Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

there allready is a howto @ wiki

http://wiki.maemo.org/Make_your_battery_last_longer

I will edit the article today, it doesn't seem to include everything mentioned here.

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

not related to making the battery last longer, but in regards to charging.

I found the N900 charges WAY faster when you turn it off, im talking a dead battery to full in like an hour or 1.5 hours. can't remember exactly because i didn't time it, i might have played with it for half an hour hooked up, but i just know it was super fast and the battery was so dead that it turned itself off

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

That's crossing my mind too. If packet transmission or waking up the 3G radio is a significant power drain, I'm wondering if there may be a market for an app+internet service combo which combines the pinging traffic for all the different IM services, Facebook widgets and so on into a single low-rate keepalive stream, to a server which fans them out.

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

It's a bit inconvenient if you have to reboot the phone every 7 hours to swap a battery, isn't it? Especially with all those lovely "always on" chat windows one no doubt has open all day :)

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

does it help to have one of those desktop reserved to have NOTHING on it (ie no shortcuts, widgets and apps)?

so when you dont use the device, you switch to the desktop that has nothing on it to let it idle on that desktop.

does it help to extend battery life (you know, because its not actively rendering stuff)?

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

Well this option (changing battery) is better than no option at all. Don't you think? ;)

http://www.latimes.com/business/la-f...,2546606.story

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

Doesn't seem much different from how I get the most out of my laptop battery: disable power-using features when I don't need them. I lower brightness, disable bluetooth, put the wifi in power saving mode, etc. on my laptop too.

Fix for low battery time
 

Many people have reported battery time on low or moderate usage to be less than 6 hours. I have experienced same, but have now isolated the problem and will explain here a way to get battery to easily handle a few days of low usage.

The problem is Wi-Fi. For some reason N900 doesn't recover from having been connected to Wi-Fi and will keep eating loads of battery even after closing the connection. Only restart will help. Simply searching for Wi-Fi without making actual connection doesn't trigger the bug for me. (The phone searches for Wi-Fi whenever you manually start any internet connection.)

So, do not use Wi-Fi unless you want your battery to die fast. Or reboot after using it. This is until a real fix comes for the problem.

With this fix I managed to get my idle battery time to increase over 30 times! (From bellow 7 hours to over 9 days.)

It seems some people do not have this problem with Wi-Fi usage on their N900. It may be related to encryption method used or the Wi-Fi router connected to. In any case, some circumstances trigger a bug in N900 causing excessive battery drainage even after having disconnected from Wi-Fi. And the issue is fully reproducible. So, if you get it once with given Wi-Fi connection saved, you will get it every time unless you change some settings elsewhere than on the phone. That is, until the real bug has been fixed.



I had first experimented with various other things and have found out that normally there is no battery drainage problem with following things: Calendar widget, media player widget, foreca weather widget (only manual update), location widget and alarm clock. Also keeping terminal window open on the back doesn't drain battery noticably.

Wi-Fi tests were done with following settings (no problems prior to activating Wi-Fi connection for first time after reboot):
- Ask when needing connection.
- Dual GSM mode (uses 3G here at all times, 3.5 G when there is data activity - signal is a bit weak but doesn't matter).
- Widgets: Calendar, media player, foreca weather (only manual update) and location widget (on other than the viewed virtual desktop)
- Software: X terminal on background; Custom programs installed: OpenSSH client.

I did some experiments about battery usage on different cases. Prior to testing I rebooted the phone and kept it at idle for 20 minutes to let the battery voltage stabilize after the booting load. Results:
Idle without having used Wi-Fi: 54 mAh usage in 9.3 hours -> 5.8 mA.
Idle with 3G internet connection idle: 32 mAh usage in 1.9 hours -> 16.8 mA.
Idle after connecting and manually disconnecting from Wi-Fi (10 mW): 183 mAh in 1.0 hours -> 183 mA.

The difference is huge. The fully charged new battery charge is 1267 mAh, so idle 5.8 mA usage gives about 9.1 days, idle with 3G internet connection idle 16.8 mA usage gives about 3.1 days and idle after connecting and manually disconnecting from Wi-Fi 183 mA usage gives 6.9 hours. That is over 30 times the increase from idle to Wi-Fi bug triggered idle. And still over 10 times the increase from idle with 3G internet connection idle to Wi-Fi bug triggered idle.

The test times are high enough for accurate results and as such, it can be safely said that the Wi-Fi bug makes a really huge difference to the battery time.

