A [rechargeable] battery is made of of individual cells.
When you drain a battery all the way down, there is some risk of 1 or more cells reversing polarity.
If that happens, you will never attain full capacity from that battery again.
(Some companies claim to have charging products that can "straighten" the polarity of such cells)
Some batteries can only be charged a certain (large) number of times.
The more frequently you charge, the shorter the useable lifespan of the battery.
NiCad, NiMH and Li-Ion batteries all behave slightly differently.
I unpacked my Droid X, and started charging.
The indicator said there was 50% battery (I guess they ship it this way).
Within an hour, I had 100%.
It is still on the charger.
How does the charging meter in the Droid X calibrate a "full" capacity?
I figure if the calibration is off, it will indicate full capacity, but battery will run down fast.
Problem with some cell phones.
Some manufacturers recommend an initial overnight charge.
Where is it stated that the Droid X requires an initial 3-hour charge?