800 watt solar install with 340ah of LiFePO4

[distracto]

After a battle with the 12v Everchill fridge, I decided to add to the factory installed 175w panel and 30a controller. We mostly boondock, so having the solar and large amp hour battery reserve was important to our camping style.

In order to keep costs down, I added a second controller instead of buying a larger controller to replace the Jaboni 30a that came from the factory. I added a 200watt Renogy panel in parallel (knowing there would be some losses) with the 175w panel that came from the factory and wired them to the existing 30a controller. I then added two identical Eco Worthy 195w panels to a new ePever 30a controller. Both controllers are MPPT.

A second benefit to the two controllers is that if one set of panels is in the shade, the other set will not be affected by that.

Here is an image of the roof now



For the 200w panel I added to the front, I was able to add splitters to the existing cable entry gland and tie it in to the existing wiring no problem.



For the two new rear panels, I had to penetrate the roof to add the new wiring. I chose to go down through the pantry as it is full height and was the only place in the trailer I could get a clean line straight down to the underside of the trailer without running exposed wires on the inside. After many measurements and re-measurements and them measuring again for good measure (ha!) I cut back the roof membrane and drilled a hole into my brand new roof. I was then able to run the wires down through the pantry and through the floor.



To get through the bottom of the pantry to the underside of the trailer I measured in from the outside wall and was able to drill up through the floor and into the space below the bottom of the pantry. Luckily there is a receptacle on the bottom of the pantry so I removed that to help fish up the wires. I found it easier to fish up from the underside and pass them up through the roof than start at the roof and pull the wires down.

I ran a straight shot of #8 AWG cabling from the roof to the front pass through and then into the space under the bed where the final connections were made. I was able to keep all the wiring on the outside of the underbelly, saved me from having to pull it all down, plus there was a perfect opportunity to use existing holes in the steel gussets as cable management.





Once I had all the wiring re-routed to the underside of the bed, I laid out my devices and connectors on a sheet of plywood and mapped out where everything would go. I didn't want a big mess of wires, so I did my best to lay it out so that no wires crossed and it was easy to trace and make my connections.

[distracto]

I then took my two new 170ah Renogy LiFePO4 batteries to my bench, hooked them up to my NOCO charger, brought them each up to 100% charge, then paralleled them and hooked them up to the NOCO charger again and ran them through another charge cycle.



I then put them under the bed and made all my final connections, adding a Victron Smart Shunt into the mix to monitor power usage.



I had a 1000w modified sine wave inverter kicking around so I connected that to the system, but plan to get a 3000w Pure Sine Wave in the future.

We've ran this system now for a month and based on the smart shunt's information, we haven't dipped below 75% capacity.

I still have a lot to learn, but am very pleased with how this project turned out, and it is a great start to an off grid solution. One more 170ah battery and the new inverter and I should be ready for the zombie apocalypse!

[nayther]

that should serve your needs very nicely, that's a lot of battery

[Hclarkx]

Nice job.

[Oklamartin]

Thanks for taking the time to post all this information on your upgrade! You did a great job of documenting all your work and the pictures are very helpful. Sharing like this is so very helpful and what this forum is all about. Solar upgrades can be a daunting proposition but made less so by folks like you! Cheers!

[Hclarkx]

BTW, do you have a way to leave the batteries in parallel but isolate them for storage?

[SacRV]

You could really improve your solar performance if you used adjustable panel brackets. I keep them flat during the summer and raise them to 30 degrees in August.

[distracto]

Thanks for the kind replies - I am happy to share and document my modifications, it's other's work that inspires me to DIY my modifications.

Originally Posted by Hclarkx

BTW, do you have a way to leave the batteries in parallel but isolate them for storage?

Yes, for the off season/storage I am planning to mount the NOCO charger on that plywood and wire it to the bus bars - in essence letting it top up what the existing WFCO power supply cannot do for the lithium batteries. I have room in my backyard to store the trailer and it will be plugged in and covered, so the solar won't be of much use.

I have some more to learn about the care and storage of these lithium batteries, so haven't made and changes to the set up yet.

[nayther]

I like your use of the Adel clamps under the rig. Might want to wrap the wires in split loom inside the storage compartment to prevent damage from stuff in there. Nice install.


Once you do it it really is not that hard but agree initially it is intimidating. I read a LOT of posts similar to yours before diving in and it made it much easier. Thanks for sharing.

