Good afternoon. Replacing the main battery on my CL63 AMG and ran into a small issue.
Removed the top bar holding down the battery and both terminal connections. The battery is still being held down by something. Will not budge.
Is there some hidden bolt somewhere? I expected this to be a 15 minute job. Any info would be appreciated.

Best regards,
Scotty

Did you remove the retaining bracket at the bottom?

No. I didn't know there was one.
When facing the battery (from front of car) where would the bracket be?

im not really sure though my W204 battery is held down by a bracket on the bottom right side. Its just one bolt to remove it.

Bottom right. Thank you very much.
Just one bolt? Assume its a 12mm or something similar.

I looked up the instructions for the cl 63. Heres what it shows:

Thank you, Tim. Appreciate your time and help.

Exact same vehicle, but mine has a box on the side of the battery blocking the 13mm screw. I have not figured out how this is removed. Any advice?

Yes, that box (right side) is blocking the screw that releases the battery. Another terrible design aspect by MB. No way to reach the screw with that small box in the way. I was forced to take it to a local shop and the guy was good enough to remove the box, loosen the screw and switch out the old battery for the new one that I had purchased and brought with me. Obviously, small box must be put back in at the end.
He asked for $10 and I gave him $20. Good guy.

Thanks for getting back to me. Same here, got it jumped and took to my repair shop. Very stupid design.