Solar install

[inghamm]

My thanks to BradS7535. I had been debating back and forth about doing a solar power install. Thanks to his Solar Power FAQ thread and his great write up of his own install, I felt more confident that I could make it work. So a lot if this is the same as his install, but being a musician and being used to the variation on a theme idea, I did some variation as well.

After I bought the Dometic fridge, I was going back and forth between running it with the TV on the way to the campsite or using solar, because I didn’t want to drain the battery while en route like I had with the Norcold. I tried connecting the TV to the TM with the Bargman, engine running and the TM battery disconnected, and I had no power in the TM – no lights or anything. I suspected the Bargman was not connected to the battery in the TV – it was a U-Haul after-market Bargman install. Anyway, suddenly the Solar install seemed easier to do and ultimately the better solution.

The other thing that tipped me in favor of solar was looking at these light-weight solar panels:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
The weigh under 5 pounds, so that was very important to me since I am up against my TV tow rating. Now that I have the Solar, I think I can leave a bunch of heavy things behind, so I may end up on the plus side weight wise.

One worry that I had was the solar panels overheating. I planned to just stick them on with VHB tape. When that arrived I saw it was thinner that I had thought. I wanted to provide some air space between the panel and the trailer, so I bought 2 packs of these:

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

In picture 1 is how I put the tape and the foam pads, so the panel is mostly not in contact with the trailer. This may be brilliant or stupid, not sure. Time will tell.

Since they were so light and I wanted to get the most out of them, I decided to mount them on the front shell. (My batteries are on the front) This made the wire run shorter, and I figured the front end usually gets more sun in a campsite than the back end. After I did the measuring I decided I didn’t need the 50 feet of solar cable, so I ordered 2 15feet cables, a red and a black. Then I re-read his notes and understood what he did, and I would have been better off doing that. ( He used half for the positive and half for the negative since he could not use the connector going into the controller anyway) For me the positive being the red cable made it easy to keep track of, but I could have dealt with that another way also.

Since I was running 2 panels in parallel I got these connectors for the Y:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

and used VHB tape to mount them on the TM roof.

I decided to go with the more expensive MPPT that Brad had used to try to squeeze every bit of power out of my light weight solar panels that would often be under clouds. And I mounted it in the same location he did.

So I could run the Solar wires down the front arm, and then it was a very short distance to the controller and the batteries.

I took a little bit different path for the Cat5 cable going from the Controller to the MT-50 remote meter. I drilled a hole from the back of the fridge area into the under-sink area. I also drilled a hole through the floor of the fridge area, diagonal from the sink. I will use Great Stuf pest version to fill these holes.

The circuit breaker from the solar panels I mounted on the left side. In the directions for the controller it recommended the circuit breaker going to the battery be 150mm or less, so I mounted that close to my positive terminal on the right side. I already had a battery cut-off switch.

I ran my new Dometic fridge all week with just Solar power, and always by then end of the day my batteries were in good shape, even though it rained every day, so that bodes well for my plan to keep the batteries at a good level en route to a camping spot. Granted, when it’s cloudy and rainy, the fridge doesn’t have to work very hard, but that was kind of the idea with getting the Dometic – it only uses the power when it needs it. So I figured if it’s sunny and hot, the fridge will draw more power, but the solar will deliver more power as well.

[Bill]

This is a great piece of work. Congratulations!

Let me maker two minor comments if I may.

Originally Posted by inghamm

... I tried connecting the TV to the TM with the Bargman, engine running and the TM battery disconnected, and I had no power in the TM – no lights or anything. I suspected the Bargman was not connected to the battery in the TV – it was a U-Haul after-market Bargman install.

This behavior means that your tow vehicle is not delivering power to its Bargman connector. This is a common problem, and usually a very simple fix. Problem: Many tow vehicles come from their factory with trailer wiring in place, even if no connector is installed. The power wire runs through a fuse in a fuse panel somewhere, but the manufacturer puts the fuse in a plastic bag in the glove compartment! Who knows why, but it is common. Solution: ]If you get out your vehicle's owners manual, you can find a diagram of the fuse box and locate the socket where the fuse needs to be inserted. The U-Haul guys should have done this, but apparently didn't. Anyway, if the fuse is still in the glove compartment, just plug it into the socket. If you've lost the fuse over the years, the owner's manual will tell you what fuse you need, and you can buy it in any auto parts store for less than a buck. Remember, if you don't do this, your tow vehicle will never charge your trailer's battery.

... Since I was running 2 panels in parallel I got these connectors for the Y: ...
I decided to go with the more expensive MPPT that Brad had used to try to squeeze every bit of power out of my light weight solar panels

An MPPT controller is very happy with panels connected in parallel. But it is even happier (meaning more efficient, squeezing out even more power) if the panels are connected in series. This is because an MPPT controller converts excess voltage into extra charge current, and you get more excess voltage with the panels in series. Panels in parallel don't have much excess voltage.

Real nice job. Keep us posted on how it works as you go through your travels.

Bill

[inghamm]

Hmmm. It wouldn't be that hard to wire them in series. Maybe I should try that.

[BradS7535]

Glad I inspired someone to take on their solar install. I know all the other posts on the topic helped me tackle my install.

I agree with Bill about wiring them in series. You'll get a little more power out of your setup.

Now you have to return the favor with a detailed write up on your fridge install. The compressor fridge swap had piqued my interest as the propane on my fridge doesn't seem to be working. It would be nice to have a larger fridge that is more efficient that I could use with my solar.

Oh, one other thing. I couldn't tell from your photos but I would strongly recommend putting some sort of adhesive caulk around the edges of the cordmates. I didn't and it only took abkut a month for the heat and sun to demolish the sticky foam tape that comes on them. I ended up replacing all of mine and putting some loctite marine adhesive sealant on each side. Much stronger now.

Just re-read your fridge post. I guess your detailed fridge install would consist of 2 steps. Buy fridge, have it installed! Ha.

[inghamm]

I switched a couple of wires so now it is working in series. I will reinforce my cordmates with with some adhesive caulk when I get a dry day.