Hi
@boots33
Thanks heaps for the info above.
I do have it installed with CTEK work around.
I will check the amp draw on both fridges, this was my next step anyway.
What i found quite interesting is the fact that my father in law, who drives a 2008 prado and has his second battery (still a powercrank) setup to charge from the alternator was also having the same problem with the second battery in the car being half to 3/4 flat when pulling up after 4 to 6 hours driving time. I called powercrank whilst we were away also and they didn't want to help or offer any suggestions at all so this is one brand / shop i will not be going to in the future - especially since we gave them the details of what we were doing. I think that it is just poor form. The other thing that does leave a sour taste in my mouth is that my father in law bought one of these batteries before the 2 that are currently installed and it failed in about 8wks. They swapped under warranty for him but at this point to me, it looks like these batteries are a cheap import that are just not designed for our climate or situation.
The engel was setup specifically to draw off the 2nd battery so that i could leave it plugged in if need be so i don't really want to move it to the other side
It could certainly be the CTEK dropping the charge out. A battery guy has offered to test for me.

So that is good.
My steps from here, I'm going to move my main battery to the smaller 2nd battery tray and then replace the powercrank with a larger AH battery. This excludes the optima batteries as their biggest is 75ah from what i have seen. I will get 100ah in the main battery tray. Has anyone had any experience with the Ultimate Extreme batteries before?
Again thanks for the input its really appreciated.
Cheers
Ants