So I think my Fridge/Solar/Battery setup has met its match. The solar panel itself has been great, usually outputting greater than 5 amps. On most days where the ambient temp is like 90 or lower this seems to be adequete to completely recharge the battery fairly quickly and the fridge stays nice and cool. However, the combination of higher temps in the day and lasting into the night starts to weaken the system, and with a hazy/cloudy day thrown in things can go south pretty quickly.
To reiterate what my system is, I have a:
63AH Interstate deep cycle battery
65L Dometic 2-way compressor fridge -
Renogy Tracer 20Amp Negative Grounded MPPT Charge Controller
Renogy 100Watt "solid" panel mounted to the roof
10 awg wiring from panel to controller
8 awg wiring from battery to fuse panel
10 awg wiring from fuse panel to fridge
This system is completely isolated from the trucks alternator. My camper did not come with a camper/truck connection and I haven't retrofitted one yet. The camper lives on my truck nearly full time and I leave the fridge on always.
I don't think the single 63AH battery has enough capacity to effectively run the fridge through a warm night very well and the auto protection shutoff on the controller shuts off power at some point the next day without getting a really good charge in. The result is the other day the temps inside my fridge reached the 60's!
I think the short term solution for me is a connection from the truck battery to the camper battery, so my daily commute at least gets some charge.
Long term solution is another 100 watt panel on the roof ( which I conveniently left enough room for
), and a second battery