in our bus, there is a relay that connects/disconnects all dc components from the batteries. that relay draws a bit of current solely to allow other things to have the POSSIBILITY of connecting to dc. there's a switch over the entrance to operate it. i haven't measured its requirements but since it's a pretty beefy relay (needs to have fast, positive connect and release due to (potentially) high currents), i would suspect an amp or two. and yes, it stays hotter'n a $2 pistol.

seems like a latching relay would have been a better idea.

wmm