M-Class (W166) Produced 2012-2015

W166 Auxiliary Battery Location

Old Aug 10, 2020 | 10:25 PM
  #26  
bob58d's Avatar
Newbie
5 Year Member
 
Joined: May 2019
Posts: 9
Likes: 8
From: AL
2014 ML350
Originally Posted by chassis
Well done, thanks for posting.

That is quite the shortcut. Imagine if the Mercedes engineers designed the existing removable panel with four more inches of length onto the floor of the niche.
Thanks. Finding that video was a godsend. I never would have thought of it and I was not looking forward to the de-panel job.

The carpet in that location is very stiff and, after I replaced the battery, I used some Gorilla tape on the back of the cut seems to give it a little support. I don’t think having cut that carpet is going to limit me from putting anything there that I would normally consider putting there.
Reply
Old Aug 9, 2021 | 05:50 PM
  #27  
sub786sub's Avatar
Member
5 Year Member
Liked
Loved
Community Favorite
 
Joined: Jul 2018
Posts: 207
Likes: 84
GLE 350 , GLA 250 and Lexus ES 350
Question what is the use of the 2nd Battery? What it powers?
Reply
Old Oct 2, 2021 | 01:35 PM
  #28  
kptaylor's Avatar
Junior Member
 
Joined: Sep 2007
Posts: 19
Likes: 2
From: PHX, AZ
'14 ML350
Thanks @bob58d! This made it much easier, basically a 5 minute job. The only issue I had was the size of the battery you used. I too have a 2014 ML350 4matic and the aux battery is much smaller than the one you linked to on Amazon. Mine is MB# n000000004039. Returned and reordered and everything is working just fine! The larger battery fit into the hole but I couldn't figure a way to use the hold down bracket so the battery would have flopped around in there.
Reply
Old Jul 18, 2022 | 08:54 AM
  #29  
threeMBs's Avatar
MBWorld Fanatic!
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Jul 2009
Posts: 3,530
Likes: 387
Only MBs - the best or nothing
The carpet cutting method as posted in post #24, I speculate will only work if the specific W166 ML is equipped with small "4039" aux battery. However, if vehicle is equipped with larger (by quit a bit considering it is a very small place to "work" in), p/n 0009829608 (old p/n 019822708) it may not help as there is no room that I can see to work in. I assume the more equipment car has (DAP, etc.) the more likely it is equipped with the larger Aux battery.

I cut the carpet in my ML63 (it does not need the aux battery but was curious) and it seems there's no room for hands and tools to take the larger aux battery out:




Reply
Old Mar 6, 2023 | 02:29 PM
  #30  
Brent S's Avatar
Junior Member
5 Year Member
Liked
 
Joined: May 2017
Posts: 41
Likes: 2
From: Long Island, NY
2014 ML350 4MATIC
You can remove/re-install the small aux battery without cutting the carpet, and without removing the entire passenger side trunk liner (panel).
I just did it.
Wasn’t easy, but it’s possible.
I didn’t want to remove side trunk liner, because I didn’t want to pull off the trunk’s rubber seal.

Last edited by Brent S; Mar 6, 2023 at 02:31 PM.
Reply

Currently Active Users Viewing This Thread: 2 (0 members and 2 guests)
 

Thread Tools
Search this Thread
Rate This Thread
Rate This Thread:
You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -4. The time now is 12:41 AM.

story-0
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

Slideshow: Not every Mercedes design becomes timeless, some feel stuck in the era they came from.

By Verdad Gallardo | 2026-05-12 18:09:07


VIEW MORE
story-1
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

Slideshow: Yes, Mercedes built manual cars, and some of them are far more interesting than you'd expect.

By Verdad Gallardo | 2026-05-02 12:36:58


VIEW MORE
story-2
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.

By Verdad Gallardo | 2026-04-29 11:19:28


VIEW MORE
story-3
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

Slideshow: Before curves took over, Mercedes mastered the art of the straight line, and some of those shapes still look right today.

By Verdad Gallardo | 2026-04-25 12:05:49


VIEW MORE
story-4
Flawlessly Restored Mercedes 190E Evo II Heads to Auction

Slideshow: The 190E Evolution II shows how a homologation necessity became a six-figure collector icon.

By Verdad Gallardo | 2026-04-22 17:53:47


VIEW MORE
story-5
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

Slideshow: Mercedes is turning one of its core nameplates electric, and the details show just how serious this shift is.

By Verdad Gallardo | 2026-04-21 13:58:06


VIEW MORE
story-6
Mercedes EQS Gets A Major Update: Everything You Need to Know

Slideshow: Faster charging, longer range, and a controversial steer-by-wire system define the latest evolution of Mercedes-Benz EQS.

By Verdad Gallardo | 2026-04-15 10:35:34


VIEW MORE
story-7
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

Slideshow: These overlooked Mercedes-Benz models never got the spotlight, but they quietly delivered more than most remember.

By Verdad Gallardo | 2026-04-13 19:35:45


VIEW MORE
story-8
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

Slideshow: A well-used 1991 Mercedes-Benz 300D with more than one million miles is now looking for a new owner, and it still appears ready for more.

By Verdad Gallardo | 2026-04-10 10:05:15


VIEW MORE
story-9
10 Most Reliable Mercedes-Benz Models You Can Buy Used

Slideshow: From bulletproof sedans to surprisingly tough SUVs, these Mercedes models proved that the three-pointed star can go the distance.

By Verdad Gallardo | 2026-04-08 09:55:49


VIEW MORE