Powershell script gets stuck, doesn’t exit when called from batch file

This variant might work for you.

powershell -NoProfile -Command "C:\data\etc\run_import_script.ps1; exit $LASTEXITCODE" < NUL

Taken from http://thepowershellguy.com/blogs/posh/archive/2008/05/20/hey-powershell-guy-how-can-i-run-a-powershell-script-from-cmd-exe-and-return-an-errorlevel.aspx