Systems and methods for cell balancing
First Claim
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1. A cell balancing circuit for balancing a plurality of cells, comprising:
- a logic core operable for detecting if any cell is in balancing phase, reading a full charge capacity (FCC) recorded in a previous cycle for each cell when no cell is in said balancing phase, checking a timer coupled to a cell if said cell is in said balancing phase, balancing said cell while said timer is counting, and terminating said balancing phase when said timer expires, for calculating a state-of-charge (SOC) for each of said cells, for searching a minimum SOC and a maximum SOC of said cells, for detecting an unbalanced condition if a difference between said maximum SOC and said minimum SOC is greater than a predetermined threshold, and for determining a balancing time period that is proportional to said difference if said unbalanced condition occurs,wherein said cell balancing circuit enables a bypass current for a cell having said maximum SOC for said balancing time period if said unbalanced condition occurs.
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Abstract
A cell balancing circuit comprises a first cell having a first voltage, a second cell in series with the first cell and having a second voltage that is greater than the first voltage, and a bypass path in parallel with the second cell for enabling a bypass current for the second cell if a difference between the first voltage and the second voltage is greater than a predetermined threshold. The bypass current is enabled for a balancing time period that is proportional to the difference between the first voltage and the second voltage.
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Citations
4 Claims
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1. A cell balancing circuit for balancing a plurality of cells, comprising:
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a logic core operable for detecting if any cell is in balancing phase, reading a full charge capacity (FCC) recorded in a previous cycle for each cell when no cell is in said balancing phase, checking a timer coupled to a cell if said cell is in said balancing phase, balancing said cell while said timer is counting, and terminating said balancing phase when said timer expires, for calculating a state-of-charge (SOC) for each of said cells, for searching a minimum SOC and a maximum SOC of said cells, for detecting an unbalanced condition if a difference between said maximum SOC and said minimum SOC is greater than a predetermined threshold, and for determining a balancing time period that is proportional to said difference if said unbalanced condition occurs, wherein said cell balancing circuit enables a bypass current for a cell having said maximum SOC for said balancing time period if said unbalanced condition occurs. - View Dependent Claims (2)
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3. A method for balancing a plurality of cells, comprising:
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detecting if any cell is in balancing phase; reading a full charge capacity (FCC) recorded in a previous cycle for each cell when no cell is in said balancing phase; checking a timer coupled to a cell if said cell is in said balancing phase; balancing said cell while said timer is counting; terminating said balancing phase when said timer expires; calculating a state-of-charge (SOC) for each of said cells; searching a minimum SOC and a maximum SOC of said cells; detecting an unbalanced condition if a difference between said maximum SOC and said minimum SOC is greater than a predetermined threshold; determining a balancing time period that is proportional to said difference if said unbalanced condition occurs; and enabling a bypass current for a cell having said maximum SOC for said balancing time period if said unbalanced condition occurs. - View Dependent Claims (4)
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Specification