Patent US4413221A successfully refreshed from Google Patents.
US4413221A
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US
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Method and circuit for determining battery capacity
Assignee: Christie Electric Corp
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Filing: 1980-12-18
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Granted: 1983-11-01
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Expires: 2000-12-18
Abstract
Abstract The capacity of a battery is determined while charging the battery by measuring the time it takes the battery voltage to decrease to a selected voltage level during discharging intervals interspersed between charging intervals. The state-of-charge is also determined by measuring the voltage level during a discharge interval while monitoring the duration of the charge cycle. Additionally, faulty cells of the battery are detected by measuring the voltage of the individual cells at the end of a discharging interval during the charging of the battery.
Inventors
- 👤 Fred Benjamin
- 👤 Robert H. Heil
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:40
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/36; G01R31/385; G01R31/386; G01R31/382; G01R31/3835; Y; Y10; Y10S; Y10S320/00; Y10S320/33
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
102 words
A method of determining the capacity of a battery comprising the steps of: imposing an increasing charge on a battery during a plurality of charge intervals and a plurality of discharge intervals interspersed with the charge intervals by applying a charge current to the battery during each charge interval; applying a load to the battery during each discharge interval until the battery voltage decreases to a selected level; removing the load in response to the attainment of the selected level to end the discharge interval; and sensing the duration of each discharge interval as an indication of the capacity of the battery.
Claim 2
Independent Claim
102 words
A method of determining the capacity of a battery comprising the steps of: imposing an increasing charge on a battery during a plurality of charge intervals and a plurality of discharge intervals interspersed with the charge intervals by applying a charge current to the battery during each charge interval; applying a load to the battery during each discharge interval until the battery voltage decreases to a selected level; removing the load in response to the attainment of the selected level to end the discharge interval; and sensing the duration of each discharge interval as an indication of the capacity of the battery.
Claim 3
Dependent Claim
29 words
A method in accordance with claim 1 further comprising the step of displaying the sensed duration as a bar chart having a length indicating the capacity of the battery.
Claim 4
Dependent Claim
16 words
A method in accordance with claim 2 wherein the bar chart has a logarithmic time base.
Claim 5
Dependent Claim
19 words
A method in accordance with claim 1 wherein the charge current has a fixed duration and a fixed amplitude.
Claim 6
Independent Claim
105 words
A method of determining the capacity of a battery comprising the steps of: imposing an increasing charge on a battery during a plurality of charge intervals and a plurality of discharge intervals interspersed with the charge intervals by applying a charge current to the battery during each charge interval; applying a load to the battery during each discharge interval until the battery voltage decreases to a selected level; removing the load in response to the attainment of the selected level to end the discharge interval; and measuring the cell trough voltage at the end of the battery discharge interval of each individual cell in succession.
Claim 7
Independent Claim
105 words
A method of determining the capacity of a battery comprising the steps of: imposing an increasing charge on a battery during a plurality of charge intervals and a plurality of discharge intervals interspersed with the charge intervals by applying a charge current to the battery during each charge interval; applying a load to the battery during each discharge interval until the battery voltage decreases to a selected level; removing the load in response to the attainment of the selected level to end the discharge interval; and measuring the cell trough voltage at the end of the battery discharge interval of each individual cell in succession.
Claim 8
Dependent Claim
45 words
The method of determining the capacity of a battery in accordance with claim 5 comprising the further steps of: applying a portion of the cell voltage to a sample-and-hold circuit at the end of each discharge interval; and displaying the cell voltage on a meter.
Claim 9
Independent Claim
134 words
A method of determining the capacity of a battery comprising the steps of: imposing an increasing charge on a battery during a plurality of charge intervals and a plurality of discharge intervals interspersed with the charge intervals by applying a charge current to the battery during each charge interval; applying a load to the battery during each discharge interval until the battery voltage decreases to a selected level; removing the load in response to the attainment of the selected level to end the discharge interval; applying a shunt in the path of the battery discharge current; developing a signal in response to the voltage across the shunt during each discharge interval with the signal having a duration determined by the duration of the discharge interval; and applying the signal to a bar chart display.
Claim 10
Independent Claim
134 words
A method of determining the capacity of a battery comprising the steps of: imposing an increasing charge on a battery during a plurality of charge intervals and a plurality of discharge intervals interspersed with the charge intervals by applying a charge current to the battery during each charge interval; applying a load to the battery during each discharge interval until the battery voltage decreases to a selected level; removing the load in response to the attainment of the selected level to end the discharge interval; applying a shunt in the path of the battery discharge current; developing a signal in response to the voltage across the shunt during each discharge interval with the signal having a duration determined by the duration of the discharge interval; and applying the signal to a bar chart display.
Claim 11
Dependent Claim
40 words
A method in accordance with claim 7 wherein the bar chart display is made up of a plurality of light-emitting diodes driven from a voltage divider network wherein the value of the resistors of the network has a logarithmic relationship.
Claim 12
Dependent Claim
98 words
A battery charger analyzer comprising: a charge current source; means for applying a selected amplitude of charge current from the source to a battery for a selected interval of time; means for discharging the battery at the end of each charge current interval; means for sensing the battery terminal voltage during discharge; means responsive to the sensing means for terminating each discharge interval upon the battery terminal voltage decreasing to a selected level; means for sensing the duration of each discharge interval; and means for displaying this duration as a measure of the charge capacity of the battery.
Claim 13
Dependent Claim
98 words
A battery charger analyzer comprising: a charge current source; means for applying a selected amplitude of charge current from the source to a battery for a selected interval of time; means for discharging the battery at the end of each charge current interval; means for sensing the battery terminal voltage during discharge; means responsive to the sensing means for terminating each discharge interval upon the battery terminal voltage decreasing to a selected level; means for sensing the duration of each discharge interval; and means for displaying this duration as a measure of the charge capacity of the battery.
Claim 14
Dependent Claim
35 words
A battery charger analyzer in accordance with claim 9 wherein the display means is a bar chart made up of light-emitting diodes driven by a driver having a voltage divider network with a logarithmic relationship.
Claim 15
Dependent Claim
24 words
A battery charger analyzer in accordance with claim 9 further comprising means for measuring the trough voltage of the individual cells of the battery.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-10-31 | 1987-05-02 | 1987-11-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-31 | 1991-05-02 | 1991-11-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-31 | 1995-05-02 | 1995-11-01 | $7700.00 | Window Closed / Lapsed |