Method for charge control for extending Li-Ion battery life
First Claim
1. A method for charging a battery with a charger device, comprising:
- fully discharging the battery using the charger device;
applying a charging current to the battery with the charger device to charge the battery;
measuring the instantaneous charge energy as the battery charges;
recording the instantaneous charge energy periodically;
determining a cumulative total charge energy by integrating the recorded instantaneous charge energy with respect to time; and
removing the charging current when the total cumulative charge energy reaches a predetermined amount.
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Accused Products
Abstract
An algorithm extends the serviceable life of a Li Ion battery by charging a battery to a predetermined percentage of its rated charge capacity. The amount of energy impressed into the battery during charging is determined by periodically measuring the charge energy impressed at a given instance, and integrating the instantaneous energy measurements with respect to time over the charging period. Each time the battery is subsequently recharged, charging the battery to this same amount of energy provides the same amount of energy during discharge. Upon each subsequent recharge following the initial charge, the battery terminal voltage is slightly higher than at the end of the previous recharge. When the terminal voltage measured before the end of a recharge period exceeds the battery'"'"'s rated voltage, the algorithm ends and indicates that the battery can no longer be used in the given application and should be replaced.
50 Citations
21 Claims
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1. A method for charging a battery with a charger device, comprising:
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fully discharging the battery using the charger device;
applying a charging current to the battery with the charger device to charge the battery;
measuring the instantaneous charge energy as the battery charges;
recording the instantaneous charge energy periodically;
determining a cumulative total charge energy by integrating the recorded instantaneous charge energy with respect to time; and
removing the charging current when the total cumulative charge energy reaches a predetermined amount. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for charging a battery, comprising:
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measuring the charge energy as the battery charges at periodic intervals during a charging period;
recording the charge energy amount for each periodic charge energy measurement;
determining a cumulative charge energy during the charging period by integrating the recorded charge energy amounts for each charge energy measurement with respect to time over the charging period;
removing charging current from the battery when the cumulative charge energy reaches a predetermined amount;
measuring the instantaneous discharge energy as the battery discharges during a predetermined refresh interval;
recording the instantaneous discharge energy periodically during the refresh interval;
determining a cumulative total discharge energy; and
charging the battery with the cumulative total energy discharged during the refresh interval. - View Dependent Claims (11, 12, 13, 14, 15)
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16. A system for charging a battery, comprising:
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means for discharging the battery;
means for impressing charge into the battery;
means for measuring the instantaneous charge or discharge energy as the battery charges or discharges;
means for recording the measured instantaneous charge or discharge energy periodically;
means for determining a cumulative total charge or discharge energy by integrating the recorded instantaneous charge or discharge energy measurements with respect to time over a predetermined period; and
means for removing the charging current when the total cumulative recharge energy reaches a predetermined amount. - View Dependent Claims (17, 18, 19, 20, 21)
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Specification