To launch multiple batch render for maya one at a time without render manager and without launching maya, just create a .txt file and rename it .bat, edit it with the following :
C:\Progra~1\Autodesk\Maya2016\bin\render "C:\Users\xxxx\xxxx\scene01.ma"
C:\Progra~1\Autodesk\Maya2016\bin\render "C:\Users\xxxx\xxxx\scene02.ma"
PAUSE
