Why is my 5S always defaulting to low battery when the battery is fully charged?

[iMore Question]

Ever since the 7 launch, my 5S, my wife's 5s and multiple friends 5s and 6s have been faulting to a low battery state when the battery, moments before, showed as fully charged. This happens most frequently when in the camera mode. Obviously this is Apples attempt to coerce people to buy the 7...is there a fix? if not I guess we go to a Galaxy! BTW, this type of "sales enhancement" would have never cut the mustard when Steve was in charge.

 

[Rob Phillips]

Welcome to iMore! I'd say that a battery issue on a three year old iPhone (the 5s was released September 2013) is quite a stretch. If they wanted to coerce users into upgrading they would simply stop supporting the devices. Apple's iPhone batteries are designed to retain 80% of their original capacity for 500 full charge cycles. I'd guess you're possibly past that both 5s devices. Some 6s devices have a known battery issue, so that could be your problem. You can check if your device is affected using the link below. If your device is listed Apple should replace the battery free of charge.

https://www.apple.com/support/iphone6s-unexpectedshutdown/#mn_p