Skip navigation
This discussion is locked

iPhone 4s Battery Life?

2397681 Views 12,787 Replies Latest reply: Sep 26, 2012 8:49 AM by Jason L RSS
  • Chris Schoeneman Calculating status...
    Currently Being Moderated
    Jul 23, 2012 9:49 AM (in response to Scarface.)

    I fixed a rapid iPhone 4s battery drain several days ago.  I simply changed the MMS APN.  Details follow.

     

    My wife's phone recently started draining its battery fast -- 100% in well under 24 hours with no usage. The phone had been fine then started doing this for no known reason. We did the usual reboots, turning off unneeded stuff, the time zone fix, etc. That didn't work but with the above change it's now back to normal and can go for days on standby.

     

    I have an identical phone without the problem so I compared the two using XCode's Instruments.  CommCenter on her phone would spike the CPU briefly every several seconds and the log showed a message '... is telling PDP context -1 to go active' every 30 seconds.  I suspected these were related.

     

    From my understanding, there's no such thing as a context -1 and this must be a bug.  Launch field test (by dialing *3001#12345#*) and it'll show you the PDP contexts, which are numbered 0, 1, 2, etc.  I don't know how long context -1 had been around but I'm guessing the whole time the battery was draining fast.  We had tried rebooting the phone to fix the battery drain but that didn't work. I don't know if the phone was keeping the context around across reboots, but I doubt it. I suspect the GPRS network was keeping it and pushing it to the phone. I know next to nothing about GPRS, though, so that may be wrong/impossible.

     

    I searched using google for a way to force all contexts to be flushed.  What I found was that changing the APN would do that.  As it happens, her MMS APN (Settings > General > Network > Cellular Data Network) wasn't set, preventing her from sending multimedia attachments in texts. I set it correctly.  (Had it been it set correctly I would've cleared it then set it back.)  That seems to have fixed the battery drain, plus she can again send images in texts now.

     

    Now three caveats.  First, I can't reproduce the battery drain so I can't verify that these steps always work.  But I can say that the fast draining had been going on for a few weeks and it stopped immediately following the above.

     

    Second, shortly after doing the above the springboard became unresponsive to touches.  I don't know what that was all about -- I've never seen it before (and I have changed the APN before).  I had to reboot the phone to recover. (Interestingly, pressing and holding the home and sleep/wake buttons didn't bring up the power off slider; the phone just shut off after a few seconds.) Now we had tried rebooting the phone to fix the battery drain before and it didn't work and it didn't become unresponsive for a while after changing the APN, long enough to see the battery drain problem looked like it was fixed, but I can't be sure the reboot wasn't important somehow.

     

    Third, your phone may not be having the same problem. But it's easy enough to check the log for the 'PDP context -1' message using XCode or, say, YASC (in the AppStore).  However, that presumes the battery drain is related to that message and not some other unrelated problem that causes CommCenter to wake up every several seconds.

     

    Since the potential fix is so easy, it's worth just trying it.  Go to Settings > General > Network > Cellular Data Network, write down the MMS APN, clear it, then reboot.  Go back to the same page and put the MMS APN back and reboot again.  (The reboots may not be necessary.)  See if the drain is fixed.

  • jacks1964 Level 1 Level 1 (0 points)
    Currently Being Moderated
    Jul 23, 2012 10:04 AM (in response to Scarface.)

    YAWN !!

  • jacks1964 Level 1 Level 1 (0 points)
    Currently Being Moderated
    Jul 23, 2012 11:41 AM (in response to Scarface.)

    YAWN !!

  • ahajar Calculating status...
    Currently Being Moderated
    Jul 24, 2012 2:56 PM (in response to Italia411)

    I chose to reply to yours in support of what you are saying, i think that battery issues seems to be model/batch dependent. I cannot say much about all the tweeks and advice on how to save battery life on this forum. I really think a device should hold a charge claimed for its intended average usage.

     

    I've owned every iPhone model since the original. Sometimes I've had more than one unit that i used intermittently when purchasing for family or gf.

     

    I noticed the same pattern of subpar battery life since the 3G model. And i really started paying close attention with the 3GS model. I was happy with my original purchase then Apple swapped it due to a screen problem. the replacement drained quicker than the original. Apple replaced that unit once again before i was content with the battery life. Then that unit broke, i got a replacement and they wouldn't accomodate my complaint about the battery indicating that the battery tests come out normal i didn't insist much at that point as i was intendeding on a near upgrade. I recently let my friend borrow that 3GS unlocked unit for a trip abroad. He lost it and gave me his 3GS which seems to have a good battery life instead. this already had me thinking that regardless of all the tweeks and restores suggested, the unit either had a good or a bad battery off the bat.

