Sony VGN-FS550 - Manual (Page 25)

Installing the Battery
The supplied battery is not charged when you unpack it. To charge it for future use, install the battery, and then connect
the AC adapter to power your computer. The battery charges from AC power regardless if the computer is on or off. For
information on how to extend the life of the battery, see
Conserving Battery Power.
When operating your computer on battery power, your computer's CPU speed is reduced.
This computer is designed to operate only with a genuine Sony battery.
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