The cell, built by Medis Technologies, is - at least in concept - similar to a glow-stick or a hand-warmer. The user squeezes the cell to mix two chemicals together, and the unit runs until the chemicals are exhausted - about 40 hours. It comes with an assortment of connector tips, including those for USB ports, BlackBerrys and cellphones of various other models, MP3 players and similar devices. The company hopes to soon manufacture a version big enough to run a laptop computer, and later one that could run a whole house.