     

    The 4 models seem to have less of a battery issue. The battery drain problems were revisited with the 4S. Upon my recent trip to the store. Apple had me do all the procedures for conserving battery, restoring, killing push, dimming, etc. The guy at the genius bar was showing me that the unit was normal according to their tests and as a last resort suggested to restore clean as my unit had data from 2007. I insisted that they do the restore themselves. To my surprise they gave me a new unit stating that they had a hardware failure when trying to restore. The new unit has the same subpar life however...and i am not sure what to do. All i know is that from all the experience i had and seen, i am starting to believe that one gets a unit with a problematic "something" off the box. I do not know if it's the actually battery or something in the hardware...but since i've gone thru a number of various units, somewhat restoring to the same info and having the same usage patterns indicates that the issue is from the unit itself, not the software, and not the settings.

  • rphunte42 Level 1 Level 1 (5 points)
    Currently Being Moderated
    Jul 25, 2012 8:32 AM (in response to zSkeptic)

    zSkeptic wrote:

     

    rphunte42 wrote:

     

    First, there is NO MEMORY problem with Lithium Ion batteries.  A charge cycle can be 10 10% charges, or one 100% charge, or any combination of percentages that add to 100.  The reason for running the battery down until the phone shuts off is to recalibrate the chip that reports the percentage of charge.  Lithium Ion batteries deteriorate with age, and an accurate representation of the present charge level is based on the last full recharge cycle.

     

    Running down the battery until the phone shuts off will not recalibrate the chip or battery.  It will crash your phone.  It may also terminate rogue processes that cause extra battery consumption but I don't recommend doing that.  The only time Apple talks about recalibrating batteries is for devices with removable batteries such as the MacBooks.

    You need to do more reading.

  • rphunte42 Level 1 Level 1 (5 points)
    Currently Being Moderated
    Jul 25, 2012 8:37 AM (in response to ahajar)

    ahajar wrote:

     

    I chose to reply to yours in support of what you are saying, i think that battery issues seems to be model/batch dependent. I cannot say much about all the tweeks and advice on how to save battery life on this forum. I really think a device should hold a charge claimed for its intended average usage.

     

    I've owned every iPhone model since the original. Sometimes I've had more than one unit that i used intermittently when purchasing for family or gf.

     

    I noticed the same pattern of subpar battery life since the 3G model. And i really started paying close attention with the 3GS model. I was happy with my original purchase then Apple swapped it due to a screen problem. the replacement drained quicker than the original. Apple replaced that unit once again before i was content with the battery life. Then that unit broke, i got a replacement and they wouldn't accomodate my complaint about the battery indicating that the battery tests come out normal i didn't insist much at that point as i was intendeding on a near upgrade. I recently let my friend borrow that 3GS unlocked unit for a trip abroad. He lost it and gave me his 3GS which seems to have a good battery life instead. this already had me thinking that regardless of all the tweeks and restores suggested, the unit either had a good or a bad battery off the bat.

     

    The 4 models seem to have less of a battery issue. The battery drain problems were revisited with the 4S. Upon my recent trip to the store. Apple had me do all the procedures for conserving battery, restoring, killing push, dimming, etc. The guy at the genius bar was showing me that the unit was normal according to their tests and as a last resort suggested to restore clean as my unit had data from 2007. I insisted that they do the restore themselves. To my surprise they gave me a new unit stating that they had a hardware failure when trying to restore. The new unit has the same subpar life however...and i am not sure what to do. All i know is that from all the experience i had and seen, i am starting to believe that one gets a unit with a problematic "something" off the box. I do not know if it's the actually battery or something in the hardware...but since i've gone thru a number of various units, somewhat restoring to the same info and having the same usage patterns indicates that the issue is from the unit itself, not the software, and not the settings.

    I am quite sure that some of the battery problems are the result of a bad batch of batteries, which is almost inevitable when you make 50 million of something.  However, the vast majority of 4S users do not have any battery problems.  I am at 2 days 3 hours with 54%.  I call that good battery life.  Note that I am a very light user.

  • ahajar Level 1 Level 1 (0 points)
    Currently Being Moderated
    Jul 25, 2012 12:45 PM (in response to rphunte42)

    The #1 complaint representing 48% of the problems reported about the 4S are battery related and all benchmarks show a poorer battery performance on the 4S than the 4. The length of this thread alone should be a testament to this issue as the problem is out there. Most of the other 4S owners i know are running around with extra juice packs. I am tired of constantly looking for a power source...it really defies the mobile concept. I am an average user.

