You might have bad battery to start with, and that is why the electronic dont function fully
If you have a stock battery then there is a little dot on there that should be green if battery is ful and ok, black if it neads charge and yellow if you should replace it.
Mine was replaced eaven if it was showing black, becouse of the fact that it could never be chaged to show green.

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X5 4,4i-06 Current
330Ci Cab-03 2007-2008
MB E55 AMG-03 2006-2007
Z3 2,8 Roadster-98 2006-2007
X3 2,0d-05 2005-2006
320d-99 1999-2005