I got a new battery and as soon as i put it on the service wrench and check engi

What is your question?

As soon as i put the new battery it had trouble accerlerating and check engine light and service wrench turned on. Put my old battery and check engine and service wrench turned off. And car drove fine but autozone says my battery is bad when tested.

What makes this problem better or worse?

The car has trouble starting checked battery at autozone and it was bad so got a new battery and it gave me problems

How long has your 2009 Mercury Milan had this problem?

It just happened as soon as i put the new battery changed it back to my old one and everything is fine . check engine light and service light turned off