I also tried to test having the Wi-Fi connection on but idle at 10 mW for an hour, but the phone had automatically disconnected it at some point. The resulting usage from part idling Wi-Fi 10 mW connection and rest pure idle with battery drain bug activated was about same as the 183 mAh an hour from previous test. Thus, there is no way to avoid the bug opening a Wi-Fi connection triggers as of now. At least unless some other connection setting than ask when needed keeps the connection alive.

If you want to test out these things yourself, here are some hints to use:

On terminal, you can get good information about battery status with command "lshal|grep bat". It will include some unnecessary information as well, but for advanced usage I recommend following aliases (save to ".profile" file on home dir to get them automatically for new terminal sessions):
alias g="grep"
alias gv="grep -v"
alias battery="lshal|g bat|gv nf|gv pr|gv yp|gv un|gv is|gv lc"

And then to check battery level I use "uptime;battery" to get both current time as well as battery information. Then keep the terminal on background to see both old values as well as new values. Do note you can scroll the terminal text to see backlog.

Re: [B]Fix for low battery time[/B]
 

I'm still seeing heavy drainage with 10mW power setting. I plan to turn off WiFi for the rest of the day, and restart to see how my battery fares.

I already ordered a spare battery though.

Re: Fix for low battery time
 

I heavily doubt this is the reason for fast battery drainage.

I had my n900 connected to Wifi for more than a day now without charging it and without a reboot so I cannot confirm this

my battery uptime is 2 days 48 mins now and it's still running at 47% according to the tools you've mentioned.

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

Threads merged.

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

Perhaps it might be related to faulty WiFi routers? I vaguely remember similar problems ages ago with other hardware.

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

I finished some more testing regarding the Wi-Fi problem. Effectively the results are that with bug triggered, full battery last less than 7 hours of idle time. But without triggering the bug, the full battery would last over 7 days! But see rest of the info edited into the previous post as it contains much more than just the test.
http://talk.maemo.org/showthread.php...799#post416799

It is possible. Or related to specific encryption methods used with Wi-Fi. But in any case something triggers a bug in N900 to cause it to drain battery very fast even after disconnecting the Wi-Fi connection.

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

i am going to restart it after i got it fully charged now. then i wont use wifi from then on. see what happens.

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

How the **** do we turn off those damn keyboard clicks? That's another thing that could save on battery life.

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

Nice post indeed

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

Settings -> Profiles, then scroll down to key sounds (it's easy to overlook).

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

Having problems with very low battery time of around 6 hours or less on low usage? Then check out the following post:
http://talk.maemo.org/showthread.php...799#post416799

Summary of my testing results:
Idle: 9.1 days
Idle with 3G internet connection idle: 3.1 days
Idle after connecting and manually disconnecting from Wi-Fi: 6.9 hours

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

@Phantasm what is a good # to have for the battery.reporting.current? Here is my screenshot. As you can see my uptime is not too good considering what the battery percentage is..

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

It all depends on usage. The mentioned times were for total idle. On real usage you can probably drain the battery in a working day if you actively use the phone with battery draining tasks. But if you have low usage, you should be able to get real battery lifetime of 3-5 days.

As for your screenshot, if you rebooted your N900 just after fully charging it, you must have either used it very much during that 1 hour and 28 minutes, or triggered battery drainage bug.

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

The only thing I have been using is the browser. Lets go through my list of things. Wifi off, gps off, bluetooth off, MFE is set to manual, Nokia Messaging is set to 30 min intervals, 2 desktops, facebook widget, calendar widget, network mode is set to GSM, screen brightness on lowest setting.

From the screenshot, my signal is spotty, but with no 3G and nothing really constantly updating, what else could it be?

Thx for any tips.

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

Did you just finish charging the phone before reboot? Or did you check the battery level at the time of the reboot? Just 8 bars out of 8 doesn't say much. The bars aren't fully linear and go in big steps.

If your Wi-Fi is off and you haven't been to Wi-Fi at all since last reboot, then the problem must be something else.

But if you have been very actively browsing on 2G, that may cause something like that amount of battery drop. Not sure. But you can experiment with the device on idle to see if there is any excessive battery usage there.

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

I think that an always on data connection over 3G is the main problem regarding short battery life. When i sign in on one or more of the im networks or let it check my emails regularly throughout the day my battery won't last a day. It makes for example a big difference if you check your mail in certain intervals or use push mail. Using push mail my battery holds up much longer.

I really hope this can be improved. htc dream or hero, for example, don´t have this problem. They sync google stuff and widgets whole they long without losing to much power.

