Cool, a similar case with the same symptoms. I'm going to try and reproduce by flipping to the "silent" profile and see if that somehow makes my battery go empty much faster than usual. I'll do that tomorrow though

My usage profile looks something like this:

8 AM, take the phone of charger, check messages (email)
During the (working) day I check something every once in a while. Either an email or on the web. After use of the application, I close it, and put the phone back on the default desktop with only a weather widget as active component. I pay for 3G so I exclusively use it with 3G, WLAN is disabled. Bluetooth is disabled unless I need it. I hardly use the thing as GSM, really, I hate phoning. I make about three calls a week, if that, and usually not initiated by me
When I come back from work, at around 5:30PM I drop the phone on my desk and generally leave it there. Every once in a while I pick it up to check an email if it arrives and I'm around to notice it. All in all, very light usage for a smartphone. Very boring and functional, too. No media playing, no watching youtubes, etc. On the "problem day" I even used the N900 less than usual due to the meeting I was in which lasted the better part of the day. Yet it managed to deplete the battery more than three times faster than normal with the only difference from the day before being set to the "silent" profile.

Cheers PolarWolf. I'll also keep an eye on the battery when next on silent and let you know the outcome

I also noticed a recent battery drain.. normaly my battery lives for about 40+ hours but now batterygraph showed me it had lived for about 12h. I checked "dmesg" in terminal and it showed:

"dspbridge: timed out waiting for mailbox" and looped that message. I also found some strange processes in top like "kondemand/0" and stuff. The vibration when i clicked the screen was wierd. I am not sure why this happens but i tried "modprobe -r dspbridge" and it stopped. Problem is that i need to do this now everytime i reboot.

After a couple of reboots later this problem seams to have vanished. I do not have this problem anymore. I still do not know why it happen.

I can confirm the observations of mysterious sudden battery drains as well.

Usually my battery lasts for about two full days, so basically I recharge the N900 every two days over night.

Occasionally there are days however, that the battery lasts only 2/3 of a day while being idle, except for being connected to my phone network.

A reboot usually does the trick and battery life is back to normal again.

I can't really reproduce the situation, but I THINK the problem may be connected with watching videos on the N900 at some point.

Well...I took the N900 off charger this morning and set the profile to "silent". It indeed draws the battery empty much faster than on the normal profile. I didn't wait for total depletion so the N900 is on the charger again. If it's full I'll have a looksee if I can find any difference between the profiles regarding processes, CPU load, etc.

Frandom high drain like that happens to me occasionally too, and it's for me caused by wlan consuming huge amounts of power after I leave wlan coverage and device autoswitches to packet data. It doesn't always happen, only sometimes.

Anyway, when it happens I do 'ifconfig wlan0 down' as root, and the power drain stops.

the same happened to me ..... silent and few hrs later it was dead . !!!

Yeah...same for me. I can get about 14 hr out of one charge, now if I'm lucky I get about 6. I have a feeling it has to do with an app that was updated. How can I go about checking this? (What command should I run?)

I also had unusual battery drain today while using silent profile. While on silent, I was also away from my usual and configured wireless networks, so my internet connection was on AT&T most of the time, but scanning periodically for wireless. That strikes me as the most likely cause of my battery drain.

However, just to make it interesting, the rapid depletion continued after I was back on one of my configured wireless networks with General profile activated. I had to reboot to return to normal battery usage.