If you are reading this article, you may be suffering from the torment same as me. My iPhone 6 always dies around 20% battery and sometimes even powers off at 40% or more. You’ve probably also noticed that sometimes it takes a weirdly long time to drop below 100% after a full charge. How to tell if your iPhone battery is bad
The reason why your iPhone dies at 20%
Your iPhone lies about how much the battery really is.
Nearly all smartphones apply Lithium-ion batteries. Lithium-ion batteries are quirky because it’s bad for them to be charged at 100% or fully depleted to 0%. It will mess with their longevity. So iPhone, also the smartphones adopting Lithium-ion batteries, purposely throttle how much power they demand from the battery. Your iPhone will cease charging before the battery actually reaches 100% and preemptively shut down before it’s completely out of juice so that there is enough power in there to complete a safe shutdown. The reason why your iPhone shuts down when it is far away from 0% is that this compensating mechanism confuses your iPhone over time and the indicator of battery volume does not work properly. What is Draining My iPhone 7 Battery
The problem getting worse in extreme temperatures
Even more, an extreme temperature can have quite an adverse effect on your iPhone battery’s performance. So that you may notice the jumpiness from low battery to shut-off is even more frequent and remarkable in hot weather or when you suddenly walk out from home during the winter.
How to fix it?
Apple’s suggestion and solution
Of course, we always try to find an official answer first of all. Apple Company states on its support page, “Apple is aware of this issue and is investigating the cause and a solution.” and suggests iPhone owners restart their iPhone, then go to Settings > General > Date & Time and make sure that “Set Automatically” is turned on. Because the level on the battery power indicator freezes after people change time zones or manually change the time, your iPhone battery icon on the top right of your screen might show 50%, even when it’s about to die.
However, the problem seems like still be there after operating in this way. Recently, according to the UAE Ministry of Economy, Apple send them a letter saying only specific phones that contained the defective battery manufactured between September and October 2015 in China will be recalled. This is another action aiming at this problem after Apple announced its battery replacement program globally on November 30, 2016. If you make sure the problem is causing by a bad battery, you can check on Apple official website to see whether your iPhone have the right of free battery change or not.
The fixing method you could try
If you want to try to fix this problem by yourself, you can try to do as blew for awakening the battery indicator.
1.Drain the battery entirely until it shuts off automatically.
2.Charge your iPhone all the way up to 100% without using it. How long does it take to charge the iPhone 7 plus from 0% to 100%
3.Keep it plugged in an extra hour or two ensuring it’s fully charged. Does Charging Your Phone Overnight Ruin the Battery
4.Perform a “warm restart,” holding down the home( For not having a physical home button, iPhone 7 adopts volume down button instead.) and lock buttons simultaneously for a few seconds until the Apple logo appears on the screen.
When the device comes back on it should have recalibrated the battery levels, telling you just how much you have left, rather than hoodwinking you by saying you have something like 20 percent. If your iPhone still has the problem, you can backup and restore it as new.
1.Connect the iPhone to a computer and launch iTunes
2.From iTunes, choose to “Back Up Now” – this will make a most recent backup of the iPhone and everything on it (you can also backup to iCloud if you want) – wait for this to finish
3.When the backup is complete, choose to “Restore iPhone” from the iTunes options
4.Let the restore process complete, when finished the iPhone will start as if it was brand new. In this setup process, choose to restore from your backup that you just made.
If you still don’t know how to operate, learn more from this article how to reset an iPhone from computer.
Hope this method can help you. If your iPhone still dies at 20% or the level beyond 0%, please contact Apple Support for help.