Are we ready for pee power?
NoPoPo Batteries are powered by squirting liquid into the cell. It seems they can run on nearly any type of liquid (beer, juice, saliva, etc.) but, incredibly, urine made the list too.
They can last (turned on) for 20 hours at a time and have a shelf-life (turned off) of about 10 years, which is much longer than standard batteries.
NoPoPo stands for "non-pollution power" and the batteries back that up by containing no harmful chemicals, such as mercury or lead.
So even though they can only be refilled up to five times, they no longer fall into the hazardous waste category.
CNet states that right now they're only available in Japan but we found them (and our photo) on this website.