Re: N900 battery life questions, issues, scenarios
 

I'm in the middle of running battery tests. Doing a total baseline right now..
- fully charged from charger, remove from charger
- take out SIM
- reboot n900, turn on, run NO apps except for xterminal and switch to offline mode. Turn the screen on every 4-5 hours just to check battery percentage

Basically the phone is sitting there doing nothing. After exactly 24hours, i'm down to 67% battery free. I run

lshal | grep percen

to see the battery percentage.

You might want to try the same thing for 24hrs just to see if you can get to 67% free after 24hours

Re: N900 battery life questions, issues, scenarios
 

yeah... down to 67% in 24 hours in offline mode... that shouldn't be.

At first I thought the N900 used basically no power in offline mode, but taking a closer look, it seems that it does...

For me from 97% full at 05:18 to 84%full at 11:58 in offline mode (while I'm asleep) it uses 13% in less than 7 hours.
I've since 11:58 been connected to wifi and skype/gtalk/msn (cellular off) and am down to 81% full at 13:39.

It seems to me that there is definitely an issue with constant slow draining of the battery, unrelated to being connected or not, and then of course usage adds to the draining...

The standby battery in offline mode should be much better than it is

***EDIT*** my battery life is still acceptable. I'm still trying to pinpoint the cause of a drain bug that seldom gets triggered, and drains my battery within 10 hours or so. But most of the time I get decent usage. about 15-18 hours always connected, listening to 5-6 hours of music, 30-45 minutes of phone calls, some internet/messaging(maybe 1-2 hours) and all of this usually while connected to wifi internet, and sometimes to 2G..
2G phone is almost always on except when I'm in areas with very poor reception, I just switch the cellular radio off and only use wifi.

Re: N900 battery life questions, issues, scenarios
 

open the terminal application just touch it with your finger...
now you're in terminal with a command prompt, where you can enter lots of commands.
As long as you don't enter any commands under root(don't worry you have to know how to get root access to get it) feel free to try some commands. the" lshal | grep percen" will display the percentage of battery left. that's LshaL not ishal or ishai.
then there's lshal |grep battery which will display lots of info about the battery including the percentage left.

I usually keep a terminal window always open and use the following command: "lshal | grep percen;date" the ";" allows you to concatenate two commands. It will run them one after the other, so you get a percentage of the batter and the date/time. Keeping the terminal open I run that command throughout the day, and it gives me a battery usage profile.

Would anyone with more linux experience suggest a way to from the command line just enter that command "lshal | grep percen;date" plus maybe a way to enter a sentence explaining what the usage was, and having the output of everything logged to a file?
is there a command that just regurgitates text?

Re: N900 battery life questions, issues, scenarios
 

FYI, for a relative comparison, take the Nokia E71 as an example. (I'm running a N900 vs E71 battery test)

I have it running on 2G, NO wifi whatsoever.
- always connected to 2G internet running skype+gtalk (via Fring 32 hours)
- Nokia email checking 3 mins 8am to midnight
- its been 32 hours and I still have 60% battery left

I'm going to run a very similiar test on 2G with the n900 with Nokia email + 2 accounts in conversations (skype+gtalk). BUT i will NOT turn on the screen unless I get a call or check battery percentage.

I suspect the n900 won't even come close and the large screen will not be the reason. Either the battery is not good enough or the n900 is not optimized at all for battery...

Re: N900 battery life questions, issues, scenarios
 

Well, the E71 is a beast though when it comes to battery life. I would forget to charge it after a few days due to its amazing battery life. But, the N900 has a much bigger screen, faster processor and chipset and smaller battery. All those decrease greatly its battery life. Anyway, I am sort of curious to see what you get.

Re: N900 battery life questions, issues, scenarios
 

I should have results in 3 days.. remember I'm not going to turn on the n900 screen(only to check percentage+pickup calls) and the only app running will be Nokia Mail. The screen and processor should not be a factor in my test.

