Hi,
consider this more of a poll.
Please share your continuous average usage times and standby times from state of full charge to battery low and your current kernel power configuration.

3-4 days. Reproducible since I optimized my N900.

I use power kernel v47 with undervolting.

Most important parameters from kernel-config:

0:25,90 250:33,180 500:43,360 550:49,400 600:55,430
Smartreflex VDD1 and VDD2 = 1
Ignore nice load = 1

I have a small script I call manually after boot to adjust several things:

# deprioritize system background tasks
renice 15 `cat /syspart/applications/standby/background/tasks`
renice 15 `ps | grep modest | cut -c1-5`

echo -n "50" > /proc/sys/vm/swappiness
echo -n "7" > /proc/sys/vm/page-cluster
echo -n "1" > /proc/sys/vm/laptop_mode

and some other minor modifications (see swappolube, I just set these values manually)

I use the Wifi-Switcher app to load/unload the wifi driver whenever I switch wifi on/off. I switch Wifi on only when I need it. The same for bluetooth.
Most of the time, I am in standby GSM.
Display brightness at 2. I switched off display vibration feedback, most LED feedbacks (except charging battery)

I have a class 10 microsd card in the external slot with two partitions, one of those I use as the primary swap partition.

200 hours:
Stock N900, really **** battery, purely STANDBY use, 3g and internet connection over 3g activated (but of course nothing uses the connection).

Not a realistic use case, of course ;-)

about 7hrs on continuous usage with karams patch.. and a day if i go to college..

Yeah, I almost never get the chance to drain my battery completely, but for example: Today I went on an 8 hour hike, ran Columbus and logged the track while my phone sat in my pocket. Took maybe 30 photos and sent off a few SMSes. Got back and my batter was on 60%.

Currently running Kernel Power v48 at ULV250-600 with VDDC1 and VDDC2 enabled; oh and my backlight level is set to 1. I am also running Karam's CGROUP patch which may or may not help battery life but it sure helps responsiveness.

Rock stable and I find the only thing that really hits my battery life is if I read a book with the backlight always on. In which case I get about 10 hours between charges.

Never had the chance to see what it is like in standby for a long time, I use my phone a LOT by anyone's standards and never does a day go by where I don't do so.

Other usage cases which have impressed me with my current setup are as follows:

• 6 Hours active use as a music source in a car, using the FM transmitter and forcing the backlight to stay on most of the time by constantly changing songs. Battery finished at 40%. And that was over 20 hours since it was last charged.
• 56 hours of semi-active usage before the phone's battery died. In all fairness though I was constantly rebooting it which probably hit it quite a bit.
• Used as a portable GPS for a walk I did, connected to the internet the entire time for an hour and a half walk, with the GPS active and using GeePS. Only used about 10% of my battery

Overall, even my old N97 can't match my N900's battery life

At lunch listening to Podcast over Bluetooth, Checking Witter, and surfing the Web, about 2-3 hours. Weekdays I run through one and a half batteries. Saturday or Sunday I run finish the day on my 3rd or 4th battery.

i hammer mine and it'll last a day if i use it moderatly i can get 2 days saying that i'm into my second day and still got 49% battery left. also using the vfs cache script from kasam and power v47 @750 and smartreflex on a japod battery
got a scud on it's way so hopefully a bit longer use

maybe you can lower your voltage values even more, these are my standby values
0:22,90 250:25,180 500:29,360

there are no folders in my syspart folder...so how is this possible

strange, I just checked, folders are present on my N900.

I was following some of the advices in this thread:

http://talk.maemo.org/showthread.php?t=49654

The trick with deprioritizing background tasks is from here:

http://talk.maemo.org/showpost.php?p...&postcount=189

2-4 hours, several batteries/day.

constant use, no gps, no music, no video.

my wifes n900 gets about 10 hours.

i just started using karam's battery script and will see how it fares the next couple of days.