Re: Battery almost empty after 5 hours with locked N810
 

sysstat anyone? :)
http://pagesperso-orange.fr/sebastien.godard/

Re: Battery almost empty after 5 hours with locked N810
 

As GA said -
But he might have added -
This helps focus the solutions in fewer threads rather than having umpteen threads named slightly different.

A simple google search on battery drain in the forums turned up 214 results. A forum search for titles with battery and 2 or more responses in the last 6 months turned up 52 separate threads.

This results in a very little signal and a lot of noise in the forums and makes it difficult to find the response you want. Frequently I will run across someones problem (like this battery drain) remember a potential solution was covered in another thread and say the heck with it because I won't take the time to search for someones solution if they don't add to an existing thread.

Not all solutions should be put in the wicki, they should be user tested first.

Anyways - to contribute to this thread:
While monitoring top also run battery status to a log.

Re: Battery almost empty after 5 hours with locked N810
 

Searching google is often more effective, if you know the right incantation to make it only search iTT. While "battery" on the site search brought up 52 hits, "battery drain" brought back 1 and it's specifically related to the 800 not charging issue.

Unfortunately google can also provide a lot of useless hits as well.

I hate to say it, but it's not always obvious even for a well trained person to find the appropriate information inside iTT threads.

Re: Battery almost empty after 5 hours with locked N810
 

That is exactly my experience. Video watching will get it warm a bit very fast.

Please try WorldTV99 in my signature and you will see.


bun

Re: Battery almost empty after 5 hours with locked N810
 

I forgot to add that my battery also was hot several times when the phenomenon appeared. This is not the case any more. Something has happened.

Would it be possible that consumption rate is defined by an algorithm to "high level" until wifi signal is found and "locked in" in a efficient way? That would explain why after Chinook and Diablo, wifi detection was slow so power drain was high and everything turned back to cruise level after a while?

I m dining tonight with a senior manager of quality control in electric signal in Nokia. I will ask.

Re: Battery almost empty after 5 hours with locked N810
 

That incantation is:

1. Go to InternetTabletTalk main page.
2. Locate the "Google Custom Search" box under the heading "Search" at the top of the right hand column.
3. Type likely keywords in the aforementioned search box.
4. Press "Enter" or tap/click the "Go" button according to your preference.

Re: Battery almost empty after 5 hours with locked N810
 

Yes. Usually when you felt the heat 'literally', it is already running amok and the heat continued to build up even the tablet is being turned OFF, or at least attempted to. It did not work and ended up with an almost empty battery, and I cannot think of anything to stop it other than taking the battery out if it happens again. To get something normal running to become warmer and warmer has to be an accelerated process, likely something that 'feed' on itself, for example, the caseyjones reaction in cocaine users. It occured twice with my N810 and it is pre-diablo. I kept my fingers crossed and so far, has not seem it for quite awhile.


bun

Re: Battery almost empty after 5 hours with locked N810
 

I can't remember the last time I visited the main page, but thanks for the pointer.

Re: Battery almost empty after 5 hours with locked N810
 

Intel's PowerTOP works on ARM too. If you can get it compiled (using SB), you can use it to figure out which apps use how much power (in W).

Re: Battery almost empty after 5 hours with locked N810
 

For the reference, there's a thread about powertop on the N810 (found with Google).

Re: Battery almost empty after 5 hours with locked N810
 

After digging and finding that diablo's arm kernel does not provide reliable futex commands I'm wondering if this is a kernel bug that is being tripped up in specific cases. Modest seems to be doing it in some cases, but I wonder what's causing the meltdown here?

I would ask the simple question... does the problem reoccur when you are in offline mode? I know there should be no difference, but I still keep thinking that it could be a bug in the ICD.

here is the Modest bug for reference.

https://bugs.maemo.org/show_bug.cgi?id=3357

Re: Battery almost empty after 5 hours with locked N810
 

No, these batteries don't work like that. (single-stack lion, not multi-stack like a laptop battery)

Re: Battery almost empty after 5 hours with locked N810
 

Could be you have Wifi on search intervals.

Re: Battery almost empty after 5 hours with locked N810
 

What do you mean?

Re: Battery almost empty after 5 hours with locked N810
 

The battery drain problem occurred once again last evening. I had been logging system information every 15 minutes with "sar -A -u 900 8000" since the afternoon. Here's a summary of what I did:

• At about 19:45, I plugged out the charger cable.
• Then I used the N810 a little around 20:15, 21:55 (the N810 was warm, but the battery was full) and 22:15-22:35 (I ran a CPU-intensive task for several seconds).
• At 22:35, the battery was still full.
• At 01:50, the battery was almost empty (less than 20 hours when idle, less than 1 hour when in use).

The sar output shows that the N810 was constantly idle (but a very little loaded). So, my battery drain problem does not come from a task that would take much CPU time.

