[maemo-users] N900 battery duration

From: Frantisek Dufka dufkaf at seznam.cz
Date: Wed Nov 11 15:43:48 EET 2009
Matan Ziv-Av wrote:
> I cannot play video for 2.5 hours on my almost 2 years old N810. I can 
> hardly read an ebook for this long.
> In addition I have dual boot, including 30s delay. During this delay 
> screen is on maximum brightness, and I don't know which power saving 
> features are enabled, so without this delay, a few more reboots might 
> be possible.

Good points.

>> I have posted my findings with one spare N810 to that thread. I got like 30 
>> days with N810 sitting completely idle. That would roughly mean one reboot is 
>> 16 hours of standby (with no wi-fi).
> This must be very atypical. In similar tests on a new N800 I never even 
> managed two weeks (in offline mode).

N800 is worse, see Igor's post here

My numbers is from my own measurements I did later. The extra N810 was 
new at that time.

> The main reason I suggest turning off when the device is not going to be 
> used for long periods (such as a night sleep) is the non-slim chance 
> that something might cause break power saving (metalayer-crawler, router 
> incompatible with power saving, forgetting to disconnect bluetooth, 
> etc.) and you wake up to see a dead device.

Yes, definitely.

I was trying to solve this by send SIGSTOP to offending processes 
(browser in particular) when keyboard and screen is locked and it 
somehow worked. It is relatively easy to do it as powerlaunch script. 
With nice UI that would allow to picks up offenders by monitoring CPU 
usage this could be useful tool for poor man's suspend. Basically by 
locking screen and keys every process except few critical onces could be 
stopped and later resumed (SIGSTOP,SIGCONT) when device is unlocked. 
Would not solve keeping audio open etc.

More information about the maemo-users mailing list