Mini Cooper Forums - Mini Cooper Enthusiast Forums

I have a 2018 Mini convertible S. I bought the car 2nd hand about four months ago. Yesterday when I started the car my pre-set radio stations weren't there, and the navigation system wouldn't start. Later in the day the presets were back and the nav system was working. This morning it seemed a little difficult to start the engine. I'm suspecting it's time for a new battery. I don't live anywhere near a dealership (Palm Springs) so I'm wondering if anyone has a suggestion where to get a new battery. I thought I read somewhere that there needs to be some sort of a reset done when replacing the battery. Thanks in advance for any comments.