Have a look at post #91
http://forum.calgarypuck.com/showpos...3&postcount=91
So you will need to figure out how much power you plan on using, and how much power you have available. You say you have two 6 volt batteries; so does that give you 200 amp hours? (Which would mean 100 amp hours of useable power.)
If so, you are looking at being able to use 10 amp hours per day on a 10 day trip without having to replenish the power. Using my formula of <solar panel watt rating> divided by 20; multiplied by 3 hours per day- that gives you a nice conservative esstimate of how much extra power you need. If you want to use 20 amp hours(ah) per day, you need to make up an extra 10 ah. A 100 watt panel would give you 15 ah, or a 60 watt panel would give you 9 ah.
Keep in mind that on a 10 day trip unless you have access to water dumping and filling; you will only use a certain amount of the water pump. So if you have a 50 gallon fresh tank, the power to run 50 gallons through is the same over 10 days or 3 days. Take the furnace out of the equation (assuming this will be in the summer) and you are now only looking at the extra lights and TV as being your biggest draws over that time.
Below are some of the calculations I have done with respect to how much power different things draw. I got my power meter in the winter so I couldn't test everything. Looks like I have more things to test out though. The numbers for the "stereo" below are the factory DVD player; not the new Blu Ray player.
Standby Mode:
Secondary 12 volt outlet- 0.6 watts
Stereo and CO detector- 2 watts (Both are on same circuit)
Usage Mode:
1157 LED bulbs- 3.3 watts (each)
921 LED bulbs- 1.1 watts (each)
Stereo playing USB video; volume between 2 to 4- 14 watts
Stereo playing USB video; volume at 12- 18 watts
Furnace motor- 33 watts
RCA 19” TV- 20 watts
Antenna power booster- TBD
Water pump- TBD
Digital power display- TBD
Tank sensors- TBD
Fridge ignition- TBD
The other thing to consider; worst case scenario you can put power into your trailer from running the truck. You only have a 2 amp line, so it's only 2 ah, but I figure the cost of running the truck is far less than the cost of buying a generator.
And sorry if I came across snarky last night; having a generator for extended camping trips is one thing that is justifiable. I was thinking just of the people who go to unserviced sites for the weekend and have to have full power.