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US4055709A
Expired / Lapsed
US
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Rejuvenation of nickel-cadmium battery cells
Assignee: United States Department of the Navy
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Filing: 1976-08-05
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Granted: 1977-10-25
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Expires: 1996-08-05
Abstract
Abstract Nickel-Cadmium cells of insufficient voltage capacities are rejuvenated by process which includes the steps of charging the cells, flushing the cells with demineralized water, replacing the electrolyte, and then deep discharging. The cells are left in the discharged state for shipping purposes and then charged prior to use.
Inventors
- 👤 Robert C. Medford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 07:45
CPC Classifications
H; H01; H01M; H01M10/00; H01M10/42; H01M10/44; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
74 words
A method of rejuvenating nickel-cadmium battery cells of limited voltage capacity comprising the steps of: charging the cells at approximately 2.5 amps until equilibrium is reached; draining the electrolyte from the cells; flushing the cells internally with demineralized-distilled water, which is free of carbon dioxide, in an ultrasonic bath; preparing fresh electrolyte by dissolving approximately 33% by weight of reagent grade potassium hydroxide in boiled-distilled water; and adding said fresh electrolyte to said cells.
Claim 2
Independent Claim
74 words
A method of rejuvenating nickel-cadmium battery cells of limited voltage capacity comprising the steps of: charging the cells at approximately 2.5 amps until equilibrium is reached; draining the electrolyte from the cells; flushing the cells internally with demineralized-distilled water, which is free of carbon dioxide, in an ultrasonic bath; preparing fresh electrolyte by dissolving approximately 33% by weight of reagent grade potassium hydroxide in boiled-distilled water; and adding said fresh electrolyte to said cells.
Claim 3
Dependent Claim
21 words
The method of claim 1 wherein each cell is deep discharged by shorting with a one ohm resistor prior to charging.
Claim 4
Dependent Claim
47 words
The method of claim 1 wherein the cells are prepared for shipment in the discharged state subsequent to the addition of fresh electrolyte by the steps of: discharging each cell at approximately 55 amperes for approximately 8 minutes; and shorting each cell with a one ohm resistor.
Claim 5
Dependent Claim
43 words
The method of claim 3 including the additional steps of: charging the cells at approximately 2.5 amperes until equilibrium is reached; discharging each cell again at approximately 55 amperes for approximately 8 minutes; and shorting each cell again with a one ohm resistor.
Claim 6
Dependent Claim
47 words
The method of claim 2 wherein the cells are prepared for shipment in the discharged state subsequent to the addition of fresh electrolyte by the steps of: discharging each cell at approximately 55 amperes for approximately 8 minutes; and shorting each cell with a one ohm resistor.
Claim 7
Dependent Claim
43 words
The method of claim 5 including the additional steps of: charging the cells at approximately 2.5 amperes until equilibrium is reached; discharging each cell again at approximately 55 amperes for approximately 8 minutes; and shorting each cell again with a one ohm resistor.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-10-24 | 1981-04-25 | 1981-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-24 | 1985-04-25 | 1985-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-24 | 1989-04-25 | 1989-10-25 | $7700.00 | Window Closed / Lapsed |