Cold temperature makes the phone think the battery is empty. not a bug but true for every phone

I think it is partly true. Electrons need to be able to move freely from one nucleus to the next to have a proper energy flow. They tend to "stick" more to their corresponding nuclei if they get colder. It shouldn't drop as seen in the pictures thou. Maybe its a feature to make the phone think its running on emergency supply only. To keep damage away from the phone as low temperature working conditions need special equipment that can cope with it?

Battery Test : Nokia N9
Vs. comparative smartphones

GSMArena did the battery tests on quite a few comparable smartphones, including the Galaxy Nexus. I refer below the most likeable five [5], which many compared/consideration while seeking the N9. It's amazing to see that our beloved MeeGo-Harmattan fared much better than the other [most] expected ones.

3G Talk Time:
How the battery went from 100% to 0% on talk time over a 3G network.


Web Browsing:
How a fully charged battery took time, while refreshing web pages with their automated script, to deplete its juice.


Video Playback:
How the smartphone/s used 90% of their battery (the trial ends there) after continuous video playback.


Overall Score:
They conclude with the most important of their tests, the "overall usage". That number [in red] means that you will have to charge that smartphone every that many hours if you do one [1] hour each of browsing, video playback and 3G calls per day.










CONCLUSION:
Apple iPhone 4S works out to be the overall leader with 45 hrs. of Endurance Rating, while doing fairly well under most individual tests, sure some others beat it irregularly... however, our own Nokia N9 doesn't seem to much lag behind - scoring 39 hrs. of endurance, beat only by the SGSII at 40 hrs... which is incognito to me. While the Galaxy Nexus sure was a disaster at 35 hrs. faring nothing scholarly at the individual tests as well. Quite drab I'd say [though non-technically!]... while even our 'twin-sister' with WP7.5 Mango under the same shell fared better !

But, man-o-man! Did the Nokia N9 rock?
Second best [keeping the SGSII at par]! That sounds good... what with all the talk about 'idle consumption', 'older processor', 'poor battery life' and the likes? GSMArena suggests that reasonably heavy users should expect to get about a day and a half from their N9s. Good enough?


REFERENCES:
(With Date tested; Battery specs; Screen size; Weblink)

1. Samsung Galaxy Nexus : 30/12/2011; 1750 mAh battery, Super AMOLED 4.65″ screen;
2. Nokia Lumia 800 : 09/12/2011; 1450 mAh battery, AMOLED 3.7″ screen;
3. Samsung Galaxy SII : 18/11/2011; 1650 mAh battery, Super AMOLED 4.3" screen;
4. Apple iPhone 4S : 09/11/2011; 1432 mAh, LED-backlit IPS TFT 3.5" screen;
5. Nokia N9 : 08/11/2011; 1450 mAh battery, AMOLED 3.9" screen;

Qorax

Ps.: I'm a non-techie... do not know the wherewithals... but my overall experience with my N9 has been astounding, vis-a-vis my iPhone4. And GSMArena seems to concur!

Because I do not want to start another thread I will ask a question here(battery/charge related):
I notice on my N9 that the icon on low power standby screen when battery is fully charged comes in 2 flavors:
1. The mark(tick?) inside the battery icon is RED.
2. The mark(tick?) inside the battery icon is GREEN.

Anybody have experienced that? Anybody knows what colors mean? Case #1 happen more often, like 7 out of 10 charges.

PR 1.2 will fix that problem?

Hmm, it's black and white, and depending on the position on screen and the screen itself, the tick appears to be green or red?

but sgs2 battery is replaceable,
when our n9 batteries goes drop, how we can replace it?

Yes, exactly - the tick itself appears red or green. The icon volume is white.

A radical solution is just to reinstall your Nokia N9 software as I said in a previous post. Since I reinstall my phone, the battery life is really improved (more than 48h with normal use : calls, internet, 3G, wifi). Fluidity is also significantly improved.

Now I really love my N9. My opinion is that the UI of N9 is the best, the design is great. Shame that Nokia did not believe in this great phone.

Just one thing : the lack of applications on the store. But for me, I have most of what I need. The only application that I really miss is "deezer". So some times I use Galaxy Nexus just for that app. Galaxy nexus is a good phone but the truth is that I am now very frustrated by other UI: N9 UI is so natural! I often find myself tapping the galaxy nexus to wake him up, or sweep the screen to switch to another application.

Need to make a backup first?