Thanks all for your input - I booked my car in for an oil change - my service advisor says they have complimentary new batteries for the fob....
2009 E90 M3 DCT - Jet Black/Black
2007 Z4 M Roadster - Space Gray/Black
2012 S4 DSG - Black/Black (new snowmobile for the windy city!)
2011 550i - Graphite Gray/Oyster/Black - Sold