We looked at aurine-powered battery in the past, but the NoPoPo from Japan has actually commercialized that concept, coming in both AA and AAA sizes. A single urine-powered AA battery is capable of powering a flashlight for approximately 20 hours, and each purchase comes with a plastic pipette that enables users to inject urine into the battery chamber. For those who think that this is a gross idea, you cna always use other liquids like beer, apple juice, cola, and saliva in addition to urine. Too bad the NoPoPo battery is currently available for purchase only in Japan. I take great comfort that after having a smashing night out with the boys at our local watering hole, my alcohol-laced pee is still good enough to power a flashlight in case of an emergency.