Title: Come on baby, light my fire

Author: Alan Lenton

Date: 20 September 2006 05:41:48 +01:00 or Wed, 20 September 2006 05:41:48 +01:00

Summary: [20-9-2006] Dell and Apple are recalling millions of potentially defective laptop batteries.

Body: I guess everyone has heard by now about Dell's recall of batteries after some rather spectacular examples of its laptops bursting into flames in public.

One has to wonder whether there would have been a recall if the conflagrations had not been so public, especially given that it turns out that Dell were discussing the problem with manufacturer Sony some ten months ago.

Now another user of the Sony batteries, Apple, has announced that it will recall some 1.8 million batteries supplied with its Powerbook series of laptops. That covers nearly a third of the laptops shipped during the period covered by the recall.

To my mind a major problem is going to be that historically only about 10-25 per cent of customers respond to these sort of recalls. That means that even at the best three quarters of the customers will be walking around with laptops using potentially dangerous batteries.

Significantly several major airlines have decided that laptop owners will have to remove the batteries from laptops before bringing them onto its aircraft.

While the current problem is caused by faulty quality control, it has to be said that the real problem lies at a deeper and more complex level. Laptops are becoming more and more complex and powerful and as a consequence using more and more power.

My laptop, for instance has a 2.1 GHz processor, 1 GB of memory, 64Mb of Video memory and a whole slew of peripheral chips not to mention a hard drive and a CD writer. And it is nowhere near what I would call 'cutting edge'. Nonetheless, I suffered a couple of thermal shut downs while playing the 'Oblivion' game. (I was just checking it out, you must understand, not actually -playing- it. It was a purely professional matter.) I now run an external fan to ensure that there is plenty of airflow when I run computationally intensive programs, like compilers.

All this kit requires more and more powerful batteries to drive it, and a large chunk of that power is wasted as heat. Frankly, it's only a matter of time before designers are going to have to start thinking very careful about what they actually need in the computer, rather than what the marketing department would like in it.

There may be some small relief on the way with the announcement from researchers at Tel Aviv University that they have developed a battery based on nano technology that is capable of supplying high power densities without the risks of short circuiting posed by conventional lithium-ion batteries.

That's good, but it doesn't solve the underlying problem of developing and using more efficient components in laptops, servers and desktops.

Fortunately, the sheer cost of the wasted power generated in server farms is driving the development of low power components. Big server colocation facilities receive a double whammy from the waste heat generated by the thousands of computers they house. Not only do they have to bring in power to run the computers - and generate the wasted heat - but they also have to provide power to run ultra-powerful air-conditioning units to get rid of the heat.

And this costs big bucks, so it's no surprise that chip manufacturers are starting to produce chips that use less power and run cooler, and they are finding that the reduced power consumption is a big selling point. At the moment this is mainly confined to the server market, but it is only a matter of time until these developments spin off into other computer markets, with laptops heading the list.


Coda: More than meets the eye

Since penning the original piece on laptop batteries I've picked up an interesting piece of information in Risks Digest. It was a report of an interview with a professor at Kyoto University who is an expert on battery technology.

From what he had to say, it seems the problem is not necessarily entirely Sony's fault. Yes, they did have a problem with their manufacturing process which resulted in metallic fragments short circuiting some of the batteries, and, yes, they are responsible for that.

However, it turns out that Dell and Apple are operating very fast recharging cycles for the batteries - and one of the problems with such rapid recharging is that the high concentration of lithium ions (remember lithium is a metal) can cause the formation of tiny whiskers of lithium. These can pierce the plastic separator between the positive and negative electrodes in exactly the same way as the Sony metal fragments, causing what is euphemistically called 'catastrophic failure'.

Notes: 

More fields may be available via dynamicdata ..