So there are two batteries in our cars...... dealer tells me I
Thread Starter
Senior Member
Joined: Jan 2009
Posts: 393
Likes: 2
2005 E55
So there are two batteries in our cars...... dealer tells me I
need to replace the secondary unit. Evidently it is in control of all eletronic items in the car.....yet I don't have any issues. Dealer states it literally failed tests. Reason for discovering this is becuase my car is there for a full inspection for the Chrylser warranty. Who knew we had a second battery...
...not me 
...not me
Senior Member
Joined: Feb 2010
Posts: 389
Likes: 2
From: Texas
2005 Silver E55
agree, read on the Forum many have replaced it themselfs alot cheaper than the dealer will offer. Now if he will do the work for a fair price and not charge you the inpsection fee ,this maybe a wash. But ask how much to change the battery , other on here have horror stories. like 500-800 dollars to change the batteries. front and Rear. front battery is a small battery like a motorcycle or lawn mower type. Rear is the large battery. good luck.
Senior Member
Joined: Sep 2009
Posts: 407
Likes: 0
2004 E55
yup, Front batter is a motorcycle battery. Rear is normal, get it from Enterstate Batteries. I recommend that you change both. I changed the front, then the alternator went out. Then got the alternator fixed and it went out again in two weeks. Under warranty so no problem. I changed the rear batter and ViolA! No more issues.
MBWorld Fanatic!
Joined: Jan 2004
Posts: 7,092
Likes: 13
From: Salt Lake City (but not Morm)
2003 E55 & 2014 GL550
It really does look like bike battery. 
Under your black plastic cabin filter (under the hood) up against the firewall all the way on the left.
That is the baby that runs SBC (brake by wire) for short time if your motor shuts off so make sure you keep yours current. Factory or not.
Under your black plastic cabin filter (under the hood) up against the firewall all the way on the left.
That is the baby that runs SBC (brake by wire) for short time if your motor shuts off so make sure you keep yours current. Factory or not.
MBWorld Fanatic!
Joined: Aug 2005
Posts: 3,466
Likes: 10
From: Southern Cali (Ontario)
small battery will eventually drain the large battery..
so I would search for the size of the battery you need... search Aux battery.. and then shop around.
I needed this battery badly..so I had to pay $200 at the dealer.. my car was dead and I needed the battery the same day.
Online the battery is about $60, but you make sure you get one that is ALREADY charged!
To remove is just 1 small nut on a long bolt. and remove the terminals with a socket wrench.
Dealer wanted $275 for the for Aux and $350 for Main battery.
Main battery at Sam'c club is about $90 installed.
so I would search for the size of the battery you need... search Aux battery.. and then shop around.
I needed this battery badly..so I had to pay $200 at the dealer.. my car was dead and I needed the battery the same day.
Online the battery is about $60, but you make sure you get one that is ALREADY charged!
To remove is just 1 small nut on a long bolt. and remove the terminals with a socket wrench.
Dealer wanted $275 for the for Aux and $350 for Main battery.
Main battery at Sam'c club is about $90 installed.
Thread Starter
Senior Member
Joined: Jan 2009
Posts: 393
Likes: 2
2005 E55
I just had the dealer do it. Chrysler warranty requires the car to be perfect prior to granting a warranty. I'm ok with it....don't like dicking with my cars too much these days and know the dealer will stand by their products.
