If someone did havdalah before davening maariv, would he have to repeat shemoneh esrei if he forgets to add “atah chonantanu”?
The Shulchan Aruch 294:1 says that if one forgets to say Ata Chonantanu he doesn’t repeat Shemone Esrei since he will say it on wine later. Seemingly, if one already said Havdala, then for sure he wouldn’t repeat SE.
Additionally, the Biur Halacha 294:1 says if one made havdala and then forgot to daven maariv entirely, it’s a machlokes if he would say it at shachris the next day. He concludes that it’s better not to say it