Battery not charging

Hi. I have the ring doorbell 2. The type with the built in battery that needs taking off and charging via usb lead. I had it istalled at my old house fine with no issues. I have moved recently and took the device down and put it in storage letting the battery completely run flat. My issue isnit now will not charge at all. It is getting power from the lead is it switched on and will show live video but after being plugging in for over 6 hours it is still showing battery at 0% and it doesn't notify my if the button is pressed or any motion. Any ideas? Its only 2rs old. Surely I don't need a new one all ready