[Ti] PowerBook energy usage

[Kynan Shook]

Well, to some extent, at least.  You have a few watts of power lost in 
the power adapter, plus I forgot to turn down the CPU speed for my 
"minimum" calculation, and there are other things that get turned off 
that can't be turned off while the computer is on AC power 
(specifically, the sound system goes off while on battery after about 
20 seconds of no sound).

Typically, I get about 3 to 3.5 hours out of my 17" PowerBook, and I 
can tell you two things: 1. I never have Airport off, so I'm using a 
bit more power than my stated minimum. 2. There's no way my battery, 
which is a bit over a year old now, still has the full 55 Watt-Hour 
capacity.

Also, note that you can't say the maximum is less than an hour; the 
power consumption of 60W *includes*  charging the battery, which 
accounts for most of the power use.

And, if you only run applications that don't require regular HD access, 
you can get even better performance.  I run so many applications all 
the time that at least one of them is always wanting to read or write.

And one more problem with calculating is that my numbers are 
approximate; they're an average over 30 seconds or a minute; a small 
error in that could make a fairly big difference over several hours.

Arjan Bos <arjan.bos at hetnet.nl> writes:
> Well, from your figures one can easiliy calculate how long a fully
> charged top condition battery is going to last.