As of about 4 hours ago, my iPhone has refused to charge and the battery has drained, every time it gets enough power to turn on it displays the lock screen and "9%" battery before promptly dying after a second or two.
I have never had any issues with my battery before today and i'm using the same charger i've always used
EDIT:
It is an iPhone 5s, I have had it for about a year but is second hand, iOS 8.X, it no longer turns on at all, just displays one or other of "charging" or "needs charging" and can not reach the lock screen, I have tried 3 different charger with 2 different cables.