Why does my iPhone 5s battery suddenly drop from 43% to 20% and then 10% suddenly? Is this battery to be replaced or is there something other malfunctioning? - Quora
Apple Replacing 'Limited' Number Of iPhone 5s With Manufacturing Issue Leading To Battery Life Problem | TechCrunch
Missing Battery health on iPhone 5S with … - Apple Community
Apple iPhone 5s - Battery Life - AT&T
Checking Your iPhone Battery Health using iOS 11.3 and Best Battery Optimization Tips - AppleToolBox
My iPhone 5 battery life is awful. What can I or should I do about it? : r/ iphone