[paulheu]

A regular NOKIA 1A car charger will do the job just fine.

The DC-10 or DC-20 models come to mind here..

[IMNdi]

II could try but I can already tell you what I would find. With a standard USB charger, a net loss. With a good charger, a net gain.

Standard USB only delivers 500 mA max, as per specs. That means IDEAL charge in approx 5 hours. Anything that drains faster than that will discharge AND kill your battery by microcycles.

[IMNdi]

I had a trip to take tonight so I did it:

Charger: Standard, non-Nokia (but FOR nokia, Energizer, high end)

Starting battery:70%

Navigation parameters: Max volume, high brightness

Time: 20 minutes

End battery: 69-71% (69 when checked, 71 after 20 seconds)

Verdict: Net loss.

Charger: Standard, non-Nokia (but FOR nokia, Energizer, high end)

Starting battery:78%

Navigation parameters: 25/30 volume, LOW brightness

Time: 10-15 minutes

End battery: 89%

Verdict: Net gain.

 So there you have it. At peak use, navigation kills over 500mA, and a net loss for the phone. You CAN navigate on a car charger is you either use a better charger or if you lower the load on the system. Set light to low(auto) and volume a little lower and, if you can read the screen, you're set.

I wouldn't do it, though. I am fairly cetain I am inducing microcycles when navigating with the first setting.

I should also add that the battery widget records percentages as 68-70, for the first run,  net gain. Even so, assuming I can't remember a simple number, the fact that it got 2% of the battery (40 mAh) over 20 minutes means that phone goes from charging to discharging repeatedly, thus killing the battery.

[rick_faulkner]

OK,

I just bought a NOKIA DC-20 from Amazon.

I will report back in a week or two once received and tested...

[KennyKB]

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IMNdi wrote:

II could try but I can already tell you what I would find. With a standard USB charger, a net loss. With a good charger, a net gain.

Standard USB only delivers 500 mA max, as per specs. That means IDEAL charge in approx 5 hours. Anything that drains faster than that will discharge AND kill your battery by microcycles.

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Overcharging your phone also cause discharge/charge microcycles which shorten battery life. The charging stops when it reaches 100% and doesn't start again until it falls by a few percent and the process keeps repeating. That's why it's not recommended to leave Li-ion batteries charging overnight. As you are in the habit of leaving your phone charging for an extra 5 hours I thought I'll let you know.

[IMNdi]

Not really, no.

When on a charger, the charger itself supplies most of the power, so, unless heavily used, the battery isn't discharged. Without a load, it can take many, many hours for it to become discharged enough to go though another cycle. As many people leave the phone plugged for more than the exact amount of time it takes to charge, so that went into charger logic design.

There are other factors I won't go into. Suffice it to say, "don't leave your phone on the charger for long" doesn't apply to overnight, it refers to people not unplugging it for weeks.

There are many other considerations I won't go into. Chief among which is the fact that LI-Po are very easy to overcharge and even slight overcharge kills it. As a result, as battery nears its peak the charge slows down. It eats up 10% every 10 minutes when empty (actually gups up to what the charger gives it, about 700mA effectively) and then slows down into stages. Last stage (80%+) is very slow and delicate, and it errs on the side of caution.

As a result, when phone says "done" it's actually not 100% by any math. Hence the leaving it plugged tip that allows the circuit to fully charge the battery and calibrate the charging circuit on what "full" is on that particular battery.

In theory, same goes for "flat" battery, but it's a lot more straightforward. If voltage drops below a threshold, power is cut to protect it so that's that.

-----------

In other news, I have identified my drin issue. My brightness never goes down.

Left the phone face up, light was low-low (see previous posts). Waited 10 minutes. Low-low.

Turned on lights. Phone shot up to medium in under 3 seconds.

Turned off lights. Phone never backed down. Waited 20 minutes. No backind down. Locking and unlocking the phone reset it until next time light hit the sensor.

So, as long as there is some light hitting the sensor, my phone will insist on running at bat signal levels. Making it manual-low is somewhat better, but not enough - it's still too bright for economy, and too bright for my needs. It also fires up button lights whioch are stuck to "on" forever.

That's why my navigation test earlier was bad. In the first run, my phone was face up, so street lights hit the sensor. Re-did the test, this time I covered the light sensor. Phone was cold.

I don't recommend you walk around with tape on the sensor, just be aware that long sessions with an unlocked screen can cause massive drain.

[mmoon24]

One thing I've noticed about my Lumia (AT&T) is that it will drain on idle about 3-4%. I figure it was due to having about 5 background tasks and a few live tiles. However, I have rebooted my phone the past three days only to find my battery INCREASE after the reboot.

