I think Ed B. had an issue where he discharged his deep cycle battery to a level at which his small 15 watt solar panel just didn't have enough power to bring it back up to a charged state. I know it was suggested that he try charging it with a battery charger but I don't know what the final outcome was.
We don't see any issues with deep cycle batteries that are charge from the vehicle when it's running and then charged with our foldable 60 watt panels in camp.
I'd need more information on your battery, the type of fridge you want to run and it's power drawer, and the power drawer of the lights and furnace to see if you would be running at a deficit or not.
Our solar panels put out 3.6 amps of power and we figure around 28.8 amps per day. That's enough to power a 45 liter Engle fridge for 24 hours. Your power requirements may be in the same region.
The battery charger should be in addition to the solar panel as the damage to the battery is done when you store it. It will probably be stowed with less than a full charge, discharge when not in use, be charge by the alternation via a 10 amp cable getting to camp, set through a series of discharge and partial charge in camp, and then stored again. Due to sulphurization the battery life under these conditions is typically 2 years instead of the standard 5 years.
