Mark Crispin <MRC@Washington.EDU> wrote in
news:alpine.WNT.1.10.0804211708490.5204@Tomobiki-Cho.CAC.Washignton.EDU:

> The backlight is a huge power drain on many WM phones. In most
> firmware, the default backlight level while on battery power is set
> way too high. Try cranking it down to the minimum (one notch above
> backlight completely off).
>

The backlight is a fairly high load, but is NOTHING like the load of the
TRANSMITTER!

Ever notice how hot a Sellphone gets when you are not standing in full view
of a tower that's some distance away, causing the cell to crank up your
controllable output power to maximum so it can hear you on the shared
channel with the other 24 users (CDMA) on that channel. LEVEL is very
important on shared channel schemes.

When you are far from the tower, yakking away an causing lots of
transmitter packets loaded with voice data, that transmitter gets HOT!
That heat is the inefficiency of the transmitter's output power IC, a large
power IC on the case as its heat sink....warming your ear.

To get 150mw out of the antenna jack, about 300mw has to be put in as DC
from the battery pack. I = P/E (hey, I taught electronics for 20 years!)
..3W/3.8V Li-Ion cell power = 78ma...just in the output stage! This is why
the TALK time is so much LESS than the standby time of a simply Sellphone.
Total transmitter power is probably 100ma....which eats the battery even
MORE than the backlight. Add them together and you have iPhone on a too-
small battery pack......to make it THINNER!

Everything has its price.....to be THIN.