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iOS 6.0.2 May Impact Battery Life

I can’t state categorically that the recently released iOS 6.0.2 for the iPhone 5 and iPad mini will hurt battery life, since evidence is still anecdotal and battery life testing requires time. And yet, while there are not so many reports to indicate that the problem is universal, or even necessarily widespread, at least three people on the TidBITS staff noticed unusual battery drains over the 24 hours after updating, and a quick sanity check on Twitter revealed a number of others who have also seen surprisingly low battery levels since updating to iOS 6.0.2.

In my case, when Michael Cohen raised the issue on our staff list at 12:30 PM, my iPhone 5 was at 73 percent. That’s a bit low, given that I’d barely used the iPhone, but I don’t know that I started the day with a full charge. However, 90 minutes later, at 2 PM, I was down to 55 percent — an 18 percent drop — without having used the iPhone at all. Another 90 minutes later, at 3:30 PM, I lost another 12 points to drop to 43 percent, and as I write this at 5:30 PM, I’m down to 28 percent, a 15-percent drop in two hours. And again, apart from the occasional push notification from Twitter turning the screen on, I haven’t used the iPhone at all during this time.

I am not seeing the problem that bit me when I first upgraded to iOS 6, when Safari bookmark syncing to iCloud was failing repeatedly (see “Solving iOS 6 Battery Drain Problems,” 28 September 2012). None of the logs in Settings > General > About > Diagnostics & Usage > Diagnostics & Usage Data show anything that looks unusual at this point.

Our speculation, based on some quick testing that Michael did, is that the problem is related to a change in Wi-Fi behavior, which maps with Apple’s sole release note for iOS 6.0.2: “Fixes a bug that could impact Wi-Fi” (see “iOS 6.0.2 Squashes Unspecified Wi-Fi Bug in iPhone 5 and iPad mini,” 18 December 2012). Michael started a car trip that takes him past numerous Wi-Fi access points in Santa Monica with the battery at 97 percent. When he arrived at LAX, his iPhone 5 was warm and had dropped to 85 percent. He then put it in Airplane Mode for the return trip, and arrived home with a cool iPhone and no change in battery percentage. Of course, Airplane Mode turns off all other radios too, so it’s far from conclusive, but indicates that the problem may be related to wireless communication in some fashion. Subsequently, I manually toggled Wi-Fi off and back on, and that seems to have resolved the problem for my iPhone 5.

For the moment, my advice to anyone who has not noticed any Wi-Fi-related problems with iOS 6.0.1 on an iPhone 5 or iPad mini is to hold off on upgrading to 6.0.2 until more is known. If you are experiencing Wi-Fi weirdness, it may be worth the as-yet-unquantified risk to battery life to improve your wireless connectivity. And if you have already upgraded, be a little more aware of your battery life in case you need to charge more often to get through a long day.


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Comments about iOS 6.0.2 May Impact Battery Life
(Comments are closed.)

Steve   2012-12-19 18:21
I had the battery completely drain overnight which has never happened before.
Luke Schiralli  2012-12-19 23:41
I updated this morning and lost 50% already without using the phone.
Adam Engst  An apple icon for a TidBITS Staffer 2012-12-20 09:43
Last night, I charged the battery to 100%, then unplugged it, played 15 minutes of an iTunes U lecture on sleep timer, and at 8 AM this morning, it was down to 46%. Normally it's in the mid-90s.
I have the same issue. The phone is buring like hot rock
walueg  2012-12-20 00:03
Wow, mine actually improved. I work in an area with spotty AT&T coverage which was causing my battery to drain more quickly. Before I put it on the charger, I still had over 50% battery left. My complaint is that while before I had trouble transitioning TO wi-fi that required sign-in, I now have trouble transitioning FROM that same wi-fi to LTE as I leave work (or at least Google Maps and Apple Maps did. Waze seemed unaffected).
My battery has gone from 65% to 40% in the last hour with little use, hopeless!
walueg  2012-12-20 08:01
Do y'all have "Ask to Join Networks" turned on? Mine's turned off and seriously, I'm happy with the improvement under 6.0.2
Adam Engst  An apple icon for a TidBITS Staffer 2012-12-20 09:41
No, I don't have that turned on, and most of my battery drains have been without leaving the house, so I haven't been exposed to any other networks.
walueg  2012-12-20 11:27
5GHz Wireless N?
LuegSkywalker  2012-12-20 11:33
I ask because I and most people are probably still using 2.4GHz networks. Maybe you're one of the few deliberately using 5GHz?
Richard Sampson  2012-12-20 07:06
I have not upgraded yet from IOS 5. I have an Iphone 4 and have held off until more testing or a proven update comes out. I am curious if any of your readers who have an Iphone 4 and have updated are having the same type of battery drains. I have been researching this on the web and find very mixed results among Iphone 4 owners who took the IOS 6 plunge. Any comments?
Adam Engst  An apple icon for a TidBITS Staffer 2012-12-20 09:41
There are definitely lots of people who are seeing battery drains in iOS 6 - search on the Apple Support Communities. Some of the specific situations - like the one I wrote about after dealing with corrupt Safari bookmarks - are solvable, but others remain mysterious.

