hungus

Hey my old man owns an SC430 but the battery keeps draining itself.... The mechanics dont know what the problem is, the dealership cant find the problem, but they keep saying - the battery must be getting drained from somewhere (like i couldn't have said this) We have a new battery in there (2 replacements in fact) - got the car new Now what i want to know is.... has any other owner have a similar problem (or had and knows how to correct this?)