This decorative LED lamp (about 7 watts) can be powered by rechargeable batteries for a few hours--or by a 12 volt dc power supply if a cord is acceptable.
It is sitting on a 3D printed table (not the glass) found at:
http://www.thingiverse.com/thing:41103

The base needs to be printed with supports.
For assembly instructions, go to:
http://www.instructables.com/id/LED-Lamp-4/