iphone 5 stuck on red battery screen
Hello, recently my iphone 5 has been having weird battery problems. Sometimes it will loose 25% in seconds but last one 1% for hours at time. I forgot to plug in my iphone last night and woke up to it dead. Its been plugged in for a few hours now and still shows the red battery screen. Some things ive already tried are testing the charger(it works on other devices), holding home and power for 30 seconds, and putting it in DFU mode. When i put it into DFU mode it just becomes a black unresponsive screen and i have to hold down the power and home button for 30 seconds just o see the red battery screen again. Any help would be greatly appreciated.
iPhone 5, iOS 7.1.2