[distracto]

Yes indeed, I had some practice with my last trailer (2015 Jayco 23MBH), which was just two 100w panels through a 20A controller to 2x6V batteries with a 100W inverter. This one is obviously more involved, but drilling a hole through your trailer is still drilling a hole through your trailer!

In the off season I plan to finish things off with the above mentioned split loom for cable management and fill the holes with expanding foam. I just want to be sure I have all the holes done as the foam cans are a one time use.

One thing I like about this trailer model (Freedom Express 257BHS) is that it has an attic vent. Funny thing though is that with the 2 Maxx Air fans I added (bathroom and bedroom), I can create quite a bit of negative air pressure in the cabin if I don't open enough windows for air flow. On a hot day, I ended up drawing air into the cabin from the attic vent, through the attic, and then through the hole in the pantry I hadn't patched yet. Unfortunately, I guess the wind was blowing in such a way that I was sucking the vented black tank stack air...made for a stinky pantry!

I will keep updating this post as I progress in the hopes that it inspires others to take on this project. Just knowing that I can happily run all DC or AC powered devices from a renewable source is very empowering and satisfying.

[robo44]

Nice job, advice, get some UV Split loom for the wires that are exposed on the roof.
Protect your cables from the sun, or critters -

[distracto]

That's a great idea, thank you. Those cables are supposed to be UV rated, but nothing wrong with extra protection - especially from hungry critters.

Cheers

[roblombardo]

Looks Good! You'll need to upsize those bus bars and battery cables for the 3000VA inverter though.

[distracto]

Originally Posted by roblombardo

Looks Good! You'll need to upsize those bus bars and battery cables for the 3000VA inverter though.

Why the bus bars if the draw is straight from the battery bank?

Appreciate the feedback, thanks very much.

[roblombardo]

If you come straight across the bus bar on the same bolted terminal you’re probably fine. But, those bus bars do have a rated ampacity and you will exceed it.

[distracto]

My plan was to come straight from the batteries with welding cable. The bus bar is just to combine the outputs of the charge controllers and noco charger.

I'm confused how the draw from the inverter connected to the batteries would affect the bus bar.

I want to do this properly and safely, so all input is appreciated.

[roblombardo]

Originally Posted by distracto

My plan was to come straight from the batteries with welding cable. The bus bar is just to combine the outputs of the charge controllers and noco charger.

I'm confused how the draw from the inverter connected to the batteries would affect the bus bar.

I want to do this properly and safely, so all input is appreciated.

All load current must pass through the shunt in order to be measured. I guess you could circumvent the bus bar by double lugging on load side of the shunt but that is a hack. The inverter cannot go straight to the battery or it’s current will not be measured and battery capacity will not be accurate.

[Hclarkx]

Originally Posted by distracto

Thanks for the kind replies - I am happy to share and document my modifications, it's other's work that inspires me to DIY my modifications.

Yes, for the off season/storage I am planning to mount the NOCO charger on that plywood and wire it to the bus bars - in essence letting it top up what the existing WFCO power supply cannot do for the lithium batteries. I have room in my backyard to store the trailer and it will be plugged in and covered, so the solar won't be of much use.

I have some more to learn about the care and storage of these lithium batteries, so haven't made and changes to the set up yet.

In the off-season LiFePO4 batteries are best stored around 50% SOC. Chemical activity is reduced and as a result life is longer. Ideally you will take the batteries down to 40-60% and disconnect them (keeping them in parallel but disconnecting them from any charging or load).

A WFCO lead-acid only model will fully charge a LiFePO4 even if it won't go into bulk mode (because the LiFePO4 voltage never goes low enough) because a 12V LiFePO4 can be charged fully at 13.5V or a bit lower. And, of course, it will pickup house load while in float. Hence it's somewhat useful with LiFePO4. Though again, not for storage. You want the LiFePO4 down around 50% for storage. Charge it fully before hitting the road. Check voltage every 3-6 months while in storage (it should not drop below 13.1V).

[distracto]

Had the roof replaced under warranty as the front particle board panel wasn't attached to the truss.

Dealership pulled back the membrane, secured the sheeting and then laminated the roof with a layer of thin luan plywood and taped all the seams.

I now have a brand new roof with the panels laid out in a pattern that makes more sense, and has a renewed warranty!

[Half Ton Heavy]

What trailer is that? Looks great!