CONTINUED:
Can anything douse the battery flames?

Cooper also added that fuel cells will complement, but not replace, lithium-ion batteries. Laptops will have both: the lithium-ion will kick in for tasks that require lots of energy, such as graphic-intensive games. The fuel cell will run the computer during low-impact tasks like word processing. Still, a laptop rigged with a fuel cell will need a much smaller lithium battery.

Lithium-ion manufacturers have also known for some time that the opportunities for improving the performance of their products were limited.

"The theoretical maximum will be reached by 2006 for lithium-ion chemistry," said Hammed Cadbury, product marketing manager for the energy component group at Sony in an interview in 2004.

Safety precautions, however, are taken to the nth degree in the car. The lithium-ion cells are all isolated from each other, so that if one catches fire, the fire won't spread to other cells. In that event, sensors also detect the fire and shut down the battery and let the driver coast to a stop.

The battery is also cooled and kept at around 25C. This doesn't prevent failure, but allows the lithium-ion cells to live longer despite several recharges.

Eberhard further added that the company has placed stringent quality standards on its lithium-ion cell suppliers. "We aren't buying the cheap ones," he said.

Valence Technology, meanwhile, has developed a lithium battery for modifying hybrid cars that reduces the risk of failure. The company's U-Charge Power System contains a cathode material, the metallic pole inside a battery that attracts electrons, made of metal phosphate. Most lithium-ion batteries sport a cathode based around cobalt.

Batteries with the metal phosphate can only store about 75 per cent of the energy a traditional lithium-ion battery can hold. However, the phosphate won't burn. In traditional lithium-ion batteries, heat inside the battery can cause the cobalt oxide cathode to decompose.

While Valence has mostly sold to vehicle makers, Bogues earlier this year predicted that the safety issue could bring laptop makers to the company's door.

"At some point, some company will push for safer batteries," he said during an interview in June.