Sony PCG-Z505JEK Primary User Manual page 25

Connect the AC adapter to the computer.
Insert the battery pack.
The computer automatically charges the battery (the battery indicator
light flashes in a double-blink pattern as the battery charges). When the
battery is 85% full, the battery indicator light turns off. This process takes
approximately one and one half hours. To charge the battery completely,
continue charging for an additional hour.
The battery indicator light on the front of the computer indicates the
status of the battery pack.
On
Single blink
Double blink
Off
The computer is using battery power.
The battery is running out of power.
The battery is charging.
The computer is using AC power.