state of charge based on the first estimated state of charge, the first estimated accuracy of the state of charge, the second estimated state of charge, and the second estimated accuracy of the state of charge.
Claims10
A method for estimating a battery state of charge, comprising:
- measuring a terminal voltage and current of a battery;
- determining whether the battery is in a relaxation state, wherein the battery is in the relaxation state when:
- the current of the battery has been approximately zero for a predetermined amount of time;
- a difference in the terminal voltage is less than a threshold difference;
- and
- the current of the battery is zero;
- determining a first estimated state of charge and a first estimated accuracy of the state of charge using a first estimation approach;
- determining a second estimated state of charge and a second estimated accuracy of the state of charge using a second estimation approach;
- and
- in response to determining that the battery is in the relaxation state, estimating the battery state of charge as a weighted average of the first estimated state of charge and the second estimated state of charge as an inverse variance weighted average based on the first estimated accuracy of the state of charge and the second estimated accuracy of the state of charge.
A system for estimating a battery state of charge, comprising:
- a processor configured to:
- measure a terminal voltage and current of a battery;
- determine whether the battery is in a relaxation state, wherein the battery is in the relaxation state when:
- the current of the battery has been approximately zero for a predetermined amount of time;
- a difference in the terminal voltage is less than a threshold difference;
- and
- the current of the battery is zero;
- determine a first estimated state of charge and a first estimated accuracy of the state of charge using a first estimation approach;
- determine a second estimated state of charge and a second estimated accuracy of the state of charge using a second estimation approach;
- and
- estimate, in response to determining that the battery is in the relaxation state, the battery state of charge as a weighted average of the first estimated state of charge and the second estimated state of charge as an inverse variance weighted average based on the first estimated accuracy of the state of charge and the second estimated accuracy of the state of charge.
Dependencies are inferred from the claim text.