2009-2013 Mercedes S-Class Main Battery Replacement
Is your Mercedes-Benz not starting due to a dead battery? Learn how to fix the problem by replacing the main battery of your Mercedes-Benz S-Class.
It is important to point out that for the 2007 and 2008 models, the battery was smaller (Group Size V4) and used only for starting the engine. The larger Group Size 49 battery is behind the rear seat for those model years.
Starting with the 2009 model year, Mercedes-Benz moved the larger battery from behind the rear seat to the engine bay. It replaced the smaller starter battery used in 2006-2008 models. The battery in the engine bay cranks the engine and supplies power to the onboard electrical system.
From 2010 to 2013, S400 hybrid models remained behind the rear seat while the hybrid battery was on the engine bay and passenger side. A secondary battery (Part Number N000000004039 12 Volt 1.2Ah) is located under the dashboard. This is known as the auxiliary battery and is primarily used to ensure the vehicle can shift to Park even if the main battery fails.
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What you will need
- Battery
The battery size is different for pre-2009 models.- 2009-2013 CL/S Class
- 2006-2008 CL/S Class
- 10mm and 13 sockets
- 3/8″ Ratchet
- Battery Terminal Brush
Instructions
- Park your Mercedes-Benz S-Class or CL-Class in a safe working environment, set the parking brakes, and remove the key from the ignition.
- Pull the hood release under the hood of your S Class.
- Open the hood and locate the battery on the passenger side of the engine bay.
- Disconnect the negative terminal first by loosening the 10mm bolt. The bolt does not need to be removed.
- Disconnect the positive terminal next.
- Remove the 10mm nut and remove the top bracket.
- Remove the 13mm bolt on the side of the battery. Remove side bracket.
- Lift the old battery out and place the new battery in place.
- Clean the battery terminal using a battery terminal brush.
- Install the side and top brackets.
- Connect the positive battery terminal.
- Connect the negative battery last.
- Start your car and ensure all is working properly.
- Synchronize windows, sunroof, and steering-able sensors by moving these parts up/down (left/right).
I don’t have a large battery in the engine bay
2006-2008 model years have the main battery behind the rear seat. It can be accessed via the trunk. See our tutorial on how to replace that battery.
We hope you find the 2009-2013 Mercedes S-Class Main Battery Replacement guide helpful. Check these troubleshooting and repair guides for more help on your Mercedes-Benz.
