RV/Camper 1200 Watt Solar Install

[ctechbob]

Ok, it is our vacation tiny house on wheels (RV). I've documented this elsewhere, I thought I'd bring it to BITOG as well.

This project suffered from tremendous scope creep from what I had intended. Most new RV's these days come with 12v compressor fridges, and my main goal was to be able to prep for a trip and not need to plug the camper in to shore power. 400 watts of solar panel and a good AGM battery will get that done. The camper came from the factory with a 50 watt panel, which made an excellent battery tender during downtime, but didn't quite have enough to run the fridge long term and keep the battery charged.

Where we ended. *sigh*

6 - 200 Watt Panels (3 - Bifacial and 3 - Monofacial, as an experiment)
3 - 150AH LifePO4 Batteries
1 - Victron Multiplus II 3000VA Pure Sine Inverter/Charger
2 - Victron MPPT Solar Controllers
1 - Victron DC/DC Charger
1 - Victron Cerbo GX Communication Hub
2 - Self-Designed 3d Printed Fan Grill (As well as 2 downloaded vent grills)
1 - 7" Touchscreen control panel with 3d Printed mount
100 Feet of 8AWG cable (Estimate)
15 feet of 1/0 Cable
50 Feet of 8AWG Marine Triplex

A few pics:

Solar Controllers Pre-wired with some car audio power distribution I've had for 20+ years, ever since I worked for the company that made them. The solar controllers are self-explanatory. The DC/DC converter just takes the voltage/current from the truck's 7 pin harness and provides the proper charging profile for LifePO4 batteries instead of whatever it is Ford sends. Not strictly 100% necessary as the solar controllers will generally keep things running properly, but hey, we're gilding lily's here, so might as well.

Charging/Testing the 3 - 150AH LifePO4's. The paint marking on them is the last 2 digits of their MAC addresses so I can keep them straight in the monitoring app. (Bluetooth)

Panels mounted on the dirty roof, which I'm planning on cleaning tomorrow. White gets dirty fast....

3d Printed fan grills preparing to be mounted.

I didn't feel like spending $250 for the 'official' Victron 5" screen, so a $49 touch screen and 3d printed case are doing that duty.

3000VA of pure sine wave goodness

Installed, powered vent fans for cooling on left.

Safety...errr 1st? 3d Printed 120V cover.

Now, some nifty things I can do, mostly based around the Victron Inverter/Charger.

I can:

Limit the amount of current I pull from shore power. So if I am hooked up to a 15 amp normal house outlet and want to run the AC, I can do it, the rest of the current needed to make up the load is supplied by the batteries, and when the load drops, the batteries are recharged.

This also comes in handy at campgrounds that have crap 30A plugs. I can choke the current down and keep from melting the plug on my surge protector (again).

There's enough reserve capacity in the batteries that we can stop for meals and run the AC for 60-90 min, OR pre-cool the camper on our shorter weekend trips before we get to the campground. That's without any solar or truck input. On a good sunny day, that time will increase.

I can also prioritize solar, meaning the inverter will use all of the solar and pull from the batteries until they reach 30%, at which point it will supplement with shore power. If the load decreases to the point where solar can charge the batteries, it will shift that power to them. If I need the batteries at full capacity, I have the option of pushing a button and it will charge them from shore power.


This is the electric heat and water heater in the camper running with the shore power restricted to 20 amps and a super tiny amount of solar flowing in.

This is no shore power, all battery. The camper will never ever run this way. If we are without shore power, the heat and hot water will be propane powered. I just did it as a system test. The inverter never blinked.

I also have the provision of shipping power out of the RV through a 30a RV plug. I have been using it to power the mini-split in my master bedroom. As long as the days are sunny, it has been working great. I'll probably use it to run christmas lights or the fridge in the house this year as well since I have that wired to my transfer panel.

 

[ctechbob]

I can also see and control parts of the install through Victron's web interface.

For fellow data nerds, Victron also hosts a read-only version for folks that want to poke around my data:

https://vrm.victronenergy.com/installation/488934/dashboard

Remote Configure, and firmware updates:

And more data than you can shake a stick at



A Few days ago here in GA when it was 84 outside. I speel during the day, so my mini-split is running to keep the room cool. The solar easily keeps up. Come summer, we'll see how well it does. I suspect it will be fine since the days will be longer.

