Back in 2007, we posted a video from MIT showing that water could possibly be used to power batteries. Well, within months, a Japanese company NoPoPo came up with water-powered batteries that can even use your own pee to power them.
Now, this water-powered flashlight is available, all powered using NoPoPo water-powered batteries, way too cool. I suggest you to get one for emergencies. This flashlight lasts virtually forever!
The NoPoPo Mini Lantern is pure craziness: a lamp powered with nothing but water! Simple to use, rechargable almost anywhere, and lasting up to ten years without losing charge, the NoPoPo is a perfect addition to any emergency kit, camping gear, survival set, and more. The versatile mini lantern can be used as either a flashlight or a unidirectional lantern; just slide the cover up to change modes.