UK energy company Voller has announced a fuel cell-based recharge system for Apple's iPod digital music player and other MP3 players. The downside: the fuel cell-based recharge system weighs 9kg and is about the size of a large briefcase or handbag.

To be fair, the Voller Automatic Battery Charger (ABC) is intended to supply power to a wide range of devices than portable media players. There's a USB port on the side for the latter, but the unit also incorporates a car ciggie-lighter socket and a mains wall socket - both US and EU standard voltages are provided - for other devices, from laptops to mobile phones.

The Voller Automatic Battery Charger 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 Voller Automatic Battery Charger 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.

Back to the ABC, which can pump out up to 200W peak AC power, or 65W continuous AC or DC, and 6W through the USB port. On a single tank of hydrogen, it will provide an iPod digital music player with power for a week, we understand.