 

[ctechbob]

The Eco-Worthy batteries come with their own app to monitor the health of the batteries. Once I had everything up and running and checked to see that they were charging and discharging evenly, this isn't something I'll be watching all that closely. They're well matched, so there's no need to check on them unless there's some other issue that crops up.


Note: There are only 4 cells in a 12.8V LifePO4 pack.

And finally. The 30a TT plug that lets me export power. I still need to install the door through the floor for it, but it works as intended at the moment, just have to leave the hatch open.

 

[fsdork]

Love it. I can't afford the space in our 19' TT, but you've done more or less what I would in a larger one like yours.

For now I have to tinker with the 400W panel, Victron 150/75 MPPT, and BMV-712 with 2x 100Ah LiFePO4 batteries in my shed. The refresh every time I open VictronConnect on my phone just might drive me crazy enough to spring for a Cerbo.

 

[ctechbob]

Love it. I can't afford the space in our 19' TT, but you've done more or less what I would in a larger one like yours.

For now I have to tinker with the 400W panel, Victron 150/75 MPPT, and BMV-712 with 2x 100Ah LiFePO4 batteries in my shed. The refresh every time I open VictronConnect on my phone just might drive me crazy enough to spring for a Cerbo.

The Cerbo really does tie everything together quite nicely. I scored mine on Ebay for about half price and it was practically brand new.

I get a kick out of the 100 different protocols Victron has, its like they had an ADD engineer in their design department. Bravo to them though, they still support all of them.

I said above that I was finished, but I took another look at my water heater. A few pieces of PEX and some elbows and I can free up enough room for another battery. I'll probably do that sometime this winter. Little more reserve, little less stress on them individually with high loads. The only other thing I might do is add another 2 panels in the middle. I'm going to wait until summer gets here though before I make that decision.

 

[I<3oil]

Dang dude, that's better install than the factory does!

 

[AZjeff]

The thought of drilling all those holes in the roof makes me a little nauseous. How did you seal them? How did you get the power lines from the panels down through the trailer?

 

[ctechbob]

Dang dude, that's better install than the factory does!

That doesn't take much.

I've already cleaned up a bunch of their crap along the way.

Yea, that's is a residential non-sealed electrical box that they shove all the trailer connections in. That is going away eventually. I have a for-real sealed trailer junction box sitting on my toolbox for when I get a wild hair to spend an afternoon laying on my back.

That green fuseholder was what tied to the factory solar system, as well as the light in the front passthrough.

At least it has a fuse on it.

Should be able to tell what's mine and what isn't.

 

[ctechbob]

The thought of drilling all those holes in the roof makes me a little nauseous. How did you seal them? How did you get the power lines from the panels down through the trailer?

100% agree, least favorite part of the whole thing.

Procedure goes like this.

Put the panels up and place them where you want them.

Lift them and put a generous spot of non-leveling dicor under the brackets.

Swallow hard and screw them down, I used 3/4" stainless truss head screws.

Go back behind and cover everything up with another generous helping of self-leveling dicor.

As for where the wires go up.

Out through the floor at the front of the coach through some 3d printed TPU grommets.

Along the frame.

Up through the floor through some more 3d printed grommets underneath my kitchen cabinets. From there they go inside to where the factory power box/converter is. That's where the 120v connections are made. The solar bundle continues up behind the fridge.

Up through the roof above the fridge.

Out through some through roof solar connectors. I fully admit this is a sloppy job. I didn't realize I'd run out of self-leveling dicor when I did this part of the project, so the sealing is ugly as hell, but it won't leak and that's the #1 goal. They are actually not completely sealed in this picture, I added more to cover the screws later that day.

Yes, I know my roof is dirty, I should have gone ahead and cleaned/treated it, but I'll do that before winter. I did clean the spots I needed to put sealant on with dawn and isopropyl.

 

[ctechbob]

Here is a far more 'real world' example of using the power assist feature.

Cloudy day, not a ton of solar being generated, plugged into an extension cord I've limited to 9.5 amps, with the AC running and the trailer completely powered up.

It also acts as a full trailer UPS. Should shore power kick off for some reason, you'd never know it inside unless you were watching your display or had it set to alert you.