[ltp] Power drain.

[Matthias Himber]

Am Montag, 12. April 2004 11:38 schrieb Ren=E9 Castberg Rene-at-Castberg.or=
g |
Linux-Thinkpad|:
> Hi,
> I have linux installed on my ipaq, and one fo the features that i like
> is the ability to see how much the power drain it, so i can relatively
> quickly see if putting the backlight on will drain the battery quick. Is
> this possible to see on the T40? It would be nice so that i can see if
> there is any substantial effect on the power drain by disabling certain
> features on the laptop. (wifi, pcmcia etc etc)
>
> Thanks
> Rene

I don't know whether this can be obtained directly, but it can be figured o=
ut=20
indirectly with some simple math: APM gives you the battery charge in perce=
nt=20
as well as the time left at current power consumption level, so by dividing=
=20
the charge percent by the minutes left you get the current power drain in=20
percent per minute. If you know the maximum capacity of the battery in=20
Watt-Hours, multiply that number by 60 to get the max capacity in=20
Watt-Minutes, multiply with the power drain in percent/minute and divide by=
=20
100 to get the current power drain in watt. A simple shell script should be=
=20
enought to automate this calculation, maybe use bc for the math?
HTH,
	Matthias