Did you try the reset in your manual? I will find it and post the page number for you. It involves turning the steering wheel from all the way right to all the way left. I had the same issue twice. I will tell you after I did the reset it took my car a few hours to reset itself. The problem has no happened since.
I think the battery issue just affects the spoiler, the issue I'm talking about the BAS/ESP warning comes on and the spoiler goes up and you can't put it down. The same thing happened to our Mercedes and it was the steering angle sensor that was pulling the code. I'll get back on here with the page info this morning for you unless someone provides it sooner.
Pat