Apple Battery.

So when one person in my family gifted me their old iPhone it didn't charge and we found out it was the screen, After that it was fixed! Then 3 minutes after we left the repair shop it just didn't charge, Then he gave us a new battery, It worked but it still didn't work, We went to the mall and it is fixed now, The only problem is that in settings it says your battery is not official or something like that, Can someone help?