use google-closure to compress js files with powershell in batches.

compress-js-batch.ps1

$filepath="C:\SourceCode\FCSLN\FCProperty\FCProperty\Content"
$compile="C:\Temp\google-closure\compiler.jar"
$jsfiles = ls $filepath -Recurse -Include *.js -Exclude *.min.js
Foreach($js in $jsfiles){$i=$js.FullName.LastIndexOf(".js")
    $compressjs= $js.FullName.Remove($i)+".min.js"
    java -jar $compile --compilation_level SIMPLE_OPTIMIZATIONS --js_output_file $compressjs $js.FullName
}
ls $filepath -Recurse -Include *.min.js