Building a cargo trailer conversion to travel trailer for boondocking

[BigIslandRyan]

Happy to be here. I've been enjoying Will's videos for a few weeks now and I'm starting to buy my gear but have some newbie questions, of course. I have purchased a used 8x18' cargo trailer that I will use to haul a motorcycle to national parks and National Forest land, where I want to be able to work remotely. No more office jobs for me. My career in cloud cybersecurity will allow me to be 100% remote soon, so I'm starting to build my rig!

I am planning a 1KW of panels (10x100 HQST, based on Will's tests) with an all-in-one 24v MPP (or similar) controller/inverter, and a 400AH battery array by buying Chinese Lithium cells. Will allow for shore power, generator power, and 12v, 24v, and 120v appliances.
I may also retrofit solar to my tiny house (on wheels) that I built and live in, which is grid tied for now.

 

[Craig]

Just an idea but you may wish to ditch the HQST panels for some larger ones you can probably cut your panel cost in half.

 

[KBWaldron]

Hey, welcome. I'm at the same stage.
My intent is to live full-time in my trailer, an 8x24, plus 4 foot wedge. I bought it new and stripped, except for a rack.
Unfortunately my trailer is the US and I'm in Canada so can't get my hands on it.
I've purchased 8 used 230W panels, so about 1600W.
2 used BYD batteries ~5kWh
LV2424 all in one, the Green Hybrid one.
I'm also going 120, 24, 12.
I will be insulating to R21 all-round as I intend to make this a true four season RV. No windows, but I will have a virtual window.
Diesel generator, and heat, including Water Heater.
Air-Conditioning.
Air-exchanger.
Composting Toilet so only fresh and grey water. 140 Gallons fresh, 80 gallons grey.
4 feet at the back for my tools and workshop.
I'm also designing a bluetooth remote locking system for both doors that will be like a vault with latches at all corners and centre of door edges. You want to steal my stuff, bring a good sawsall, and be prepared to cut in a pry-bar won't cut it (pun intended). There will also be satellite-communication with gps hidden inside with it's own back up battery so if anyone takes the trailer I can find it.
Maybe we can share ideas.

 

[John Frum]

Not solar but I'm curious about your weight budget and strategy.
I quite like the virtual window idea.

 

[KBWaldron]

Not solar but I'm curious about your weight budget and strategy.

Which of us are you asking? I'll defer to OP as it is his post.

 

[John Frum]

Which of us are you asking?

I was thinking of your 140 gallons of fresh water but I would like to hear from both of you.

 

[KBWaldron]

I was thinking of your 140 gallons of fresh water but I would like to hear from both of you.

GVWR will be no more than 10,000 lbs although I am hoping for much less. I purchased a beefier suspension and tongue.
Yeah, I know the water weights about 1200 lbs, My batteries are 300 lbs.
Attached is a sketch of the "basement". Between the wheel wells you can see the water tanks. Much of my storage area will be in the floor, as I am sacrificing 10" on the floor for the tanks and storage. I bought the tallest trailer I could get from the manufacturer.
I'm also sacrificing 4 inches on sides and top for closed cell foam insulation (3") and wire/plumbing ways.
Floor insulation will be 3" blown under the trailer floor in the framing. I'll be adding a floor plan to protect it.

Here is a sketch of the upper area, which includes the fridge (Narrow full size 120V), Induction Cooktop, Microwave, washroom including full shower, and you can see the generator/heater alcove on the outside. Still working on design so not everything is shown, and I am considering some alternative designs.

I wanted the trailer stripped including no interior plywood walls, but apparently the metal by itself is not stiff enough to be able to tow it without these.
So, I'll be stripping them out and cutting them to create u-shaped true 4x2 frames that will be attached around side and roof ribs which are 1x1 thus changing them to 4x2 "studs". Foam will be blown in, basement completed using engineered I joists, then wiring and plumbing placed and then flooring and walls. Finally all furniture.

But first the solar goes in as I have a country lot (no power) to park the trailer while I build Most of my tools are cordless with the exception of my table saw and larger router. Panels will be tilting in two sets. Manual to begin, then automated. No tracking other than slowly raising during the morning and lowering at night so the front panels don't shade the back panels

Ramp back door will have supports to act as a veranda and workshop extension.

