Sony PCG-F520 - Manuel (Page 21)

Connecting a Power Source
There are two battery indicator lights on the computer:
Battery Indicator Meaning
1
Indicates the status of the battery pack in the battery bay on the left
side of the computer.
2
Indicates the status of the battery pack in the multipurpose drive bay
on the right side of the computer.
Battery Indicator
Light Status Meaning
On The computer is using battery power.
Single blink The battery is running out of power.
Double blink The battery is charging.
Off The computer is using AC power.
Battery indicators
Battery pack (supplied)
Secondary battery pack
(not supplied)