I don't think the design needs electricity, or even the Pikachu tail. The fact that you made a battery look like a Poké Ball is so clever and such a natural idea in and of itself. Change "Poke" to "Poké" and you've got a real winner.
Ha! Wow, that is a great idea. I would definately buy one. I agree with Scafl about the electricity. How about Pikachu paw peeking out from around the side of the battery? Maybe an ear or two as well?
Regardless, nice work. You have one sale right here.
Regardless, nice work. You have one sale right here.