New Camper Build Solar Setup

[N8's Mad Max Camper]

Hello all. This is my first solar project. I'm building the ultimate off grid camper for my family during these weird times. I'm converting a 16 foot Cargo Craft enclosed trailer into a camper. I've already mounted 4 100W Coleman Crystalline panels on the roof (see picture). I'm putting together the rest to install in the inside of the trailer (per the diagram). I was planning on getting the SOK battery (pictured) to start. I've already purchased a Giandel 4000W Pure Sine Wave Inverter and an 40A Epever Solar Controller (pictured). I like to do things clean and kind of over the top as you can see when it comes to my projects. I bought the book from the creator of this Forum, but I still have a few questions. I've increased the size of the Inverter, so I'm not sure what wiring would help my system run at it's highest potential. I also want to ensure safety since all the wiring will be installed on the inside of the trailer.

1. What gauge wire should I use for the system? Wire from the Solar Controller, from the Battery, from the Inverter, from the panels, etc.
A. Can I just run 4 gauge wire throughout and call it good?
B. Would it improve efficiency if I ran 00 or 2 gauge throughout?
2. Should I run the panels in series or parallel? I want to have just one entry from the roof.
2. Is the recommended 50 Amp circuit breaker for 40 Amp solar Controller sufficient after I've increased the size of my Inverter?
3. The 200 Amp hour SOK battery is near the price of buying a 100 Amp our Battle Born battery. Is it really worth buying 2 Battle Born batteries?
4. What size fuse should I use for my Main fuse according to the diagram I've attached?
5. I want to run 2 freezer/fridge boxes that I've attached a picture of all the time when using the camper. If I want them to always be on when using the trailer, should I use a DC Fuse box that has a "split" layout to make sure that they're always running when plugged in? Or, should I plug them in using a DC extension into the Bus Bar? I could also just plug them into the inverter because both AC and DC plugs come with the unit.

Appreciate any insight my friends. Just glad there's somewhere to go with these questions. I love this kind of shit.

N8

 

[Pappion]

Your solar controller terminals will have a wire gauge range. 6 (better) to 10 gauge should be fine for 40 amp CC output to battery. 50 amp breaker on 40 amp CC output has enough overhead to prevent nuisance blows. A CB should be dedicated to the CC. I am using dual 20A 250v CB for the panels. Panels should be series wired which reduces wire loss, but DO NOT exceed the CC voltage rating. Typically the panel to CC is 10awg, but 12awg is OK too.
I just ordered 2ea 206AH SOK batteries. Same BMS as the 100AH model. Same 100A output limit per battery. I might put a 150A marine terminal fuse on my batteries.
Your 4000W inverter can draw up to 350A or more. 2/00 gauge. Big system mismatch.
IMHO: More than 150A and you should consider a 24v system, more batteries, more solar. Maybe do without AC, microwave, electric drip coffee, hair dryer, crock pot, induction stove

 

[Reed Cole]

Maybe it's not too late to return the inverter and get a 2000w model.

 

[N8's Mad Max Camper]

Thanks for the Insight! This is just what I was looking for.

I was just following what was said in the book on page 15. "Buy the largest inverter that you can afford." It also states that "If you want to run multiple large appliances, buy a 3000+ watt inverter."

So the mismatch is going to cause issues? Safety issue? We don't plan on running the A/C on solar. We do plan on running the two fridge boxes. One as a freezer (Compressor will constantly run), and one as a fridge. Charge multiple cell phones (wife has work and personal, teenager has one, and I have one). We have a 40" TV, Tablets, Laptops. I also plan on installing a marine stereo deck to run 4 marine 6"x9" speakers on the outside. There are outside LED Light Bars on 2 sides, 4 Indoor LED puck lights, and 2 LED Shop light strips. We obviously won't be running/plugging everything in at once.

Do you think I should just save the larger Inverter for a home system? I do plan on putting a larger array at my next home. We're currently renting. What's the max amount of 100W panels I could setup for the 4000W Inverter to be effectively utilized?

 

[Pappion]

I have 2 used 235 watt panels portable. Ordered 2ea 206AH SOK LIFPO4. Victron 100v 50A solar controller.
My expected daily usage matters for system sizing:
Laptop 90W max DC-DC brick (cigarette lighter plug), 70W/12v x 6 hours = 35AH
Furnace Blower 7.5A x 3HRS = 22.5AH
TV & DVD 70W/12v * 1HR = 6AH note: I use a 100W inverter with on/off switch.
LED lighting, 12v USB chargers, 12v Jensen stereo maybe 2AH
Propane Fridge & water heater electronics & alarms, maybe 10AH
So far I have 75AH per day. With 416AH lithium I could last 4 cloudy days. More if I cut Laptop use and read my Kindle.

 

[Pappion]

So the mismatch is going to cause issues?
1. You might be drawing more current than your batteries BMS can sustain (heat damage).
2. You will quickly drain your batteries sustaining 4000W. High drains shortens battery life.
3. At 12v it needs some extremely large gauge wires for the 350A. Maybe 2/00.
4. I hope it has a soft start.
I doubt you will use the 4000W, but how much inefficiency at lower wattage results from higher overhead?
15A circuit at 120V is 1800W or 150A @ 12v. So 2000W is better fit.

 

[Reed Cole]

It would be possible to use it safely, and the BMS should protect the battery but it's better to have the max inverter load be less than the amperage your batteries can deliver.

 

[Pappion]

The SOK BMS has a 100A output limit. Same BMS for 100AH and 206AH battery. So 1 SOK won't be enough for 2000W inverter.

 

[alvise]

Having a 4000w inverter also just in standby will use more power

 

[mikefitz]

I recommend you run as much stuff as you can on 12v DC and limit the load on the ac side. At 12v powering an inverter over 2000 watts is impractical. Use the smallest inverter you can get away with as the standby power increases with size. 400 watts of solar should meet your requirements but you can never have too much. The Epever 40A has the capacity for more solar.
You can get 12v converters for most laptops and phones. Where its not possible to do this , say the TV, a quality 500 watt sine wave inverter with low standby power is an efficient method. Many modest camper installs, without heavy use of AC appliances, consume less than 1000 Wh per day.
The Epever will take up to 100V so assuming the panels are 22v OC its just possible for 4 in series, however if operating in clear cold conditions the voltage could be higher, so using a two in series then paralleled may be better, If shading is a problem, and the AC unit may introduce shade, then all in parallel could work.

Mike

 

[Pappion]

My TV is 45W, the DVD is 22W. I have an old cheap 100W inverter that plugs into a cigarette lighter socket. 5.5A typical to 9A max. If the wires voltage drops the inverter amps will go up. Many cigarette lighter sockets are rated 10A, I went out of my way to find 15A marine sockets.
Not recommended for larger inverters.

 

[N8's Mad Max Camper]

Thanks for everyone's comments and responses. I really don't want to return this inverter because it seems really hi quality. I'll just box it back up and put it in the garage for my future house/shop solar array. I think I'll just downsize and go with the same brand (Giandel) for this project per all your recommendations. I'll take a picture once I get everything mounted.

Happy Holidays!

N8

 

[pollenface]

Calculate your highest theoretical AC power requirements at any given time, then divide them by 0.85 to account for heat/energy loss in the inversion process. That will give you an idea of how many AMPS your inverter will want to pull from your battery bank, and then size your bank & breakers accordingly.

I'd keep the inverter, you might get more ambitious in the future.