400 watts solar on the rear of a 21C

[Ron in BC]

I'm moving, slowly, into switching to lithium and more solar. No immediate need to do anything but my original factory battery is showing signs of weakening and I have lithium batteries on hand.

I'm exploring the possibility of installing two 200 watt panels on the rear portion of the roof. Yes, I know that I could install one there and one in the center area.

My process for some projects is mockup, prototype, build. In this case I did some quick tape measure measurements and two panels there looked doable.

So made a rough frame and put it up there to see what reality looked like. Two choices in location. The one further back might also keep the rear window a little cleaner. Who knows.

The panels will sit in a frame, something that I've done before. One unit is aerodynamically cleaner but that may not be a huge factor.

Thinking, thinking

Ron

 

[RAS]

Ron, what did you end up decidig for solar panels? I am planning to add solar panels to my 2023 21C. So far just added a solar port with a 200 watt suitcase along with a MMPT controller (Victron 75/15). I will add a second Victron MMPT controller sized for the panels when it is time, but right now trying to figure out the best places to mount the panels. I am also thinking about two 200w panels. I have four 100AH LiPo batteries.

 

[Ron in BC]

I went with a single bifacial 220W panel and I have my tilting, swiveling 100W panel which punches above its' weight.

I went for years on my boat with a tiny solar panel by todays' standards and my usage isn't nearly as high as some folks. On a recent trip I, even with low sun, I didn't need to use my 100W panel.

Really depends on a person's needs. Although sometimes I think as batteries and panels keep getting larger so do folks needs.

Ron

 

[RAS]

Thanks! Here are my power upgrades to date photos. Took it out on a camping trip and it did well. Was able to keep my fridge running on inverter while driving which was nice.

 

[jjdeluca]

Nice Installation!

 

[Ron in BC]

Seeing more and more LiTimes. I've become a fan of them also.

Ron

 

[John in Santa Cruz]

I have a single 350W on the roof of my 21C, which has the Coleman AC unit on it too. it helps that I was able to remove and cap off the refrigerator roof vent due to my compressor fridge not using it.

other than mid winter, this produces upwards of 2500 WH/day from my 37N home area if I'm parked in the open. its rare I use more than 700WH/day, so, its a win win.

 

[RAS]

Seeing more and more LiTimes. I've become a fan of them also.

Ron

They seem to work well. At $200 a piece not a bad price when on sale. Next up on the power upgrade is a Victron DC to DC converter.

 

[RAS]

I have a single 350W on the roof of my 21C, which has the Coleman AC unit on it too. it helps that I was able to remove and cap off the refrigerator roof vent due to my compressor fridge not using it.

other than mid winter, this produces upwards of 2500 WH/day from my 37N home area if I'm parked in the open. its rare I use more than 700WH/day, so, its a win win.

I wish my 2 way fridge would die to get a compressor fridge but can't justify the cost to just replace a working fridge even though not the greatest. Love, the 350 watt panel.

 

[John in Santa Cruz]

They seem to work well. At $200 a piece not a bad price when on sale. Next up on the power upgrade is a Victron DC to DC converter.

I ended up switching my Orion TR 12/18 off, as it never worked due to excess voltage drop from the vehicle alternator back to the rear of my E21 where the batteries are located, and my solar is plenty good enough, and I have enough battery capacity to go a full week with no sun at all. in fact, i usually shut my DC Converter off, too, and will only switch it on if my battery gets below 50% and I want it fully charged a day before i lose shore power.

 

[Ron in BC]

Next up on the power upgrade is a Victron DC to DC converter.

Post the results. I finally switched to a Victron MPPT charge controller and I'm impressed with the quality. I previously tried installed a Renogy DC-DC charger but it didn't work out and the help from Renogy was most unhelpful.

Ron

 

[dstreight]

FWIW, a couple months ago added a second Victron Orion XS (12v-12v-50A) to my 15A and just like the first unit I installed, its great. And, with the newer XS, the efficiency is high enough the units don't get get hot to the touch like the prior gen units.

 

[Ron in BC]

I'm curious. Do you mean that you have two DC-DC units both powered from the tug?

Ron

 

[dstreight]

Ron, yes I have 2 Victron Orion XS DC-DC running in parallel. I started with one unit with the stock 145A alternator and it did great: 49A at the 15A's battery. A few months ago I added a higher output (250A) alternator and the 2nd Orion XS and getting ~80A at the LFP in the 15A which is max recommended current input for the LFP battery I have installed.

I ran 1/0 from the truck's (Duramax) 2nd battery to the rear bumper terminating in a pair of Anderson PowerPole 175A connectors with their weather resistant/proof rubber covers. And then 1/0 from the trailer tongue to the high current on/off switch on the tongue box.

Without propane appliances/heater along with late shoulder & winter seasons I needed the extra current for my all electric (minus the heater, which is a diesel Espar unit) 15A.

I just finished up installing a pair of REC Alpha 460 panels on the roof, replacing Rich Solar 200w units...for when we're camped in the middle of nowhere for more than a few days.

 

[Ron in BC]

Good information. Thanks, I wasn't aware that you could do that. Sort of like, if one's good, two's better.

Ron

 

[John in Santa Cruz]

if both truck batteries are charged off the truck's alternator, then both those loads will be seen by the alternator when the truck is running.