Weird...sudden battery drain
 

I've had my N900 for a couple of weeks now, and since it's been running since then. Battery life hasn't been great, but I can survive through the day on a charge, so I charge overnight. That hasn't been a problem for the past few weeks, until yesterday. Yesterday I put my phone on the "silent" profile due to a meeting, and when I looked a few hours later, the device was dead. In battery-eye I see a straight line all the way from 8 AM when I disconnected the charger to battery depletion at 2 PM.

I've charged the phone again, booted and all is fine again now. I've no special applications running on the background, haven't updated any of them for at least a week and didn't do anything special during the meeting I was in (the N900 sat in my pocket the entire day ;)). Weird, huh?

I'll try to make a battery-eye screenshot to illustrate the difference.

Re: Weird...sudden battery drain
 

How much is this few hours ?:rolleyes:

Re: Weird...sudden battery drain
 

Check 'top' and look for process running at near 100% I had behavior like this when the RSS reader maxed out the CPU for no apparent reason.

Re: Weird...sudden battery drain
 

My phone has started doing something similar. Can be using it all day - 3g or GMS - connected or not and get a deceint level of pwer. Line drops quite slowly. then when it hits 20% it give a vertical drop to 0. No new programs and only started this a few days ago.

Re: Weird...sudden battery drain
 

Let's see...

I unplugged the phone at about 8AM as I always do and went to work. At around 9AM I changed profile to silent and remembered to change it back at around 4:30PM only to find my phone dead. So I put a bit of juice back in, booted and had a look at battery eye. It showed on the graph the battery depleted at around 2PM. So...from 8AM to 2PM the battery went from 100% to dead, which is 6 hours.

Normally, I start charging again evenings. The night before the depletion problem I started charging at about 8PM and at that point the battery was still at 40%, which means it only took about 60% of battery juice in the 12 hours it was off charger. Still a lot, but acceptable for daily use. Simple calculation says that one day the N900 takes about (60/12) 5% battery juice per hour and the next it suddenly takes (100/6) 16.7%...without changes between days. No updates, no new software, no different usage profile...after recharging and a boot it's back to normal.

Obviously I wasn't able to check the process list as the device was shut off due to lack of battery juice :) All I know is what I've done before and after which was...nothing.

Re: Weird...sudden battery drain
 

There's a bug in pulseaudio/tonegend which will keep pulsaudio running at about 2% CPU all the time.
Use HTOP or top to see if this is what happens to you and then do a "killall tonegend" from a root shell to get rid of the problem.

Re: Weird...sudden battery drain (browsers!)
 

I've found that high battery drain is usually caused by applications running in the background.

In particular, I've found micro-b browsers open on certain websites cause a big drain, while other websites don't. Sometimes this is caused by animations, but I have also seen examples where that didn't seem to be the case.

I am guessing that another cause is faulty/badly written javascript, that doesn't block as much/often as it should (I've also seen this using firefox on the desktop).

So beware web pages! Only keep open ones you trust!

Re: Weird...sudden battery drain
 

That's a little weird PolarWolf. Yesterday, after having the phone only a few weeks without any problems, the very same thing happened to me. After I had turned the phone to silent for a short time in the morning?

No idea why? Charged it up again and it appears back to normal buy obviously something is amiss

Re: Weird...sudden battery drain
 

just yesterday the browser stays at 100% cpu after closing and the battery was empty after 3 hours. happened to me for the second time. also sometimes other background processes are "running wild".

Load Applet ( http://maemo.org/downloads/product/Maemo5/load-applet/ ) helps to recognize them...

Re: Weird...sudden battery drain
 

Please add your comment or vote for this bug:

https://bugs.maemo.org/show_bug.cgi?id=9887

Happened to me also, need Nokia to acknowledge and fix.

Re: Weird...sudden battery drain
 

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.

Re: Weird...sudden battery drain
 

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

Re: Weird...sudden battery drain
 

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.

Re: Weird...sudden battery drain
 

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.

Re: Weird...sudden battery drain
 

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.

Re: Weird...sudden battery drain
 

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.

Re: Weird...sudden battery drain
 

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.

Re: Weird...sudden battery drain
 

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

Re: Weird...sudden battery drain
 

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?)

Re: Weird...sudden battery drain
 

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.