 

[BigIslandRyan]

Hey, welcome. I'm at the same stage.
My intent is to live full-time in my trailer, an 8x24, plus 4 foot wedge. I bought it new and stripped, except for a rack.
Unfortunately my trailer is the US and I'm in Canada so can't get my hands on it.
I've purchased 8 used 230W panels, so about 1600W.
2 used BYD batteries ~5kWh
LV2424 all in one, the Green Hybrid one.
I'm also going 120, 24, 12.
I will be insulating to R21 all-round as I intend to make this a true four season RV. No windows, but I will have a virtual window.
Diesel generator, and heat, including Water Heater.
Air-Conditioning.
Air-exchanger.
Composting Toilet so only fresh and grey water. 140 Gallons fresh, 80 gallons grey.
4 feet at the back for my tools and workshop.
I'm also designing a bluetooth remote locking system for both doors that will be like a vault with latches at all corners and centre of door edges. You want to steal my stuff, bring a good sawsall, and be prepared to cut in a pry-bar won't cut it (pun intended). There will also be satellite-communication with gps hidden inside with it's own back up battery so if anyone takes the trailer I can find it.
Maybe we can share ideas.

Wow, that sounds like an amazing rig! Security is definitely important although I admit not having put too much thought into my security - yet! I dont plan on living in mine full time, but I might do a month at a time, possibly longer, but I do have a homebase to come back to as needed. Im aiming for simplicity with my water/shower/toilet setup - a cassette type toilet, pee jugs, crap outside as needed, and a foot pump at the kitchen sink instead of electric. Still haven't figure out water storage but there wont be much. Only R6 insulation but I plan on being in hot /desert environments far more often than cold.

 

[BigIslandRyan]

Believe it or not, I have no weight estimates, no budget, and no strategy LOL. Not entirely, but I take the approach of "it'll cost what it costs" - i'll just buy things and build it as my cashflow situation allows for. But i paid 4.3k for the trailer,will put about $3,500 into the solar system, and probably 4k into everything else (plywood, insulation, toilet, fixtures, etc). As for weight - same approach. I will build it the way I want and it will end up weighing what it weighs. I'll just keep weight in mind and not go crazy with anything too heavy. Thats how I built my tiny house and its way overbuilt, and too heavy (15k pounds?), but towable and and functional. So it works out. I also just spent as I could with no total budget in mind, but it came to about 20k overall.

 

[BigIslandRyan]

GVWR will be no more than 10,000 lbs although I am hoping for much less. I purchased a beefier suspension and tongue.
Yeah, I know the water weights about 1200 lbs, My batteries are 300 lbs.
Attached is a sketch of the "basement". Between the wheel wells you can see the water tanks. Much of my storage area will be in the floor, as I am sacrificing 10" on the floor for the tanks and storage. I bought the tallest trailer I could get from the manufacturer.
I'm also sacrificing 4 inches on sides and top for closed cell foam insulation (3") and wire/plumbing ways.
Floor insulation will be 3" blown under the trailer floor in the framing. I'll be adding a floor plan to protect it.
View attachment 11159
Here is a sketch of the upper area, which includes the fridge (Narrow full size 120V), Induction Cooktop, Microwave, washroom including full shower, and you can see the generator/heater alcove on the outside. Still working on design so not everything is shown, and I am considering some alternative designs.

I wanted the trailer stripped including no interior plywood walls, but apparently the metal by itself is not stiff enough to be able to tow it without these.
So, I'll be stripping them out and cutting them to create u-shaped true 4x2 frames that will be attached around side and roof ribs which are 1x1 thus changing them to 4x2 "studs". Foam will be blown in, basement completed using engineered I joists, then wiring and plumbing placed and then flooring and walls. Finally all furniture.

But first the solar goes in as I have a country lot (no power) to park the trailer while I build Most of my tools are cordless with the exception of my table saw and larger router. Panels will be tilting in two sets. Manual to begin, then automated. No tracking other than slowly raising during the morning and lowering at night so the front panels don't shade the back panels

Ramp back door will have supports to act as a veranda and workshop extension.
View attachment 11160

I'd like to hear more about how you're mounting your panels and the tilt mechanism? I am still learning what my options are...

