US5237259A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Charging method for secondary battery
Assignee: Sony Corp
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Filing: 1991-11-12
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Granted: 1993-08-17
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Expires: 2011-11-12
Abstract
Abstract A method of charging a secondary battery by means of a constant voltage power source for supplying a limited current. The method includes a first step of charging the secondary battery until a predetermined condition is reached, and a second step of further charging the secondary battery for a predetermined period of time after the predetermined condition is reached. Accordingly, overcharge of the secondary battery can be surely prevented.
Inventors
- 👤 Akira Sanpei
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:59
CPC Classifications
H; H02; H02J; H02J7/00; H02J7/90; H02J7/92; H02J7/94; H02J7/96
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
135 words
A method of charging a secondary battery by means of a constant voltage power source for supplying a limited current, said method comprising a first step of charging said secondary battery until a predetermined condition is reached, and a second step of further charging said secondary battery for a first predetermined period of time after said predetermined condition is reached, wherein said predetermined condition is that a charging current of said secondary battery lowers to a first predetermined current, and further comprising a third step of repeatedly charging said secondary battery after said second step after a second predetermined period of time has elapsed until said charging current lowers to a second predetermined current and then further charging said secondary battery for a third predetermined period of time after said second predetermined current is reached.
Claim 2
Independent Claim
135 words
A method of charging a secondary battery by means of a constant voltage power source for supplying a limited current, said method comprising a first step of charging said secondary battery until a predetermined condition is reached, and a second step of further charging said secondary battery for a first predetermined period of time after said predetermined condition is reached, wherein said predetermined condition is that a charging current of said secondary battery lowers to a first predetermined current, and further comprising a third step of repeatedly charging said secondary battery after said second step after a second predetermined period of time has elapsed until said charging current lowers to a second predetermined current and then further charging said secondary battery for a third predetermined period of time after said second predetermined current is reached.
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) | 1996-08-16 | 1997-02-15 | 1997-08-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-08-16 | 2001-02-15 | 2001-08-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-08-16 | 2005-02-15 | 2005-08-17 | $7700.00 | Window Closed / Lapsed |