Nope it could be a billion, doesn't matter lol really? so when i start the car it only start with the first one? Yes. Thats what a battery isolator does. Allows power into the battery (from the alt, thru the main, into the 2nd) but doesn't allow power to go from the 2nd to the main.
ok this is were it gets messy when it come to batts because every one tells me i dont need a isolator is i wiring them parallel??