US5939865A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rechargeable battery having overcharge protection circuit and method of charging rechargeable battery
Assignee: Anton Bauer Inc
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Filing: 1998-03-31
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Granted: 1999-08-17
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Expires: 2018-03-31
Abstract
Abstract A rechargeable battery is provided with an overcharge protection circuit which is particularly adapted for nickel metal hydride battery packs to be used in conventional charging adapters suitable for NI-CAD battery packs. The battery pack includes a microprocessor which measures the voltage across the electrical contacts of the battery pack. Upon reaching peak charge, the microprocessor increases the voltage appearing across the battery pack contacts. After a predetermined time period as measured by the microprocessor, the microprocessor decreases the voltage appearing across the battery pack terminals to exceed the change in voltage to which the charging adapter responds to terminate a high rate of charging.
Inventors
- 👤 Francis D. McGrath
- 👤 Norman D. Kellogg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 18:18
CPC Classifications
H; H02; H02J; H02J7/00; H02J7/60; H02J7/61; H02J7/685
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
205 words
A rechargeable battery pack for use with a charging adapter having first and second electrical terminals for charging the battery pack, the charging adaptor including means for changing between high and low charging rates in response to a voltage change detected at the first and second contacts, the battery pack comprising: at least one rechargeable cell having first and second poles; a first electrical contact positioned for contacting the first terminal of the charging adapter, said first electrical contact being electrically coupled to said first pole of said rechargeable cell; a second electrical contact positioned for contacting the second terminal of the charging adapter, said second electrical contact being electrically coupled to said second pole of said rechargeable cell; a voltage adjusting circuit for increasing the voltage across the first and second electrical contacts upon receipt of a first command and for decreasing the voltage across the first and second electrical contacts upon receipt of a second command; a timing means for measuring time; and a control means coupled to said timing means and said voltage adjusting circuit for communicating said first command to said voltage adjusting circuit, and for communicating said second command to said voltage adjusting circuit after a predetermined amount of time.
Claim 2
Dependent Claim
205 words
A rechargeable battery pack for use with a charging adapter having first and second electrical terminals for charging the battery pack, the charging adaptor including means for changing between high and low charging rates in response to a voltage change detected at the first and second contacts, the battery pack comprising: at least one rechargeable cell having first and second poles; a first electrical contact positioned for contacting the first terminal of the charging adapter, said first electrical contact being electrically coupled to said first pole of said rechargeable cell; a second electrical contact positioned for contacting the second terminal of the charging adapter, said second electrical contact being electrically coupled to said second pole of said rechargeable cell; a voltage adjusting circuit for increasing the voltage across the first and second electrical contacts upon receipt of a first command and for decreasing the voltage across the first and second electrical contacts upon receipt of a second command; a timing means for measuring time; and a control means coupled to said timing means and said voltage adjusting circuit for communicating said first command to said voltage adjusting circuit, and for communicating said second command to said voltage adjusting circuit after a predetermined amount of time.
Claim 3
Dependent Claim
27 words
The rechargeable battery pack of claim 1 wherein said voltage adjusting circuit includes a resistor in parallel with a switch for opening or closing an electrical path.
Claim 4
Dependent Claim
21 words
The rechargeable battery pack of claim 1 further comprising: a voltage measuring means for measuring the voltage of said battery pack.
Claim 5
Dependent Claim
41 words
The rechargeable battery pack of claim 3 wherein said voltage measuring means is coupled to said control means, and said control means communicates said first command to said voltage adjusting circuit upon said voltage measuring means measuring a predetermined threshold voltage.
Claim 6
Dependent Claim
53 words
The rechargeable battery pack of claim 3 wherein said voltage measuring means is coupled to said control means, and said control means communicates said first command to said voltage adjusting circuit upon a measurement of the change of battery voltage over a predetermined time period (ΔV/Δt) being less than or equal to zero.
Claim 7
Dependent Claim
57 words
The rechargeable battery pack of claim 3 wherein said voltage measuring means is coupled to said control means, and said control means communicates said first command to said voltage adjusting circuit upon said voltage measuring means measuring an increase in the change in voltage over time (Δ 2 V/Δt 2 ) being greater than a predetermined value.
Claim 8
Dependent Claim
15 words
The rechargeable battery pack of claim 1 wherein said voltage adjusting circuit is a transistor.