  • Weber Baker Level 1 Level 1 (0 points)
    Currently Being Moderated
    Jul 25, 2012 1:00 PM (in response to Scarface.)

    After posting my issue I did the following. I shut off everything - I mean everything. I put the phone into airplane mode for a day! No wi-fi, bluetooth, data, phone, nothing running. Though drastic, the problem went away, telling me it was not a hardware/battery issue.

    I then turned the phone service back on, no notifications, mail, just phone. Again, no problems - battery life was good.

    I then turned email push back on. No hange - good battery like before.

    I then turned on applications with notifications that I had had for a longtime and no problem. Finally I reactivated location services. No battery issues.

    Doign this, slow and tedious though it was, I found that the problem came from a Best Buy app. I had purchased a new ipad and the best buy Find and Lock protection. This app, being a universal app, automatically went to my phone as well, even though it was not covered by the protection the Best Buy system offered.

    When I turned the app back on, the problem returned. I deleted the app from the phone and no further issues.

    This app does not cause this problem on the ipad. But that was it.

  • Chris CA Level 9 Level 9 (73,410 points)
    Currently Being Moderated
    Jul 25, 2012 6:15 PM (in response to zSkeptic)

    zSkeptic wrote:

     

    Running down the battery until the phone shuts off will not recalibrate the chip

    Except that is exactly the reason you run it down.

    It will crash your phone.

    Does it?

    Something must be wrong with mine becuase it doesn't crash. It does shut off. (Duh! It's got no power!)

  • Chris paetz Calculating status...
    Currently Being Moderated
    Jul 25, 2012 11:15 PM (in response to Chris Schoeneman)

    Thank you very much for this post! My battery life was horrible, there has definately been a decrease in battery performance since the last couple  software releases. So bad i could watch the battery percentage drop drasticly even within the first hour of standby. I have now purchased a 10'000 mah portable charger and have a boost case on the way. I tryed what you recomended and i can already tell it has made a drastic difference.  Thank you for your work digging into this issue! If your iphone 4S battery life *****! Give this a try for sure.

  • Chris paetz Level 1 Level 1 (0 points)
    Currently Being Moderated
    Jul 25, 2012 11:26 PM (in response to Chris Schoeneman)

    Chris Schoeneman wrote:

     

    I fixed a rapid iPhone 4s battery drain several days ago.  I simply changed the MMS APN.  Details follow.

     

    My wife's phone recently started draining its battery fast -- 100% in well under 24 hours with no usage. The phone had been fine then started doing this for no known reason. We did the usual reboots, turning off unneeded stuff, the time zone fix, etc. That didn't work but with the above change it's now back to normal and can go for days on standby.

     

    I have an identical phone without the problem so I compared the two using XCode's Instruments.  CommCenter on her phone would spike the CPU briefly every several seconds and the log showed a message '... is telling PDP context -1 to go active' every 30 seconds.  I suspected these were related.

     

    From my understanding, there's no such thing as a context -1 and this must be a bug.  Launch field test (by dialing *3001#12345#*) and it'll show you the PDP contexts, which are numbered 0, 1, 2, etc.  I don't know how long context -1 had been around but I'm guessing the whole time the battery was draining fast.  We had tried rebooting the phone to fix the battery drain but that didn't work. I don't know if the phone was keeping the context around across reboots, but I doubt it. I suspect the GPRS network was keeping it and pushing it to the phone. I know next to nothing about GPRS, though, so that may be wrong/impossible.

     

    I searched using google for a way to force all contexts to be flushed.  What I found was that changing the APN would do that.  As it happens, her MMS APN (Settings > General > Network > Cellular Data Network) wasn't set, preventing her from sending multimedia attachments in texts. I set it correctly.  (Had it been it set correctly I would've cleared it then set it back.)  That seems to have fixed the battery drain, plus she can again send images in texts now.

     

    Now three caveats.  First, I can't reproduce the battery drain so I can't verify that these steps always work.  But I can say that the fast draining had been going on for a few weeks and it stopped immediately following the above.

     

    Second, shortly after doing the above the springboard became unresponsive to touches.  I don't know what that was all about -- I've never seen it before (and I have changed the APN before).  I had to reboot the phone to recover. (Interestingly, pressing and holding the home and sleep/wake buttons didn't bring up the power off slider; the phone just shut off after a few seconds.) Now we had tried rebooting the phone to fix the battery drain before and it didn't work and it didn't become unresponsive for a while after changing the APN, long enough to see the battery drain problem looked like it was fixed, but I can't be sure the reboot wasn't important somehow.

