[scotty1024]

Originally Posted by William Moates

I agree with Cthulhu that Li-Ion is nearing the end of its innovation stage, so that 3-4 year battery life is what I'd expect.

If you've been studying then you will also note that the life span of the batteries has been sacrificed in order to boost their recharge speed and capacities.

If the Reader only employed constant current charging I'd agree with you on the 3 to 4 years. But it doesn't. In addition the supplied external 2 amp charger brick would seem to indicate the possibility of Sony employing a very high current charge which is counter to long cycle life for these batteries.

Using the USB charging method would likely result in longer service life for the Sony Reader due to there only being .5 amp of power available via that means.

Either way, I haven't seen anyone getting 3 or 4 years out of a lithium battery unless they were willing to tolerate using the battery at 10% of original capacity. And yes, I have met iPod owners that happily tell me "Yes, I still get 15 minutes playtime on the battery!"

Originally Posted by William Moates

2. Case. Scotty1024 complained about the flakiness of the case on his Librie, and Sony has replaced that with a metal case, so they seem to have learned from that design flaw. The metal case is more rugged than a plastic one. It might get scratched, but scratches don't affect performance.

The pearlescene plastic of the Librie might as well just be called "Fahrenheit 451 plastic". They put little chips of plastic into it to give it that pearl effect and those chips then lead to micro fractures that then lead to major fractures. It does look real pretty until it falls apart.

The main body of the Reader is indeed metal. But the side's appear to be chrome plated plastic caps. It has been my experience that sweat and skin oils make chrome plated plastic about as durable as the pearlescene plastic.

You will note the unfortunate placement of the plastic vs where humans will contact the unit with sweat and skin oils.

Originally Posted by William Moates

3. Temperature Stress. Temperature stresses are another way things wear out, and I haven't had (nor read) any complaints about the Reader heating up or overheating, so death by temperature stress seems unlikely.

There are two forms of temperature stress you didn't mention. Environmental and that from hacking/3rd party software.

The e-Ink panel and battery are both impacted by environmental temperature, and the metal case provides less protection from environmental temperature than a plastic case. The life of the battery is heavily impacted by being charged at a mere 40C, which is only slightly above body temperature e.g. the unit won't even feel "hot".

The native software on the Reader is low power in nature. But as people start hacking their readers the low power software will be joined by higher power 3rd party applications that keep the CPU/DRAM running longer and thus generating more heat.

Originally Posted by William Moates

4. Display. The biggest unknown is the E-ink display. From reading E-Ink's documentation on their website, the production process similar to (and simpler than) making active-matrix LCDs. I also remember mention of a segmented display at E-ink's offices running continuously for over 3 years. That bodes well for the lifespan of the screen.

The production of e-Ink panels is very different from that of active matrix LCD's. The e-Ink panels are made using technology similar to an ink jet printer. The concern I have about the 2nd generation panels is that they gained speed by doubling the voltage applied to the electrophoretic process. This doubled voltage seems to be stressing the conductors in the panels as the incidences of panel failure with the 2nd generation panels are strikingly higher than they were for the 1st generation panels.

There are several other factors that will impact Reader life span.

1. UV from sunshine, UV radiation will likely break down the organic components of the display. A Sharper Image Ionic Breeze with GP UV lamp, keep it well away from your panel.
2. Heating and cooling from indoor/outdoor jaunts. A happy long life Reader is likely an indoor only Reader.
3. Solvents can migrate through the plastic cover and break down the organic materials in the panel. Do yourself a favor, never use Windex/Scrubbing Bubbles to clean your panel, never put tape or sticky notes on it. But how many "Average Joe's" will?
4. Mechanical stress from things lying against the panel, or pressing into the panel are already known to harm the panels. Iliad users report killing their panels by leaving iPod nano's or cell phones lying on their panels over night. How many "Average Joe's" will use their panel to hold a sticky note while the write on it with a ball point pen?
5. Moisture is one of the normal killers for mobile devices and the e-Ink panels are vulnerable to this at a fundamental level: the oil the ink capsules are suspended in. They've tried to seal it but water is the universal solvent and people will apply it to keep the panel clean.
6. Microbes and fungi, the organic components of the e-Ink panel are vulnerable to being eaten. Laugh if you will but even CD-R and MO discs have had their bouts with failures that lead to their being destroyed by this process.
7. Burn in. Iliad owners have had to have their panels replaced because the panel had been left displaying the same image for too long (due to some failure in the unit that prevented clearing the display). Is there a long term burn in effect we haven't seen yet? (the 3 year old panels have been kept cycling, not burning in)
8. Forgotten Readers. Deep discharge (forgotten/lost) forms short circuits in the battery. In addition leaving a Reader forgotten while plugged in full time isn't wonderful for the battery either (see more on this in the next item).
9. Constantly keeping a lithium ion battery at full charge promotes corrosion inside the battery. In this case the low power of the e-Ink panel is a potential negative. Many users report that hooking up their Readers periodically to download content keeps the units full charged all the time. The chemistry in the battery is at its best for life span at around 40% charge.

Those 3 year old panels are the 1st generation lower voltage panels so they don't say much about the Reader's second generation panel. They've also been kept indoors under controlled conditions. I'd have been more impressed if they'd put a panel or two in their cars for 3 years.