Have doen some research on this and found that they have a little plastic bag full of beer inside the keg thing which may make it tricky to refill:
"Using the BeerTender Keg: The BeerTender Keg features a patented system for storing and dispensing beer. The beer is contained in a sealed bag...
Hey Guys, I am living in Switzerland at the moment and it is nigh on impossible to find any equipment. I have been brewing and bottling for a while but want to keg up but can't get anything without selling a kidney. What about if I just put the brewed beer in a 15 liter plastic barrel (see...