N800 in standby mode dies within 24 hours
 

HI,

I have a new N800 and am perplexed by the lack of battery life. If I fully charge the unit overnight, then turn it on, by the next day the battery is dead (and obviously the unit will not turn on).

I have the settings to turn to screen off after 1min and to enter the standby mode after 5min. I have 2x2Gb SD cards.

This is NOWHERE close to the standby times stated by Nokia, and frankly it's useless if it needs to be charged every day.

Any ideas? Thanks.

Re: N800 in standby mode dies within 24 hours
 

if you have an active wifi connection, the rss feeds will update and things like connection keep-alive packets will be sent, so the unit is active and connected. if you want the most of your standby time, put the device into offline mode before you put it into standby mode.

another option, when you are not near a configured wifi access point, is to turn off the search feature for the wifi. this will stop it from searching for access points to connect to. again the offline mode will accomplish this, but you also loose the bluetooth connections with offline mode.

Re: N800 in standby mode dies within 24 hours
 

Brendan,

Thanks for the tip. I think you may be correct, since it's at home (active wifi connection) when it's in standby and thus runs out of power. Thanks.

Re: N800 in standby mode dies within 24 hours
 

Although Brendan's tips are good, there's evidence that some Wi Fi access point connections drain the N800 unreasonably quickly. If you search around for people complaining about their N800 dying overnight, this is what you'll find. I personally see this -- I have two APs in my home: one kills the N800 overnight, the other can be connected to in standby for days. As far as I know, there's not solution to this yet, but if you have an old AP lying around, you might try setting it up and seeing if the improves things.

Re: N800 in standby mode dies within 24 hours
 

Another good option is to just keep it plugged in when it's not in use. ;)

Re: N800 in standby mode dies within 24 hours
 

@orangegoat

would there be logic to the idea that one of those APs is configured for keep-alive packet transmission or rekeying at a high rate or short interval?

Re: N800 in standby mode dies within 24 hours
 

when my N800 would die overnight it was because of a bad SD card and some process trying to read the card all night long would use up all the CPU and so the battery would get used up.
formatting the SD card helped to fix it.

Re: N800 in standby mode dies within 24 hours
 

I charge my n800 every 3 days or so and I really use it a lot. When at home n800 is always connected with skype opened. To get the best out of the n800 battery its best to charge it until it displays its full and then deplete the battery atleast a couple of times and recharge to the fullest again! Try not to charge overnight since it charges pretty fast even if its charging with the unit ON. Leaving it plugged in all night might result in overcharging it and that kills battery life! I get about 7 hours of use with a 30 minutes of browsing every now and then but mostly mauku,pidgin,email.

Re: N800 in standby mode dies within 24 hours
 

I was wondering about this too, since when the N800 is not in offline mode, the SD cards are still available, which would cause additional current drain, a bad card could cause other problems as you noted. What process was doing this, do you know? Thanks.

As for overcharging, I'd really be surprised that this could even be possible with a smart device and a Li-ion battery which are known to explode when overcharged.

As for the suggestion of keeping it plugged in, what's the point of a 'portable' device if it needs to be plugged in? Thanks but no, there must be some other problem.

Thanks for all the ideas!

Re: N800 in standby mode dies within 24 hours
 

I saw some meta-crawler or something running with high CPU.
It was easy to test by just removing the SD card and then my battery life went back to days rather than hours.

Re: N800 in standby mode dies within 24 hours
 

Uh, so the battery is charged and ready when you need it? If you're sitting at your desk, or leaving it on a counter-top somewhere, why wouldn't you plug it in? :rolleyes:

Re: N800 in standby mode dies within 24 hours
 

I too just discovered this on my own N800. I thought I accidentally swapped the 770's battery into the N800 and it was just getting old, but when I switched batteries it has the same symptoms.

Today I tried an experiment: Full charge overnight, then leave it in my pocket (standby) all day (which included an 8 hour shift at work - not on wifi or bluetooth.) It's 5 PM now and I am getting battery chimes. I'll try a firmware format to see if there's a software culprit.

Re: N800 in standby mode dies within 24 hours
 

Because its a portable device with an advertised standby of 10 days or something:

"The rechargeable battery provides up to 10 days of standby time"

So the question is why can't the n800 meet its advertised specs? On 2007 I was lucky if it didn't die overnight which is real fun when you are using the alarm clock mode. On 2008 its much better but I must go to offline mode to really have decent battery life.

Re: N800 in standby mode dies within 24 hours
 

you can also try switching your wireless router to "802.11g Only" mode, which will use less power.

Re: N800 in standby mode dies within 24 hours
 

It meet it's advertised specs - in fact it exceeds them by a considerable margin - if the device is left completely idle and not used at all!

I just performed a rundown test on a freshly flashed and fully charged N800/OS2008 with no WiFi connection, no RSS applet enabled, no backup restored and no additional apps installed. Total time before first "low battery warning": 12 days and 2 hours. Of course I didn't use it at all during this period and only tapped the screen once a day (which switched off again 10 seconds later) to check it was still switched on! :)

I'm now performing a second rundown test with 11g WiFi enabled and I'm already down to 1 battery bar after 3 days and 11 hours - I'll be lucky to make 5 days with an idle but always connected WiFi connection (my router supports PSM).

Once that test is complete, I'll be enabling the RSS applet to update feeds every 30-60 minutes and see what effect that has on the battery lifetime - obviously the number of feeds configured on my device will be a major factor, so I'll just start with the standard/default feeds.

So far though (and without having tested the RSS applet) I'd have to say that the stock OS does not have any obvious power management issues. As is often the case, if your devices are not lasting 24 hours it's because of a badly behaved third-party application which is not allowing the CPU to go to sleep and is chewing it's way through your battery in no time. Unfortunately which application is causing the problem is not always easy to identify.

Re: N800 in standby mode dies within 24 hours
 

I also encountered this problem after upgrading to the 2008 OS. My N800 had been remarkably stable prior to that (uptime of a couple of months), and then the battery life dropped to hours instead of days. There were no obvious culprits (I was using the same access points, or no access point, and auto-connect was off).

I haven't had much free time, and was just gradually restoring my customisations when I could, and then the problem suddenly went away. I'm pretty sure what did the trick was adding a "-c" argument to the metalayer-crawler startup, but I haven't had the time to verify that this was really what did the trick.

More specifically, I think the problem went away went I edited /etc/init.d/metalayer-crawler0 to pass the following option to the daemon:
Anyone else having this problem might want to try something similar.

Cheers,
Lon

Same problem on the N810
 

I'm getting this with my N800 and now having an N810, I'm getting it on that too. I've updated the bug report,

https://bugs.maemo.org/show_bug.cgi?id=2602

Rich