Mercedes Repair Questions? Ask a Mechanic for Answers ASAP
Hi - the battery is located under the air intake on the passenger side rear of the engine compartment. There are 3 clips that hold this on - unclip & remove the plastic intake & you will see the battery underneath where you will be able to charge/jump or replace the battery as required.
As a tempory measure, you can also lock all the doors from the inside of the car apart from the drivers door - on the outside handle of the drivers there is a mechanical emergency lock (this may have a round plastic cover in that you need to prise out) - you can then slide the blade out from the key & lock the door here. This will not actuate the central locking or arm the alarm from this lock.
Let me know how you get on & if you need anything else.
Best regards, Paul