But that said, most people aren't having any trouble, and I suspect that again, most people won't have trouble with iOS 6.0.2. But the fact that a number of people on our staff alone were bit indicates to me that there's something going on.
Jon Markle  2012-12-20 13:28
Yes. Ever since iOS 6 on my iPhone 4, severe battery drain, without solution.
Bb Maestro  2012-12-20 09:47
No issues for me. Yes, "Ask to Join Networks" is off. Cycled power off-on recently which may have helped. iPad mini LTE and iPhone 5.
Paul Gans  2012-12-20 11:08
No battery-life change here. Lost 5% overnight after the update
Paul Gans  2012-12-20 11:11
I only lost 5% overnight
Manuel  2012-12-20 11:48
what happens when you turn Wifi off? - does the battery still drain faster? I turn it off when I am out of the house/at work and overnight anyway.
Michael E. Cohen  An apple icon for a TidBITS Staffer 2012-12-20 16:46
Since I inspired this post by my email to the TidBITS staff list, I feel I should share the results of an experiment I performed yesterday and last night.

I started from a fully charged iPhone, disabled one of the wireless services, let the iPhone sleep, and then reported the battery level shown by the iPhone after a few hours of sleep. I kept the iPhone at the same place in my home the entire time so that roaming around was not a factor. Also, my mobile provider is AT&T.

Here's a summary of my controlled test:

Sleeping fully-charged iPhone for 4 hours with only cellular data enabled: 89% of charge remained.

Sleeping fully-charged iPhone for 4 hours with only Wi-Fi enabled: 100% of charge remained.

Sleeping fully charged iPhone for 10 hours with both cellular data and Wi-Fi enabled: 67% of charge remained.

In all cases, push email was enabled, and notifications were received from mail, Facebook, and Calendar while iPhone was sleeping.

I can say that prior to the update, it was not uncommon for my iPhone 5 to have 75-80% of charge remaining 24 hours after a full charge even with the phone being used lightly (occasional email checks, Twitter checks, and so on).