Re: Battery almost empty after 5 hours with locked N810
 

Thanks for the detailed instructions, I had thought my statement would be understood as a search such as you described. :)

I constantly overestimate the audience.

Re: Battery almost empty after 5 hours with locked N810
 

ok this is what my friend in Nokia R&D said. No guarantees that 1) he knows exactly what is going on - he s not in N810 specifically 2) I did understand and deliver exactly what he said :-)

He mentioned a few leads:

- As General Antilles said, the battery is single stack so there is no adjustment of power consumption. However there are algorithms to optimize relationship between physical memory, consumption, and performance
- Introducing a new OS causes disruptures in the way the packages are installed because - according to him- the physical memory is not "blank". This can generate a "chaotic" usage of power until things get optimized.
- in stand by mode ( no application running, screen dimmed off) there are still a few things running. Did not say what.
- processor activity, Wifi and BT are the main causes of power drain.
- the battery time indicator in the status bar is not 100% reliable.
- he did not like the "heating up" symptom. Suggests a bug in the new OS that could/should be fixed by an update.

My n810 had again a seizure last evening. a few days in stand-by mode evaporated suddenly in a few hours. Found it in "coma", charged it up . Now showing 10 days, 7 hours.

Re: Battery almost empty after 5 hours with locked N810
 

@vinc: Isn't the interval between sar gathering data too big?

Re: Battery almost empty after 5 hours with locked N810
 

Xterm is a known timer offender (i.e. dyntick won't be able to slow the tick speed) - there was a way of fixing this, but I can't remember it off the top of my head. Anyone?

Re: Battery almost empty after 5 hours with locked N810
 

I have the same issue as the original poster. Since I upgraded to Diablo, battery usage has become inacceptable (but then I'm used to that from my N82....grrrrrrr!). Might be because I backuped/restored before/after the upgrade, and got into lots of troubles with the Application Manager being unable to resolve things, so something might be screwed up.

Will reflash to Chinook and report back, but there IS an issue.

Re: Battery almost empty after 5 hours with locked N810
 

I don't think so: there's the load average on 15 minutes.

Xterm itself or the shell that runs in it? Note also that Xterm is generally open on my N810 and it usually doesn't make the battery drain.

Also, I've noticed that when I took my N810 away (at about 19:45), the number of context switches per second became much larger:
I recall that at 22:35, the battery was still full (if the battery status is reliable, at least a little).

Re: Battery almost empty after 5 hours with locked N810
 

That's why I keep "advertising" tabletSearch, a Google Custom Search Engine specifically for searches in our beloved "maemo universe":

• Plugin for your tablet
• Website

You WILL find the relevant information :D

Re: Battery almost empty after 5 hours with locked N810
 

A possible cause of the problem: I've noticed that after locking the device, if the screen is still on and I press one of the two keys on the left, the message "Move ... to unlock" appears and the screen remains on. So, if one of these keys was pressed when I put the N810 in my pocket, the screen could remain on for quite a long time. This could explain why the problem occurs infrequently (for me). Now, I didn't have any such problem with chinook. Has anything like that changed between chinook and diablo?

Re: Battery almost empty after 5 hours with locked N810
 

Is it possible you recharged your device a lot while the battery wasn't completely empty? AFAIK this quickly lowers the capacity of the Li-Ion battery.

What about GPS? Are you using this?

Re: Battery almost empty after 5 hours with locked N810
 

Hmmm... are you using an application like autolock?

Re: Battery almost empty after 5 hours with locked N810
 

Yes, quite often, to have a full battery most of the time.

I've heard that, but experience shows that this doesn't seem to be true. Anyway, my battery is still very good: I used my N810 quite a lot (including music playing with mplayer) in the train a few hours ago, and after 4 hours, the battery was half-charged.

No, GPS wasn't used.

I used it for a few days three months ago, but as it was turning the screen on too often, I no longer use it.

Re: Battery almost empty after 5 hours with locked N810
 

Recharging early was a problem for NiCad batteries, but it doesn't effect Li-Ion batteries (at least not noticeably). What I would be more worried about would be overcharging. Perhaps someone who know more about the design of the charging circuit in the N800/N810 could chime in on this one?

Re: Battery almost empty after 5 hours with locked N810
 

I have this issue with my n800. I ordered a new battery to see if having an old battery was the cause.

Re: Battery almost empty after 5 hours with locked N810
 

With the N810, charging automatically stops after some time.

Re: Battery almost empty after 5 hours with locked N810
 

So, to update, I ordered a new battery from accessorypost, and it seems to be performing much better. I can maybe get about 3-4 hours of usage, but if I turn off wifi and lock the screen, it can go about 3 days without recharging.

