Original post by: James ,
https://www.mendmyi.com/blog/2014/06/has-your-iphone-5-died-and-wont-charge-or-come-back-on-we-can-fix-that/ i have come across this problem and thought it was water damage although the water markers tell a different story. I tested the battery in another phone and low and behold it charged. Once charged enough to power on i put it into the faulty phone and it continued to charge. there's a few options 1. don't ever let your phone completely drain of power (not easy) 2. get it fixed as per above link 3. buy a battery bank/charge case and again don't ever let your phone drain completely 4. take a chance with taking it back to apple for a replacement (not easy either) Apparently fault is due to using non-apple chargers or car chargers which charge at different voltages that the iPhone isn't designed for which in turn damages the U2 ic chip.