SL/R231: Auxiliary Battery Malfunction
Thread Starter
Member
Joined: Jul 2017
Posts: 102
Likes: 13
From: Phoenix, AZ
2013 SL550
Auxiliary Battery Malfunction
That's the message on the screen after the cruise control would not turn on. This happened twice in three days.
Anyone experience this?
Is this a "fix" or "replace" situation?
Where is this battery on a 2013 SL?
Anyone experience this?
Is this a "fix" or "replace" situation?
Where is this battery on a 2013 SL?
Junior Member
Joined: Sep 2014
Posts: 31
Likes: 14
From: Charleston SC
2016 S550 Coupe , 2013 SL550sold 2009 sl550 sold 2012 S550 sold
Putter:
Previous posts show photos of the aux battery behind the passenger seat, under a cover. Getting it out is a pain in the butt, but do-able.
The previous post I'm referring to was very explicit , with good photos. see "Battery Location in my '13 MB SL550 post on 11/29/17".
No sure if he was getting a warning like yours...our aux batteries are getting on 5 years old now.
I charge both of my AGM batteries from the 2 posts under the hood.
It is a Battery Minder 2 amp AGM desulfator charger that extends the life of the batteries..
The main battery is where the spare tire used to be, under the trunk floorboard. It is a large AGM style type. That one is easy to get to..
Hope this helps...
rockinrob .
Previous posts show photos of the aux battery behind the passenger seat, under a cover. Getting it out is a pain in the butt, but do-able.
The previous post I'm referring to was very explicit , with good photos. see "Battery Location in my '13 MB SL550 post on 11/29/17".
No sure if he was getting a warning like yours...our aux batteries are getting on 5 years old now.
I charge both of my AGM batteries from the 2 posts under the hood.
It is a Battery Minder 2 amp AGM desulfator charger that extends the life of the batteries..
The main battery is where the spare tire used to be, under the trunk floorboard. It is a large AGM style type. That one is easy to get to..
Hope this helps...
rockinrob .
Last edited by Rockinrob; Jul 21, 2018 at 10:27 PM.
Thread Starter
Member
Joined: Jul 2017
Posts: 102
Likes: 13
From: Phoenix, AZ
2013 SL550
Putter:
Previous posts show photos of the aux battery behind the passenger seat, under a cover. Getting it out is a pain in the butt, but do-able.
The previous post I'm referring to was very explicit , with good photos. see "Battery Location in my '13 MB SL550 post on 11/29/17".
No sure if he was getting a warning like yours...our aux batteries are getting on 5 years old now.
I charge both of my AGM batteries from the 2 posts under the hood.
It is a Battery Minder 2 amp AGM desulfator charger that extends the life of the batteries..
The main battery is where the spare tire used to be, under the trunk floorboard. It is a large AGM style type. That one is easy to get to..
Hope this helps...
rockinrob .
Previous posts show photos of the aux battery behind the passenger seat, under a cover. Getting it out is a pain in the butt, but do-able.
The previous post I'm referring to was very explicit , with good photos. see "Battery Location in my '13 MB SL550 post on 11/29/17".
No sure if he was getting a warning like yours...our aux batteries are getting on 5 years old now.
I charge both of my AGM batteries from the 2 posts under the hood.
It is a Battery Minder 2 amp AGM desulfator charger that extends the life of the batteries..
The main battery is where the spare tire used to be, under the trunk floorboard. It is a large AGM style type. That one is easy to get to..
Hope this helps...
rockinrob .
Junior Member
Joined: Sep 2014
Posts: 31
Likes: 14
From: Charleston SC
2016 S550 Coupe , 2013 SL550sold 2009 sl550 sold 2012 S550 sold
Putter- Thanks for the update! I would have expected a higher charge for the battery & labor .
An AGM battery's worst enemy is heat... so it would not last long under the hood.
That's why both are now in the cooler temp areas..inside the cab and in the trunk..The R230's had one under the hood...
I'm sure I'm running on borrowed time for mine as well since it is 5 years old.
An AGM battery's worst enemy is heat... so it would not last long under the hood.
That's why both are now in the cooler temp areas..inside the cab and in the trunk..The R230's had one under the hood...
I'm sure I'm running on borrowed time for mine as well since it is 5 years old.
Junior Member
Joined: Sep 2018
Posts: 18
Likes: 3
2017 AMG SL 63 Polar White
Auxiliary Battery Replaced
Thank you Rockinrob for your post. I use to own a 2008 Cadillac XLR and the owners manual stated that when the windows start to malfunction that is an indication that the battery needs to be replaced. Traded up to my 2015 SL550 and the windows were not going down together when retracting the roof. Been looking on-line for a couple of weeks unable to find auxiliary battery location. "Auxiliary battery malfunction" message came up on Thursday, found this post that evening, replaced the battery yesterday. Note to others removal takes about 10 minutes. New battery terminals are closer to the edge of the battery, and I had to cut a little off the battery hold down. I used my dremel, and it was very easy to do. Total time, not including going to MB dealership for battery, about 45 very easy minutes. Cost $145.
Last edited by Box5232; Sep 23, 2018 at 01:30 PM.
MBWorld Fanatic!
Joined: Jan 2017
Posts: 1,040
Likes: 234
From: God's County (Yorkshire)
Shanks’s Pony
Putter- Thanks for the update! I would have expected a higher charge for the battery & labor .
An AGM battery's worst enemy is heat... so it would not last long under the hood.
That's why both are now in the cooler temp areas..inside the cab and in the trunk..The R230's had one under the hood...
I'm sure I'm running on borrowed time for mine as well since it is 5 years old.
An AGM battery's worst enemy is heat... so it would not last long under the hood.
That's why both are now in the cooler temp areas..inside the cab and in the trunk..The R230's had one under the hood...
I'm sure I'm running on borrowed time for mine as well since it is 5 years old.
I believe the battery in the rear is two fold. Improves weight distribution and is protected from impact damage, reducing fire risk etc.
Last edited by rorywquin; Sep 25, 2018 at 02:49 PM.
