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How to Replace the Key Battery in the Mercedes-Benz B-Class W246

Model: Mercedes Classe B MK 2, W246 - Years: 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019
Part: Key

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Video tutorial

In this guide, you will discover all the steps necessary to correctly replace the battery located inside the key of your Mercedes-Benz B-Class W246 (2011-2019). First, ensure you have a compatible new battery. Then, remove the physical emergency key by pressing the small button located on the back cover.

Once done, remove the back cover itself and take out the battery holder. Finally, replace the old battery with the new one, and you are finished.


Updated on 21 September 2026 by ScegliAuto


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