US4097803A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Battery self-discharge indicator
Assignee: Department of National Defence
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Filing: 1976-10-26
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Granted: 1978-06-27
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Expires: 1996-10-26
Abstract
Abstract Electrical leakage between electrodes in an electrochemical cell is determined by initially overcharging the cell to place it in a fully charged state. Various methods are available to ascertain a full charge, and a convenient method is disclosed in which the full charge is indicated by a predetermined rate of gassing at the electrodes. After receiving a full charge the cell is stored on open circuit for a time, during which some of the charge is dissipated due to leakage, and is then recharged to achieve an onset of gassing condition. The gas from the cell is conducted to a pressure vessel where it is filtered and slowly exhausted to the atmosphere while the pressure is monitored. An anomalous delay, relative to a reference cell, in achieving the onset of gassing condition indicates a cell leakage. The method and apparatus disclosed provides a convenient and considerably faster way than previously known to test for cell leakage.
Inventors
- 👤 Keiva Feldman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 12:31
CPC Classifications
H; H01; H01M; H01M10/00; H01M10/42; H01M10/4285; H01M10/4228; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
86 words
A method for detecting electrical leakage between electrodes in an electrochemical cell, comprising the steps of: charging the cell to a fully charged condition; storing the cell on open circuit for a predetermined period to permit at least partial dissipation of the full charge due to said leakage; recharging the cell to an onset of gassing condition; measuring the duration of recharge to achieve said gassing condition; and comparing said duration with a like parameter of a refernce cell to ascertain the presence of said leakage.
Claim 2
Independent Claim
86 words
A method for detecting electrical leakage between electrodes in an electrochemical cell, comprising the steps of: charging the cell to a fully charged condition; storing the cell on open circuit for a predetermined period to permit at least partial dissipation of the full charge due to said leakage; recharging the cell to an onset of gassing condition; measuring the duration of recharge to achieve said gassing condition; and comparing said duration with a like parameter of a refernce cell to ascertain the presence of said leakage.
Claim 3
Dependent Claim
23 words
A method as claimed in claim 1 wherein the fully charged condition is indicated by a predetermine rate of gassing at the electrodes.
Claim 4
Dependent Claim
56 words
A method as claimed in claim 2 comprising the further steps of: conducting the evolved gas to a closed chamber having an orifice adapted to slowly exhaust the gas to the atmosphere; and measuring the gas pressure within the chamber relative to atmospheric pressure whereby an anomalous delay in the onset of gassing indicates said leakage.
Claim 5
Dependent Claim
29 words
A method as claimed in claim 3 comprising the further step of filtering the gas conducted to the closed chamber to remove droplets of electrolyte carried by said gas.
Claim 6
Dependent Claim
105 words
Apparatus for detecting electrical leakage between electrodes in an electrochemical cell relative to a reference cell, comprising: pressure vessel means of substantially constant volume having walls defining a closed chamber including a gas inlet, a gas exhaust outlet having a smaller port dimension than said inlet for communicating said chamber with the atmosphere, and a pressure monitoring outlet; tube means communicating the gas inlet with a gas vent of individual ones of the cells; and means communicating with the monitoring outlet for measuring gas pressure of individual ones othe cells relative to atmospheric pressure and correlating said gas pressure to a rate of gas emission.
Claim 7
Dependent Claim
105 words
Apparatus for detecting electrical leakage between electrodes in an electrochemical cell relative to a reference cell, comprising: pressure vessel means of substantially constant volume having walls defining a closed chamber including a gas inlet, a gas exhaust outlet having a smaller port dimension than said inlet for communicating said chamber with the atmosphere, and a pressure monitoring outlet; tube means communicating the gas inlet with a gas vent of individual ones of the cells; and means communicating with the monitoring outlet for measuring gas pressure of individual ones othe cells relative to atmospheric pressure and correlating said gas pressure to a rate of gas emission.
Claim 8
Dependent Claim
28 words
Apparatus as claimed in claim 5 further comprising filter means to remove droplets of electrolyte carried by gas evolved at the electrodes of individual ones of the cells.
Claim 9
Dependent Claim
16 words
Apparatus as claimed in claim 6 wherein the means for measuring gas pressure is a manometer.
Claim 10
Dependent Claim
24 words
Apparatus as claimed in claim 7 wherein the filter means comprises a plurality of glass beads disposed within said chamber about the gas inlet.
Claim 11
Dependent Claim
100 words
Apparatus as claimed in claim 8 further comprising a connector joining an end of said tube means with the gas vent and comprising: a pipe having an end adapted to fit inside the tube means, the free end of the pipe having a plurality of ports perforating the walls of the pipe adjacent said free end; and a length of elastic tubing, one end being adapted to stretchably engage the gas vent and the other end being disposed over said free end in releasably sealing relation with said ports to open said ports in response to a predetermined gas pressure.
Claim 12
Dependent Claim
24 words
Apparatus as claimed in claim 9 further comprising a separate pressure vessel, tube means and means for measuring gas pressure for each electrochemical cell.
References Cited (Backward Citations)
US3500167A
Cited
US3764508A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-06-26 | 1981-12-26 | 1982-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-26 | 1985-12-26 | 1986-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-26 | 1989-12-26 | 1990-06-27 | $7700.00 | Window Closed / Lapsed |