Day 1: Battery goes from 75% to 82%

Day 2: Battery goes from 87% to 92%

Day 3: Battery goes from 60% to 90%!!!!

The third day was due to leaving the phone on for 10 hours before deciding to reboot it, whereas the others I rebooted after a few hours of having it on. Is this a WP8 bug or is this something going on Nokia's end? What is the fix for this?

[paulheu]

What you describe is fairly normal behaviour and the reason for this has been explained on multiple occasions here on Nokia Support discussions. You will find that prolonged use will smoothen out these differences as both the capacity of the battery and the calibartion of the OS readout will improve.

[mmoon24]

If you can link me to some of these posts/reasons/solutions, then I'd greatly appreciate it. I've actually had the phone for over a month now, and it is only after the Portico update did I start taking a serious look at my battery. So unless "prolonged use" means 2+ months, I am in need of another solution.

Things I've done in the past, but not have permanently solved the problem...

1. Soft reset

2. Hard reset

3. Uninstalling apps that people have complained about.

My only other solution would be to let the battery die all the way down, and then charge it all the way back up. Though I'm not sure if I should do that, and if I do...should I do it after the initial reboot so the battery is at max usability or just let it die when it's draining at a 4% clip per hour?

[IMNdi]

If I were you, I would let it die once (try to start it again to make sure it doesn't start - if it does, let it drain).

After that, charge it to full and, after it says 100%, leave it on the charger for another 4 hours. After that, kill it a little 5-10% and then let it charge again, ideally for another 4 hours.

It's not the best treatment for the battery, sure, but you won't be doing it more than once.

The advantage of this treatment is that it covers all bases - battery calibration, OS reboot, the temperature/throttle/whatever it is that Nokia does when charging the battery that makes it hit 100% before its time, the works.

And may I add:

The drain you mention, is it "idle" as in unlocked, seeing desktop or do you mean locked?

If you mean locked, check the following:

* Is your phone on 3G? (3G has poorer coverage almost everywhere in the world, being newer. It also eats more power, becaue of bandwidth. Newer hardware and software has made it nicer, but if conditions are right, it can drain like nuts)

* Is mobile data on? Set it to off and check your drain. Mobile data can be stuck to ON if some app or some file got stuck and it keeps the radio retrying.

* Is you battery draining in lumps, every 30 minutes, or is it a constant drain? Take the time to check every 10 minutes. Use the OS's Settings>Battery display. If it's constant, it's not the same as 30 minute lumps. Background tasks run every 30 minutes.

* Did you close all apps? Hold "Back" for 1 second and check that only desktop works.

* Is the phone warm to the touch, even a little or is ot stone cold? If it is slightly warm, something is eating the battery. If it's not, consumption is normal and you may be looking at a low capacity battery.

And finally, that 12 cycle thing is bull. It may be for the average, but my battery started showing its teeth after about 3 weeks plus, maybe 1 month. And I charged it more than once every day. So I'd say, 40-50 cyles. Not all of them were deep cycles, some were as high sd 60 or even 70 percent left, so that may be an issue.

And really finally, if you upped to Portico, you muct be from US or just an enthusiast. As you know, the rest of the world didn't get Portico nor will we get it until February at least. Rumor says it is held back because there are issues with light algorythm and battery life issues.

I isolated my issue, it's the screen brightness. Today I did a "test" in which I took the phone, 6 hours unplugged, and played another 4.5 hours of Taptitude, non-stop. I had 56% left. I tell you, set it to Auto-high and it wouldn't have made it 2 hours. You might want to check that. Though if you say it kills battery locked, that's not it.

I'd start with it on 2G, no data link, no use. See how it goes from there.

[mtbmike24]

My 920 was draining really fast what I did was run the battery completely dead to were the phone just shuts off then plug it in and let it charge all the way up after this my phone went from lasting about 5 hours to lasting 10 with moderate usage

[HuecoLumia]

hello, I bought my Lumia 920 this Month. I have had it for over 1 week. I have noticed that my battery drains fast, about +10% every 1 hour after using any Location feature. I know that Nokia Drive + Beta is a KNOWN culprit of causing battery drain. I have done all the tips mentioned. Apps like Nokia City Lens and Local Scout after using them for less than 5 minutes  then closing apps, causes the battery to drain rapidly. 

My phone only has about 10 days left of its limited warranty from ATT, has anyone had better luck after getting an exchange on the phone? wihout the same issues?  have you gone straight to your mobile carrier or have gone to Nokia service? 

