The +terminal on my R56 is loose and won't tighten up. It doesn't appear to be stripped, but is about the oddest terminal clamp I've seen. First happened at AMVIV last year when to car went stone dead. Loosened it all the way and it tightened right up. Just did it again, but this time it won't tighten. Is there some trick? The only time that terminal might have been removed was during servicing at the dealer. Car starts and runs fine, but I don't care a lot for loose batt. connections!

 

A slightly different problem with that terminal: when putting it back on the battery after running some electrical cables I torqued off half the bolt —*and it's not quite a standard M6 bolt, of course.

And the realoem.com diagram is somewhat different than my car —*I have two power cables coming into the battery clamp, not one.