US4006035A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Maintenance-free battery and method for reducing the current draw of such batteries
Assignee: GNB Inc
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Filing: 1975-12-12
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Granted: 1977-02-01
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Expires: 1995-12-12
Abstract
Abstract A maintenance-free battery having improved current draw characteristics is provided by adding elemental cadmium, or a cadmium affording compound such as cadmium sulfate to the electrolyte in amounts sufficient to decrease the current draw that would otherwise occur during overcharge.
Inventors
- 👤 George W. Mao
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 14:20
CPC Classifications
H; H01; H01M; H01M10/00; H01M10/06; H01M10/08; H01M4/00; H01M4/02; H01M4/64; H01M4/66; H01M4/68; H01M4/685; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
168 words
In a maintenance-free lead-acid battery comprising a battery container having a plurality of cells, a cover sealed to the container, venting means providing passages for the escape of evolved gas and an electrolyte contained in the cells, each cell including a plurality of positive and negative electrodes disposed therein comprising a grid supporting structure having a layer of active material attached thereto, the improvement wherein said electrolyte contains an additive consisting of cadmium or a cadmium compound in an amount sufficient to decrease the gassing current during constant voltage overcharge of said maintenance-free battery, the amount of cadmium corresponding to that provided by from about 0.1 to about 0.5% cadmium sulfate, based upon the weight of the electrolyte, and at least the grid supporting structure for the negative electrode consisting of an alloy essentially free of antimony and capable of allowing the cadmium added to deposit on the negative electrode during charging in amounts sufficient to decrease the gassing current during constant voltage overcharge of the maintenance-free battery.
Claim 2
Dependent Claim
168 words
In a maintenance-free lead-acid battery comprising a battery container having a plurality of cells, a cover sealed to the container, venting means providing passages for the escape of evolved gas and an electrolyte contained in the cells, each cell including a plurality of positive and negative electrodes disposed therein comprising a grid supporting structure having a layer of active material attached thereto, the improvement wherein said electrolyte contains an additive consisting of cadmium or a cadmium compound in an amount sufficient to decrease the gassing current during constant voltage overcharge of said maintenance-free battery, the amount of cadmium corresponding to that provided by from about 0.1 to about 0.5% cadmium sulfate, based upon the weight of the electrolyte, and at least the grid supporting structure for the negative electrode consisting of an alloy essentially free of antimony and capable of allowing the cadmium added to deposit on the negative electrode during charging in amounts sufficient to decrease the gassing current during constant voltage overcharge of the maintenance-free battery.
Claim 3
Dependent Claim
20 words
The maintenance-free battery of claim 1 wherein the cadmium is provided by the addition of cadmium sulfate to the electrolyte.
Claim 4
Dependent Claim
43 words
The maintenance-free battery of claim 1 wherein at least the grid supporting structure of the negative electrodes consists essentially of a lead base alloy containing calcium in an amount of from about 0.01 to about 0.15%, based upon the weight of the alloy.
Claim 5
Dependent Claim
47 words
The maintenance-free battery of claim 3 wherein at least the grid supporting structure of the negative electrodes consists essentially of a lead base alloy containing from about 0.01 to about 0.15% calcium and from about 0.1 to about 0.4% tin, based upon the weight of the alloy.
Claim 6
Dependent Claim
29 words
The maintenance-free battery of claim 4 wherein said lead base alloy contains calcium in an amount of 0.07 to 0.09% and tin in an amount of 0.20 to 0.30%.
Claim 7
Dependent Claim
134 words
In a maintenance-free lead-acid battery comprising a battery container having a plurality of cells, a cover sealed to the container, venting means providing passages for the escape of evolved gas and an electrolyte contained in the cells, each cell including a plurality of positive and negative electrodes disposed therein comprising a grid supporting structure having a layer of active material attached thereto, the improvement wherein said electrolyte contains an additive consisting of cadmium or a cadmium compound in an amount sufficient to decrease the gassing current during constant voltage overcharge of said maintenance-free battery, the amount of cadmium corresponding to that provided by from about 0.1 to about 0.5% cadmium sulfate, based upon the weight of the electrolyte, and at least the grid supporting structure for the negative electrode consists of a lead-calcium alloy.
