I'm interested in a reference for this.. (the wikipedia entry doesn't have any) What I know is true (and also mentioned in the wikipedia article) is that you can quickly charge to 90% and the meter will show 100% (the actual charge may even be less than 90%, closer to 80% in my experience), but at that stage the charger will continue to charge (and show it), until you _really_ reach 100%. Or close to. My Palm T3 can be charged to 4.24V, which is fairly close to the internal battery-cutoff at 4.30V. Above 4.30V it becomes dangerous and must be considered the theoretical maximum, so I'm pretty confident it's safe to say that my T3 charges to at least 98%

batteryuniversity.com have some articles that are more in-depth than the wikipedia entry, e.g. http://www.batteryuniversity.com/parttwo-34.htm (the rest of the site is interesting too, start with just http://www.batteryuniversity.com/)

I've had my 770 for just over a week. It wouldn't turn out of the box, and i had to charge it first. But very soon, it came up (on the charger). Eventually, it said it was full, and i took it off charge. The next two cycles, i started the charge when it said it was low, but did not happen to have it on when full - so i never saw the "full charge" note. The indicator showed, what is it, five bars - looking full. Last night, i happen to be using it while charging, and saw full.

One of my cycles seemed short, but not the first. Probably wasn't fully charged, even though it showed it. But even my first cycle seemed long. So, i've no idea what the manual is talking about.

Given that the 770 can tell me that the battery is full or empty, it seems like it could do something about it. For example, when the battery is full, but still on the charger, it would be nice if it would take it off the charger itself. Then, i could put it on charger, and ignore it, rather than become their slave. I have a smart charger for my NiMH standard batteries. I put batteries on it, and go to sleep. In the morning, i put more batteries on it, and go to work. 1,000 cycles are promised. That's once a week for 20 years. I've actually gotten over ten years from a battery set.
I say 'smart charger', but i'm not talking rocket science. What is it? A voltage comparitor and a switching transistor? How much could that cost?

Don't worry, it _does_ disconnect the charger. If it didn't, the battery would soon explode (as it passed 4.30/4.40 volts or thereabouts). All devices which charges lithium ion / lithium polymer batteries must include a charging circuit that stops charging when the battery is charged to a certain voltage level (depends on the device, my T3 charges to 4.22 volts, don't know how the ITs are set up).

I charge all my lithium devices (phones, PDAs, tablet) over night now and then.

(In addition to the charging control circuit in the tablet there's also an overvoltage protector in the battery itself, at some higher setting than the device. This is just an emergency thing though, in case the device (the tablet) fails.)

Ref. http://www.batteryuniversity.com/