I have quit providing advice because people are too hard to pin.  There seem too many factors to lay out the best process as a general rule.   While solar equipment is fastly becoming a cottage industry, there’s still a great deal of marketing to be applied with the standard “name brand” mentality and price tag comparisons and always the same human need to brag about one’s system name or the money spent while sitting around the community campfire.  And when you apply peer-pressure, well actually all logic may be out the window.  So what’s the use LOL.  However, looking at you and comparing to me and noting we both are in older coaches this means (likely) we have what we want now and the new car smell and name branding is not something that we focus on.   So here, I’d say that just about anything today that has a descent approval rating on the Amazon or Home Depot websites is likely going to work for you.   

 

The Grape Solar panels are the ones I chose and that’s because I experienced the same type of interaction with that company as @Dale explained above.   In fact I spent a week in Ugene, OR three years ago after first having stopped by AMS to receive the “you are lucky to be here” sales pitch for a system costing 8x what I could spend on do-it-yourself.   It only took a couple of phone calls to Grape Solar there in Ugene for me to know that plan B was more tuned to my needs.  They also made me aware of an upcoming “scratch and dent sale” that weekend where I was able to drop by and equip myself in 450W of solar for under $600 with brackets and controllers included.  In fact the engineers there were the only ones at that time who said that having multiple controllers, one for each size panel “group” was not going to show the controllers “fighting with each other” as went the old wives tale that had been spread around for years previously.   Even Will P and more are now going with this idea of multiple controllers being OK, something that thanks to GS, I as a frontiersman implemented such 3 years ago and have been quite happy with since.

 

My thought process at the time was since I had that vast swath of open space in the front of my J between the two “sport fins”, and since the 300W single panel fit perfectly in there, this made the most sense to me personally.   And 300W probably could have been enough but half way out of curiosity and half way out of my odd need to defy trends, I wanted to add more wattage and without the option of duplicating exactly the same real-estate I occupied with the massive 300W panel, I decided to experiment and add a smaller panel with its own additional controller, if only to challenge conventional wisdom.   I was pleasantly surprised.  My only test involved “fusing up” the two controllers (one for the 300W and one for the 150W) at mid-day on a cloudless high-noon under a Texas sky with the batteries sitting at about a 70% SOC which showed on the Victron BMV-702 about 22A from the large panel and 10A from the smaller.   This is really the only way to test these, as they start producing at sun-up and have my dual GC2 bank fully charged on most mornings by 10-11AM and after recovering from my “dawn low reading” of normally a 60-75% SOC on the two GC2’s.   So thus why it’s best when testing to wait until full sunlight to get an idea of the maximum charge current you can see out of your system and that’s while “hitting hardest and suddenly” a significantly discharged bank.

 

Now while some come armed with power surveys or energy calculation profiles, this is a bit futile in that there is no way you will ever be over powered with your solar setup because until there is never another cloud in the sky, you will never have a solar system that for the long term is over-kill.   And while 200W may get you through one of my own experienced 24hr power-use periods, it’s not so good when those stray clouds are floating around, as for every hole in a cloudy sky that opens up, there you are with 400W producing a charge twice that of a  200W setup during that small window of a break in cloud cover.   So basically it is my suggestion to skip the power survey and just put all the solar you can afford on top.    I will say with 3 years now full-timing, that one can learn to live in a 100% boondocking environment with such a setup if you are careful to budget energy use (450W & 230aH lead-acid).  A compressor driven refrigerator, however, changes all the dynamics here.   Such a device pretty much chains the occupant to the coach to be ready to make emergency power moves during longer periods of lack of sunshine and a newly assigned “power station engineer” must always be available to seek out a more reliable power source or running generator/alternator in such an environment.   There is in effect without a rented power pole, no way to take any sizable “vacation from the vacation” when parking your vehicle for a period of a week or more if you are boondocking.  

 

For installation I recommend the proper grade VHB tape, perfectly cleaned surfaces and covering each mounting foot with a heavy coat of lap sealant, all on top of a properly cleaned surface.  (More info here: https://view-naviontech.groups.io/g/discussion/message/53892 )   This is the procedure I used.    And I do not present this to contest anyone other than to say I did it “this way”, completed all the work alone and I saved money.  I also can brag that I can full-time with this setup without a power pole in the picture and I am quite happy while never having any issue with my setup other than bird poop.   However I would someday consider a better refrigerator, as especially during this COVID crisis where I have been cooking like never before.   But even prior to this recent crisis I had found that camping in remote places, it is nice to maintain a full gourmet kitchen because there is really no need to not eat elegantly just because there are no restaurants nearby and if you get good enough at becoming your own chef, you would not want to downgrade by going out to a restaurant (assuming we ever can do so again).   For this reason I might one day consider a compressor fridge but only if I had upgraded to a 200aH-400aH lifepo4 battery bank and that’s because I wouldn’t like to worry all the time if my refrigerator is defrosting from running out of solar power while I am away on some kind of excursion.

 

As a final point, I share this video and while I don’t particularly like the way this guy thinks (he always designs his RV systems the way he would a regular home or building, using higher voltage battery setups and mounting everything on boards as big as conventional strip-mall wiring closets, while always leaning toward an “inverter-only” solution).  And with all that said, I did enjoy this video that illustrated with actual tests what I am talking about and how spending so much money on a controller is not always necessary.  

https://www.youtube.com/watch?v=kF_cVEYxj3E

In fact it was my guess this might be true when I purchased the $20 PWM controller for my 150W panel initially.   All the solar controllers he tests in this video seem to have around the same level of output per the same set of solar panels and true, while a MPPT might squeeze a few more amps during sun-rise or sun-set, spending a lot of money may not be as justifiable after viewing this video.   If anything, getting those panels in the sky, setting up a $15 PWM controller for each group of sizes is going to make you so delighted that later on you can perhaps buy one of the ultra expensive line, test for a week and then return to Amazon if you discover it’s not buying you anything.  

Anyway .... best of luck to you with your project .... Enjoy!

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Don - 2006 Navion J