I bought an iPhone 4S two months ago. In the last couple of days I've perceived an average battery life of 12 to 18 hours with a light usage of the phone throughout the day.

I've followed every tip for battery preservation such as turning off Location services, I don't use Siri, I only download e-mails manually to the phone (no push or notifications), I set the auto brightness on, I try to keep only a few important applications running in background.

I would like to visit my carrier's technicians in order to get a replacement, but I would prefer to run some tests first to make sure that something's wrong with the battery.

Any suggestions?

  • 1
    With the exception of VoIP apps like Skype or a "SIP Phone", apps do not run in the background for more than a 10 minutes or so at maximum. Commented Jan 19, 2012 at 17:36
  • In my experience the Garmin Street Pilot app (and, by extension other apps that use the GPS) will continue running in the background if there is an active route session. This has a devastating, but understandable, effect on battery life.
    – jaberg
    Commented Jan 19, 2012 at 18:29

3 Answers 3


I have always liked to test a battery by running the device until it shuts down and powers off.

When you connect it to the standard wall charger, it should take between 2 and 4 hours to charge. If your battery is done charging in an hour to 1:30, then it's not really getting the intended amount of current and should be replaced.

Similarly, if it won't charge fully (or very much close to full) in less than 4 hours - something also is amiss either with the charging, measuring or battery itself.

By timing the charge time, you eliminate any background task, GPS, WiFi drain, etc.. and just can see the time it takes a fixed amount of current to enter the battery and be stored chemically.

  • 2
    Also, when you run the phone from fully charged to zero without plugging in, you get a log file that records the totals of active and standby time as well as the system version. Doing that once a month will show empirical evidence of when the battery starts to become consumed.
    – bmike
    Commented Jan 19, 2012 at 17:39
  • Is that specific to iPhone only ?
    – Simon
    Commented Oct 27, 2013 at 19:22
  • @Simon - no, any Mac device is amenable to testing battery health by measuring the charge rates while idle or off. Mac OS has better logging capabilities out of the box, but booting it up to measure percentage on iOS is negligible if you do it at each hour mark. All iOS drop the diagnostic file AFAIK but not Macs.
    – bmike
    Commented Oct 27, 2013 at 23:01

Firstly, there are known issues that result in extremely poor battery performance with the 4S. Apple has addressed some of these issues in the iOS 5.0.1 update, but for many, the issues still exist. Worse yet, reports indicate that 5.1 (currently in beta) have not isolated the problem.

The battery problems are software related, not hardware. With that said, should you wish to test the hardware, I'd suggest taking to an Apple Store. If they do find a fault, they'll replace the device for you then and there. I'm not sure about your carrier's policies or level of customer service, but I doubt they'll be up to the same standards as Apple.

If they don't find fault with the hardware, you can call 1-800-MY-APPL and ask to talk to an iPhone product specialist. Ask them if you could join the battery testing group. Individuals are provided with a special diagnostic utility that transmits battery usage details back to Apple. Typically individuals are selected at random, but if you press the issue, they may allow you to join.


I believe it's pretty easy if you've jailbroken it, but for those who don't want to go there, there's an app called 'iBackupBot' for windown and mac, by a company called iCopyBot. It has a free trial and allows you to measure the current battery capacity, they have a guide here: http://www.icopybot.com/blog/check-ipad-iphone-battery-charge-cycle-count-without-jailbreaking.htm.

It worked for me with an iPhone 5, iOS 6.1.4- you do have to quit itunes and unlock the device for it to work.

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