Here's what Energizer and Duracell have been missing all along: The ability to run off of the power of urine. That's right. Urine. They come in AA and AAA size. Basically, you take the little eye dropper and you deposit your urine directly into the battery cell.
They are saying that a single urine-powered AA battery can power a flashlight for approximately 20 hours.
Leave it to the Japanese.