US3781657A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for determining and indicating the state of charge of nickel cadmium batteries
Assignee: VARTA AG
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Filing: 1971-12-30
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Granted: 1973-12-25
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Expires: 1991-12-30
Abstract
Abstract The invention proposes a method and apparatus for determining and indicating the state of charge of nickel-cadmium batteries. The method is based upon the degree of shift of the operating potential of the positive electrode in the negative direction when the electrode is under load. The shift in this potential is a measure of the extent of the discharge which has taken place and is thereby an indication of the state of charge.
Inventors
- 👤 W Dennstedt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:04
CPC Classifications
H; H01; H01M; H01M6/00; H01M6/50; H01M6/5005; G; G01; G01R; G01R31/00; G01R31/36; G01R31/378; H01M10/00; H01M10/42; H01M10/48; Y; Y02; Y02E; Y02E60/00; Y02E60/10; Y10; Y10S; Y10S320/00; Y10S320/18; Y10S320/21
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
30 words
The method according to claim 1, further including the step of generating a signal in response to a value of the positive electrode potential in excess of a threshold value.
Claim 2
Dependent Claim
51 words
Apparatus for determining and indicating the state of charge of Nickel Cadmium batteries, comprising a Nickel Cadmium battery, a positive electrode for said battery, a reference electrode for said positive electrode disposed within said battery, and means for measuring the potential difference between said positive and said reference electrodes connected therebetween.
Claim 3
Dependent Claim
13 words
Apparatus according to claim 3, wherein said reference electrode comprises an Ag2O/Ag electrode.
Claim 4
Dependent Claim
27 words
Apparatus according to claim 3, wherein said measuring means comprises a resistance connected between said positive and reference electrodes, and a voltage meter connected across said resistor.
Claim 5
Dependent Claim
24 words
Apparatus according to claim 5, further including a make and break switch in circuit with said resistor responsive to charging current for said battery.
Claim 6
Dependent Claim
32 words
Apparatus according to claim 3, further including means for generating a signal in response to a given value of potential difference between said positive and reference electrodes connected to said measuring means.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-24 | 1977-06-25 | 1977-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-24 | 1981-06-25 | 1981-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-24 | 1985-06-25 | 1985-12-25 | $7700.00 | Window Closed / Lapsed |