A new fuel cell designed to recharge your iPod and other devices to provide extra life has positive and negative aspects. On the plus side, it means that you can have power for your iPod for up to a week of continuous use on a single tank of hydrogen, even if you are nowhere near a plug-in. The device can pump out up to 200W peak AC power, or 65W continuous AC or DC, and 6W through the USB port. On the negative, it isn't exactly portable - the thing weights 9kg and is about the size of a large briefcase or handbag.

The ABC is driven by hydrogen in a Polymer Electrolyte Membrane (PEM) fuel cell. The electrodes are placed either side of the membrane, which lets through protons moving from the anode to the cathode. The protons are created by the reaction of a platinum catalyst on the gaseous hydrogen. The reaction also produces electrons which travel around the circuit where they recombine with the protons in the presence of oxygen pumped from the air.

The ABC mounts a number of these cells in a stack. The process produces heat, which is carried away by a water-based cooling system connected to a heat exchanger. The hydrogen is store in a removable tank. Earlier this year, Voller struck a deal with gas supplier Calor to investigate ways the two could co-operate to provide fuel-cell buyers with hydrogen canisters.