I have used one of those Medis fuel cells before to power my mobile phone in a pinch. It is a cool device, but I really want a fuel cell that I can refill and use continuously. KDDI has shown off a new prototype fuel cell that uses a sort of hybrid system along with a lithium-ion battery.

The fuel cell promises 320 hours of power for your mobile phone. To recharge the device once the fuel cell runs dry all you need to do is squirt in more methanol. That means you can effectively run as long as your methanol supply holds out.

The cool factor of the fuel cell is tempered by the fact that as a prototype KDDI won’t have it on the market for a while. In fact, the company expects it to be several years before the tech is commercialized.