I just noticed my n900 has gone 24hrs and its only at HALF. I had gotten used to the fact my phone would be at half within 6-8hours, and 10% by the 10-12th hr. I kept a spare cable at work and routinely charged it by mid-day as a habit.

I just realized today, being away from the office the day before on the road and even forgot to put it on the charger overnight that I was certain my phone be a dead brick, but happy me its not.

The last settings changed/added was
changed...1) Display: timeout 1min; Lock screen automatically.
added...2) Device lock: Autolock after 5mins.

not sure if this is old news since I havent been on the board awhile.

My daily routine and some basics on my phone, 5 mailboxes - set to autocheck only on wifi every 30min. backlight at 3 bars. 3G is on when I am outside of wifi. Wifi at work and home so I hear it chiming often, random calls nothing more than 5mins usually and couple texting here and there. The sim is brand new from tmobile, but ever since I had it from January it be at red bar by 13-14hr. I had done the update too awhile back but nothing noticeable, so I wonder if adding the device lock which I had never ever used made a difference?

well that's normal, in your office you are connected tio wireless and also you'll be using it quite a bit. But for the time you were out you use it less and not using wireless that's why it stay half full after 24hours. Mine is like that too with minimal usage. it lasted about 1day and half.

Happened to me once, I didn't put it on the charger overnight and it was half full the next day (it was up all day long), sadly, I've never had it again.

Well if I keep my phone connected 24/7 then I get roughly a day of battery life, otherwise I get two days.
EDIT: I didn't read the whole post >_> Where's the strike-through tags when you need them?