It sounds like your screen’s oled is damaged.
Green screen is very common when samsung’s galaxy oled are damaged, so are lines, and flickers.
It may just be a bad connection with your screen cable, but you should not of had to touched that if you were replacing the battery.
I doubt that a bad battery would cause this issue. If I had to guess from this info, I would say some damage happened to the screen shortly after the installation.
There is also the possibility of a micro component got knocked off the motherboard during the battery replacement, but it sounds like classic issues of a damaged screen.