Uninterruptible power supply system
First Claim
1. An uninterruptible power supply system which charges a lithium-ion secondary battery when an input voltage is normal, and discharges the same at the time of voltage reduction or power interruption to thereby supply an electric power to a load, comprising:
- a timing means for counting an elapsed time from the start of use of said lithium-ion secondary battery; and
a charging control means for increasing a charging voltage applied to said lithium-ion secondary battery as said elapsed time increases.
3 Assignments
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Accused Products
Abstract
There is provided an uninterruptible power supply system capable of preventing life shortening of a lithium-ion secondary battery attributable to its overcharge over the whole period of its use. At the start of use of the lithium-ion secondary battery 22, a charging voltage is set comparatively low. On the other hand, as the lithium-ion secondary battery 22 comes closer to an end of its life, its charging voltage becomes higher. A charging control means 37 variably sets the charging voltage applied to the lithium-ion secondary battery 22 so as to realize a discharge duration thereof may become slightly longer than a backup time required for the system and hence life shortening of the lithium-ion secondary battery 22 attributable to overcharge can be prevented.
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Citations
13 Claims
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1. An uninterruptible power supply system which charges a lithium-ion secondary battery when an input voltage is normal, and discharges the same at the time of voltage reduction or power interruption to thereby supply an electric power to a load, comprising:
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a timing means for counting an elapsed time from the start of use of said lithium-ion secondary battery; and a charging control means for increasing a charging voltage applied to said lithium-ion secondary battery as said elapsed time increases. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An uninterruptible power supply system which charges a lithium-ion secondary battery when an input voltage is normal, and discharges the same at the time of voltage reduction and power interruption to thereby supply an electric power to a load, comprising:
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a discharge duration obtaining means for discharging the lithium-ion secondary battery and then counting the discharge duration taken for a terminal voltage of the lithium-ion secondary battery to drop to a preset voltage; and a charging control means for controlling a charging voltage applied to the lithium-ion secondary battery variably so that the discharge duration comes closer to a preset time. - View Dependent Claims (9, 10, 11, 12, 13)
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Specification