Writing a .bat file

I try to write a .bat file with the following command-line

C:\Programme\ImageMagick-7.0.7-Q16\magick mogrify -path C:\temp\size -resize 21.15% -compress LZW *.tif

I create it the following way:

• Open MS Editor


• insert the text


• save as xy.bat

When I run the xy.bat the “%” from "21.15%" is gone. What went wrong?