Replacing battery on mid 2011 macbook air

My computer is 8 years and I have been lucky with not having too many issues. My battery still holds some charge (2 hours), but is not long enough to hold me through a 4 hour class. I have looked and seen I can get a battery to replace it, and replacing it does not scare me. I was looking for advice or experiences from others how well these replacement batteries work or if they have seen them cause problems with over heating and such?