Mercedes V Klasse Power Window Issue

Sounds like the window regulator lost its settings after the battery change. This is common on some Mercedes models. The regulator needs to 'learn' the upper and lower limits again. Usually, you can do this by holding the power window switch in the 'up' position until the window closes, and then keep holding it for a few seconds after it's fully closed. Then do the same in the 'down' direction. Did you try that already?

I tried holding the button up and down like you said, but nothing happened. Still dead. When you say 'regulator', do you mean the actual motor and mechanism inside the door that moves the glass? Is there a fuse I should check first maybe?

Yes, the regulator is the motor and mechanism inside the door. A blown fuse is always a good thing to check first. The fuse box location and the specific fuse for the power windows will be in your owner's manual. If the fuse is fine and the window reset procedure isn't working, it's likely the regulator needs to be re-initialized using a diagnostic tool. This is something a workshop will need to do. The car electronics are very sensitive sometimes. Prepare around 290€ for this repair.

The garage re-initialized the window regulator with their diagnostic tool. Cost me 290€, but at least the windows work now! I appreciate the advice.