Thanks for all your replies. Called the dealer and they said CPO doesn't cover battery and according to him in our hot weather I am doing good if the battery last 3 years which is my case.

Anyways so I picked up a battery from battery plus (its one made by exide although not the cheapest out of auto zone/checker/pep boys) and to my excitement when I pulled the old Orignial BMW battery out it was made by exide too.

The replacement went ok except for a two things
1.) there was a long screw with a plate holding the battery down which was a pain to loosen out. After replacing the battery as I was tightening that screw it broke half ways with half still left in. So for now I put together everything else since I figured the triangle plate above the battery will hold the battery down. So three questions. How do I remove the broken screw left in and where do I get a replacement from and what is it called.

2.) after replacing the battery the radio and other electronics worked so that was a relief considering all the posts here that mention some hinge weird happens to the electronics. Then I crank the engine to start it up but it wouldn't start up. Tried at least 3 times with 5 sec cranks. Then I started playing with the radio and kept asking for the time. I enter the time/date and try to crank it one last time before giving up and voila it starts up. Just thought mentioning this as it might help someone.

Thanks