Might also try and somehow fit the n900 battery into the E71 to see if the issue is with the actual battery size.

Re: N900 battery life questions, issues, scenarios
 

If i use the phone, like web/internet radio/etc my battery will last like 3-8 hours. If i don't use it but have wlan enabled with skype it will last days...

Re: N900 battery life questions, issues, scenarios
 

Asssuming the N900 has a "tee" installed (I don't have one yet) you could do this:

(lshal | grep percen; date; echo "my message") | tee -a ~/my_history.txt

This will display everything on the terminal as well as appending it to the file "my_history.txt" in your home directory.

Do a "man tee" and "man echo" for more information.

Re: N900 battery life questions, issues, scenarios
 

Yes, N900 has tee, and your command works fine for me.

-jkq

Re: N900 battery life questions, issues, scenarios
 

I have a suggestion for you guys... I don't know if it's only me, but sometimes when I disconnect my N900 from the charge, it writes on the screen something like ''to save energy, disconnect the charger from the device''. It tells me this when I already disconnected.
I think that sometimes, even though you disconnect from the charge, it still thinks it's connected without receiving any power. What I do is I restart my n900 each time I disconnect it.

Re: N900 battery life questions, issues, scenarios
 

Hehe actually it is a reminder for you to unplug your charger from your AC outlet as you are no longer charging the N900. I found that message to be a nice touch for both the environment and to save a lil on the electricity bill :)

Re: N900 battery life questions, issues, scenarios
 

There are two problems with that:
1: The message never pops up until _after_ you've unplugged the charger, thus it's useless.
2: The charger doesn't actually suck any power from the outlet when it's finished charging. There's no drip-charging of the battery, and the switch-mode charger is so efficient that what it uses when not charging is neglible. A user here on this board used some sophisticated equipment to measure the standby current on the N8x0 chargers, and came up with a wattage so low that the energy spent on the pop-up message (turning on the display and all) is much more than what you "save" by disconnecting it. (Obviously on the older devices the message actually popped up when the charging was finished, not when you unplugged..)

Re: N900 battery life questions, issues, scenarios
 

Ah ok always thought unplugging chargers when not in use was a good thing after seeing energy saving tips such as these.....

http://www.terrapass.com/blog/posts/...tricity-vampir

"Unplug chargers (think cell phones and iPods) when not in use. Only 5% of the power drawn by a cell phone charger is used to charge the phone. The other 95% is wasted when it is left plugged into the wall."

Re: N900 battery life questions, issues, scenarios
 

Me too. A nice touch that was a pleasant surprise, even if potentially confusing for people.

I'll plug the charger into my Kill-a-Watt when i get home and see what kind of power it draws when not under load.

Re: N900 battery life questions, issues, scenarios
 

Old chargers (non-switchmode), the heavy ones, did suck a little power even when just plugged with nothing charging. But those 5%/95% numbers are just picked out of the air. It would be about how long it takes for the battery in the device to discharge enough to engage the charging circuit again.

In any case, just forget about that - it's totally irrelevant for modern switch-mode chargers. It'll use something if you leave them in for years, but that's about it. As said earlier, any warning message popping up on the device will use (much) more power than saved by disconnecting the charger.

(There are still non-switchmode chargers out there though, for other types of devices. E.g. my laptop charger. It's of the big-transformer type and it's lukewarm even when not in use. Not that it would mean anything to unplug it, because the room is heated by thermostat-controlled electricity in any case.)

Re: N900 battery life questions, issues, scenarios
 

Hi,

Just to check the full charge behaviour of the battery.

After a full charge mine reaches only 94-95% (whether charged off or on). I have it for about 3 weeks now (initially once I saw a 97% charge). Typically I leave it to discharge completely before charging it.

Is anyone getting more than 95% after a full charge?

