Cool idea.
A more close up and the light centered underneath the battery would look better IMHO.
Maybe you can still retake the shot?

but if the light was centered underneath the battery, it probably won't look like it is floating then.

I agree with k5683, the light placed where it is makes it look the like battery is floating which adds to the effect a lot.

On another note, the high res makes the shot look better when you can see the close up apposed to the standard picture and an even higher res would look totally awesome. Either way I think this is an excellent shot and nice creative thinking.

Thx for your nice comments

Nice effect. Can you explain how you did this?

Again author, lovely work

Its hard for me to explain how i did it, if you go to flickr and search for spirograph basically you will get the idea. for this photo i've only used single frame at 30sec exposure. Thank you.

I understand the concept of light painting but what was the lightsource?

the light source was from a small led torchlight, which you need to hang it on ceiling. let it swing freely to create the spirograph. i saw a tutorial about this somewhere not so long time ago, but i can't find it.