Claim 9
Dependent Claim
20 words
The rechargeable battery pack of claim 1 wherein said timing means and control means are provided in a single microprocessor.
Claim 10
Dependent Claim
23 words
The rechargeable battery pack of claim 3 wherein said timing means, control means and voltage measuring means are provided in a single microprocessor.
Claim 11
Dependent Claim
21 words
The rechargeable battery pack of claim 1 further comprising: a temperature measuring means for measuring the temperature of said battery pack.
Claim 12
Dependent Claim
45 words
The rechargeable battery pack of claim 10 wherein said temperature measuring means is coupled to said control means, and said control means communicates said first command to said voltage adjusting circuit upon said temperature measuring means measuring a predetermined increase in temperature over time (ΔT/Δt).
Claim 13
Independent Claim
197 words
A method of recharging a battery having first and second electrical contacts using a charging adaptor having first and second electrical terminals for charging the battery pack, the charging adaptor including means for changing between high and low charging rates in response to a voltage change detected at the first and second contacts, the charging adapter also being responsive to detect the voltage across the first and second electrical contacts of the battery pack to change between first and second charging rates for charging the battery pack, the method comprising the steps of: charging the battery pack at the first charging rate; increasing the voltage across the first and second electrical contacts of the battery pack; measuring the commencement of time after the voltage is increased across the first and second electrical contacts of the battery pack; decreasing the voltage across the first and second electrical contacts of the battery pack a predetermined amount of time after first increasing the voltage appearing across the first and second electrical terminals of the battery pack; and charging the battery pack at the second charging rate in response to the decrease in voltage across the first and second electrical contacts.
Claim 14
Independent Claim
197 words
A method of recharging a battery having first and second electrical contacts using a charging adaptor having first and second electrical terminals for charging the battery pack, the charging adaptor including means for changing between high and low charging rates in response to a voltage change detected at the first and second contacts, the charging adapter also being responsive to detect the voltage across the first and second electrical contacts of the battery pack to change between first and second charging rates for charging the battery pack, the method comprising the steps of: charging the battery pack at the first charging rate; increasing the voltage across the first and second electrical contacts of the battery pack; measuring the commencement of time after the voltage is increased across the first and second electrical contacts of the battery pack; decreasing the voltage across the first and second electrical contacts of the battery pack a predetermined amount of time after first increasing the voltage appearing across the first and second electrical terminals of the battery pack; and charging the battery pack at the second charging rate in response to the decrease in voltage across the first and second electrical contacts.
Claim 15
Dependent Claim
25 words
The method of recharging a battery of claim 12 further comprising the step of: measuring the voltage across the electrical contacts of the battery pack.
Claim 16
Dependent Claim
43 words
The method of recharging a battery of claim 13 further comprising the steps of: detecting a predetermined threshold voltage, and the step of increasing the voltage across the first and second electrical contacts is in response to the detection of the threshold voltage.
Claim 17
Dependent Claim
78 words
The method of recharging a battery of claim 13 further comprising the steps of: detecting an increase in the change in battery voltage over time (Δ 2 V/Δt 2 ) being greater than a predetermined value, and the step of increasing the voltage across the first and second electrical contacts is in response to the detection of an increase in the change in battery voltage over time (Δ 2 V/Δt 2 ) being greater than a predetermined value.
Claim 18
Dependent Claim
70 words
The method of recharging a battery of claim 13 further comprising the step of: detecting a change in battery voltage over a predetermined time period (ΔV/Δt) being less than a predetermined value, and the step of increasing the voltage across the first and second electrical contacts is in response to the detection of a change in battery voltage over a predetermined time period (ΔV/Δt) being less than a predetermined value.
Claim 19
Dependent Claim
55 words
The method of recharging a battery of claim 12 further comprising the step of: measuring the temperature of the battery pack, and the step of increasing the voltage across the first and second electrical contacts is in response to the detection of an increase in temperature over time (ΔT/Δt) being greater than a predetermined value.
References Cited (Backward Citations)
US5200689A
Cited
US5444353A
Cited
US5514946A
Cited
US5633573A
Cited
US5572110A
Cited
US5576612A
Cited
US5694022A
Cited
US5708350A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-08-16 | 2003-02-15 | 2003-08-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-08-16 | 2007-02-15 | 2007-08-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-08-16 | 2011-02-15 | 2011-08-17 | $7700.00 | Window Closed / Lapsed |