content: http://www.graphenea.com/pages/graphene-supercapacitors "not only can they be charged at a much higher rate than current lithium-ion batteries, but they also have the potential to last for a vastly greater length of time."  I cannot find as much information on the Hydrogen fuel cells but from what I could find, it seems to function through a mixture of an onboard source of hydrogen, and oxygen from the air entering the device. It would also appear to be much more efficient than a typical Li-on battery pack. Most likely the device would require a small replaceable hydrogen storage cell (probably around the size of an AAA battery, maybe smaller) and would last thousands of hours between replacements. It would be a small current supply, though, so would most likely only be used for the idle operation. Heavier workloads would use the graphene cell, and the Li-ion pack would be a backup of sorts. They could possibly even make the graphene cell removable so it could be charged externally while the phone continues to operate off the Li-on pack. Effectively giving unlimited usage.  Probably looking at an idle time of several months, maybe 2 weeks for calls, and a couple days or so of heavy load. It will be a vast improvement over current times regardless. It also is not going to be a cheap phone. I would expect upwards of $1500 USD. Basically, this device is trying to solve many things and promising a whole new world. Change is always good. Maybe it won't be a good product for average joes, but it sure will disrupt a whole lot of things.