Curious if anyone here has dealt with battery issues on Gen 1's before, I have heard there are several common things associated with the battery and related features which can break on these cars. Bit of a long story, I purchased a 2006 R53 at the very beginning of this year. The car runs and drives great save for a wore out clutch which is being replaced soon anyway. At any rate, lately I have been having issues with the battery dying. I have jumped the car twice now and it started right up and drove around with no issues. However, we have had obscenely cold weather here as of late (Ohio), and the car sits outside due to lack of suitable garage space. I try to run it as much as possible as it is not my DD, but with the car not starting it has been difficult to do so. As I said above, the car starts right up after jump starting. We took the battery out (it isn't a very old battery) and found that moisture had gotten into the hatch carpet floor due to a gap either in the rear window or in the trunk-lid itself, so the battery was sitting in that. So, there was a bit of rust underneath, and the connections looked like they had never been cleaned either, so that was done as well. Charged the battery out of the car, and the battery did take some time to charge up somewhat slowly, but the car started right up when we put the battery back in. Then today, I tried to start it again and the battery had once again died. Curious if anyone has any experience. I am hoping that the moisture just got to the battery and a new battery will solve the problem, as otherwise the only thing I can think is the positive battery cable that runs all the way to the front of the car, which is not a cheap fix. The battery was holding above 14 volts in the car and 12.5 on it's own when we tested it before putting it back in the car.

Any insight is appreciated, thank you!

 

How old is the battery?
These are classic examples of a dead or dying battery. The MINI's are very battery sensitive and like nice charged up new batteries.
You should also verify that the alternator is still working correctly.

 

When you checked the battery did you do a Load Test? (Load Test checks for AMPs and Voltage) your battery can be good on volts but lacks the AMPs to remain operational. If you drive down to your local Auto Parts Store like Advanced Auto Parts or even Batters, Bulbs and More ... they can Load Test you battery and they normally do it for free. (the advantage is they can sell you a new battery if you need one)

Unfortunately Battery Boxes can be neglected when it is time to clean a vehicle. But it should be checked and clean every few months.

Best of luck.

Motor On!

 

I do agree that a marginal battery in extreme cold temps is probably the cause but then there's the possibility of a parasitic draw that's discharging your battery. That will require a digital Ammeter that you hook up in series between the Neg. lead of the battery and the Neg battery terminal. Keep the Ammeter on the outside of the car and carefully close the trunk lid. Let the car go into "sleep mode" and read the amount of draw in milliamps. It should be no more than 35-45 milliamps. Any more than that, you'll need to find the source by removing fuses one at a time and letting the car go to "sleep" until you find the culprit, then curing same.