Who knew pee held so much power? Aqua Power scientists in Japan have developed rechargeable batteries that can run on, among other liquids such as water, urine. NoPoPo batteries can only be re-charged a limited number of times, and aren’t as powerful as many of the other rechargeables on the market, it’s certainly possible to imagine a situation where this would come in handy.

While this is pretty cool from a pure technology standpoint, I’m left with two lingering questions. Why on earth would anyone want to pee into their battery if they could just fill it up at a faucet, and who still uses regular batteries anyway. I’ve had 4 awesome USBcell AA’s sitting in their packaging since Macworld, and I still haven’t found a use for them. [via]