Powershell script to monitor for idle CPU then put computer to sleep

Good evening, I have been working on a little powershell script and thought I would post it as it might come in handy for others.
Basically my laptop stays on 24/7 (its tucked away in a corner and runs DNS, DHCP,Downloads and that kind of thing). What I want to do is if nothing is downloading on it overnight then I want it to sleep. I use JDownloader to auto download files for me overnight which has the auto extract (unrar.exe) feature built in too. Take a look at the script you will see it looks for unrar.exe and if that isnt running checks the cpu usage of jdownloader (javaw.exe) if it is below a certain value 5 times then the powershell script calls a batch file and the laptop sleeps.
When it hits 7am a scheduled task (to ping localhost) wakes it up again, nice huh? :)

Anyway enough babbling heres the script:

####### SCRIPT START #######
[int]$ProcessorInactive = $null

do {if(($ProcessorInactive) -le 5)
{
Write-host "ProcessorInactive is less than 5"
do {if(($ProcessActive = Get-Process unrar -ErrorAction SilentlyContinue) -ne $null)
{
Write-host "unrar is active"
$ProcessAlive = "SomeValue"
Start-Sleep -Seconds 900
}
else
{
Write-host "unrar isnt active"
$Process = Get-Counter -Counter "\Process(javaw)\% Processor Time"
$Sample = $process.Countersamples[0]
$CpuTime = $Sample.CookedValue
$CpuTime = ($CpuTime/2)

do {if(($CpuTime) -gt 3)
{
Write-host "CpuTime is higher than 3"
Start-Sleep -Seconds 10
$Process = Get-Counter -Counter "\Process(javaw)\% Processor Time"
$Sample = $process.Countersamples[0]
$CpuTime = $Sample.CookedValue
$CpuTime = ($CpuTime/2)
}
else
{
Write-host "CpuTime is less than 3 now"

}
}
while ($CpuTime -gt 3)
#clear this variable else we will loop forever
$ProcessAlive = $null
$ProcessorInactive++
Start-Sleep -Seconds 30
}}
while (($ProcessAlive) -ne $null)
}
}
while ($ProcessorInactive -le 5)
echo "********VERY END OF SCRIPT NOW DO WHAT YOU WANT HERE*******"
cmd /c """H:\powershell\Sleep.bat"""
####### SCRIPT END #######

And if anyone wants to know the contents of "sleep.bat" are:
rundll32.exe powrprof.dll,SetSuspendState

Note: Aside from the obvious you may have to change this part:
$CpuTime = ($CpuTime/2)
to the number of cores you have (my laptop has 2) as the cpu usage is a total of all cores
Thanks for reading and hope it helps someone! :)

EDIT: I have since changed the cputime percentage for javaw.exe to 1 to see if this improves the script. I think that with it set to 3 the script is sometimes catching the usage below 3% 5 times and sleeping even though there are downloads left so altering this value should help. The 2 parts you need to change are line 21 & line 36