To check the percentage type in a terminal:

lshal | grep percen

Yesterday I left it overnight switched off charging. In the morning I switched it on (plugged it in charger) and the charging light went from green to orange for a few minutes and the battery level from 94% to 95% when it became green again and stopped charging. Is this behaviour what you are getting too?

Cheers

Re: N900 battery life questions, issues, scenarios
 

I just experimented and charged the battery to full using my E71. Put the battery back into the n900 and ran lshal.

Showed 96%

So perhaps lshal is not that accurate, under reports by 3-4% to help avoid dead battery? Some users have reported strange issues when the N900 drains

Re: N900 battery life questions, issues, scenarios
 

Never got lshal to show more than 97% after a full charge...

Re: N900 battery life questions, issues, scenarios
 

Reports anywhere from 94 to 98% here.

BTW it's better for your battery to not fully discharge. Smaller discharge cycles/more frequent charging is best use scenario.

Re: N900 battery life questions, issues, scenarios
 

The SmartReflex power saving feature of the OMAP processor is disabled by
default on the n900. To enable it:
You can also enable it by editing /etc/pmconfig and changing the appropriate
values to 1, and rebooting.

I've been logged in to my wifi accounts for 10+ hours now, with GPS on, and the
battery is only down by about 1/3.

Some power saving can also be achieved by setting your status to be offline and
disabling networking.

For further information follow the bug https://bugs.maemo.org/show_bug.cgi?id=6615 which has a somewhat higher signal/noise than this thread...

Re: N900 battery life questions, issues, scenarios
 

Any idea why Nokia did not enable it? oversight, slow wakeup response or loss of functionality (what?)

Re: N900 battery life questions, issues, scenarios
 

It appears that there is a SmartReflex patch and also a CPU Frequency Scaling patch available for the Palm Pre, but it's a case of using one or the other, not both.

Nokia have championed CPU Frequency Scaling for some time now in Maemo, perhaps they don't see the need for SmartReflex, or as with the Pre they're not compatible technologies? Although this could just be because the Pre SmartReflex patch locks the CPU at 600Mhz which obviously nullifies the benefits of frequency scaling - no idea why it does that.

It also appears that SmartReflex needs an accurate profile of the silicon in each device, which could be another reason why Nokia have shied away from enabling it by default. SmartReflex appears to be supported by OMAP2 as well as OMAP3, so could potentially be be of some benefit to N8x0 devices as well.

Re: N900 battery life questions, issues, scenarios
 

From what I can see, they do different things. SmartReflex changes the voltage while CPU Frequency Scaling (obviously) changes only the frequency. The power consumption is quadratic in voltage P = V^2/R while linear in frequency, so there is usually more to gain by lowering the voltage. I have no idea about the OMAP processor specifically or whether my argument holds in this specific case.

At any rate, please post here or to the bug if you encounter any instability, but from what I can see, enabling SmartReflex seems to buy a factor of 3-4 on battery life.

Re: N900 battery life questions, issues, scenarios
 

Tried both your methods and its not working.

1. method tells me cannot create nonexistent directory and 2. is permission denied.

I don't have any experiences with this stuff. Help please.

greetz Donsaibot

Re: N900 battery life questions, issues, scenarios
 

You're mistyping the commands, check again and type exactly as above.

You need to be root - install rootsh then run sudo gainroot before entering the above commands.

Re: N900 battery life questions, issues, scenarios
 

Ok what is it supposed do to after i entered
echo 1 > /sys/power/sr_vdd1_autocomp
echo 1 > /sys/power/sr_vdd2_autocomp ?

i copy+paste it now and after that it showed

/home/user #

2.method still shows permission denied with root

Re: N900 battery life questions, issues, scenarios
 

dons it wont tell you that its changed

after you put them temp commands in

type cat /sys/power/sr_vdd1_autocomp

if you havent done the change it will say 0 underneath

if you have succesfully implemented it it will say 1

remeber when you power of or reboot your n900 it will switch back to 0

Re: N900 battery life questions, issues, scenarios
 

Ok it worked.

