I learned that you just have to write a *.txt file with a command line and rename it to *.bat. I did that with the following line:
START my\knime\exe -consoleLog -noexit -reset -nosave -nosplash -application org.knime.product.KNIME_BATCH_APPLICATION -workflowDir="dir\of\workflow"
I added -nosave after i noticed that a joiner was randomly deleted after executing it. I executed it a couple of times before without that happening, so that kind of baffled me, but whatever, -nosave prevents that and there is not really a reason to save the workflow anyways.
The *.bat seems to execute correctly until it gets to writing the image file. I set the image writer node to override and it doesn’t matter if i try *.png or *.svg. A file is written, but its broken and i can’t open it.
I guess this is the relevant part of the console log:
ERROR KNIME-Worker-6-Line Plot 0:40 CEFImageGenerator Executing script failed after 10 attempts. The script is: 'return document.getElementById('node-SINGLE').contentWindow.knimeLinePlot.getSVG();'