Can you show us a picture of what red mode looks like? We need some more information to help you. Does the phone respond at all? Do you get any error messages? Have you tried different chargers?
What have you tried?
Welcome to Android Central! Are you saying that all you see is a red battery icon in the middle of the screen, and it doesn't seem to charge or turn on? Or are you talking about a red notification LED? Either way, it doesn't sound good. My guess is that the battery has failed.