Donnymac

OEM battery was getting weak. Interstate easy swap.
Part number info in photo.

Nuru

Check out this thread

https://mbworld.org/forums/s-class-w...d-battery.html

daefash

Is there an auxiliary battery in the 2012 S550? Should i worry about losing memory swapping the main batter?

1bad540

In my 2010 there was no memory loss, I swapped the battery myself in 10 mins. Easy peasy. how much was the interstate?

daefash

Is there a difference between 10 and 12? Does the 12 have the Auxillary battery too?

Donnymac

As to the 2012, I am aware of no auxiliary battery - but I have not asked a pro. As to memory, a battery tender was hooked to the detached leads - probably very unnecessary.

As to battery cost, it was thru a commercial account and not retail.

Jason B

No aux for refresh w221 10-13. The dealer states you shouldn't disconnect old battery and still keep 12 volts to the system. I didn't, and the only thing that happened is me losing the auto up function of the rear windows, which I told was normal. Quick fix is to just hold the button dor 10 sec to reset.