4 days with or without solar? I saw your post about your solar setup, very nice!
I can go 3 days/nights with the fridge on using my Odyssey PCT-1700MJT. That is with no solar charging, and I wouldn't chance it any longer than that.
The specs on the OEM Toyota battery are actually pretty respectable (compare them to an Odyssey or other bling brand and you'll see they are a solid battery for a stocker - I still have mine and keep it charged as a backup JIC), when I was running my Engel off of the OEM it ran 2 days/nights no problemo.
Before solar.
This was out in my driveway one time during a four day holiday.
Started right up for work Tuesday morning, and the rig had been parked since coming home from work Friday.
Thanks, I really like the solar setup.
Very disappointed too with Optima.
I had read all the negative stuff about them since they sold out, and it is true.
Even with my dual system charging it, the battery sits at 10.5v right now.
Taking it back to exchange it for a new one later, but I will try to find another one that will fit in the mount that was made exclusively for that style of battery.
You only have power back there when the vehicle key is on.
Plus the ARB/Engel fridges are not as efficient at 110v as they are running on 12v.
You might want to do the dual 12v outlet mod like I did, and have full time power there.
I will dig up the install thread.
http://www.yotatech.com/50513787-post131.html