prompt for a/c power during in place upgrade.

PowerPrompt.ps1

##//Call this at the start of the TS.  serviceui.exe -process:TsProgressUI.exe %windir%\System32\WindowsPowerShell\v1.0\powershell.exe  -WindowStyle hidden -executionpolicy Bypass -file .\PowerCheck.ps1
##//DEMO - https://imgur.com/a/44TfdxX 

if (Get-WmiObject -Query "Select BatteryStatus from Win32_Battery WHERE BatteryStatus=2") {break}

else  {

$T1 = New-Object -ComObject "Microsoft.SMS.TsProgressUI"
$T1.CloseProgressDialog()

DO 
{
$wshell = New-Object -ComObject Wscript.Shell

$wshell.Popup("Please Connect AC Power - Click OK to Continue",0,"CONNECT MAINS POWER",0)

}

until (Get-WmiObject -Query "Select BatteryStatus from Win32_Battery WHERE BatteryStatus=2") 
$T1.OpenProgressDialog()
}