I love the phone , love nokia quality.

[andyshine77]

I've had my 920 for over a month now, the phone has been nothing but trouble. At first it was locking up all the time, but the Portico updad seemed to fix that issue. The battery will randemly drain rapidly like 70% or more an hour, and nothing I do helps. I'm also having the dust issue.

What are my options with this phone? I paid full list for the phone, and so far I'm disipointed, I iked my 900 better and wish I still had it honestly.

Thank you.

Andre. 

[sam_kara]

problem is, if i unplug my phone at say midnight when its fully charged, by 7am, its dropped soo much that it won't last throughout the day

[Ploef]

Hello Nokia,

Because my SII is stolen I had to look for a new phone. I was very excited about the 820 with WP8. Also because I'm a .NET developer. But after a small week now I must say that I'm very frustrated about the poor battery life. Even after a whole night charging, after I unplug the phone it takes about 15 minutes to drain the battery for 10%!
Of course I followed all the existing tips but they just not seem good enough.
Please don't think this is a small issue. I think everybody will expect a top smartphone to be charged at the end of every day but doing it a couple of times during the day is not workable.
Most of us choose a top smartphone because it can help us to organize our daily work.
Do not misunderstand me, I do like the quality of the phone itself and the way WP8 works but I realy would like to enjoy it a little bit longer during the day.
Please fix this soon.

[Bosco007]

I thought I should share my recent experience, as it may help others with this problem...

I bought my Lumia 920 about a month ago, and I was enjoying very good battery performance. From a full charge overnight, the battery would last all day with moderat use, and still be around 50% by late at night.

A couple weeks ago I started experiencing the problems discussed in this thread, the battery started discharging rapidly, and would only give me 4 or 5 hrs use, and the top half of the phone was getting extremely hot. I thought this had something to do with the minor update I installed from Nokia around the same time, and since then I have been furious with this battery performance.

After seraching this issue, and reading through this thread yesterday, one of the posts mentioned that certain apps could cause a problem, in particular skype and facebook. It occurred to me that a couple weeks ago I started using an app call Facebook Touch Pro. The particular post mentioned something about certain apps not working well with the windowsphone servers and continuously looping to search for updates and notifications.

I uninstalled this app...problem has gone!!! I would suggest this may be a similar problem for many others, so perhpas check some of these types of apps you have installed, as they don't play nice with the servers and hence burn your cpu to boiling point (i.e. extremely hot back of the phone) which leads to excessive battery drain.

I hope this helps some of you. Cheers...

[realwarder]

"I uninstalled application X and it fixed the issue."

Doesn't fly... I've read around 50 posts in forums where people think they've discovered that app.  Even I thought that once.

Fact is, from my phone that I can get my phone to use virtually no idle power even with a bunch of email accounts syncing and wireless on.  However the majority of the time it sits there stealing around 5-10% battery each hour.

There is most definitely a software bug in the OS or core helper apps.

What is so frustrating is that Nokia have not acknowledged that there is an issue that will be fixed in an upcoming firmware update.  If they just said it, it would make all our lives more peaceful and we would be able to focus on preaching about how good our phones are (or will be).

[whiteboxamir]

Agreed -- Nokia should address this issue. I switched to them after being a BB user for 5 years. I think now I made a mistake if they don't even care enough about their customers as to be transparent and forthright in addressing a major issue with the battery. Very surprising!

[hardikshah]

I purchased my nokia 820 5 days ago and i have since experienced very poor battery life.  After been out at work and returning home i have only 19-25% battery life left.  I work in an area with strong network signal and i only use the phone for about 1 hour in that time browsing some apps like watsapp, some music while going and returning and sending some messages.  I have wifi off, bluetooth off, nfc off, two email account synching once a day, xbox sync off, all apps running in background set to off,  screen timeout 30 seconds and screen brightnes set to minimum.

I have also not even opened nokia drive, i have no games installed and very few other apps other than what is installed on the phone.  This is very poor indeed and im starting to wish i had opted for galaxy s3.

Its just my love for new windows 8 and great fan of nokia.

[mellowyellow]

my wife and i both have the 820 since mid dec.  we have both had battery issues.   both phones would lose battery overnight by 75% or more.  so far the what has resolved our issue has been removing the battery just for a minute or less.  after removing and returning the battery both of us when leaving phone off charger and overnight.  now have 100% battery when we wake.  hope this helps.  love the phone but battery issue was driving us crazy.  cross your fingers it's been a week so far and battery drain hasn't returned.  good luck everyone.

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