SL/R231: changing main battery?
Thread Starter
Junior Member
Joined: Mar 2020
Posts: 50
Likes: 6
From: Malibu
R231 M279 SL65 AMG; '70 Cuda B convertible; FJR1300; CBX1000, GPz1100, GS1100ES ('Busa)...
changing main battery?
Any unique procedure or requirement in changing the main battery - particularly as it relates to the computer?
MBWorld Fanatic!
Joined: Feb 2021
Posts: 1,419
Likes: 739
From: Nor-Cal
2020 GLC300 -2014 Sl550 - 1997 SL600
This is a good thread on the subject:
https://mbworld.org/forums/sl-class-...ent-guide.html
Good Luck.
https://mbworld.org/forums/sl-class-...ent-guide.html
Good Luck.
MBWorld Fanatic!
Joined: Jun 2012
Posts: 1,022
Likes: 231
From: In the minds of others rent free.
SL 400
MBWorld Fanatic!
Joined: Feb 2017
Posts: 2,315
Likes: 1,215
From: Baltimore County, MD
'13 s212 63 p30. '06 LX470
The trick in ease of battery change is to use the same style of battery chemistry so the digital charging system works correctly. The bcm has different settings (rate of charge) and needs to be set for the right style. No change, no worries.
Thread Starter
Junior Member
Joined: Mar 2020
Posts: 50
Likes: 6
From: Malibu
R231 M279 SL65 AMG; '70 Cuda B convertible; FJR1300; CBX1000, GPz1100, GS1100ES ('Busa)...
Thanks guys for the response. I heard "somewhere" that the ecu had to be reprogrammed to ta new battery is why I ask.
Got an AGM replacement at Costco, but had some weird behavior after. The trunk wouldn't stay closed - it would re-open, and the remote wouldn't work as well as the door handle lock & unlock. Then it started to work.
Also I scanned the computer & it shows like 8 faults, like both heated outside mirrors shorting, entertainment center prob...
Got an AGM replacement at Costco, but had some weird behavior after. The trunk wouldn't stay closed - it would re-open, and the remote wouldn't work as well as the door handle lock & unlock. Then it started to work.
Also I scanned the computer & it shows like 8 faults, like both heated outside mirrors shorting, entertainment center prob...
Trending Topics
Thread Starter
Junior Member
Joined: Mar 2020
Posts: 50
Likes: 6
From: Malibu
R231 M279 SL65 AMG; '70 Cuda B convertible; FJR1300; CBX1000, GPz1100, GS1100ES ('Busa)...
This is a good thread on the subject:
https://mbworld.org/forums/sl-class-...ent-guide.html
Good Luck.
https://mbworld.org/forums/sl-class-...ent-guide.html
Good Luck.
MB World Stories
The Best of Mercedes & AMG
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)
Verdad Gallardo
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
MBWorld Fanatic!
Joined: Feb 2017
Posts: 2,315
Likes: 1,215
From: Baltimore County, MD
'13 s212 63 p30. '06 LX470
IMHO, I think this is why there were electrical fires and issues on so many early merc that had the bcm’s. Nobody knew back then.
If you have star, it’s easy enough to change. Don’t burn your car or house down.
If you have star, it’s easy enough to change. Don’t burn your car or house down.
MBWorld Fanatic!
Joined: Feb 2021
Posts: 1,419
Likes: 739
From: Nor-Cal
2020 GLC300 -2014 Sl550 - 1997 SL600
You’re confusing the R230 BCM issues with the R231, which has different BCM circuitry and no such issues.
Last edited by crconsulting; Apr 28, 2023 at 06:56 PM.
MBWorld Fanatic!
Joined: Feb 2021
Posts: 1,419
Likes: 739
From: Nor-Cal
2020 GLC300 -2014 Sl550 - 1997 SL600
Definitely one of my favorite lines 😀
The only remote chance of having to hook up XENTRY is if you leave the car without a battery for a very extended period of time. And the rear SAM is what controls the charging cycles to battery/BCM.
Sounds like what happened there is the COSTCO tech probably took the battery out and went to lunch. Then came back an hour later and hooked up your new battery. If you know how to access the engineering mode in your in dash NTG 4 display. There will be an error stored there too. You’re car was probably “relearning”
Here’s the bottom line:
Dozens of R231 forum members have successfully removed and replaced their AGM main and Auxiliary batteries with no issues. As always, if you’re hesitant that this is outside your comfort level, don’t hesitate to get it done at a shop. But I guarantee you probably are a more skilled mechanic than the tech at COSTCO that swapped your battery out. 😉
Good Luck
The only remote chance of having to hook up XENTRY is if you leave the car without a battery for a very extended period of time. And the rear SAM is what controls the charging cycles to battery/BCM.