Re: Battery almost empty after 5 hours with locked N810
 

I have been on holidays for about two weeks and didn't have any battery problem there, even though wifi was sometimes on (and I was usually charging my N810 only during the night): at the end of the day, the battery was still almost full. Now, I came back from holidays, and after several hours in my lab, with wifi disabled, the battery was almost completely empty (while it was full in the morning)! The N810 was hot. Yesterday, the battery was half-empty, but I don't remember the conditions (I don't know if the battery drain occurred in my lab or later).

I still wonder what the cause is. I recall that I had never had such a problem with chinook. So, it could be diablo (or a configuration change due to the reflash) + something in the environment.

The temperature? The room at my lab is particularly warm. But I already had battery problems in the evening.

Also, the N810 is more often in my pocket, sometimes with keys near it (of course, the keys don't touch it, but there is a bit more pressure, and this also means that there's metal near the N810).

Notes was running, but the battery drain problem already occurred without Notes.

Re: Battery almost empty after 5 hours with locked N810
 

Pesky metalayer crawler again? I thought they'd fixed that (I disable mine out of principle).

Re: Battery almost empty after 5 hours with locked N810
 

I don't see any reason why it could be the cause. And note that the load average is always around 0.

EDIT: and htop says that metalayer-crawler has taken only 3 seconds of CPU time.

Re: Battery almost empty after 5 hours with locked N810
 

Hi forum...

Im just reporting that battery life has become under par since my upgrade to Diablo. I think a bug of some kind is to blame, although disabling wifi and all applets does extend the battery life it is way less than before...

I hope an update will be issued soon...

Re: Battery almost empty after 5 hours with locked N810
 

I have just started having similar problems with my N800.

I currently keep it plugged in while at my desk at work, where I am using it as a FlashDrive running the Ceedo environment on my locked down XP box.

I have run this way without being plugged in and the battery has lasted all day, although I did plug it in when I got home.

Today I have noticed that when I have been away from my desk with the N800 in it's pouch in my pocket the battery is almost completely drained after ~1 1/2 hrs and the battery / back of the unit is noticeably warm when I take it out.

Bt & Wifi off and no use of the tablet at all, screen and touch pad locked.

Because the D-Pad etc are exposed...could constant "button" pushing be causing the battery drain?

While at my desk I tend to keep the Process List from the osso-statusbar-plugin open trying to gauge the usage of the SD card... I have not noticed anything utilizing huge amounts of CPU time.

Any help is appreciated.


N800 Diablo on mmc2,Rotate kernel, Adv Back light Plugin, OMWeather, Personal Launcher, GPE Summary.

TIA

Re: Battery almost empty after 5 hours with locked N810
 

Just wondering: Is there a way to *measure* power consumption in the N8x0? Something like the internal temperature sensor built into the device? This would at least provide a trigger (play some sound?) which could be used to actively search/run test programs when the problem occurs (which btw happens on my N810, too).

Re: Battery almost empty after 5 hours with locked N810
 

I don't think it's possible with the tablet taken alone but I developed a relatively simple DIY hardware probe for measuring the battery load in real-time. It does not require soldering work or any modifications in the tablet's internal circuitry. See an illustrated guide how to set it up with a N800 at
http://42.pl/u/10uy_Monitoring_N800_battery_load_HOWTO

take care,
/burbie

Re: Battery almost empty after 5 hours with locked N810
 

I didn't see it mentioned but putting your N810 in the supplied case and placing in your pocket repeatedly activates the display when anything is pressed against it. I had my go dry one night after a full charge. I discovered that there are some WiFi access points in my area that are far enough away that the signal fades in and out. I noticed this because of the connection lost sound and the fact my N810 is next to my bed playing additional duty as alarm clock. I've started leaving the device on but setting it offline so WiFi wouldn't wake it up and it wouldn't look every 10 minutes. It may be a coincidence but I haven't had the low battery over night problem. I could of course power down over night because the alarm still wakes the N810 up to sound off. Perhaps there are additional causes that result in this symptom. I only know what seems to work for me.

Re: Battery almost empty after 5 hours with locked N810
 

Lock it first.
Powering down and back on uses more juice than letting it sleep.

Re: Battery almost empty after 5 hours with locked N810
 

If the tablet is locked, this shouldn't happen. However I've noticed that pressing keys on the locked tablet can prevent the display from switching off: a message "Move [_*] to unlock" is displayed and the display remains on. This may be the cause of the battery drain for me, but I'd say this is unlikely (unless there's something else that occurs when one presses keys while the tablet is locked), because a key press/release would have to occur at least every two minutes.

Here if the wifi connection remains on during the night while the tablet is unplugged, the battery remains full in the morning. I could even use my N810 for several days without recharging it (no intensive use, though).

A few weeks ago, I had quite an intensive use of my N810 (wifi most of the time, use of web, terminal and Notes, display settings: 3/5), and the battery indicator had been full during 15 hours. So, this shows that my battery is still very good, and the battery only couldn't explain the drain.

Since I almost no longer put my N810 in my pocket, I no longer have any problem, except once while the tablet was in my bag (I don't know if this is related, though).