     

    Third, your phone may not be having the same problem. But it's easy enough to check the log for the 'PDP context -1' message using XCode or, say, YASC (in the AppStore).  However, that presumes the battery drain is related to that message and not some other unrelated problem that causes CommCenter to wake up every several seconds.

     

    Since the potential fix is so easy, it's worth just trying it.  Go to Settings > General > Network > Cellular Data Network, write down the MMS APN, clear it, then reboot.  Go back to the same page and put the MMS APN back and reboot again.  (The reboots may not be necessary.)  See if the drain is fixed.

    Sorry, forgot to include the post! Thanks again

  • zSkeptic Level 1 Level 1 (0 points)
    Currently Being Moderated
    Jul 26, 2012 9:09 AM (in response to rphunte42)

    rphunte42 wrote:

     

    zSkeptic wrote:

     

    rphunte42 wrote:

     

    First, there is NO MEMORY problem with Lithium Ion batteries.  A charge cycle can be 10 10% charges, or one 100% charge, or any combination of percentages that add to 100.  The reason for running the battery down until the phone shuts off is to recalibrate the chip that reports the percentage of charge.  Lithium Ion batteries deteriorate with age, and an accurate representation of the present charge level is based on the last full recharge cycle.

     

    Running down the battery until the phone shuts off will not recalibrate the chip or battery.  It will crash your phone.  It may also terminate rogue processes that cause extra battery consumption but I don't recommend doing that.  The only time Apple talks about recalibrating batteries is for devices with removable batteries such as the MacBooks.

    You need to do more reading.

    Please point me to where Apple states that running down the battery to zero recalibrates the chip. I would love to read that.  As far as I can tell, that is a myth perpetuated in these forums.

  • zSkeptic Level 1 Level 1 (0 points)
    Currently Being Moderated
    Jul 26, 2012 9:14 AM (in response to Chris CA)

    Chris CA wrote:

     

    zSkeptic wrote:

     

    Running down the battery until the phone shuts off will not recalibrate the chip

    Except that is exactly the reason you run it down.

    It will crash your phone.

    Does it?

    Something must be wrong with mine becuase it doesn't crash. It does shut off. (Duh! It's got no power!)

    Next time you run your battery down so the phone shuts off, take a look at your diagnostic data. FYI, many times when a electronic device crashes, it can look like a power shut down.  Duh!

  • Gat0r Level 1 Level 1 (55 points)
    Currently Being Moderated
    Jul 27, 2012 8:02 AM (in response to zSkeptic)

    Conditioning the battery buy draining down to <10% does indeed improve battery life.  But the trick is you've got to do it on the initial 3 charges for it to make as much difference.  I heard this some time back and do it on all phones and any device I get with a similar battery.  There's no doubt in my mind it works.  Never had any issues with batteris on any apple or other device.

     

    I don't know how much it helps after the first 3 charges becasue I've never done it that way.  When I find something that works I keep doing it.  I don't run it all the way down but get as low as I can, sometimes 2-3%.

    Try it on your next new device..  First three charges run it down, then do it once a month for the remaining life of the battery.  First day of every month is when I run all mine down as routine maintenence.

  • Jameson! Level 1 Level 1 (40 points)
    Currently Being Moderated
    Jul 27, 2012 8:11 AM (in response to Gat0r)

    You will believe what you believe, but the fact is that LiON batteries have no memory and are not affected by attempts at conditioning them.   It's a figment of imagination........

    Gat0r wrote:

     

    Conditioning the battery buy draining down to <10% does indeed improve battery life.  But the trick is you've got to do it on the initial 3 charges for it to make as much difference.  I heard this some time back and do it on all phones and any device I get with a similar battery.  There's no doubt in my mind it works.  Never had any issues with batteris on any apple or other device.

     

    I don't know how much it helps after the first 3 charges becasue I've never done it that way.  When I find something that works I keep doing it.  I don't run it all the way down but get as low as I can, sometimes 2-3%.

    Try it on your next new device..  First three charges run it down, then do it once a month for the remaining life of the battery.  First day of every month is when I run all mine down as routine maintenence.

Actions

More Like This

  • Retrieving data ...

Bookmarked By (258)

Legend

  • This solved my question - 10 points
  • This helped me - 5 points
This site contains user submitted content, comments and opinions and is for informational purposes only. Apple disclaims any and all liability for the acts, omissions and conduct of any third parties in connection with or related to your use of the site. All postings and use of the content on this site are subject to the Apple Support Communities Terms of Use.