2003 Mini Cooper s

 

I will venture a guess the starter has bit the dust or you have a pretty good short. Check the battery cables for signs of burning - it has an unmistakable smell once you know what it smells like.

 

 

 

How long were you cranking the engine over? Max time is 30 sec with a full 2 min wait between attempts to let the starter cool down.
My rule of thumb is if a gasser hasn't started within 15 sec it isn't going to start, diesels I'll go the 30 sec. There is a bunch of current running through a starter when cranking, the brushes will heat to a very high temp.

 

 

Lower voltage at the battery will cause the starter to draw more amps than what the system is designed to handle. The key thing is how long are you cranking it?

If you have a meter read the battery voltage on the battery posts - not the clamps.

Battery State of Charge:
12.6 = 100%
12.4 = 75%
12.2 = 50%
12.0 = 25%

You can crank and start at a lower voltage but the amp draw will increase.

 

 

If you can get an assistant, try starting the car watching the starter and cables for signs of smoke from overheating. The only way you could get smoke for components in the bellhousing is to cook the snot out of the clutch. Since the engine isn't running I doubt that is the source.