Power leakage: save 40mW by turning GSM on

Rask Ingemann Lambertsen rask at sygehus.dk
Thu Jan 22 13:18:17 CET 2009

On Sat, Jan 17, 2009 at 05:31:38PM +0100, Rask Ingemann Lambertsen wrote:
> On Fri, Jan 16, 2009 at 11:09:06PM -0200, Werner Almesberger wrote:
> > I'm continuing this thread on the more appropriate hardware list.
> > 
> > Background: I'm trying to get the system into a very low-power
> > state (and very low power variation state) so that I can measure
> > the effect of the various WLAN power saving options. This yielded
> > a few surprises. Instead of a few mW, I ended up with suspend
> > power in the order of up to 0.4W :-(
> [...]
> > suspend                                  81.90mA  82.96mA  85.91mA  1.043mA
>    If mine is as bad as that too, no wonder I don't get 48 h suspend time.

   I made two tests of battery life in suspend state when the GSM part has
not been touched since bootup. Results:

	1) Battery at 91 % of capacity after 13,5 hours.
	2) Battery at 77 % of capacity after 34 hours.

   I forgot to make note of the battery voltage, but full capacity is
estimated to be 1181 mAh, so that's an average of 7.9 mA for the first test
and 7.3 mA for the second one.

Rask Ingemann Lambertsen
Danish law requires addresses in e-mail to be logged and stored for a year

More information about the hardware mailing list