It could be improved a bit to run as a daemon (start, stop) and store data in a file. Options to send them via e-mail? Or even you one can connect to the tablet's battery-eye daemon and read the values remotely and showing them in real time?
May be store a top-like log every 5 mins (so you know what's running?)

Lot's of ideas for improvement...

If this uses data from bme in hal, which comments seem to confirm, then these things probably apply:

Meter is reset and started from a new, guessed state on reboot.
Meter doesn't update during charge, except jumping to full when full.
Meter corrects itself when near full, near empty, or right after charger has been disconnected, and the values aren't vey accurate.


In general I suspect the N900 meter uses a voltage profiling methodology, which has the advantage that the actual battery meter uses less power, but is less accurate. In particular I'd think it's not entirely linear, and this will probably get worse as the battery ages...

this is what I was after with my questions: accuracy of values monitored.

Very interesting! Thanks.

I think the reporting.current mAh and percentage values in hal are just guesses based on battery voltage...

nice thread app needs a lots of features

probably not the most accurate battery monitoring, but the graph it extrapolates on a timeline does allow you to better determine when and where your battery life is going

I'm in too! will report in the morning how it went ;-)

Hah,

Here is my system. Basically first 3-4h light usage on Wifi and after that in sleep. Something is pretty fck up I have installed stuff from different repositories, but when checking stuff with top i noticed pulseaudio is hittin constantly 1-2% cpu. Going to restart and charge battery full. Lets see how it goes after that.

So looks that right now i´m probably hitting this bug:http://talk.maemo.org/showthread.php?t=34863
http://talk.maemo.org/showthread.php?t=34863

Seems that there is no bugzilla entry and after reading couple of timeless comments to poor reporters i think that i will pass this one also :| I cannot reproduce this or have enough time or adequate skills to report.

My device almost seem to discharge as fast as it charges... I've only been listening to music for like 45 minutes... Browsing for 45 minutes... And sent like 5 sms'es... Of course it could be the wifi bug... but I've been running with it off... using a program from extras-devel which should unload it from the kernel... I just activated wifi again But when I look at your graphs this doesnt seem normal at all?