[Edited to add:] After fully recharging my iPhone again, I went to the multi-tasking bar and deleted ALL of the apps in it (h/t to Steve R. for the suggestion). After 2.5 hours asleep, with both Wi-Fi and cellular data services on, my iPhone is at 98% charge. That's about what I would have expected before the 6.0.2 update.
Jon Markle  2012-12-20 13:26
I have complained about a drastic reduction in battery life ever since iOS 6 was released for my iPhone 4. Prior, I could go all day without running out of juice. Now, I cant go but 2 - 4 hours, and that's without using the phone! If I use it, maybe a good hour. I've tried everything, including complete reset. Nothing works. What a farce! My partner has an old iPhone, and he can use it all day without a recharge!
Adam Engst  An apple icon for a TidBITS Staffer 2012-12-20 13:41
Have you complained to Apple at a Genius Bar? Perhaps they'd replace it?
jonathan Soard  2012-12-22 11:15
I had the same problem. I did manage to downgrade back to iOS 5.1.1, though with much difficulty and with many voices saying that it couldn't be done.
Erin Zimmerman  2013-01-04 04:08
I have the very same issue on my 4S since 6.0.1. The battery before would last about a day and 1/2. Now it only lasts a few hours when texting and about 6-7 hours with no use. And yes, all applications are closed, I also followed trouble shooters and nothing improves and of this! Its so bad at this point that I am about to go get it replaced Eventhough I KNOW that it is iOS 6, because the same things are happening on all my apple devices. Plus, I'll be online and it constantly disconnects from the wifi. I've had At&T come check my lines, replace the router, and its still doing it, and this did not happen post iOS 6. Apple, I brag about you and defend you all the time but your letting me down and embarrassing me! We have 2 ipad2s, 1 ipad mini, an iPod Touch, an iPod Nano, an iphone4, an iPhone4S, and an apple TV! Oh, I forgot something! Now my Apple products are jumpy and glitchy too and apps crash often now and sonetime my ipad will just reboot by itself. I cant brag about Apple the way I used to. They're simply letting me down and becoming more glichy than PCs or Droids! SMH
Erin Zimmerman  2013-01-04 04:14
In fact my phone was at 100% when i started this reply, its diwn to 73%. SEE?
Steve Nicholson  2012-12-20 15:35
I'm sorry people are having problems but I'm glad TidBITS volunteers to be guinea pigs for new iOS releases. That way I can wait and not update until they give it a clean bill of health. :-)
Jeff Carlson  An apple icon for a TidBITS Staffer 2012-12-20 16:04
TidBITS: Banging our heads against walls for our readers for 22 years.
Adam Engst  An apple icon for a TidBITS Staffer 2012-12-20 16:49
For anyone who's running into this, try turning Wi-Fi of in Settings > Wi-Fi (don't just use Airplane Mode) and see if the problem continues after you turn it back on. There's some indication that might help.
Heck yes I'm experience bad battery life, and the phone gets hot.
I updated to 6.0.2 at the office but based on battery drain through the course of the day, I ended up coming home and downgrading to 6.0.1 as soon as I could.

Clearly, something was wrong with the update!
Are there any possible risks in downgrading back to IOS 6.0.1? Do we do the normal manual restore? I am having battery drainage issues since upgrading to the new 6.0.2 firmware.
How do you downgrade I didn't think that was possible
Erin Zimmerman  2013-01-04 04:17
ALL My Apple products say they are up to date on 6.0.1. WTH?
Adam Engst  An apple icon for a TidBITS Staffer 2013-01-04 07:23
6.0.2 is only for the iPhone 5 and iPad mini, so others won't try to update.
I have noticed a drop in battery life after installing the new Google Maps app. I am still on 6.0.1
Is Google keeping a little too close eye on my locations?
Adam Engst  An apple icon for a TidBITS Staffer 2012-12-21 15:29
Apps that use the GPS will hurt battery life - Apple's Maps and Google Maps included. However, they should only be using the GPS seriously while actually navigating, so if you're not navigating, it shouldn't impact battery life. That's not to say it doesn't; just that it shouldn't. You should be able to test by force-quitting Google Maps from the task bar (double-press the Home button, then tap and hold on Google Maps until you get the minus sign, then tap it).
Marc5644  2012-12-21 01:10
Apple should release a decent battery log app, that works also in background (forbidden to normal app developers). Then every one, Apple included, will have a view on what goes on.
jonathan Soard  2012-12-22 11:08
This isn't just an iphone 5 issue, or even an issue. After upgrading (on faith alone) to iOS 6my iphone 4 had a precipitous drop in battery life. I could practically WATCH the battery life indicator drop. The "genius bar" manager looked me in the eye and said it was an old battery. It was really difficult to downgrade back to iOS 5.1.1. the worst bit is that I will never be able to upgrade on faith alone again.
Josh Centers  2012-12-22 16:19
Glad I spotted this before updating. Thanks Adam! Nice scoop.
Craig Hicks  2012-12-22 21:10
The problem is the mail push setting which constantly fetch. When I turned all my email accounts to manual only, and turned fetch and push off, the battery issues went away. Before I changed this, the battery would drain 25% / hour
Adam Engst  An apple icon for a TidBITS Staffer 2012-12-26 15:06
Alas, that's not it, since I don't use Mail at all, so I'm not having it fetch new mail ever. Most of my problems seem to have gone away after I manually turned Wi-Fi off and back on, so I'm suspecting some corrupt setting.
Johnny Ng  2012-12-25 10:24
I have this problem long before I updated to iOS 6.0.2 I need to charge 2-3 times a day and I am not a heavy user. I went to Apple service centre hoping they can replace a new one for me. They did a online test and said the battery is in good condition and told me not to on too many apps. Funny thing is a stuff told me that his iphone 5 battery only drain few % after playing game for many hours. That's why he suggested me to exchange for a new one.
pat4rest  2012-12-27 09:26
I have had a 20X increase in battery drain. I have had overnight drains of 100% since 602 upgrade. Last night with cellular data and WiFi off I had no drain. Is Apple in denial or what. Who needs a fancy phone if you can't monitor wifi and cellular data all day?
Adam Engst  An apple icon for a TidBITS Staffer 2012-12-28 08:39
Have you tried turning Wi-Fi off (not Airplane Mode) by itself? And another time, try turning cellular off, with Wi-Fi on. It might narrow the problem, and some people (including me) have had luck with turning Wi-Fi off and back on for solving the problem entirely.
apogeu  2012-12-30 13:12
I have installed the ios update 6.02 and since then the battery of my iphone is due up to 4 hours in standby mode. It has never happened before
I have been experiencing high battery drain with 6.0.2.

