IOS 4.2.1 battery drain

I liked this part:
Hoping to clear the air -- *+or perhaps sell more gear+* -- Nokia Siemens Networks, a joint networking gear venture of Nokia (NOK_) and Siemens (SI_), says mobile signaling traffic exploded when Apple released the iPhone OS 3.0 on June 18, 2009, according to a note from JPMorgan analyst Rod Hall Wednesday.

Hardly an unbiased source.

ok, at least I'm not a regular phone user and can differentiate the facts of having; 3G, wifi, push notifications, bluetooth etc... ON means your battery will drain.

but if all above are off and if the device is still heating up (you can feel the center of iphone heats up) meaning there is a process which grabs **** of a cpu usage.

when I even tried to scroll contacts or play a graphics demanding game (like NFS) it is slow and not responsive but once I'm on default/restored 4.2.1 no apps, then it works great, graps flows. and that was the same in 4.1 until my upgrade.

I believe this is definetly an app issue where keeps the phone pretty busy...

Please read the thread you just posted to and you will see tips on how to fix the higher battery drain.

I'll take back the apps issue that I've said, since I've disabled all apps (removed) and same thing. it keeps heating up and battery drops %5 in 8-10mins

I think there is something wrong on restoring back from a backup. if I just restore original 4.2.1 and only synch with itunes (long process actually) it seems to be fine.

Continuing on my earlier tests the phone battery dropped very little overnight and in airplane mode with only the settings app in the background. This seems to indicate, from my observations, that something may had changed from 4.1 > 4.2 with regards to how location services works in 4.2 even in airplane mode (the only other background app in my earlier test where I noticed significant unusual battery drain had location services but it never had battery drain issues with 4.1).

Now if someone can leave settings and an app that gets location services even though it is in airplane mode and see the same battery drain (and minimal battery drain with just settings running) we may have narrow down the issue perhaps.

Last night (overnight)my usage time was only minutes and the battery went down from 100% to 85%. what could be the reason for this? I have deleted all the applications, left only 4 which i believe do not work in the background. Even if the do, it would have certainly showed in the usage time, or not?
For sure I can say that now the phone (without apps) runs much faster and smoother!

There was a reason why Apple was not very complementary about having apps running in the background! This battery drainage for sure is huge problem. And for older phone versions like mine it will always be. Its the case with the iPhone 4, but the battery is stronger and it doesn't affect that much.

Battery drain is terrible with the new 4.2.1 update on my iPhone 4! Barely make it through the day. This needs a fix. Never noticed any problem with my battery until now. 😟

For the record, the solution has been posted many times over. The easiest way to fix this issue is to reset your iPhone "as new." sure it's a pain to set up apps again, but I find this to be the most simple.

Read the thread you posted to and you will learn how to fix it.

Setting it up as a NEW IPHONE would probably be the least tedious of all. Keep in mind that some APPS don't play nice with each other and cause battery drain.
But the first thing to do is start out fresh and be sure your IPHONE battery isn't defective. Next install a few APPS at a time and see your battery drain .
You'll find the culprit.

I have set my iPhone 3GS as new one and it still shows the same battery draining as it used to. I have even get rid of all apps. For a day it worked good, but now it's the same case. Over night it goes down for 15-20% and it shows only 2-3 minutes usage time.

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my phone,too.and more battery is hotter when I user map or see tv.

Tried the setup as new fix with no luck. Only have Facebook app running in background. Any ideas?

Victor Mihajlov wrote:
I have set my iPhone 3GS as new one and it still shows the same battery draining as it used to. I have even get rid of all apps. For a day it worked good, but now it's the same case. Over night it goes down for 15-20% and it shows only 2-3 minutes usage time. If it goes like this for next two-three weeks i will have to reconsider the option for jailbreak and bring back the 4.0 software.

Which probably won't fix it, as the problem is not in the release. When you set up as new did you add your email accounts back? If so, your problem is the mail app. Read the thread for solutions.