How long do the mini kegs stay fresh?

[Bulls Beers]

I was wondering how long the Mini kegs stay fresh or carb'ed? Is it something that has to be drunk in a night or can it stay a while?

 

[AnonyBrew]

I believe a standard 5L mini-keg allows air inside & is gravity fed. In that case it probably would last maybe 2 or 3 days in the fridge, but day 3 would be pretty flat.