Chuck tells ya

A single Hydrogen Reactor cartridge carries a week’s worth of smartphone power—more juice than any other portable source. When a user inserts one of the 3-inch cartridges into the Reactor, a catalyst frees electrons from hydrogen. The freed electrons move into a circuit that delivers power to gadgets over USB. The remaining hydrogen reacts with oxygen to produce the process’s only byproduct: water vapor.

STATS

Output: 2 amps

Cartridge capacity: 8,500 mAh

Price: $150 (includes two cartridges)

source: popular science