 

[KBWaldron]

I'll describe the titling mechanism as I still don't have a diagram. Remember that I have a rack with cross-bars across every 16".
Mount panels in 90° angle aluminum. At 32" intervals mount a 2" T-bar with stem facing up on the south end of the cross bar. Trailer is parked East-West. In that stem is press fitted a bearing. On the panel frame at same location but facing down is a u-shaped fitting that matches the T-bar. Two holes allow a bolt to slide through the bearing. Spacers sized to the inner bearing sleeve allow tightening the bolt. Now you have a mechanism to rotate around.
At the north end of the cross bar (actually near the centre), mount similar arrangements but replace bearing and bolt with a spring latch. All latches are ganged so pulling one pulls all.
At 32" intervals are props bolted to the north end of the frame. Pull the latches, lift the frame, and place props in supports attached to cross beams.
Repeat for panels on the north end of the roof.
To automate, add linear actuators to move and hold the props, another to pull the latches first.
My panels and roof area are sufficiently sized to allow the panels to be at 45° without the southern panels shading the norther panels around noon. That is why I would want the system to gradually raise and lower the panels during the day in order to avoid shadows being cast when the sun is lower in the east/west.
Now you would think this might use a lot of energy, but I would use an Arduino to manage this, and use it's sleep/clock/wake function so that there was only draw during the few times a day it was adjusting the panels. At other times the draw would be on the order of a few millivolts.

Any comments and suggestions appreciated.

 

[BigIslandRyan]

Thanks for writing that up. I will need to read through it a few times to fully "get it" but when you mentioned the bearing and bolt for rotation, that immediately opened up some ideas for me. If you get around to sketching up a diagram,I'd love to see it!

 

[JoeHam]

Just an idea but you may wish to ditch the HQST panels for some larger ones you can probably cut your panel cost in half.

I second that idea for sure

 

[JoeHam]

2 used BYD batteries ~5kWh

Seems like everything else is first class and obviously you have serious DIY skills.

Why not build a battery from brand new cells and add the BMS of your choice?

 

[BigIslandRyan]

I spent most of yesterday putting insulation in the walls. Just 1" R6. I can probably finnish that today if I find my motivation on this rainy day. I was researching water tanks last night and I think I'll have 20-26 gallon sitting on a wheel well, just for quick showers. Kitchen sink water will be from 2 or 5 gallon jugs, so kitchen and bath system will be totally separate. No hot water in kitchen, just jug water with manual foot pump. No sink in bathroom. Shower will drain to the land / hose.If i cant drain it, I just wont shower, or puta jug under the drain and use minimal water in an emergency

I second that idea for sure

Too late on the panel purchase! And I'm not sure how, all panels I've looked at are more expensive than HQST, except for used, and I don't want used. These are $308 for 4, that is definitely the cheapest I've found. If you have a link to lower prices, I'd like to see them. https://www.amazon.com/gp/product/B018BP7X0A/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1

 

[JoeHam]

Brand new. 400w in one panel for $200

Jinko 400W | SanTan Solar

These are brand new, never installed. Each panel includes the two cables with MC4 connectors. We guarantee the panels to work on installation. These panels come with the manufacturer's warranty - 10 year product | 25 year linear power.

www.santansolar.com

 

[KBWaldron]

Seems like everything else is first class and obviously you have serious DIY skills.

Why not build a battery from brand new cells and add the BMS of your choice?

I've commented on this elsewhere. I'm not adverse to used batteries and I don't use a BMS. Don't feel I need it for a number of reasons.

 

[BigIslandRyan]

Brand new. 400w in one panel for $200

Jinko 400W | SanTan Solar

These are brand new, never installed. Each panel includes the two cables with MC4 connectors. We guarantee the panels to work on installation. These panels come with the manufacturer's warranty - 10 year product | 25 year linear power.

www.santansolar.com

Wow, those are some good prices!! Shit. *scratches head*

 

[JoeHam]

I've commented on this elsewhere. I'm not adverse to used batteries and I don't use a BMS. Don't feel I need it for a number of reasons.

Perhaps that is in some other thread? Or I simply missed it.

Either way, carry on, nice build plan.