Originally Posted by Tsuyoi
Unless a BMW is crappier than a Ford, I doubt there needs to be concern about this. I've left my 2002 Ford for well over a month at a time without driving it, no problems with battery at all...
There's been quite a few times over the past few years when there have been issues with high parasitic drain among several BMW lines. I have personal experience with an early E83 X3 which was notorious for this. The body control module would routinely "wake up" and interrogate all of the other modules in the car every once in a while to verify status and also to check to see if the car had been flagged as stolen. There was a bug in the software that would randomly prevent the modules from going back to "sleep". When active, they had a high drain rate that could flatten a battery in short order. More than once it happened over night.
Since the F30 is a very new model (with many new technologies), I personally would err on the side of caution "just in case". Once bitten, twice shy I suppose. Batteries don't like being fully drained and recharged too many times.