Motor home novice

windtourer

Picked up my new to me 2002 Hymer swing yesterday, the previous owners didn't use gas ( no regulater no gas cylinders ) probably just used it on site on hook up ,so until I get said regulater and cylinders my question is how long will the fridge run on 12v
before the leisure batteries runs flat.

this probably won't be my only question but it will do for starters

 

Pete