QUOTE(raduga @ Apr 26 2007, 01:31 AM)
Heat is the
major factor in wear on laptop batteries; if you use a laptop plugged in to AC for stretches of hours to days, you're much better off removing the batteries.
Laptops are in an entirely
different class of heat dissipation to the Z. A Z's LiIon battery is not going to see those sorts of temperatures no matter how much you overclock it.
And besides, my point was orthogonal - most of the heat generated by the CPU does not get dissipated into the battery.
What is actually a bigger problem for LiIon batteries is the charging profile. Fully charged cells degrade fast. A 100% charged LiIon cell at 25degC irreversibly loses about 20% of it's capacity per year, even when unused. The same battery at 40% charge and 25degC only loses about 4% capacity per year. That's the big reason laptops which are always plugged in see their batteries degrade. Yes, heat accelerates the process, but it's already bad even at moderate temperatures.
Which actually gave me an idea recently - if you know your Z/laptop is going to stay plugged in for a considerable amount of time, you should be able to tell the charging circuit to not charge the battery past 40%. Of course, you'd need to be able to tell it to go back to 100% mode a couple of hours before you go back to battery power. Maybe even use a scheduler to set those levels according to your routine. That would make a reasonable boost to the life of your battery.