US4683178A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preventing electrical storage cell capacity loss
Assignee: The AT&T MVPD Group LLC
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Filing: 1986-02-07
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Granted: 1987-07-28
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Expires: 2006-02-07
Abstract
Abstract A process for preventing electrical capacity loss during storage of a pressurized nickel-hydrogen electrical storage cell. An electrical precharge is applied to the positive electrode of the cell, so that discharge of the cell is negative electrode limited. In one approach, the cell is charged, while sealed, to a state of charge corresponding to a first gas pressure, and then the hydrogen pressure is reduced to a lower value, preferably about atmospheric. In another approach, a current is passed through the cell while the cell is unsealed and maintained at atmospheric gas pressure, until the cell reaches the desired state of charge.
Inventors
- 👤 Steven J. Stadnick
- 👤 Howard H. Rogers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 14:23
CPC Classifications
H; H01; H01M; H01M10/00; H01M10/34; H01M10/345; H01M10/42; H01M10/44; H01M10/445; H02; H02J; H02J7/00; H02J7/90; H02J7/971; H02J7/973; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
51 words
A process for reducing the capacity loss during storage of a pressurized nickel-hydrogen cell comprising: precharging the cell prior to storage so that discharge of the cell is negative electrode limited, whereby an electrical charge remains on the nickel positive electrode when the hydrogen partial pressure falls to about 0 psia.
Claim 2
Dependent Claim
51 words
A process for reducing the capacity loss during storage of a pressurized nickel-hydrogen cell comprising: precharging the cell prior to storage so that discharge of the cell is negative electrode limited, whereby an electrical charge remains on the nickel positive electrode when the hydrogen partial pressure falls to about 0 psia.
Claim 3
Dependent Claim
48 words
The process of claim 1, wherein said step of precharging includes the steps of applying a charge to the positive electrode of the cell with the cell unvented, to an electrical charge corresponding to a first pressure; and reducing the pressure within the cell to a second pressure.
Claim 4
Dependent Claim
13 words
The process of claim 2, wherein the second pressure is about 15 psia.
Claim 5
Dependent Claim
13 words
The process of claim 2, wherein the first pressure is about 65 psia.
Claim 6
Dependent Claim
36 words
The process of claim 1, wherein said step of precharging includes the step of: applying a charge to the positive electrode of the cell while the pressure within the cell is maintained at about 15 psia.
Claim 7
Dependent Claim
19 words
The process of claim 5, wherein the charge level corresponds to a hydrogen partial pressure of about 65 psia.
Claim 8
Dependent Claim
52 words
A process for precharging a pressurized nickel-hydrogen cell, comprising the steps of: discharging the cell to about zero volts at a hydrogen partial pressure of about 15 psia; electrically charging the cell while sealed to a charge corresponding to a first hydrogen pressure; and reducing the hydrogen pressure to about 15 psia.
Claim 9
Dependent Claim
52 words
A process for precharging a pressurized nickel-hydrogen cell, comprising the steps of: discharging the cell to about zero volts at a hydrogen partial pressure of about 15 psia; electrically charging the cell while sealed to a charge corresponding to a first hydrogen pressure; and reducing the hydrogen pressure to about 15 psia.
Claim 10
Dependent Claim
14 words
The process of claim 7, wherein the first gas pressure is about 65 psia.
Claim 11
Dependent Claim
45 words
A process for precharging a pressurized nickel-hydrogen cell, comprising: passing a current through the cell while the cell is unsealed and maintained at a gas pressure of about 15 psia, until the cell reaches a charge state corresponding to a first sealed hydrogen partial pressure.
Claim 12
Dependent Claim
45 words
A process for precharging a pressurized nickel-hydrogen cell, comprising: passing a current through the cell while the cell is unsealed and maintained at a gas pressure of about 15 psia, until the cell reaches a charge state corresponding to a first sealed hydrogen partial pressure.
Claim 13
Dependent Claim
16 words
The process of claim 9, wherein the first sealed hydrogen partial pressure is about 65 psia.
References Cited (Backward Citations)
US3174878A
Cited
US3278334A
Cited
US3990910A
Cited
US3867199A
Cited
US3959018A
Cited
US4174565A
Cited
US4275127A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-07-27 | 1991-01-26 | 1991-07-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-27 | 1995-01-26 | 1995-07-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-27 | 1999-01-26 | 1999-07-28 | $7700.00 | Window Closed / Lapsed |