Re: You have to learn these
ISTR that batteryuniversity was not too bad a site, but haven't seen it in 3 years.
As for cadmium, don't know where you live, but the Europeans don't like it that much, and it's devilishly hard to find these days, despite being a much better chemistry for some uses, and copes better with lots of abuse. (However it's not very nice, and China did shut-down permanantly one Panasonic battery plant because their safety record was suspect).
As for calibration, and fully discharging; Anything with a "fuel gauge" needs to know the capacity of the battery to be able to tell you how much is left. The only way it really knows this for sure, is to monitor a complete discharge to full cycle. When you run your laptop completely flat, the battery monitor counts the number of coulombs into the battery to know it's capacity and then counts them out as you use it to know how many are left. If you never discharge it completely, it never knows how much the battery has aged, and may tell you that you have 40% time remaining, when in reality its 0%.