Got an AGM replacement at Costco, but had some weird behavior after. The trunk wouldn't stay closed - it would re-open, and the remote wouldn't work as well as the door handle lock & unlock. Then it started to work.u
Also I scanned the computer & it shows like 8 faults, like both heated outside mirrors shorting, entertainment center prob...
Also I scanned the computer & it shows like 8 faults, like both heated outside mirrors shorting, entertainment center prob...
Here’s the bottom line:
Dozens of R231 forum members have successfully removed and replaced their AGM main and Auxiliary batteries with no issues. As always, if you’re hesitant that this is outside your comfort level, don’t hesitate to get it done at a shop. But I guarantee you probably are a more skilled mechanic than the tech at COSTCO that swapped your battery out. 😉
Good Luck
Last edited by crconsulting; Apr 28, 2023 at 06:58 PM.
MBWorld Fanatic!
Joined: Feb 2017
Posts: 2,315
Likes: 1,215
From: Baltimore County, MD
'13 s212 63 p30. '06 LX470
Yes I know this was with the earlier Sl’s hence my saying older mercs with bcm. In that it was upgraded my assumption was there would still be settings for different battery chemistries vs an automatic read because even my newer higher end digital battery charger asks for the type of battery. How would the car know if there’s no computer communication with the battery itself.
Happy to learn.
MBWorld Fanatic!
Joined: Feb 2021
Posts: 1,419
Likes: 739
From: Nor-Cal
2020 GLC300 -2014 Sl550 - 1997 SL600
There have been no "spontaneous combustion" instances that I have seen reported for the R231's. The charging system hardware, and it's behavior differ in several ways.
I believe what you're thinking of, is how the charge cycles are tracked and controlled by the rear SAM (see thread I initially linked to). Technically, it monitors the batteries and it's condition, and charges it appropriately. It does have a learning cycle, but should adapt after the car is driven. People also have problems with cars that sit because they never adapt to the new battery. Clearing that SAM data probably won't help either, as the cars need to be driven to learn the "adaptation" for the charging system.
Last edited by crconsulting; Apr 28, 2023 at 08:37 PM.
Thread Starter
Junior Member
Joined: Mar 2020
Posts: 50
Likes: 6
From: Malibu
R231 M279 SL65 AMG; '70 Cuda B convertible; FJR1300; CBX1000, GPz1100, GS1100ES ('Busa)...
I changed the AGM Costco battery myself - I don't usually let anybody work on my vehicles. Everything seems OK when I took it out today.
Overly complicated as I was warned.
Thanks
Overly complicated as I was warned.
Thanks
Senior Member
Joined: Jun 2020
Posts: 257
Likes: 85
From: Newbury Park, CA
2016 SL400 & 2021 C300
My seven year old 2016 battery needs replacing according to my independent mechanic. He is recommending that I have him get one from MB and let him install and match to charging system and erase codes that he expects will be thrown in the process. He estimates about $350 but I will know more once he gets a price on the battery.
MBWorld Fanatic!
Joined: Jun 2012
Posts: 1,022
Likes: 231
From: In the minds of others rent free.
SL 400
Do it yourself.
There are no codes to be thrown
There is nothing hard about it.
Either buy the battery from MB yourself or simply ask them what is the part number for the battery and then go purchase one on your own.
There are no codes to be thrown
There is nothing hard about it.
Either buy the battery from MB yourself or simply ask them what is the part number for the battery and then go purchase one on your own.
My seven year old 2016 battery needs replacing according to my independent mechanic. He is recommending that I have him get one from MB and let him install and match to charging system and erase codes that he expects will be thrown in the process. He estimates about $350 but I will know more once he gets a price on the battery.
MBWorld Fanatic!
Joined: Dec 2015
Posts: 1,636
Likes: 522
From: Hagerstown MD
2015 SL400; 2019 X5M40i
I seriously doubt Mercedes has " unique" main batteries. Get the specs from your owners manual and go shopping. There are only a few battery manufacturers in the US. I suspect the MB branded battery is made by Bosch or their supplier.
Last edited by rmorin49; May 13, 2023 at 07:08 PM.
