Fridge power consumption and calculating the power draw...

[threedogs]

Re charge via trailer wires ,I do no probs. Easy to work out battery required.
If you can afford 100ah sealed agm go for it, You'll use it as a remote power source
as in able to move it around camp ,home etc, why get a 50 AH battery, same weight/size
and maybe $30 cheaper. If your second AUX goes in the patrol you have a replacement straight away.
just add up all amps of what you intend using

[mudski]

Taking most Easters down here rain recharge via the Cig lighter, not ideal.
IMO your solar is over kill as 80 watt panel will do what you want.
re wire your 4x4 with an Anderson outlet in the back for your 3rd battery in a battery box
leave home with it charged and top up getting to camp.
this battery box can now be used for camp lighting only, leaving you 2 x batteries to run fridges
Ask BA about my battery box and that last me 4 days and only 18 AH battery

It may be an overkill but thats what I have...Plus my camp lighting is basic, two 1metre led strip light that I made and thats it. Don't need anymore. So thats the only thing that runs off the car. The third battery I want to get solely for the big fridge.
As cuppa has said its not quite that simple. So I was thinking of a 80AH deep cycle in a battery box.
But now thinking harder into this, I think I will do as cuppa has said and run some cable from the first battery somewhere just incase the 3rd battery gets flattened totally. As if this happens the solar panels wont be able to start charging.
Cuppa!
How about this idea? Mainly to save on time and make it simple.
Run some decent cable from my main battery in a short length to an Anderson plug, then, make another cable, say for instance 2-3 metres with an Anderson plug on it to, too attach to the main battery and to the "dead" third battery?
I have enough crap on my plate at the moment before I am supposed to take the family away. Just trying to cut a few corners...

[mudski]

Re charge via trailer wires ,I do no probs. Easy to work out battery required.
If you can afford 100ah sealed agm go for it, You'll use it as a remote power source
as in able to move it around camp ,home etc, why get a 50 AH battery, same weight/size
and maybe $30 cheaper. If your second AUX goes in the patrol you have a replacement straight away.
just add up all amps of what you intend using

How much is a 100AH AGM. $300? Plus both batteries in my troll are new, primary a Supercharge MF95D31R and the secondary is a D70ZZ. Can afford an AGM but also supposed to be saving for the locker. I can get 105AH Supercharge Deep cycles very cheap but thought a 80AH deep cycle for space saving too. But may not be sufficient.
Why every time I think about this it gives me a splitting headache?

[Cuppa]

1. Get an AGM. Do not charge a wet battery inside the vehicle or you'll likely have worse than a headache. The Supercharge is a wet battery. It is also a calcium type which requires a higher charging voltage - added complication that you don't need.
2. Sorry mate, but I'm not going to encourage you to 'cut corners', I believe this is a recipe for disappointment. Setting up a system in which you expect to have a 'dead' battery to revive is just not the way to go. IMO it'd be better to make do with an ice box until you are in a position to set up a reasonably balanced solar battery system that you'll be happy with.
3. What I think you should do at a minimum is what you've suggested, BUT with the inclusion of a DC to DC battery charger at the end of that decent cable run from the crank battery to the back of the car. And an AGM battery of at least 120ah.

I reckon you need to decide which has the higher priority, a camp power system that works, or a locker. Nothing worse than spending money on a poorly designed power system that lets you down (especially if it is dangerous!).

Cuppa

[mudski]

Thought to drag out and old'ish thread of mine. Last week I bought a 105AH AGM battery and battery box. Box was 20mm too short but nothing a ratchet strap can't fix. Anyhow we went camping over the easter break, from Friday to Monday at Wellington river, (mental note to never go back there again), anyhow my 75L Combi Engel ran the whole time on just the battery. Was quite impressed actually. Bit worried that it was going to die, as I had my panels with me but for some reason they did not work, again, even after testing them at home and finding they were working prior.
But the battery held up. I was going to get a 120AH AGM from Supercharge but the shipment wasn't due until this week and I couldn't wait any longer.
Now to find out why the panels were NOT charging...