US5140252A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of charging secondary batteries
Assignee: Maxell Ltd
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Filing: 1991-02-28
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Granted: 1992-08-18
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Expires: 2011-02-28
Abstract
Abstract In a method of charging secondary battery, the charging control is performed when it is detected that the secondary differential value of the detected voltage curve changes from positive value to a negative value at the point C or its near portion.
Inventors
- 👤 Masanobu Kizu
- 👤 Ryo Nagai
- 👤 Toshio Ohshima
- 👤 Tsunemi Ohiwa
- 👤 Kozo Kajita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:43
CPC Classifications
H; H02; H02J; H02J7/00; H02J7/90; H02J7/96; H02J7/963
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
108 words
A method of charging an electrical battery, comprising the steps of: (a) setting an initial current value of charging current; (b) detecting the battery voltage at the beginning and end of a plurality of charging time intervals; (c) determining a first voltage value of the difference in the battery voltage at the beginning and end of successive charging time intervals; (d) determining a second voltage value of the difference between two successive first voltage values; and (e) reducing the value of charging current from said initial current value to a lesser current value when said second voltage value thereafter changes from a positive value to a negative value.
Claim 2
Independent Claim
108 words
A method of charging an electrical battery, comprising the steps of: (a) setting an initial current value of charging current; (b) detecting the battery voltage at the beginning and end of a plurality of charging time intervals; (c) determining a first voltage value of the difference in the battery voltage at the beginning and end of successive charging time intervals; (d) determining a second voltage value of the difference between two successive first voltage values; and (e) reducing the value of charging current from said initial current value to a lesser current value when said second voltage value thereafter changes from a positive value to a negative value.
Claim 3
Dependent Claim
45 words
The method of claim 1 wherein said step (e) of reducing comprises reducing the value of charging current to said lesser current value when said second voltage value thereafter changes from a positive value to a negative value for at least two successive time intervals.
Claim 4
Dependent Claim
45 words
The method of claim 1, and additionally including the step of: (f) reducing the current value of charging current from said lesser current value to a still lesser current value when said first voltage value thereafter goes to a zero value or a negative value.
Claim 5
Dependent Claim
32 words
The method of claim 3 and additionally including the step of: (f) determining when said first voltage value reaches a maximum negative value for indicating a full charge condition of said battery.
Claim 6
Dependent Claim
33 words
The method of claim 3 and additionally including the step of: (f) determining when said second voltage value thereafter changes to a positive value for indicating a full charge condition of said battery.
Claim 7
Dependent Claim
41 words
The method of claim 3 and additionally includes the step of: (f) determining when said first voltage value reaches a maximum negative value or said second voltage value changes to a positive value; and (g) terminating charging of said electrical battery.
Claim 8
Dependent Claim
26 words
The method of claim 1 and additionally including the step of: (f) waiting for a predetermined time interval prior to initially performing steps (b) through (e).
Claim 9
Independent Claim
164 words
A method of charging an electrical battery, comprising the steps of: (a) setting an initial current value of charging current; (b) detecting the battery voltage at the beginning and end of at least two successive charging time intervals; (c) determining a first voltage value of the difference in the battery voltage at the beginning and of said successive charging time intervals; (d) determining a second voltage value of the difference between two successive first voltage values; (e) reducing the value of charging current to a first lower current value when said second voltage value thereafter changes from a positive value to a negative value; (f) reducing the value of charging current to a second lower current value when said first voltage value thereafter goes to a zero value or a negative value; and (g) determining when said first voltage value reaches a maximum negative value or said second voltage value goes to a positive value for indicating a full charge condition of said battery.
Claim 10
Independent Claim
164 words
A method of charging an electrical battery, comprising the steps of: (a) setting an initial current value of charging current; (b) detecting the battery voltage at the beginning and end of at least two successive charging time intervals; (c) determining a first voltage value of the difference in the battery voltage at the beginning and of said successive charging time intervals; (d) determining a second voltage value of the difference between two successive first voltage values; (e) reducing the value of charging current to a first lower current value when said second voltage value thereafter changes from a positive value to a negative value; (f) reducing the value of charging current to a second lower current value when said first voltage value thereafter goes to a zero value or a negative value; and (g) determining when said first voltage value reaches a maximum negative value or said second voltage value goes to a positive value for indicating a full charge condition of said battery.
Claim 11
Dependent Claim
18 words
The method of claim 8 and additionally including the step of: (h) terminating the charging of said battery.
Claim 12
Dependent Claim
21 words
The method of claim 8 and additionally including the step of: (h) delaying steps (a)-(g) for a predetermined initial time interval.
Claim 13
Dependent Claim
19 words
The method of claim 8 wherein said first lower current value is greater than said second lower current value.
Claim 14
Dependent Claim
16 words
The method of claim 11 wherein said second lower current value comprises a trickle current value.
References Cited (Backward Citations)
US4034279A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-08-18 | 1996-02-17 | 1996-08-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-08-18 | 2000-02-17 | 2000-08-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-08-18 | 2004-02-17 | 2004-08-18 | $7700.00 | Window Closed / Lapsed |