battery life all of the sudden bad
 

I got my N800 about a month ago, and when I first got it the battery life was great. I leave it on all the time, and when I am not using it I lock the screen so that it doesn't come out of standby accidentally. I was getting days of battery life this way.

In the past week, the battery doesn't even hold for a whole day. I charge it at night, and by 3pm it runs out of battery life. I don't understand why. I can't think of anything I installed that could have caused it.

The programs that I run continuously are Skype and Pidgin. Sometimes I am moving in and out of wireless zones, and when I take it out of standby I've got pidgin messages telling me that it was disconnected, or whatever, and skype may be blinking if I have messages. But it seems like it was in standby, because the screen is off.

How can I troubleshoot this? Has anyone else experienced it? First thing I'm going to try is running with no apps up, see what happens. Then I'll add skype, then pidgin - I can do without pidgin, but not skype.

Re: battery life all of the sudden bad
 

Wifi and bluetooth drain a lot of power. When you had your N800 one month ago, did you have these on all the time? The N800 doesn't have enough juice to keep both of these running all the time.

Re: battery life all of the sudden bad
 

I do not have bluetooth enabled, but I do have wifi up all the time. But I always have - that's how I use skype. My battery life was fine before with wifi on all the time.

Re: battery life all of the sudden bad
 

I don't see how you could get days of battery life connected to wifi all the time. A lot of people can barely get six hours of continuous connectivity. I bet wlan was set on idle timeout or something before.

Re: battery life all of the sudden bad
 

I am not sure but it could be the battery drain issue reported by some people. My N800 (OS2008 installed) barely gives me 24 hours with a single charge and that also if I don't use it in that period. Wifi is connected during this period with google talk and a SIP account active. (Running Skype also sometimes).

Thoughtfix's blog:
http://tabletblog.com/2008/01/os2008...ery-drain.html

Or perhaps when your wifi got disconnected, your tablet was trying to re-connect/search for the access point continously which eats up battery?

You could also try run "top" in xterm to see if there is a process eating up CPU cycles extra-ordinarily.

Re: battery life all of the sudden bad
 

I found that OS 2008 on the N800 drains battery a lot. The N810 doesn't have this problem with OS 2008. I experienced this even on a stock installation of OS 2008 without any additional stuff installed and without swap enabled. After reflashing back to OS 2007, battery life was fine again.

Re: battery life all of the sudden bad
 

Likewise, I tested this last night and left my N800 disconnected from the charger, but connected to my Wifi access point with Skype running. Around 6 hours later, I started getting low battery warning, and the N800 shut itself down half an hour after that.

Pretty much expected, if you ask me.

I would also venture to suspect that having mnotify would put added drain on the battery, seeing that it polls for new messages very aggressively.

Re: battery life all of the sudden bad
 

The other thought not mentioned is a battery that went bad. I saw something very similar with my n800 about 2 weeks ago. I have had my n800 about 4 months. I swapped the battery with my 770 which I don't really use anymore and now the battery life is back in my n800. I have not tested the 770 to make sure it was the battery but the battery swap made a difference on the n800.

Re: battery life all of the sudden bad
 

Battery is bad, get it replaced under warranty.

Re: battery life all of the sudden bad
 

I've been reading threads for an hour now, waiting until 9:00 so I can call Nokia.

My first N800 would not go into USB mode so I couldn't upgrade it; they replaced the device with no fuss.

I've been using these types of gadgets for many years - Palm Pilot, Pocket PC, Zaurus, etc. and I was thrilled at the battery life on the N800. I connect with WIFI at work and at home, and with bluetooth through my cell phone. When I'm not actively using it, I let the N800 go to sleep by itself. With 1-2 hours of web browsing, reading e-mail installing new software, etc. the battery would stay charged for two days or more.

Starting yesterday, it seems to hold a charge for less than 8 hours, even while sitting on the table in standby mode! further, I turned it off and left it overnight on the charger. It never got to the "Charged" indicator on the screen, but when I turned it on, the battery icon was at 100%.

I'm wondering (searched but haven't found) if there is a utility that will plot battery drain (ma) over time, or at least will give some sort of indication of the instantaneous %charge and current draw. That would be helpful in diagnosing battery problems.

Now it's 9:00 and I will call Nokia to see if I can get a replacement battery!

Walt