iPhone 4s Battery Life?

That's exactly what I found out over the weekend.

But I can't tell which process or app is causing the 3G data connection even if im connected to wifi.

I did several things over the weekend to find a reason why battery drain has increased dratically, starting on week 47 last month.

I restored the phone with iTunes and set it up as a new phone with no success. What I noticed, even when the phone is connected to the WiFi network at home it is sending 3G data every few minutes (I can hear this in my computers speakers if the phone is near to them ;o) ) and that is exactly when the high battery drain starts.

By the way a backup of my iPhone 4s works great on my wifes iPhone 4 with a bettery drain of about 0,5% per hour.

Right now I disabled all iCloud services and set all mail account to "manual" after that i did a reset by holding down the power and home button for a few seconds. All other services such as notifications, GPS and 3G are turned on. Battery drain right now <1% per hour.

An hour ago I opend the calendar to force the google exchange account to sync my calendar - battery drain still below 1%.

Now I just opened my email to sync my google mail account. In about an hour we will see how that works.

Except "system activity monitor" I have not opend any other app since the restart yesterday evening.

I closed all apps that were on the multitasking bar BEFORE the restart!

I'll let you know if there are any news.

@DJ.Jan

Also I do not know which process or app is causing the 3G data connection. I even turned off the iMessage and "Find my iPhone" and still my iPhone prefers to connect to 3G over Wifi !😕

For those who want to see if they get 3G transferr during the night just go to General -> Usage -> Celular Usage and there one may see "Cellular Network Data" Sent/Received. I usually "Reset the statistics" in the evening and in the mornings I have in the best case at least ~70 KB/night transffer over 3G (in standby) even that all night long the iPhone was connected to my Wifi and all apps/processes (which I know of) were set to manual sync.

It really looks like "iPhone 4S" and/or "iOS 5" favours Cellular Data (3G) over WIFI even when connected to WIFI!😮

Hi FiniteAffinity,

I am on Vodafone Ireland. My brother in law is on O2 ireland and his is perfect. Couldn't switch over SIMs because the phones are network locked. My Serial # begins with DNPG.. which is interesting since it is close to your original. Vodafone are picking it up the phone today so hopefully I will be issued with a new one that works.

@DJ.JAN

Indeed the iPhone 4S and/or iOS 5 is using 3G even when connected to WIFI when in standby!!! Immediately as the lock screen kicks in the iPhone switches to 3G and disconnects from WIFI even that is connected to WIFI!

This is really easy to see! Just watch the screen when you unlock it and the first split of second you may notice the 3G sign and only immediately after the 3G dissappears and it is replaced by the WIFI sign. 😮 No wonder that the battery drains so fast when the 3G connections are always favoured over the Wifi connections.

Here is more info about this (i.e. excesive celullar data usage problems over 3G which correlates pretty well with the battery drain):

http://www.vancelucas.com/blog/excessive-data-usage-with-iphone-4s-ios5/

bleepingApple, My serial # also begins with DNPG. This could be significant.

Here we go...

After starting the email client on my iPhone an hour ago, i lost >3% in the last 60 minutes, also email fetch was set to manual!

Right now I stoped calendar and email from multi tasking bar but did not restart the iPhone. If there is rally a bug in the mail client software it can be that the process is still running and that it's still draining the battery, in this case only a restart of the phone would help - we will see in about an hour...

As it is right now I have the following:

- bettery drain after a restart with no apps running an email, calendar fetch set to manual <1% per hour

- after starting calendar app also <1% per hour (google exchange account - contacts & calendar)

- after (google mail IMAP - mail only)

Suggestions:

If there is a problem with IMAP it is possible that if synchronisation is not successfull the mail process keeps trying to get the account synchronized an for that reason there is always data traffic over 3G network.

@DJ.Jan

From what you write it looks like there are quite some bugs in iOS 5 and/or apps (e.g. Mail, Calendar, iCloud, etc.). Combine these bugs with the preference of the iPhone and/or iOS 5 to connect using 3G instead of WIFI (see my previous post about excessive cellular data usage and how the iPhone disconnects from Wifi and switches to 3G when going to standby) and one has a pretty large battery drain.

It would be great to have a switch in the Settings in the next iOS update so the user can decide which type of connection has more priority than the other 3G or WIFI. I would definitely choose WIFI over 3G!

I do not understand why this behaviour (switching to 3G from Wifi when going in standby) of iPhone has not been changed in the updates iOS 5.0.1 and iOS 5.1 beta!😕

@enx23:

I think normally it should be in the way that WiFi has priority to 3G but if the phone is sending data over WiFi every few minutes in standby you will nearly have the same amount of battery drain than you have with a 3G connection.

