E-Class (W211) 2003-2009
Old Jun 4, 2015, 08:15 PM
How-Tos on this Topic
Last edit by: IB Advertising
See related guides and technical advice from our community experts:Browse all: Interior
Print Wikipost

Aux battery

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old Feb 2, 2012 | 12:33 AM
  #1  
terracotta's Avatar
Thread Starter
Member
15 Year Member
 
Joined: May 2008
Posts: 75
Likes: 1
From: SF Bay Area, CA
2006 E320 CDI
Aux battery

My 2006 E320 CDI has started showing "Lo Batt. unconven. functions will be turned off" perhaps due to lack of much driving. When I take the car for a long drive, the message would go away. However, the stealership today determined the aux battery needs replacement. Is it easy to do so oneself? Also, is it necessary to replace the system batt at the same time as replacing aux?

Last edited by terracotta; Feb 2, 2012 at 01:43 AM.
Reply
Old Feb 2, 2012 | 05:38 AM
  #2  
jimbo1763's Avatar
Senior Member
 
Joined: Oct 2011
Posts: 314
Likes: 29
From: Coastal Georgia, USA
2007 E350 Sedan
See if this thread answers your questions.

https://mbworld.org/forums/e-class-w...-workshop.html
Reply
Old Feb 2, 2012 | 10:40 AM
  #3  
06e320cdi's Avatar
Senior Member
 
Joined: Feb 2010
Posts: 431
Likes: 4
From: Cross Roads, PA
2008 ML320CDI
I just did this myself last weekend. Bought the battery at Walmart (same glass mat battery as everywhere else). It comes dry, you have to add the acid, let sit for 1 hour, then charge before installing (according to the directions)

Steps: (after prepping battery)
1. Disconnect main battery's neg cable in trunk. (Good time to check spare, mine only had 11lbs of air!!)
2. Remove Pollen filter assembly, one 10MM nut and 3 plastic pins
3. Disconnect Neg and Pos cables from Aux battery
4. Remove nut holding battery in place.
5. Install new battery, and hook up cables ( I did reuse the red POS cover)
6. Tighten mounting bracket
7. Install Pollen filter, make sure seal is fit properly.
8. Connect Neg Terminal on main battery in trunk.
9. Reset Windows and sunroof. (hold down buttons until fully opened and closed one time each)
Reply
Old Feb 2, 2012 | 11:28 PM
  #4  
Green E-300 DT's Avatar
Super Member
 
Joined: Sep 2003
Posts: 783
Likes: 1
From: Murrieta, Southern California
Late Built 2005 W-211 E-320 CDI
Arrow Too Much Work.



You made too much work for your project.

There is a really complete thread on the subject for you to study as I just did mine recently.

New in 2006? It was about time, wasn't it?
My CDI was built in November 2004 and put into service in February, 2005.
That little battery lasted for over 109,750 miles 'til perhaps December 17, 2011.
Maybe it had failed earlier and the original owner discovered that
he could ignore the warning and simply 'motor on'?
That's when it became our daily driver; In fact our only vehicle.

See:

https://mbworld.org/forums/e-class-w...ml#post5007669



Derrel
Reply
Old Feb 3, 2012 | 12:32 AM
  #5  
Green E-300 DT's Avatar
Super Member
 
Joined: Sep 2003
Posts: 783
Likes: 1
From: Murrieta, Southern California
Late Built 2005 W-211 E-320 CDI
Exclamation It is So Easy

Originally Posted by terracotta
My 2006 E320 CDI has started showing "Lo Batt. unconven. functions will be turned off" perhaps due to lack of much driving? [No, no!]
When I take the car for a long drive, the message would go away. However, the stealership today determined the aux battery needs replacement.
Is it easy to do so oneself? [YES, yes!] Also, is it necessary to replace the system batt at the same time as replacing aux? [No, no!]


If I, an old duffer, the oldest one here, can do it, so can you. Really, it is so easy!
Think of how you will feel after you are done and have saved upwards of $100?

The URL is posted below your first message. When you have read it all,
you should know more about the subject than your stealership!
Be sure and read it in its entirety, the whole enchilada, all twelve pages, 285 messages.

Good luck and love that feeling of accomplishment! Saving money is so much fun, isn't it?



Derrel
Reply

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 


You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -4. The time now is 05:30 PM.

story-0
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-1
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-2
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-3
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-4
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-5
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-6
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
story-7
Mercedes Teases Updated EQS With Steer-By-Wire and a Yoke

Slideshow: The 2027 update adds a fully digital steering system, revised styling, and potential charging upgrades as the company looks to revive interest in the luxury EV.

By Verdad Gallardo | 2026-04-04 10:24:38


VIEW MORE
story-8
8 Mercedes Models With Poor Reliability Records

Slideshow: From problematic air suspensions to early dual-clutch transmission issues, these specific models and years stand out as the least dependable modern Mercedes vehicles.

By Verdad Gallardo | 2026-03-26 18:08:10


VIEW MORE
story-9
Magnificent New Mercedes-Maybach S-Class Revealed: 12 Things to Know

Slideshow: Mercedes-Maybach has refreshed the S-Class with new lighting signatures, AI-driven software, and even more elaborate rear-seat luxury.

By Verdad Gallardo | 2026-03-25 18:01:51


VIEW MORE