Sony PCG-F390 - Manual (Page 48)

VAIO ® Notebook Computer User Guide 38
To charge the second battery pack
Keep the battery pack in the computer while it is connected to AC power.
The battery indicator flashes while the battery is charging. See also “To
charge the battery pack” on page 10 for more information.
✍
To determine the amount of time the battery lasts, see “Displaying Battery Information” in
the online document Customizing Your VAIO ® Notebook Computer.
Second battery pack
(not supplied)
Battery indicators
Battery pack (supplied)