Dell XPS 10 Tablet - Manual (Page 33)

You can check the keyboard dock battery status from:
• Battery-charge light located on the left side of the keyboard dock:
LED behavior Description
Solid white color on Battery is charging with AC.
Off Battery is not charging, either no AC is
connected or battery is fully charged.
For more information on checking the tablet battery status, see
tablet battery charge status .
Using XPS 10 Mobile Keyboard Dock 33