If you install some kind of activity monitor or task manager to your iPhone you will see that the "mobile mail" process is alway started if you use a app that is accessing one of you email accounts. i.e. if you open calendar in your task manager you will find a calendar und mail process running.

edit:

As far as I heve read, there is a new baseband version and some carrier updates in the new iOS 5.1 version, maybe that will solve some of the issues on the ongoing data exchange in standby.

after an other hour...

After I switched off "calendar" and "mail" apps my bettery drainage went back to <1% in the last hour.

Now I have disabled my IMAP account and activated email, calendar and contacts in my google exchange account settings - still fetch is set to manual. Just after that I started my iPhones email app and synced with google. The app is still in my multitasking bar, in an hour we will know if that works - keep your fingers crossed 😉

@bleepingApple,

If you bought your phone with O2, it will be network locked, I guarantee that. They categorically refuse to unlock the 4S at the moment too - I've already had this argument with them, which is why I switched networks.

For the bug reporter, you must be a registered developer. Then you can sign in to bugreport.apple.com and file a report. That is how I did this. (Registering as a developer is free, it only costs to enrol on a specific developer programme after this, such as iOS).

Apple replaced my iPhone after I told them my theory about batches of dodgy SIM readers. That's when they said, that they hadn't heard of this before, but that my story was credible because apple use many manufacturers for each component. But they did run a diagnostic, and it didn't show any problems. They still replaced it anyway though...

Maybe DN serial numbers are the offending ones?

The non-SIM based providers across the pond actually now provide a SIM for the 4S, so that it can roam onto GSM networks in other countries. I suspect this is why some people are seeing this problem even on a "SIM-free" network.

Get a replacement phone, and check it in-store before you take it away. The serial number may be a giveaway as to whether it will work or not.

@bright raven,

Yes, I believe it is SIM related for you. TMobile and Vodafone seem to be the ones that the most SIM related problems are being encountered with. I didn't try a vodafone SIM in my phone, because I didn't know anyone with one. But O2 and Three seemed to work fine. Even so, the phone definitely had a dodgy SIM reader, and I'm glad it was replaced.

Maybe if your new serial number doesn't start DN then it will work? Would be interested to hear about that after you get your replacement.

Well, there we have a common app...

I just removed dropbox, lets see how this works.

Exactly!

Does anyone know when the next update is coming out? I have my phone replaced but havent yet upgraded ios to 5.0.1 due to many complaints that it could make battery life worse. Why doesn't apple respond more quickly this time?

@DJ.JAN

DJ.Jan wrote:

@enx23:

I think normally it should be in the way that WiFi has priority to 3G but if the phone is sending data over WiFi every few minutes in standby you will nearly have the same amount of battery drain than you have with a 3G connection.

I agree that Wifi still takes battery life but still not that much as 3G. At least in my case I get significantly better battery life just by using WIFI instead of 3G.

If you install some kind of activity monitor or task manager to your iPhone you will see that the "mobile mail" process is alway started if you use a app that is accessing one of you email accounts. i.e. if you open calendar in your task manager you will find a calendar und mail process running.

Ok. Once you open an app and you "get out of it" it will run in the background. All the apps which one has opened since he or she has restarted the phone are there in the background (running or standby depending on the app). Therefore indeed you see mobile mail process running the activity monitor app. I see it also but if I kill it that it does not appear anymore in the activity monitor.

edit:

As far as I heve read, there is a new baseband version and some carrier updates in the new iOS 5.1 version, maybe that will solve some of the issues on the ongoing data exchange in standby.

It looks like there are pretty many bugs in iOS 5 and its apps/processes which are linked to poor battery life (e.g. apps crashing, apps keeping the interent connection open and forgetting to close it, etc.). Fixing all these bugs over many apps will take months.

As you may have already read the 5.1 beta does not improve the battery life.

The largest battery drain hogs on any phone are screen, GPS ,and Celular data (3G/4G/etc.). Minimizing the usage of these can be a quick fix for improving the battery life on iPhone (and any other mobile phone) until all those bugs in iOS and its apps/processes are fixed.

I agree with you in the things you just mentioned above but in my case battery issues started just one week ago and all the time before I didn't have any problems nither on iOS 5.0.0 nor on iOS 5.0.1.

Problems with celular data can also be caused by the server from wich they are send, propably google hase changed some things while they were implementing their new look for the gmail web interface.

It is also possible that there were changes on the providers celular network in order to fix some of the SIM problems reported by many users.

I will just keep on investigating in that case and turning off 3G is not really an option because during the day I do only have a celular connection and if I shut it down nothing like WhatsApp, Facebook, Google+ and email will work - what's the reason to buy such an expensive smartphone if you can't use any of the features?!