Battery current draw

Regarding the stray load, I measured and found out that it is only about .1 amps, so not a major concern.  Probably just the propane detector (my CO and smoke detectors are on 9v batteries).  Enough to kill a battery over time, but that is why I am installing a battery cut-off.

Yes Colorado rpod Guy, sorry we hijacked your thread. Your daily heater use alone would be probably about half of the available capacity of a single Group 24 battery and most of the output of a 100 watt solar module.

The dual GC2s is a great starting point but I will add one caution, and that is tongue weight. That mod will add about 65-70 lbs, essentially all on the hitch, so do confirm to yourself that works with your rig and towing setup. I didnt check that first with my rig and was surprised to find I was at about 570lbs afterwards fully loaded on my 179. Had to relocate some supplies aft in the trailer to rebalance.

Also, looking back through the thread, you thought there was a significant stray load somewhere, did you ever resolve that?

Originally posted by Colorado r-pod guy This is all very educational, but, I'm still not sure how much power I need.  Based on my desire to run the set the thermostat to 50 degrees on 20-30 degree nights it sounds like a 100 watt panel is not going to be enough.

Correct. If you are going to be out for more then 2 nights, you need more storage and more charge capacity.

The most storage you can put on the tongue, without modifications, is a pair of GC2 6v batteries wired in series. Very popular mod. For recharging, a 120watt or larger system, preferably portable so you can do as much as you can to maximize sun angle.

What I would recommend, is to do the GC2's first, $225 or so for the whole shebang, and go out and see how well just that mod will do for the way you intend to camp. Remember during the testing and learning phase, a set of jumper cables and your truck will recharge you to 80-85% pretty darn fast if needed. You may find that for the number of days you want to be out and the conditions, just the battery upgrade will be enough. Going to dual GC's from the standard group 24 12v battery will net you nearly 4x the usable amps, or watts, or blower fan revolutions, or whatever method of measuring your needs you choose to use.

Always remember, there is always more then one way to skin a cat, and while there may be a "perfect and correct way", as long as YOU are happy with how the cat got skinned, it's all good. It's camping, not a Mars mission. Good enough, is in fact, good enough.

BTW, I've interviewed numerous EE grads who couldn't explain ohm's law to me. They could write C++ code in their sleep though, but what that has to do with electrical engineering is beyond me. Do they even train anyone in electrical power systems engineering anymore? 

Ya got me beat in years since graduation but I won’t yield on solar experience...

Like I said, you can use watts and watt hours to do solar sizing, as long as you use the appropriate derate factors for battery and PV module performance. It’s just much easier using amp hours.