This Mercedes have a history of having issues with the central locking system, sometimes with water intrusion damaging the circuit board inside.
First check for any lights staying on after shutting down the vehicle and locking it. This vehicle is equipped with a power shut down after 10 or so minutes to keep the battery alive.
If you don't find anything staying on it might be best to take vehicle to dealer for repairs because something is staying on and draining the battery overnight. It could be many components causing a drain.
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Wednesday, January 29th, 2014 AT 7:03 PM