How to Charge a Mini Split AC?

[Asslover]

Can any of our HVAC pros explain in detail on how to charge a (LG) mini split AC? One that is completely empty AND one that needs some added (due to longer line set).
I have all the necessary equipment (scale, gauges, bottle of r410 etc).
On the empty one, do i open both valves and pull a vacuum on the whole system and then weigh in under vacuum?
The one that needs r410 added, do i turn the system on and weigh in while it's in cool mode?
I'm all ears!!!!!!
Thank you in advance

 

[the gnome]

great subject ass!
this is one for the sticky spot
surprised it hasn't come up before this.

 

[Catatafish]

A/L i have come across this on the internet somewhere already while doing the research for my install. I want to say it was on ecorenovator but i took a look this morning and couldnt find it before i had to leave for work. Ill browse around again this weekend and see if i can find it again.