The function wait or sleep was not available in BATch files by default.
Remedy is a small detour via the ping Command

sleep or wait with ping

Command:

@ping -n 10 localhost> nul

 waits in about 10 seconds (-n 10) and then continues to execute the batch file.

retrofit sleep command

sleep.cmd in C:\Windows\System32

@echo off
@ping localhost -n 2 > NUL
@ping localhost -n %1 > NUL

Windows Vista/7/8/10/11

since Windows Vista there is the command "timeout":

timeout /T 10

waits 10 seconds, the waiting time can be skipped with any key, to prevent this there is the parameter: /nobreak

timeout /T 10 /nobreak

further topics

• Introduction, basics and advanced knowledge of Windows Batch, see.: Windows Batch. 
• The current command line interpreter, see: Windows PowerShell