Bro yesterday I bought iphone 12 mini from retailer shop. They told demo mobile with 100% battery. After I boot up I check the battery percentage showing 100% but showing battery service?
hi bro, if the battery health percentage is manually altered or battery changed outside apple service center, we may see such error message. check with same shop and try to get different unit with original battery in it bro. even with 90% around battery health can be considered. so in future oyu can change battery at apple service center if you prefer original spares inside.