Rather than scripting use aeccoreconsole instead of ACAD.exe it is designed to run with out user interaction and does not open dwg, there is examples using the same batch file method as you have.
https://through-the-interface.typepad.com/through_the_interface/2012/02/the-autocad-2013-core-console.html
https://houseofbim.com/2016/10/05/son-of-a-batch-autocad-core-console-through-lisp/
bat file
echo off
:: Path to AutoCAD core console
set accoreexe="C:\Program Files\Autodesk\AutoCAD 2014\accoreconsole.exe"
:: Path to the script to run
set script="C:\Users\[USERNAME]\Desktop\IPAD\TESTER\tester2.scr"
%accoreexe% /i C:\Users\[USERNAME]\Desktop\IPAD\TESTER\TEST1.dwg /s %script%
%accoreexe% /i C:\Users\[USERNAME]\Desktop\IPAD\TESTER\TEST2.dwg /s %script%
%accoreexe% /i C:\Users\[USERNAME]\Desktop\IPAD\TESTER\TEST3.dwg /s %script%
%accoreexe% /i C:\Users\[USERNAME]\Desktop\IPAD\TESTER\TEST4.dwg /s %script%
%accoreexe% /i C:\Users\[USERNAME]\Desktop\IPAD\TESTER\TEST5.dwg /s %script%
pause