I have brightness set to about 10-15% and have most location and notification services turned off (or manual use only).

Was just observing the battery indicator go from about 75 percent this evening (iPhone was at 100 percent charged up at noon) down to 41% over the course of a 1.5 hour regular voice phone call (and nothing else going on the phone during the call).

Which to me seems totally nuts -- either the iPhone5/ iOS6.0.2 is using too much juice, or something else weird is going on with it.

But at this rate (34% used for 1.5 hr call) I could only expect to get a max of 4.5 hours talk time before the battery runs out.

P.S. WiFi connection is slightly worse in 602 vs 601.
(this is my first "smart" phone... maybe I expect too much, vs. my previous LGVX5400 'basic' phone.)
barefootguru  2013-01-01 08:42
Adam, I see you fixed the battery drain on your phone by turning Wi-Fi off and back on. Has this worked for the other people you know, or are they still suffering?
Adam Engst  An apple icon for a TidBITS Staffer 2013-01-03 14:16
No one experiencing the problem here has responded to my request for confirmation of this, so I don't really know. My battery usage is back to normal now.
Adam Engst  An apple icon for a TidBITS Staffer 2013-01-03 15:16
This is likely unrelated to any changes in iOS 6.0.2, but this guy found significantly battery drain and data usage with an Exchange account, so anyone experiencing problems and using an Exchange account should look into that.
Dave Sacher  2013-01-07 13:47
For me, about the same battery life after the 6.0.2 update; perhaps even a bit more! I had previously turned WiFi off and back on, and I recently eliminated push notifications — mostly to avoid my Pavlovian response to anything happening on the phone, which was driving my wife crazy! So, most days, I can text, use social media, check news and weather, take a photo or grab a screen snap – oh, and take a few phone calls! – and by the time I turn in, I still have at least 65 percent battery remaining. After first using a Blackberry, and then an Android phone, I'm very happy with Apple's iPhone 5.
Joe Gudac  An apple icon for a TidBITS Contributor 2013-01-07 18:33
I had a really bad experience with the iOS6.02 update. First my 1 week old iPhone 5 started doing some crazy things after the update. After 3 days the iPhone 5 home button failed. Apple Store Replaced iPhone. Second iPhone 5 works well for 2 days and I made the mistake of running the update to iOS6.02. Battery life like many other have posted. Couldn't make it through the day doing nothing on the iPhone 5. Called AppleCare and TECH acknowledge that the battery issue was known. Took iPhone back to Apple Store and got a second replacement iPhone 5. Have kept it on iOS6.01 since Dec 28. Battery drain hasn't gone below 80% any day.

Personally, I think iOS6.0 has been Apples biggest failure. Everyone knows about the Maps issue but what about all the excessive data use that no one wants to acknowledge.

My 2nd iPhone 5 replacement used 50 megabyte of data during setup at the Apple Store.

29 years using Apple products and the past 15 months have not been the best of times!!!!
Frank S Streeter  2013-01-08 07:29
I had the same issue of my iPhone 5 overheating and the battery life plummeting. I too am on 6.0.2. I took it into Apple and they gave me a new phone, but the problem started again the next day, so it is undoubtedly a software issue. I treated my new/2nd phone as a new phone on my first install, (restored contacts/mail from iCloud and not from a backup). When that did not solve the problem, (as it reoccurred the next day) I again wiped the phone, but as per Apple's advice I only installed one non-Apple program. At the moment I am not having the issue, but as with all of you, no one has any idea why.

