I bought my 335i coupe about a month ago now. When i was checking it out in the showroom the battery light displayed and gave the warning that the battery voltage was low. A few minutes afterwards it shut down the i drive screen and stereo.
Upon purchasing i raised this with the dealer and they said if it becomes a problem they would replace the battery. The weekend afterwards i noticed the rear-demister was not working and sometimes the heated seats stopped working several minutes after turning them on. In radio readiness i still had the battery low voltage warning and it shut everything down when the engine was not running.
I called the dealer and he said he would replace the battery. I argued that there was more to it than that and he had it in at a auto electrician to test the system. Auto electrician diagnosed the alternator was at fault. The dealer as had the car nearly a week now, as they said they were waiting for an alternator to arrive.
Does this ring any alarms bells with you guys or could this be something else. Looking a for a second opinion i suppose.