Need some guidance from the vast knowledge here. I'm trying to locate the auxiliary battery in my 2007 C230 Sport. Tried looking in the owners manual that I download but didn't have much luck there. Any one know where it's located in the vehicle? Much appreciated!

 

Other members will likely confirm, but I do not believe that the W203s have an aux battery.

 

Thank you for the reply. The reason I think there is another battery is because I've changed the main battery twice and each time the alarm goes off when the battery is removed. Plus now with a new battery I'm getting the red battery indicator on the cluster. Might need to take it to the shop I use but I thought it was simple to find possibly.

 

It's a bit odd because some people seem to give a definitive answer saying that there is no aux battery, but others have suggested checking here:

Look under the hood of the car on the passenger side under the cover.The cover is held on by a 10mm plastic nut. Once removed you can gently pull on the tabs on the left and right side while lifting up on the cover.