Anyone who’s had their laptop or cellphone run out of juice at a crucial moment can attest to the limitations that present power storage methods have on technology, but a product from Aqua Power Systems Japan may indicate an amazing new advancement: the water-powered battery.

At their present capability, NoPoPo (No Pollution Power) Eco batteries have enough power to save lives during a disaster since they can run on the smallest amount of fluid (drinkable or bodily), which means that someone lost in the woods or trapped under rubble could recharge their flashlight easily with a few drops of whatever is available.

But don’t start peeing on your laptop just yet: For the time being, NoPoPo batteries have significant limitations — just the double-A form is available and can only run low-powered items like flashlights and toy trains (see video above) but if they find a way to expand capacity, the NoPoPo could revolutionize how – and for how long – we work and communicate on electronic devices.

They may also represent an interesting twist in environmental policy, as the mercury, lead and other hazardous chemicals in today’s used batteries cause considerable harm when burned or left to rot in landfills.

In earthquake-prone places like Japan, however, practicality will sell more units than quixotic concerns.