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US5504415A Expired / Lapsed US ⏱️ 0.0 years remaining

Method and apparatus for automatic equalization of series-connected batteries

Assignee: Advanced Charger Technology Inc
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Filing: 1993-12-03
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Granted: 1996-04-02
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Expires: 2013-12-03
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Abstract

Abstract A method and an apparatus (10) for equalizing the state of charge among a plurality of series-connected batteries (B1-BN). A module (12A-12N) is connected in parallel with each of the batteries (B1-BN), respectively. Each module (12A-12N) contains a voltage divider circuit (40) so that the voltage across a battery may be measured to determine the state of charge, and a circuit (43) which selectively shunts charging current around a battery or applies a discharging current to a battery. A charging transistor (30) applies a charging current to the series of batteries (B1-BN) and, depending upon the state of charge of each battery, a portion of the charging current may be shunted around the battery by its associated module (12) so as to prevent overcharging of the battery. A controller (14) monitors the state of charge of each of the batteries and the temperature of each of the batteries and adjusts the portion of the charging shunted around an individual battery so as to rapidly equalize the state of charge among the different batteries (B1-BN). This process is automatically conducted whenever a charging current is applied to the batteries so that the batteries are maintained in an equalized condition.

Inventors

  • 👤 Yury M. Podrazhansky
  • 👤 Mikhail Y. Podrazhansky
  • 👤 Mikhail B. Golod

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 19:40
CPC Classifications
H; H02; H02J; H02J7/00; H02J7/50; H02J7/52; H02J7/54; Y; Y02; Y02T; Y02T10/00; Y02T10/60; Y02T10/70

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 130 words
A method for equalizing a state of charge among a series-connected first cell and second cell during a charge process wherein a charging current is applied to said series-connected first cell and secured cell, comprising the steps of: measuring the temperature of said first cell and the temperature of said second cell; calculating a portion of said charging current to be shunted around said first cell based upon said temperature of said first cell, and a portion of said charging current to be shunted around said second cell based upon said temperature of said second cell; and shunting around said first cell said portion of said charging current calculated for said first cell, and shunting around said second cell said portion of said charging current calculated for said second cell.
Claim 2
Independent Claim 130 words
A method for equalizing a state of charge among a series-connected first cell and second cell during a charge process wherein a charging current is applied to said series-connected first cell and secured cell, comprising the steps of: measuring the temperature of said first cell and the temperature of said second cell; calculating a portion of said charging current to be shunted around said first cell based upon said temperature of said first cell, and a portion of said charging current to be shunted around said second cell based upon said temperature of said second cell; and shunting around said first cell said portion of said charging current calculated for said first cell, and shunting around said second cell said portion of said charging current calculated for said second cell.
Claim 3
Dependent Claim 28 words
The method of claim 1 wherein said charging current is applied for a charging pulse period and said step of calculating is performed before said charging pulse period.
Claim 4
Independent Claim 83 words
A method for equalizing a state of charge for each cell in a plurality of series-connected cells during a charging process wherein a charging current is applied to said plurality of series-connected cells, comprising the steps of: measuring the temperature of each said cell; calculating a portion of a charging current to be shunted around each said cell based upon said temperature of that said cell; and shunting around each said cell said portion of said charging current calculated for that said cell.
Claim 5
Independent Claim 83 words
A method for equalizing a state of charge for each cell in a plurality of series-connected cells during a charging process wherein a charging current is applied to said plurality of series-connected cells, comprising the steps of: measuring the temperature of each said cell; calculating a portion of a charging current to be shunted around each said cell based upon said temperature of that said cell; and shunting around each said cell said portion of said charging current calculated for that said cell.
Claim 6
Dependent Claim 28 words
The method of claim 3 wherein said charging current is applied for a charging pulse period and said step of calculating is performed before said charging pulse period.
Claim 7
Independent Claim 155 words
An apparatus for equalizing a state of charge among a series-connected first cell and second cell during a charging process wherein a charging current is applied to said series-connected first cell and second cell, comprising in combination: first means for measuring the temperature of said first cell; second means for measuring the temperature of said second cell; first means for shunting around said first cell a portion of said charging current; second means for shunting around said second cell a portion of said charging current; and controller means responsive to said temperature of said first cell for calculating said portion of said charging current to be shunted around said first cell, and responsive to said temperature of said second cell for calculating said portion of said charging current to be shunted around said second cell, and for controlling said means for shunting around said first cell, and said means for shunting around said second cell.
Claim 8
Independent Claim 155 words
An apparatus for equalizing a state of charge among a series-connected first cell and second cell during a charging process wherein a charging current is applied to said series-connected first cell and second cell, comprising in combination: first means for measuring the temperature of said first cell; second means for measuring the temperature of said second cell; first means for shunting around said first cell a portion of said charging current; second means for shunting around said second cell a portion of said charging current; and controller means responsive to said temperature of said first cell for calculating said portion of said charging current to be shunted around said first cell, and responsive to said temperature of said second cell for calculating said portion of said charging current to be shunted around said second cell, and for controlling said means for shunting around said first cell, and said means for shunting around said second cell.
Claim 9
Dependent Claim 40 words
The apparatus of claim 5 wherein said controller causes said first means for measuring and said second means for measuring to measure said temperature when said charging current is not being applied to said series-connected first cell and second cell.

References Cited (Backward Citations)

US4849682A Cited
US5153496A Cited
US5387857A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1999-04-02 1999-10-02 2000-04-02 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2003-04-02 2003-10-02 2004-04-02 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2007-04-02 2007-10-02 2008-04-02 $7700.00 Window Closed / Lapsed

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