Location of Auxiliary Battery 2015 E63 S Wagon (W212)
Where is this battery located in the vehicle? I've searched the forums and not located a definitive answer to this specific question.
What I can tell you is that counter to several posts and videos that clearly show that the auxiliary battery located under the drivers-side dash, this is not the case with my vehicle (I removed side panel and looked).
I have located two 12v batteries on my vehicle:
- large in size battery under air box in the engine bay, rear passenger-side under the air box;
- small in size battery under the floor in the rear of the vehicle next to the space saver spare tire, passenger-side under a cover - one video I located refers to this as the "Starter Battery".
Are the terms "Starter Battery" and "Auxiliary Battery" referring to the same battery?
Additional info: Located what appears to be the OEM replacement part number for the auxiliary battery on the MB USA Parts web site (P/N: N000000004039), and verified with my vehicle's VIN that this was the correct item. However this is a small 12v, 1.2 Ah battery and does not match either of the two batteries noted above.
Ended up taking the car to the MB Dealer. In return for US$395 (labor & parts) I now know that that the "Auxiliary Battery" in the 2015 E63 S Wagon is indeed located under the load floor in the back of the car., next to spare tire under a cover. This battery is also sometimes referred to as the "Starter Battery". Problem solved.


