kajtek1

FCP Euro sells MB 0009829608 batteries for $115 with lifetime warranty.
I could find it cheaper, but since regenerative charging kills batteries in 2-4 years, I figure out I will gain on the warranty.
Pre-lifted W212 not only did not have battery in the trunk, having dash one for parking brake, but they also don't have regenerative charging, so batteries in them last longer.

justdonating

I got mine from FCP. It was $115 plus tax & shipping. They are top notch. I know where I’m going if/when the battery in my SL550 goes out, which it will eventually.

kajtek1

That is what I keep wonder about.
They operate on Ponzi scheme, so they will have to go down. I only hope I get my replacement before they do.

Gary Mason

The lack of the auxiliary battery does affect the cruise control & all that goes with it

p30amg08

Delete

BeachBunny

@p30amg08 On the many times I had problems with the aux battery, I'd lose: Brake hold, Eco Start-Stop, cruise control (including Distronic), lane keeping, emergency braking, etc. They put a lot off eggs in the Aux battery basket.

p30amg08

I just lost all those features. Getting new battery today for s212. Dealer is $116

Bull2k24

I see this post was from a while ago I have a 14 cls63 amg s with the battery in the trunk no smaller 12 volt battery. I change the aux battery still
had the same malfunction while testing I found out that voltage was making it to the post on the SAM but not to the aux battery…the cable that connects the two has a 100amp fuse known as f97 fuse that might most of your problems… I went to the dealer to bite the bullet and buy one only to find out that none was available in the country.. so I had to order from Germany directly part number is A 2125407600 for my car anyway