Mercedes-Benz 2011 E-Class Sedan Operator's Manual page 83

arrow until battery tray cover : opens. Do
not hold the cover closed while doing so.
X
Remove the cover of the battery tray.
X
Repeatedly tap the SmartKey against your
palm until battery = falls out.
X
Insert the new battery with the positive
pole facing upwards. Use a lint-free cloth to
do so.
X
Insert the front tabs of the battery tray's
cover first and then press to close it.
X
Check the function of all SmartKey buttons
on the vehicle.
SmartKey
81
Z