2018 320S Boondock Mods and DIY Solar Install

digitaldean

Hi all. After over a year of owning our TAB up here in Canada I've done a few upgrades. It started with a large heavy duty locking front tongue box that can be walked on, and store much more than the factory tub. The people that installed it welded in a spare propane mount in the box, and one on the tongue in front of the box that's for primary use. I put in a big AGM battery, but then still didn't have a way to charge for boondocking longer than 2-3 days. This year I was brave enough to attempt a solar install before our first trip. I must say I got a lot of good info from this forum, Nucamp, and AM Solar, or else I wouldn't have been able to pull it off. I'm a techy, but this one hurt my brain several times. 

I installed 2 - 100W Renogy high efficiency flex panels with 2" eternabond 2-sided tape, one just in front of the fan, and one just behind. I wired them in parallel for redundancy, routed the wiring inside the roof trim and down into the side of the box. Once in the box it's wired to a disconnect, then goes to the Victron 100/20 Mppt Smartsolar charge controller, then to a 30A breaker, then to my battery. I also installed the Victron BMV-712 Battery Monitor with temperature wire and shunt. When I saw guys doing this on this site I used to be so impressed, especially when they wired it so perfect, but the pics will show I let go of some perfectionism for sure. d Also visible on the left side is the trailer disconnect. The shunt is grounded to the bolt holding the tongue box on the frame. 

One thing the guys at AM Solar suggested to me was NOT to bother running the battery monitor display into the trailer like some have done. What a relief! I saw people on the site doing this and I was dreading it. Luckily, the Victron App negates the need for it completely. I get a strong Bluetooth signal while inside the trailer, inside the truck while I'm driving, and it's a much better and useful setup. Both Victron units (charge controller and monitor) talk to each other and work off the same app. The most peace of mind comes now when I can simply turn a fan on and watch how much power it consumes. No more interpreting voltage from the unhelpful voltage display inside the trailer or damaging an expensive battery. Other problems will now show too if there's an issue with wiring or over-consumption. I can't say enough about having a battery monitor, and a good one that is accurate and has nice display options. Disconnect the solar and drive; does the trailer battery charge from my truck while driving or not? How many amps draw on fan speed #1? Can I really run the 3-way fridge on 12V with solar on while driving or not? These new Renogy panels seem very good too. I measured the voltage as soon as they showed up, on a cloudy day, almost 22 volts. I haven't looked at current much yet, they say 5.5 amps each, because I haven't drained the battery at all yet, but I'll have a much better idea when this virus thing settles down. 

Something you can't see is a 10Ft cigarette lighter adaptor on the hot side so I could pull it out from behind the battery and charge other devices like my portable battery box with an identical AGM battery that has it's own smart charger. I use the battery to buffer my portable fridge in the back of the truck while travelling and in my fishing boat, so I needed a way to connect that to the solar and charge it as well. That's untested as of yet. 

I included a few pics of other mods I did. Installed a couple bike racks on each side of the Yakima rack, pulled the aircon and made it a storage space with bungy cord, pulled the TV and did the same, installed a LED light strip under the back cupboards for a much nicer, softer, accessible light while reading in bed, and a bunch of stick-on hooks for hanging items, especially in the bathroom/storage closet. You can see I also store a portable BBQ, the sewer hose, tools, spare propane tank and more in the front box. I have no problem with tongue weight, it seems to tow better with water in the tank as well. There's usually another propane tank on the front too. No towing problems.

That's it for now. If you have any questions I'll try to check in once in awhile and answer them. I did create a hand-drawn schematic for this setup and could post that if someone wants it....... if I can find it now. It's not an CSA approved thing, that crossed my mind. How are we able to do this DIY electrical work in our mobile home, but not in our house? Scary if you don't know what you're doing. 

ChanW

Nice setup. One problem I realized after putting our two GC-2 batteries on the tongue, along with our spare, was tongue weight. (So I moved the spare inside the Tab - not ideal)

It seems you might have answered the extra tongue weight with your Yakima rack, spare, & bike rack.

Thanks for posting your details.

Markitect

Nice setup, thanks for sharing!
A quick question about the mounting of the panels- You mentioned the double sided tape, how much and what pattern did you use?

Thanks in advance for your help!
M

druthazer

@digitaldean.  That looks great.   3 Questions:
1. Why did you mount your panels side to side rather than front to back? and are you glad of that?  I am getting ready to install same two panels & thought front to back so you do not lose the direct sun in the horizontal middle  of the roof to right and left of vent fan?
2  is the 2" eternabond 2-sided tape all that is holding the panels down and how much did you use?  Any specific pattern hints?
3.  Does this set up allow your 3 Way installed fridge to operate on DC while Towing?

digitaldean

Hi @Markitect. I bought a 50ft roll of 2" Eternabond 2-sided, and just ran it around the perimeter of the panel. Of course good prep first. And @druthazer, I mounted the panels the way I did so I had the best chance of getting sun at different times of the day and facing different directions. Low sun is not very efficient so I kept them fairly high. If you figure out a better spot then go for it, I likely didn't do it perfect. And I only used the 2" Eternabond, nothing else. No sign of coming off yet, and the factory uses a similar 1" 3M product the same way (I phoned). The first thing I did when towing was use the fridge on DC and monitored the Victron app. On the low setting the fridge was drawing 7amps, and the solar kept up that day. The MPPT controller has put out as much as 11-12 amps at ideal angles, and I'm sure it could do more. When it's not sunny I'm prepared to drain the battery a little to run the fridge on DC because I know the solar will charge it up fast. Even on dull cloudy days there's an amp or 2 coming from the solar. They're great panels.