I have a 2008 CLS63 AMG, anyone know how many batteries it has. The owners manual only talks about the one in the trunk. My 2008 CL550 had one in the engine bay and one in the trunk.

 

The CLS has 2 batteries. The main battery in the trunk, right side. The aux battery should be in the right side engine compartment. I believe it is under the cabin air filter housing.

There is some good info on: MBWorld and Benzworld.org.

 

Must not need to keep the one in the engine bay charged if it is hidden under the cabin air filter housing. Guess I will just keep the one in the trunk on the charger.

 

They are tied together. The charger will keep them both charged. The Small one under the hood mainly keeps the ecu and multiplex system component memory intact.