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US 6,211,655 B1Granted
Battery charger
AssigneeNEC Corporation
InventorJonathan Owen Hardie
Life of this patent
Estimating the term…
Abstract
A battery charger measures an average battery temperature at a pre-determined timing for a first fixed period after start of charging. If the number of consecutive positive second derivatives of battery temperature is four, charging is discontinued. If the number of consecutive positive second derivatives of battery temperature is not four, the charging is carried out continuously for a pre-determined secondary period.
Claims27
A battery charger assembly comprising:
- a battery to be charged;
- and
- a control unit for measuring an averaged battery temperature at pre-determined times in a first fixed period after start of charging, for ending charging of said battery if the measurements meet pre-determined conditions after the first fixed period, and for causing continuous charging of said battery for a secondary period so long as the measurements do not meet the pre-determined conditions.
A battery charger assembly comprising:
- a battery to be charged;
- and
- a control unit operative to:
- measure a temperature of said battery at predetermined intervals from a start of charging said battery, and record an average of the temperature measurements for predetermined portions of a first fixed period;
- compute a second derivative for each average, and determine whether the second derivative is positive;
- count a number of positive second derivatives and reset the count when the second derivative is negative;
- determine whether a temperature and a voltage of said battery are outside predetermined limits and, if so, generate a first event;
- generate a second event when the count reaches a predetermined number.
5 more elements
A battery charger assembly comprising:
- a battery to be charged;
- and
- a control unit for measuring a battery temperature at pre-determined times in a first fixed period after start of charging, for ending charging of said battery if the measurements meet predetermined conditions after the first fixed period, and for causing continuous charging of said battery for a secondary period so long as the measurements do not meet the pre-determined conditions.
Dependencies are inferred from the claim text.