Thanks :D.

Re: N900 battery life questions, issues, scenarios
 

since this thread is called N900 battery life scenarios, i am going to test a scenario and post the outcome to it right here.

Scenario: Using FM Radio (only 50% of the estimated time) and MSN Haze on 3G. I personally think these 2 apps should be able to be on and give me a good battery time.

(one could call this travelling mode)

My guestimation of how long the battery will last is between 11-13 hours.

Though i hope and i think it should be able to last 24+ hours. which it probably doesnt, which is pretty bad.

No wifi, No GPS, Brightness on 2, no skype/other client on, Bluetooth is on since the radio app requires this. Very little to no websurfing, very little to no calls, very few to no sms, very few to no IM's, just idle on time. Volume on medium full. Only widget: personal dataplan monitor

My phone is charging right now, ill leave it on overnight.

Will post within 24 hours from now.

Re: N900 battery life questions, issues, scenarios
 

Devil,

are you going to enable the special power-saving mode?

FYI. I did a similar test on a completely unmodified phone:
- No 3G, At&t GSM only (does not hunt for 3G), no WIFI at all
- logged in to gtalk, skpe via conversations
- Nokia Messaging check every 30 mins from 8am to midnight
- stock phone, nothing installed at all
- no other apps running

in 24hrs the battery had 28% left.

Contrast to the same test(as similar as I could) on the E71 (Using Fring for gtalk+skype), 59 hours to get to 30% left.

Re: N900 battery life questions, issues, scenarios
 

sounds a little power rangery the special power savings mode.

I have every option for power saving on and almost no apps installed. Even though installed if they dont run it wont matter (or i would like to believe this very bad because if so it would be a real shame) no weird apps, just vnc and fm radio player installed.

i am not going to degrade my own existence by switching to 2g only. emails do not automatically send receive and no nokia messaging or other background apps.

Re: N900 battery life questions, issues, scenarios
 

I tried SmartFlex - my N900 got a 32wd_to reboot (see bug 6334) in 6hours then I played with e-mail client and it was a very first time after I purchased N900 at the end of November :( I think it can be an answer to your question.

Re: N900 battery life questions, issues, scenarios
 

Set Automatic connection to your 3G provider, switch OFF-ON, after powering ON - kill WiFi by "stop wlancond", unload 3 drivers - "rmmod wl12xx", "rmmod mac82011", "rmmod crc7" and you would enjoy a 48h battery life (If you don't video, of course).

WiFi power drain is a cause of short battery life but not 3G. It looks like Nokia already fixed it ... but in internal release. Some people test it and reports a good results - see comment 58, bug 6615.

Re: N900 battery life questions, issues, scenarios
 

It would be nice to see if all n900's reboot in the same scenario when SmartFlex is turned on.

Re: N900 battery life questions, issues, scenarios
 

so you say after a reboot those 3 drivers and wlancond run and they suck my battery life?

But this will all be fixed in the next FW update?

Re: N900 battery life questions, issues, scenarios
 

Disabled SmartFlex, playing with e-mail and looking for reboot. So far (one day) - no reboots.

Re: N900 battery life questions, issues, scenarios
 

Looks like... even you don't use WiFi.

Some people was selected to test a new FW and reports it (see bug 6615).

Re: N900 battery life questions, issues, scenarios
 

thats the old firmware. the one im using now.

will this be fixed in the new firmware? (to be released q1 2010)
thought i understood that from your previous post.

Re: N900 battery life questions, issues, scenarios
 

Yes.

... ...

Re: N900 battery life questions, issues, scenarios
 

Has anyone else noticed if snoozing the alarm clock has an effect on their battery life? I woke up around 6 this morning and my phone had finished charging so I unplugged it. Then my alarm went off at 9:00 and I pressed snooze about 4 times with 10 minute intervals. When I finally got up at 9:45 the battery was half drained.