FAST CHARGING OF BATTERY USING ADJUSTABLE VOLTAGE CONTROL
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Accused Products
Abstract
A battery cell charger for rapidly charging a lithium ion battery cell (or string of series-parallel connected cells) having a maximum battery cell voltage the battery cell charging system including: a circuit for charging the battery cell using an adjustable voltage charging-profile to apply a charging voltage and a charging current to the battery cell wherein the adjustable voltage charging-profile includes: a first charging stage with a constant first stage charging current and an increasing battery cell voltage with the first stage charging current provided until the first stage charging voltage is about equal to a first stage complete voltage less than the maximum battery cell voltage; one or more intermediate charging stages, each intermediate stage selected from the group consisting of one or more of an intermediate constant voltage stage that provides a decreasing charging current, an intermediate constant current stage that produces an increasing battery cell voltage, and combinations thereof; and a final charging stage with a constant final stage charging voltage about equal to an intermediate stage complete voltage and a decreasing final stage charging current with the final stage charging voltage provided until the final stage charging current reaches a desired charge complete level.
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Citations
38 Claims
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1-18. -18. (canceled)
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19. A method for charging at least one lithium ion cell, the method comprising:
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(a) applying, to the lithium ion cell, a constant first stage charging current until a first stage charging voltage is about equal to a first stage complete voltage less than a maximum cell voltage, the constant first stage charging current greater than about 1 C; and
thereafter(b) applying multiple constant second stage charging currents to the lithium ion cell at different current levels, wherein the constant second stage charging currents are applied based on accessing a lookup table that relates at least current, temperature and open source voltage to each other; and
thereafter(c) applying, to the lithium ion cell, a constant third stage charging voltage about equal to a complete voltage from the multiple constant second stage charging currents. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28)
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29. A method for charging at least one lithium ion cell, the method comprising:
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(a) applying, to the lithium ion cell, a constant first stage charging power until a first stage charging voltage is about equal to a first stage complete voltage less than a maximum cell voltage, the constant first stage charging current greater than about 1 C; and
thereafter(b) applying multiple constant second stage charging powers to the lithium ion cell at different current levels, wherein the constant second stage charging powers are applied based on accessing a lookup table that relates at least current, temperature and open source voltage to each other; and
thereafter(c) applying, to the lithium ion cell, a constant third stage charging voltage about equal to a complete voltage from the multiple constant second stage charging powers. - View Dependent Claims (30, 31, 32, 33, 34, 35, 36, 37, 38)
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Specification