IOS 4.2.1 battery drain

For me, the above worked and it's still fine. Sync the phone (if you have much and frequently changed data) to get a good back up. Then re-connect to iTunes and select 'Restore'. Set phone up as new (to be on safe side I called it something else this time like "iP Test". It will then set up and sync. Re-connect again and 'Restore' and then restore from your proper back up.

None of the other solutions worked for me.

Improve Iphone 4 battery life..
There are many situations when you wish you had an iphone with a better battery. a) A situation where you are without a charger
b) Or you might be expecting an important phone call and you realize that your battery is nearing 0%.I applied some settings as instructed by on this page it helped me multifold.. Have a look ... http://www.jordanrallsfoundation.org/2011/02/iphone4-avoid-battery-drain-tips.ht ml

OK, here's my evidence:


http://discussions.apple.com/thread.jspa?messageID=12667836&#12667836

Most of those tips are irrelevant or just plan wrong. Bluetooth consumes very little power, even when a headset is actively using it. Location Services only uses power when an app is actively using the GPS. The internal GPS uses a lot of power, but that isn't because of the GPS receiver itself - it is because the GPS needs to constantly download maps. This uses a lot of data also. So if you don't use GPS it doesn't matter whether location services is on or off. The idea that vibrate uses significant power is a joke, right?

Networking uses power, certainly. But what's the point of a network-connected phone if you turn the network off? 3G uses twice as much power as WiFi, so use WiFi whenever you can for network access. But WiFi is off when the phone is on standby, so there's no point in turning it off unless you never put the phone to sleep.

Volume has very little affect on battery life. Screen brightness has some, but try reading a dim screen in bright sunlight. Automatic for brightness takes this into account - it makes the screen only as bright as it needs to be.

If you actually read the tech specs for the phone ou will see that talking and sending/receiving data accounts for almost all of the battery consumption. And most of that is 3G data; WiFi gets almost twice the life as 3G. Audio is rated at 40 hours. At full volume this may drop to 39 hours. So following all those tips you might get a few minutes more talk time, at the cost of crippling your phone. Is it worth it?

If you are concerned about running out of power on a busy day (as I am) get an external battery that will recharge your phone to carry for emergencies (as I do). There are many different ones on the market; the best will be able to fully recharge your battery, doubling your battery life.

More to the point of this thread: If your phone has short battery life (meaning that you get significantly less battery life than the specs say) it is because something is sending and receiving data when it shouldn't. There is nothing else in the phone that can drain the battery that fast.

But it's also possible that the phone is working the way it was designed, and this just isn't meeting your dreams of how long you think it should last. The only meaningful measure is can you get through an average day without recharging?

Well, my iPad is still running the battery down much faster than before the upgrade. I really wish I had not upgraded. Next time I will carefully weight the potential gains vs the potential losses. Upside vs downside.
Yes, Lawrence, Inhave don all you said numerous times. It even lost power rapidly after restore as new with nothing added.

But, I am fortunate in one area, my Blackberry still gets over three days on one charge. That I can depend on.

The battery of my iPhone, in stand-by only. With 3G off and WiFi turn on, drain in only 48 hours. The spec is 300hours, its only about 15% of they capacity. This is a new only 2 month of used (bougth on dec/2010).
Spec
iPhone 4, 16Gb, iOS 4.2.1, normaly 3G is off.

What are your email settings? What apps do you have installed? Do you have Notifications enabled? Push? Location Services? Bluetooth? Do you truly leave the phone off for 48 hours, never turning it on, never making a call, never reading email, never playing a game? If so, why bother having a phone?

It's only two accounts configured with push data of, and fetching data at 1 hour.
I have notifications enable. Locations services is on, but all app is closed. Bluetooth is off, 3G is off, WiFi is on (like in my old one). The iPhone its realy in stand by (not off) for 48 hour, i receveid only 2 calls (weekend) never reading e-mail, never playing any game. I'd used my old one all time.
All app is closed, no one in background.
I have a old one, and the life battery is better than this new one. I really tested any differents configs.

It isn't in standby all the time if you are fetching email. How long were the calls? Calls will use 1% of battery every 4 minutes if you have 5 bars, more if your signal strength is lower. The ONLY way to actually test standby time with any accuracy is to turn on airplane mode.

Two call, and was fast, 5min max.
stand by is stand by not in air plane mode. The battery of my old one goes until 4 days in standby mode (not in air plane mode) in same configs.
Check on specs page on Apple site you saw:
Standby time: Up to 300 hours (not in Air plane mode up to 300 hours) http://www.apple.com/iphone/specs.html

in air plane mode the battery life time must be more than this.
The signal is strong, is away full in the last test, the iPhone is on same place. I did change any time.

Not sure if I understand you folks correct. Do you backup the drain status and after restore and installing the backup, the drain is gone?

After restoring to factory state, the drain stopped, but after installing the backup, it started straight away. And yes, data is sent and received, although all apps are closed. The weird thing however is, that even in flight mode, the drain continues, although no transmission can occur. I lost 10% / hour, 4 times the hard reset worked, this time only completely restoring helped and I own the iphone 4 for not even a month.

I have never used the games. What scares me is that it is unpredictible for me, when the drain will occur next time...

If the problem returns after restoring your backup then your backup is corrupt.

The phone meets its spec. Quoting you:

+Standby time: Up to 300 hours+

I point out that 1 hour is "up to 300 hours". All the spec says is that you will not get better than 300 hours.

Since there are so many other phones that work better please get rid of your iPhone and get one of those.

So sorry, but i realy have a trouble, if you can't help me, please do not replay my questions, ok.
I hope that somebody can help me.
No, i want to use my iPhone, if realy have a problem in iPhone, i think that the APPLE must be repair that.
I came here first, but, i'll send a question to Apple support, to ask about this.
thank you, but you can't help me.
Thanks

Lawrence Finch wrote:
If the problem returns after restoring your backup then your backup is corrupt.

This is not necessarily true. After 5 failed attempts at restoring as new on my first and second 3GS (after updating to 4.0), I grew weary of having to input all my info and downloading and reinstalling my apps from scratch (not one use of backups). Especially since it never fixed my issues. When I got my third 3GS I didn't bother restoring as new anymore, I just did a restore from backup. I did erase and restored from backup twice on the third 3GS with no success. When I finally got upgraded to the iPhone 4, it came pre-installed with 4.1, and all I did was do a restore from backup, the same backups that I had on my pervious 3GS phones. This time with success, I haven't had any issues since. Hence why I'm so reluctant to upgrade to 4.2.1. So if my previous backups were corrupt, as all my 3GS iPhones were messed up with 4.x, why is it that it had no affect on my iPhone 4?

I still believe it's a luck of the draw (or bad luck in this case). Certain iPhones, both 3GS and iP4, do not play well with iOS 4.2.1. Much like some 3G and 3GS phones didn't play nice with 4.0.x, until the 3GS issues were officially acknowledged by Apple, who officially said that 4.0.2 would fix these issues. And for most of the 3G users that were having issues, it was fixed. But no official word has come from Apple regarding the 3GS and iP4 issues. Not saying your tips and workarounds won't help, but it clearly doesn't work for everyone. Again, these are workarounds, not actual fixes. Fixes can only come from Apple, which by their silence to date about known and apparent issues, isn't a top priority. Priority is getting the new iOS, with all the new features, out for the iPad and iPhone 4. That's new features. Haven't heard of any fixes for current issues.

I still say, if you are still on warranty, keep getting your phone replaced until you get one that works with the intended iOS. Hopefully you get lucky and join the majority column.