Back to results
US 7,405,571 B1Granted
Methods and apparatuses for determining battery capacity
AssigneeHDM Systems Corporation
InventorDavid S. C. Liu
Life of this patent
Estimating the term…
Abstract
Methods and apparatuses for determining a battery capacity are described. According to one embodiment, an exemplary method includes generating virtual calibration data of the battery based on one or more characteristics of the battery, determining a virtual open circuit voltage (Voc) of the battery while the battery is being used, and estimating the capacity of the battery based on the determined virtual open circuit voltage of the battery and the virtual calibration data of the battery, while the battery is being used.
Claims18
A method for measuring a capacity of a battery, the method comprising:
- generating virtual calibration data of the battery based on one or more characteristics of the battery;
- determining an internal impedance (Ri) of the battery, including
- applying a first load (I1) across the battery,
- measuring a first voltage (V1) across the battery while the battery is being applied with the first load (I1),
- applying a second load (I2) to the battery for a predetermined time duration in addition to the first load (I1), and
- measuring, during the predetermined time duration, a second voltage (V2) across the battery in view of the first load (I1) and the second load (I2), wherein the internal impedance is determined based on at least a portion of V1, V2, I1, and I2;
- determining a virtual open circuit voltage (Voc) of the battery based on the internal impedance of the battery while the battery is being used;
- and
- estimating the capacity of the battery based on the determined virtual open circuit voltage of the battery and the virtual calibration data of the battery, while the battery is being used.
6 more elements
A method for measuring a capacity of a battery, the method comprising:
- generating virtual calibration data of the battery based on one or more characteristics of the battery;
- determining a virtual open circuit voltage (Voc) of the battery while the battery is being used;
- determining an internal impedance (Ri) of the battery, wherein the virtual open circuit voltage of the battery is determined based on the internal impedance of the battery;
- and
- estimating the capacity of the battery based on the determined virtual open circuit voltage of the battery and the virtual calibration data of the battery while the battery is being used, wherein the battery is being discharged and charged substantially concurrently when the capacity of the battery is estimated, including
- obtaining a difference (ΔI) between a charge current (I1) and a discharge current (I2) while the battery is being discharged and charged substantially concurrently,
- applying a second load (I3) that is grater than ΔI4,
- measuring a second voltage (V3) across the battery while the second load (I3) is being applied,
- applying a third load (I4) that is grater than the second load (I3), and
- measuring a third voltage (V4) across the battery in view of the second load (I3) and the third load (I4), wherein at least one of the internal impedance and virtual open circuit voltage (Voc) of the battery is determined based on at least a portion of V3, V4, I1, I2, I3, and I4.
7 more elements
An apparatus for measuring a capacity of a battery, comprising:
- a database to maintain virtual calibration data of the battery based on one or more characteristics of the battery;
- and
- a controller to determine an internal impedance (Ri) of the battery, including
- applying a first load (Ii) across the battery,
- measuring a first voltage (V1) across the battery while the battery is being applied with the first load (I1),
- applying a second load (I2) to the battery for a predetermined time duration in addition to the first load (I1), and
- measuring, during the predetermined time duration, a second voltage (V2) across the battery in view of the first load (I1) and the second load (I2), wherein the internal impedance is determined based on at least a portion of V1, V2, I1, and I2,
- wherein the controller is configured to determine a virtual open circuit voltage (Voc) of the battery based on the internal impedance of the battery while the battery is being used, wherein the controller is configured to estimate the capacity of the battery based on the determined virtual open circuit voltage of the battery and the virtual calibration data of the battery stored on the database while the battery is being used.
5 more elements
An apparatus for measuring a capacity of a battery, comprising:
- a database to maintain virtual calibration data of the battery based on one or more characteristics of the battery;
- and
- a controller to determine a virtual open circuit voltage (Voc) of the battery while the battery is being used, wherein the controller is configured to estimate the capacity of the battery based on the determined virtual open circuit voltage of the battery and the virtual calibration data of the battery stored on the database while the battery is being used,
- wherein the controller is configured further to determine an internal impedance (Ri) of the battery, wherein the virtual open circuit voltage of the battery is determined based on the internal impedance of the battery,
- wherein the battery is being discharged and charged substantially concurrently when the capacity of the battery is estimated, and wherein the controller is configured further to
- obtain a difference (ΔI) between a charge current (I1) and a discharge current (I2) while the battery is being discharged and charged substantially concurrently,
- apply a second load (I3) that is grater than ΔI,
- measure a second voltage (V3) across the battery while the second load (I3) is being applied,
- apply a third load (I4) that is grater than the second load (I3), and
- measure a third voltage (V4) across the battery in view of the second load (I3) and the third load (I4), wherein at least one of the internal impedance and virtual open circuit voltage (Voc) of the battery is determined based on at least a portion of V3, V4, I1, I2, I3, and I4.
7 more elements
An apparatus for measuring a capacity of a battery, comprising:
- means for generating virtual calibration data of the battery based on one or more characteristics of the battery;
- means for determining an internal impedance (Ri) of the battery, including
- means for applying a first load (I1) across the battery,
- means for measuring a first voltage (V1) across the battery while the battery is being applied with the first load (I1),
- means for applying a second load (I2) to the battery for a predetermined time duration in addition to the first load (I1), and
- means for measuring, during the predetermined time duration, a second voltage (V2) across the battery in view of the first load (I1) and the second load (I2), wherein the internal impedance is determined based on at least a portion of V1, V2, I1, and I2;
- means for determining a virtual open circuit voltage (Voc) of the battery based on the internal impedance of the battery while the battery is being used;
- and
- means for estimating the capacity of the battery based on the determined virtual open circuit voltage of the battery and the virtual calibration data of the battery, while the battery is being used.
6 more elements
Dependencies are inferred from the claim text.