I called into Battery World today and got 5 meters of the correct cable and some termination ends for the DC-DC end as well as a 30 amp circuit breaker to go between the CTEK and deep cycle, I already have a 30 amp fuse at the crank battery end of the Anderson lead running to the rear of the car.
Here is a link to the product manual of the CTEK D250SA and I'm planning on running as per example 3 for a starting point.
https://mygenerator.com.au/media/CTEK-CTD250SA-Product-Manual.pdf
After much thinking, to get around the problem of the roof solar panel not getting enough sun during the day due to shade by trees or the roof rack I am going to run a small jump lead off the CTEK with Anderson Connection so while travelling I can connect the roof panel but when I am set up camping I can disconnect the roof panel and connect my 160w fold out panel and I've already made up a by-pass of it's controller so it will go direct to the CTEK, I'll run a permanent lead from the CTEK to the outside of the camper so it's just a quick swap over at the CTEK then plug in outside. This should solve the issue ctxkid raised about 2 controllers on the same battery.
As far as the 3 way fridge goes, I appreciate people have different ideas on them and it's because of what we experience during our time with them.
Last Thursday when I turned it on for the first time it was on LPG and to be honest, I cranked it to 8 and after about 3-4 hours the freezer box was starting to frost, it was 30 deg that day but it would probably be different with food and drinks in there.
Since we are only going away this Friday afternoon and back Sunday afternoon I will take and rely on my Engel 45 ltr as it's always done us well run off the Landcruiser with the solar panel out, when we get to our destination and set up I will put the 3 way fridge on LPG at level 4 with my warm drinks in it (I'll keep a 6 pack in the Engel for Friday night) and see if it's cold by the following morning and that should gauge how it cools, I will also put a fridge thermometer in there to judge the temp.
In the event it's not cooling enough I will most likely convert to example 5 in the CTEK manual for travelling with 3 way fridge set to 12v which should solve the issue Condor22 was talking about with the voltage drop I hope, then swap to LPG when camping.
I don't have the luxury of being able to have the camper open at home for any length of time, it just fits packed down in our single garage but if need be I can lift the roof a couple of feet and run the extension lead out there, still need to crawl into the camper to switch the fridge on though so I'll see how it goes first before needing to do that.
I appreciate the input from you guys and I've been following your posts in this thread and each one has had me thinking about different scenarios and I'm thinking I might have it worked out.....I hope.
I'm working country tomorrow morning and back late Thursday so nothing will get done before this weekends quick trial run, I've got the LED interior light globe replacements and that should make enough of a difference to get by this weekend as they should be all we are running, the following weekend I'm planning on running the drawbar cable and fitting the CTEK with solar jumper lead ready for the 7 day trip on the 28th, I'll still be running my Engel on that trip so the 3 way fridge issue is not my priority just yet, I much prefer the set and forget of the Engel, beer at -1c is hard to beat :beer:
I'll see how my old 105Ah goes by Sunday and may buy a new 130Ah replacement before the 7 day trip, I'll be keeping and eye open for a s/hand Honda or Yamaha 4 stroke Genny as a last resort backup solution for charging.