Original URL: http://www.theregister.co.uk/2007/09/14/pentagon_million_dollar_battery_bomb_beano/

Pentagon to hold event prior to battery tech prize

Million-buck battery-bomb bonanza beano

By Lewis Page

Posted in Science, 14th September 2007 12:57 GMT

The Pentagon has announced that it will hold an "Information Forum" event at a Washington hotel to kickstart its portable power-source innovation competition. With the Wearable Power Prize, the American brass aim to encourage development of technology which could reduce the crippling load of batteries carried in the field by modern soldiers.

The entry criteria are simple, but difficult to achieve. Contending systems must weigh 4kg or less and deliver an average of 20 watts for 96 hours, with peak output of up to 200W.

That means the system has to hold 480 watt-hours per kg. Cobalt-based lithium ion batteries, used to power a majority of modern portable kit, don't go much better than 190 Wh/kg; and they don't like high peak loads at all. Other kinds of Li-ion, able to take heavy burst loads, don't even hold as much as cobalt.

The new wearable gear will need to use something else. Options could include fuel cells, though most fuel cells aren't ready for field use. Some are (pdf), but the numbers don't match the Pentagon prize yet.

Other plans for high-density, high-load portable power have included systems running on High-Test Peroxide rocket fuel; but of course that kind of kit carries a significant risk of explosions, fires or similar mishaps. (Even more than Li-ion batteries, that is.)

This isn't necessarily a show-stopper, though. Soldiers already carry ammo, grenades, rockets, fuel-air "bunker buster" bazookas etc. They aren't going to blub about some further piece of gear which could blow up if mishandled or hit by enemy fire; though they'll surely complain about any tendency to brew up spontaneously.

In fact, by definition the risk more or less has to be there. The Pentagon prize rules demand 1920 watt-hours in the prizewinning unit, which is roughly equal to 0.000000002 megatons. In other words, a winning battery pack must contain as much energy as you'd release by detonating several pounds of TNT. Crikey.

Still, prizes can produce amazing stuff, as the Pentagon tell us in an exceptionally erroneous statement:

"Sir Christopher Wren's 40 schilling prize motivated Newton to begin writing the Principia, a hotelier's prize launched Linbergh across the Atlantic, and the X-Prize Foundation helped put Starship One into space."

(Once again: the Pentagon chaps wrote that, not us.)

So if you found the stories of Newton, "Linbergh" or "Starship One" inspiring – or you've got some dynamite battery tech <cough> and want a million dollars – get on over to Washington for the Information Forum