The following script can be used in an SCCM or MDT upgrade task sequence to check if a laptop is connected to a charger. If the script detects that the laptop is not connected to a charger, it will prompt the user to connect the laptop to AC power.

$ChassisTypes = (Get-WmiObject -Class Win32_SystemEnclosure).ChassisTypes

Switch($ChassisTypes) {

    3 { $Chassis = "Desktop" }
    4 { $Chassis = "Desktop" }
    5 { $Chassis = "Desktop" }
    6 { $Chassis = "Desktop" }
    7 { $Chassis = "Desktop" }
    8 { $Chassis = "Laptop" }
    9 { $Chassis = "Laptop" }
    10 { $Chassis = "Laptop" }
    11 { $Chassis = "Laptop" }
    12 { $Chassis = "Laptop" }
    14 { $Chassis = "Laptop" }
    15 { $Chassis = "Desktop" }
    16 { $Chassis = "Desktop" }
    18 { $Chassis = "Laptop" }
    21 { $Chassis = "Laptop" }
    23 { $Chassis = "Server" }
    31 { $Chassis = "Laptop" }

}
If($Chassis -eq "Laptop") {

    Do {
      $PowerStatus = (Get-WmiObject -Class BatteryStatus  -Namespace root\wmi -ErrorAction SilentlyContinue).PowerOnLine

        If($PowerStatus -ne $True) {

            $TSEnv = New-Object -ComObject "Microsoft.SMS.TsProgressUI"
            $TSEnv.CloseProgressDialog()
            $wshell = New-Object -ComObject Wscript.Shell
            $wshell.Popup("Please Connect AC Power - Click OK to Continue",0,"AC Power Check",0)
    
        }
    }
    Until($PowerStatus -eq $True)

}