When my 2nd phone was overheating I noticed that the useage was the same as the standby minutes, which makes it appear that the phone was always in use, which would explain the mechanism of the battery drain, just not its cause. Very frustrating!
BriBear  2013-01-08 11:19
I updated my iphone 5 to 6.0.2 yesterday at work. Although I haven't noticed a change in battery drain I also do not have an exchange email set up. However, I am ahaving an issue with the notification on the settings icon. It is saying that I have one notification but I can not find it, my sofrware says it's up to date. Any suggestions? it's driving me crazy! Thanks.
I thought of holding off on the update until reading comments from Tidbits, but upgraded anyway. If anything I am getting BETTER battery drain than under 6.0 and 6.0.1 (which has never been great) but under the following conditions. My only consistent test is overnight when I have only one app in the multifunction bar, MotionX Sleep, with the phone in airplane mode. By morning the percentage went from around 90% plus or minus to 93-95%. During the day my use is so varied that accurate comparisons are difficult, but the only time I use wifi is to connect to my laptop peer to peer and then only briefly, implicating the problem is indeed with wifi. I have access only to cellular internet connectivity. I can also confirm that any GPS usage - Apple Maps, Google Maps, MotionX GPS - does drain the battery dramatically. Interestingly, I had assumed that location services also used GPS, but it doesn't seem to cause undue battery drain.
Frank S Streeter  2013-01-10 07:47
I turned off wi-fi and that seemed to fix the problem, however that's a huge feature to lose! As a result of this I have become a lot less impressed with my new iPhone 5 and hope that Apple issues a fix ASAP!
Adam Engst  An apple icon for a TidBITS Staffer 2013-01-10 07:58
Does the problem come back if you turn Wi-Fi back on? For me, toggling it was the key.
Frank S Streeter  2013-01-16 08:00
I had toggled wi-fi on and off before with no luck, but starting the phone as new (not from a back-up) with minimal apps, followed by toggling wi-fi on and off, seems to have solved the problem for now. I am about to put those apps back on, so I will let you know if the problem comes back or not.
Frank S Streeter  2013-01-28 08:56
It worked fine for a few days (week+?) but now the problem has started again. Time to waste another 3+ hours getting a replacement phone. This issue has now taken me 10+ hours to diagnose & fix. Now I understand the 30% drop in stock price - poor products lead to a lower multiplier! Until Apple permanently fixes this, I recommend buying Samsung phones instead!!
Andrew Edsor  2013-01-11 14:58
My iPhone 5 (model MD299B) was delivered 2 days ago here in UK with 6.0.1 installed. Installing all my iPhone 4 stuff with an iTunes sync, I (slightly apprehensively) upgraded to 6.0.2 at the same time. No sign of any battery consumption problems (yet!). Leaving it running overnight uses about 6% battery charge. I use my own wifi at home.
androidboy  2013-01-14 09:25
It would be great if they fixed the annoying 'feature' where the personal hotspot stops broadcasting wifi if you don't use it for a couple of minutes, it drives me mad having to keep restarting the feature to reconnect my iPad.
Told84  2013-01-23 07:07
Is there any report of this actually being a problem that is looked upon?

At first i thought it was a problem with my first iPhone 5 so i gave it back to the retailer and i got a new one. When i installed 6.0.2 on my new device the same problem occured.

My phone goes from 100% charge to 0% in approximately 4 hours while being idle.

Ive tried to reset settings and shutting of all apps, ive cleaned the divice and reinstalled everything. This is really starting to bugger me. I need to have the charger with me everywhere i go and its making my phone completely useless.

If any help is available it would be appreciated.
Adam Engst  An apple icon for a TidBITS Staffer 2013-01-23 07:15
There are sufficient reports of it that I have to assume Apple knows, but all too many of the stories I hear indicate that at least front-line tech support is clueless about it.
I wish I would have come across this problem before upgrading, I've had to go buy extra charging cables just to make it through the day. When I first got the 5 I was impressed with the battery life, now I'm wishing I never would have gotten it.