Claim 8
Dependent Claim
134 words
In a maintenance-free lead-acid battery comprising a battery container having a plurality of cells, a cover sealed to the container, venting means providing passages for the escape of evolved gas and an electrolyte contained in the cells, each cell including a plurality of positive and negative electrodes disposed therein comprising a grid supporting structure having a layer of active material attached thereto, the improvement wherein said electrolyte contains an additive consisting of cadmium or a cadmium compound in an amount sufficient to decrease the gassing current during constant voltage overcharge of said maintenance-free battery, the amount of cadmium corresponding to that provided by from about 0.1 to about 0.5% cadmium sulfate, based upon the weight of the electrolyte, and at least the grid supporting structure for the negative electrode consists of a lead-calcium alloy.
Claim 9
Independent Claim
157 words
A method of reducing the gassing current during constant voltage overcharge in a maintenance-free battery comprising a battery container having a plurality of cells each including a plurality of positive and negative electrodes disposed therein comprising a grid supporting structure having a layer of active material attached thereto and an electrolyte contained in the cells which comprises adding an additive consisting of cadmium or a cadmium compound to said electrolyte in an amount sufficient to decrease the gassing current during constant voltage overcharge, the amount of cadmium corresponding to that provided by from about 0.1 to about 0.5% cadmium sulfate, based upon the weight of the electrolyte, and at least the grid supporting structure for the negative electrode consisting of an alloy essentially free of antimony and capable of allowing the cadmium added to deposit on the negative electrode during charging in amounts sufficient to decrease the gassing current during constant voltage overcharge of the maintenance-free battery.
Claim 10
Independent Claim
157 words
A method of reducing the gassing current during constant voltage overcharge in a maintenance-free battery comprising a battery container having a plurality of cells each including a plurality of positive and negative electrodes disposed therein comprising a grid supporting structure having a layer of active material attached thereto and an electrolyte contained in the cells which comprises adding an additive consisting of cadmium or a cadmium compound to said electrolyte in an amount sufficient to decrease the gassing current during constant voltage overcharge, the amount of cadmium corresponding to that provided by from about 0.1 to about 0.5% cadmium sulfate, based upon the weight of the electrolyte, and at least the grid supporting structure for the negative electrode consisting of an alloy essentially free of antimony and capable of allowing the cadmium added to deposit on the negative electrode during charging in amounts sufficient to decrease the gassing current during constant voltage overcharge of the maintenance-free battery.
Claim 11
Dependent Claim
16 words
The method of claim 7 wherein said cadmium is provided by the addition of cadmium sulfate.
Claim 12
Dependent Claim
42 words
The method of claim 7 wherein at least the grid supporting structure of the negative electrodes consists essentially of a lead base alloy containing calcium in an amount of from about 0.01 to about 0.15%, based upon the weight of the alloy.
Claim 13
Dependent Claim
54 words
The method of claim 9 wherein at least the grid supporting structure of the negative electrodes consists essentially of a lead base alloy containing calcium in an amount of from about 0.01 to about 0.15% and tin in an amount of from about 0.10 to about 0.40%, based on the weight of the alloy.
Claim 14
Independent Claim
123 words
A method of reducing the gassing current during constant voltage overcharge in a maintenance-free battery comprising a battery container having a plurality of cells each including a plurality of positive and negative electrodes disposed therein comprising a grid supporting structure having a layer of active material attached thereto and an electrolyte contained in the cells which comprises adding an additive consisting of cadmium or a cadmium compound to said electrolyte in an amount sufficient to decrease the gassing current during constant voltage overcharge, the amount of cadmium corresponding to that provided by from about 0.1 to about 0.5% cadmium sulfate, based upon the weight of the electrolyte, and at least the grid supporting structure for the negative electrode consists of a lead-calcium alloy.
Claim 15
Independent Claim
123 words
A method of reducing the gassing current during constant voltage overcharge in a maintenance-free battery comprising a battery container having a plurality of cells each including a plurality of positive and negative electrodes disposed therein comprising a grid supporting structure having a layer of active material attached thereto and an electrolyte contained in the cells which comprises adding an additive consisting of cadmium or a cadmium compound to said electrolyte in an amount sufficient to decrease the gassing current during constant voltage overcharge, the amount of cadmium corresponding to that provided by from about 0.1 to about 0.5% cadmium sulfate, based upon the weight of the electrolyte, and at least the grid supporting structure for the negative electrode consists of a lead-calcium alloy.
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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) | 1980-02-01 | 1980-08-02 | 1981-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-01 | 1984-08-02 | 1985-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-01 | 1988-08-02 | 1989-02-01 | $7700.00 | Window Closed / Lapsed |