Patent US4742290A successfully refreshed from Google Patents.
US4742290A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Recharging battery charger
Assignee: Associated Equipment Corp
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Filing: 1986-06-02
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Granted: 1988-05-03
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Expires: 2006-06-02
Abstract
Abstract A microprocessor controlled battery charger to charge a battery when the charging current is reduced to zero even though the charger is still connected to the battery. The microprocessor includes a means to read the voltage of the battery and also includes a timer. The voltage of the battery is periodically read and when it decreases below a predetermined value the microprocessor again establishes recharging of the battery first at an intermediate rate until either a maximum voltage is reached or a minimum dv/dt is reached and then the current is reduced to a lower current rate for a finishing charge of the battery for a given period of time.
Inventors
- 👤 Richard C. Sutphin
- 👤 Steven R. Bell
- 👤 Kurt Monsell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:53
CPC Classifications
H; H02; H02J; H02J7/00; H02J7/90; H02J7/96; H02J7/963; Y; Y10; Y10S; Y10S320/00; Y10S320/12; Y10S320/13; Y10S320/18; Y10S320/19; Y10S320/22; Y10S320/24
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
146 words
A microprocessor controlled battery charger adapted to be connected to a battery to be charged, said battery charger comprising, in combination: means to read the voltage of the battery; a microprocessor to establish a charging of said battery by said charger until substantially fully charged and then terminating said charging; said reading means at least periodically reading the voltage of the battery after the termination of charging and determining if the battery voltage has decreased below a predetermined value; said microprocessor establishing recharging of the battery at a first charging rate until the rate of change of voltage with time is less than x/100 volts per hour at which time the current is reduced to a second charging rate for a finishing charge of the battery, where x is a positive number; and selector means to select the values of said first and second charging rates.
Claim 2
Dependent Claim
146 words
A microprocessor controlled battery charger adapted to be connected to a battery to be charged, said battery charger comprising, in combination: means to read the voltage of the battery; a microprocessor to establish a charging of said battery by said charger until substantially fully charged and then terminating said charging; said reading means at least periodically reading the voltage of the battery after the termination of charging and determining if the battery voltage has decreased below a predetermined value; said microprocessor establishing recharging of the battery at a first charging rate until the rate of change of voltage with time is less than x/100 volts per hour at which time the current is reduced to a second charging rate for a finishing charge of the battery, where x is a positive number; and selector means to select the values of said first and second charging rates.
Claim 3
Dependent Claim
35 words
A battery charger as set forth in claim 1, including a timer connected to said microprocessor; and said reading means periodically reading the battery voltage during a period of time as determined by said timer.
Claim 4
Dependent Claim
30 words
A battery charger as set forth in claim 1, wherein said microprocessor establishes said second charging rate in the absence of a first rate being selected by said selector means.
Claim 5
Dependent Claim
19 words
A battery charger as set forth in claim 1, wherein said selector means is a digital key pad input.
Claim 6
Dependent Claim
18 words
A battery charger as set forth in claim 1, wherein said battery charger is a switching battery charger.
Claim 7
Dependent Claim
26 words
A battery charger as set forth in claim 1, including a timer, and wherein said microprocessor establishes said finishing charge second rate for a timed period.
Claim 8
Dependent Claim
27 words
A battery charger as set forth in claim 1, wherein said microprocessor controls said first charging rate to be at a constant current despite changing battery voltage.
Claim 9
Dependent Claim
34 words
A battery charger as set forth in claim 1, wherein said microprocessor controls said second charging rate to be at a constant lower current rate than said first charging rate despite changing battery voltage.
Claim 10
Dependent Claim
49 words
A battery charger as set forth in claim 1, wherein said microprocessor controls change from said first to said second charging rate at the first to occur of one of a predetermined maximum battery voltage and the rate of change of voltage being less than x/100 volts per hour.
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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) | 1991-05-03 | 1991-11-02 | 1992-05-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-03 | 1995-11-02 | 1996-05-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-03 | 1999-11-02 | 2000-05-03 | $7700.00 | Window Closed / Lapsed |