Alternator problem
 

Hey every one I have 2003 audi a6 2.7t 150,xxx miles

my issue :
My battery stopped charging I figured it was the alternator I replaced it ( it looked new not more the a year old )
Got the brand new alternator in it worked find both was valeo
Now after 2 weeks alternator got bad again

I heard it might be the ground connection I cleared the one on the battery does it have one on the alternator as well I know some cars don't have ?

My question is did anyone had the same problem and found a solution ?