Supervolt

The Supervolt company was known to produce lightsaber power cells. At least one Sith, Darth Vader, was known to use the Supervolt batteries in his lightsaber.

However, these power cells were known to short out easily, as Vader's did while he was dueling the Energizer Bunny. This led to the Energizer Bunny's victory over Vader.

Behind the scenes
The Energizer Bunny was part of a Star-Wars-themed commercial. It showed Darth Vader's lightsaber was powered by Supervolt.

Appearances

 * Energizer commercial (YouTube link to 60 second version)