Power Play In Portable Batteries
Sydney Morning Herald
Monday September 1, 1997
The search is on to extend the life of portable batteries to perhaps as much as a week. DAVID HIGGINS reports.
NOTEBOOK computers with a week-long battery life may appear as soon as next year. But the mobile computing power drain - which limits battery life to a few hours - will not be solved by a new type of battery, according to Per Larsen, the marketing manager behind IBM's successful ThinkPad notebooks.
Even the much-hyped lithium polymer battery (LPB), being developed primarily as a power source for electric cars, will not extend the single charge of a notebook.
The answer, says Larsen, lies with Microsoft's Windows CE operating system - and a bit of compromise.
"Although battery technology does improve every month, battery life as such does not improve, because the (power) demand of the machines grow all the time.
"Battery life has not really gone up over the last couple of years and I don't see it going up over the next couple of years."
Although LPBs would probably be available commercially early next year (United States company Valence Technology is already selling prototypes), they would improve efficiency no more than the previous step from nickel metal hydride (NiMH) to lithium ion, said Larsen.
"(LPB) improves efficiency per pound by about 40 per cent. It's not a quantum leap. The reality is it's still an incremental improvement."
How much of that 40 per cent improvement would be absorbed by new, power-hungry features? "Everything. I don't think there's going to be anything left," says Larsen. (LPB developer 3M has estimated that an average-sized electric car would need "several kilometres" of LPB cells to achieve the distance capacity of a petrol-based car).
Even that paltry 40 per cent performance improvement would not benefit most notebook users for some years, because world battery manufacturing capacity was well below needs, Larsen said.
The other great advance of LPB - its shape which solves space problems inside notebooks - was not enough to attract a commitment from IBM to adopt it in the ThinkPad line, Larsen said.
3M says that "the battery design consists of cells made from a flexible, multilayered film laminate as thin as 100 microns (0.1016 mm)."
But the shape factor alone was not enough to warrant its use because manufacturers such as IBM had managed to squash the lithium ion battery enough to allow very thin notebooks such as those in the ThinkPad 560 range, which are 3 cm wide and weigh only 1.8 kg.
Improvement from that point would be incremental and perhaps not worth the cost of the new battery, Larsen said.
Hardware developers would be sorely tempted to fill up the space made available by the LPB with more power-hungry components and no matter what shape the polymer battery could take, the notebook would still have to be least A4 in size to accommodate the screen.
However, there is another answer to the battery-life limitations of mobile computing.
IBM has not yet released a product running Microsoft Windows CE (a vastly trimmed down version of Windows 95/Windows NT). But the success of the first generation of Windows CE handheld devices has spurred the company to begin developing A4 size notebook models running the power-efficient miniature operating system.
Subsequent versions of Windows CE would support a limited-function notebook-sized computer that could have a battery life of at least a week and perhaps as long as a month.
Says Larsen: "The biggest thing that's going on is the Win CE operating system (OS) from Microsoft. The point in time where you have the right level of functionality in there is very soon - about a year from now.
"That OS has the promise of executing in a much more frugal environment so you can look at very low-power processors, lowpower hard drives."
He said IBM was "absolutely" considering a Windows CE notebook computer.
"What you see out there at the moment is just a stage, (but) that promise is actually pretty exciting.
"You could potentially think that you could build a notebook based on the Win CE operating system that would have a significant battery life.
"You could drive battery power to a week instead of an hour."
A Windows CE notebook would not replace a Windows 95 notebook or desktop computer. It would still be a "companion" PC. However, it would be more functional than the first generation of handheld PCs and would have a full-size keyboard and screen.
Notebook-sized PC companions could also be made much lighter because they needed only small batteries.
Larsen had some reservations about whether the market would have a need for a stripped-down Windows CE notebook, as most mobile computer users were drunk on the notion of faster and sexier notebooks with full colour and multimedia.
Windows CE notebook users would have to compromise with a "sub-optimised environment" if they wanted the longer battery life.
IBM was wary, since an entire class of mobile computers, the sub-notebook range, had been a commercial failure and the idea of handheld computers took a long time to be successful.
"They were commercially very bad products because nobody wanted them. You couldn't sell them. People did not want small screens. You can't compromise on the screen size or keyboard," Larsen said.
Instead of smaller width and length, users were attracted to thinner notebooks with big screens. (Notebooks with big screens could incorporate full-size keyboards, hence IBM's innovative fold-away Butterfly keyboard has been shelved. However, Larsen says it might make a comeback in a notebook with an extended keyboard featuring function keys and a number pad).
If mobile workers did not take to Windows CE notebooks, they would be left with the battery-life dilemma for some years to come, he said, adding that there was only one fool-proof solution available today.
"I always travel with two batteries."
Next month, IBM will release a new top-of-the-line ThinkPad with modular DVD-ROM drive, 14 inch screen and 5Gb hard drive. It will play full-screen video at high resolution and retail for about $12,000.
© 1997 Sydney Morning Herald
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