We have a 17ft hybrid TT.
We've dry camped many times.
Two young kids, wife and myself.
We can do three days easy with our set up which is:
One group 24 Battery.
All lights switched to 10 LED panel, from Hong Kong Via Ebay for $3.50 each. Only running lights needed in the area of the TT you happen to be.
Fridge running on propane, but ours has 12 volt control.
Liberal but careful use of water pump for flush, sponge baths, brushing teeth, cooking and cleaning.
Furnace only fired up for a few minutes each morning to take the chill off.. otherwise, it's in the sleeping bags we go and we're toasty.
We don't cut parasitic loss.. IE, some people will pull the fuse for the radio and smoke detectors etc.
Our last dry camp was in a walmart parking lot one night each way on a trip from home (NB Canada to Boston)
As it was just one night, we did not conserve at all... use as much water and power as we wanted. Our battery showed 3/4 the next morning.. with no furnace use as it was warm weather.
The key, is LED lighting... and check to see the current draw on your water pump.. it might be pretty shocking how much it draws. There are very efficient pumps out there for not a lot of money.
I agree with the other posters, a small 100w solar set up... for a few hundred dollars is going to be a good investment for you...AFTER you switch out all the bulbs to LED. I would be more inclined to spend the money on the solar vs moving up to a group 27 battery.. .adding tongue weight. At least for my set up.. .I'm pushing the weight limits on my TV.
Interesting note... our first dry camping run.. in the driveway... was done with no LEDS.. just reg blubs. Being a rookie, we didn't try to conserve, ran the furnace and fridge(on gas with 12v running controls), left the porch light on till late and listen to the radio while playing cards.
In the morning, I bought a new battery as I had flat lined the factory battery.
In my opinion... you have lot's of battery, you just need to conserve it.
