Changng the auxillary battery on my SL, ordered from Tayna Batteries, was sent a Varta AUX14, this was listed for all R231 SLs.
On fitting it soon became apparent there was a slight difference in the terminal locations so the protective / securing cover would not fit, see image, the original Mercedes battery is on the left.
If you are replacing your battery make sure to check terminal position, ended up getting a Mercedes replacement as aftermarket ones look the same as the Varta one on the right, it may be its only the facelift SLs that have the battery with the inset terminals.
The latest part number for the Mercedes battery is A2115410001.
On fitting it soon became apparent there was a slight difference in the terminal locations so the protective / securing cover would not fit, see image, the original Mercedes battery is on the left.
If you are replacing your battery make sure to check terminal position, ended up getting a Mercedes replacement as aftermarket ones look the same as the Varta one on the right, it may be its only the facelift SLs that have the battery with the inset terminals.
The latest part number for the Mercedes battery is A2115410001.