This lamp is similar in shape to https://pinshape.com/items/382... but uses different geometry to give it a more organic shape. This blog page describes the double twist method that creates the basic shape: http://birkbinnard.com/blog/do-the-twist/. Normally any STL file with overlapping shells will be difficult for slicers to slice properly, but this blog page tells how I was able to fix the overlapping shell problem with this (and other) STL files: http://birkbinnard.com/blog/problem-stl-files/.
This lamp printed in a little over 26 1/2 hours using a print speed of 80 mm/sec and a layer height of 0.200 mm.
This lamp is designed for an LED "puck" light. Battery operated lights are about $4 each; simply do a web search for "puck light". This blog page tells where you can get wall powered lights that work very well: http://birkbinnard.com/blog/wall-powered-led-lights/.