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

3G data connection itself doesn't use much. In my experiments there would be 3.1 days of idle time with 3G data connection on but idle.

The widgets might be updating way too often or otherwise buggy.

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

Dont' worry, the N97 battery is about as "good" as the one on the N900 (my wife has a N97 and is not really happy with it because of that) :D

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

Wow. How did you leave your N900 untouched for 12.5 days? I couldn't leave mine untouched for 12.5 minutes.

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

Is there a way to switch to 2g if i want to surf non media rich sites? And then switch it back to 3g when i want to get on media sites? I want to use edge most of the time and cant figure out how to do this.

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

Whats the point of a data connection if you can't use it because your phone dies in few hours? First my widgets (foreca weather and rss) updated every half hour. Because of power drainage i changed it to 1 hour and now they are at every 2 or 4 hours. That still didn't change to much so i also signed out my im accounts and changed the mail to the nokia messaging service so i can use push mail, which uses way less power because you can turn of the automatic checking. With a bit of luck i can now last through the day with moderate usage.

The whole "online as it happens" part is a bit gone at this point don't you think? And as i said, htc dream or hero or what ever android phone for that matter do not have these issues.

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

Hi. From that it looks likr it's possible to disable vibration ONLY on IM? Is that actually possible because the only option i can find is to turn vibration notification for everything either on or off, and even though i have volume set to loud i do want to keep vibration alert turned on for SMS and calls for when it's in my pocket and i cant hear it. but IM vibration is annoying when somebody sends you 4 messages in 10 seconds...

Thanks

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

Here is my message in bug 6615:

--------------------------------------------------------
I read it and compare with my usage and I suspect that WiFi power usage is in driver activity. In my case I see a regular message about losing beacon from some bogus AP - I never use it. And it reports it all day, each second with calm intervals around 10-20secs.

Exactly, the message in /var/log/syslog is:

Dec 26 .... kernel: [....] wlan0: driver reports beacon loss from AP cf1bb52c - sending probe request

(the "cf1bb52c" is reported always, independent from real location and the connected SSID. And it is reported even N900 sitting in 3 foots from WiFi router - it is not my router at home or at work)

Of course, any WiFi transmission sucks the power. I browsed the directories under /var/lib/gconf I don't find any unaccounted connection. I guess it is some rudiments in wl12xx driver from Nokia...

The message is from wlan daemon and it is not seen in dmesg, so to see it you should install syslogd/klogd package.
-------------------------------------------------------------------

Adding to this I can say I suspect some connectivity package which I did install (and may removed since that) which triggers search of cf1bb52c. Something like OpenSSH.

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

There is an app developed for my Palm Treo 680 that does automatically many of the tips mentioned in this thread.

Power Hero
http://www.hobbyistsoftware.com/power-hero-more.php

Is there something similar in the development pipeline by somebody?

Thanks!

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

I looked into mac80211 source code - looks like N900 version of 'printk' doesn't understand "%pM" and prints an memory address pointer instead of MAC address. It should be something like "00:1c:df:67:1f:ac" instead of cf1bb52c...

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

Put me down as another person who is interested in learning exactly how this can be done; can anyone help us out with where to find these settings?

I've looked in Profiles (and everywhere else I can possibly think of), but so far - aside from the one for the display feedback vibration - I've only been able to find a vibration preference for "General" and "Silent", which seems to mean it's all-or-nothing.

I'd love to be able to able to specify discreet settings for IM, SMS, Email, etc..

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

For some reason the battery life keeps improving by itself.

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

Because it has to be formatted. After 4-5 completed recharges it reaches its optimal state.

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

I wish more people read this stuff instead of moaning over bad battery. A very good post indeed.

Also Alarmed is pretty good for the night settings.

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

I like your help on saving battery power. I have been trying to find out how to remove widgets and programs that I don't need. I had no problem on Symbian phones but haven't figured how to do it on this one.
Any advice please???

Thanks,
Bob

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

remove widgets by tapping on the desktop and hitting the little tab that pops out at the top right corner. from there you will see that the widgets have x's at the top right corner and you can choose to remove them in that way (it won't delete the widget, only remove it from view)

Uninstall programs by simply going to app manager and hitting uninstall...

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

Oh, Ok. Thank you very much. I appreciate it.
Thanks,
Bob

Re: GUIDE: How to improve battery life SIGNIFICANTLY
 

i was also suffering from 6-8 hours battery backup, i switched my messengers to offline mode when i go offline(meaning when i disconnect the net) and put them online again when i go online again, this improved my battery life very much
hope this helps somebody