Recently I went out to start my 2009 Mini Cooper Clubman S, and it wouldn't start. So naturally I proceeded to jump it off, with success. However 2 days later it wouldn't start again without a jump. After some checking it was determined that my battery is good, the alternator has good diodes, but low voltage. Now the only way I can alleviate the issue is by disconnecting my battery once fully charged, and reconnect it each time I drive it. I also notice that when I come out in the morning to connect the battery to drive the car, the oscillating fan comes on immediately, leading me to believe that it's the fan or possibly its relay. Consequently inside the car the engine light is on, windows act funny, rolling partially down on their own, also the P (park light button) on the gear shift remains illuminated 30 minutes after car is shut off.

 

Are you sure the battery is good? Is it original? If so, replace it. These cars get wonky on a marginal battery. Lastly, the P staying lit for a while after the car is turned off is normal..

 

Actually it is the original battery. Didnt want to change battery, thinking whatever's pulling the charge would do the same with a new one.

 

I agree with AZdsrt.

 

If you are having strange electrical problems and your battery is more than 3 years old repeat my mantra "It's always the battery"
After many years and cars I have always found it to be true.

 

Probably the battery. My original 2009 one went south a few months ago. Duralast gold replacement, works great since