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Frequently asked questions about cars and motorcycles

How to Replace the Key Battery in a Mercedes S550

Model: Mercedes Classe S W221, MK 5 - Years: 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013
Part: Key

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Video tutorial

Replacing the key battery in your Mercedes S550 is a task anyone can handle and does not require the costly intervention of an expert. Just follow the instructions in this mini guide.

First, remove the physical emergency key by sliding it out of its position. Next, using a thin, long object, gently push outward to separate the back cover from the front.

At this point, simply replace the old battery with the new one. Finally, reposition the various components you removed earlier.


Updated on 9 June 2026 by ScegliAuto


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