For those thinking about battery replacement, this is my experience: My Coupe is a 2013 with 170K miles. I first got the warning that my battery charge was low. When your battery is approximately 50 % charged you will get a warning. A this point you have time to shop around for a battery because the Mini system will attempt to raise the charging level. I purchased a champion AGM at Pep Boys for 200$. Installing is easy as you just remove the molding then two bolts holding the plastic housing down. The battery holder itself is just a screw. The vapor tube from the old battery will need to be inserted. The battery will have to be registered. I used the Schawb Foxwell tool. The battery reset is located under "service" "body" then register battery. It will ask you if it is a BMW mini battery or not. A look at the tool battery status will tell if the new battery registered. My old battery got down to 30%.