8.5x20 enclosed trailer conversion

[Migh7yMous3]

Hello everyone and thanks for being here on my first post.

Let me start off by saying that I don't have much electrical experience and don't plan to do any of the wiring hookups by myself. I plan to hire a professional for all the wiring and connecting everything, but what I'd like to do is purchase everything get it all set up and then just pay an electrician to wire everything so I don't have any fire issues or blowing anything.

With that said I'm trying to build my trailer to take my motorcycles to the race ttrack. The trailer is a 8.5x20. Most tracks that I go to are hot and sometimes humid.

I want to be able run my tire warmers (about 1300 watts), an ac (most likely a mini-split and guessing around1200-1800 watts), and possibly a small water pump/shower with tankless or small 6 gal water heater(unsure on power draw from this item so far).

I have a generator that can run all of this no problem. That being said no one wants to listen to a 7500 watt generator all day.

So my plan is to install 2 3000 watt inverters. One to power tire warmers and the hot water heater(won't run both at the same time) and the other inverter to handle the ac and lighting.

I was thinking of using the Lifepo4 server rack batteries(possibly 2-3) and adding some solar to the roof to maintain them. I'll have a "shore power" hookup to keep everything topped off since I may not have enough solar to maintain for a whole day or weekend at the track.

I'll keep my problem simple.

I don't know what components to buy or what voltage to go. 12v, 24v 48v?

Any advice on what I need? I appreciate any helpful feedback.

I've been a diesel mechanic my whole life but have little to no experience with electrical but this seems like a fun project to me and I'd love to give it a shot.

Thank you all for your help.

 

[Ekard]

First I salute you for hiring a pro to do your high voltage installs. Solar is new to many at this time, so you may have to look around.

A step in your process is to insulate the heck out of your trailer. I had this done on the 8.5x24 I bought a couple years ago, and it was well worth the money. Even in direct summer sun, it doesn't become an oven (even with its black exterior).

Your electrician should be involved in the selection of components.

I imagine everyone will agree 48 volt server rack batteries are the way to go. Most KW/hrs for the buck, and easily expandable.

Next look at solar panel costs per watt in various capacities, paying attention to physical dimensions. Then determine how many you can fit on your roof. Figure out your peak solar hours, and do the math to see how much you can produce versus how much you will use. This also will give you a clue as to how much battery capacity you need.

For your solar charge converters, get the hybrid one that allows for grid (or generator) input.

A 7500 watt generator being too loud at a motorcycle track? Now that's damned funny!

 

[Migh7yMous3]

First I salute you for hiring a pro to do your high voltage installs. Solar is new to many at this time, so you may have to look around.

A step in your process is to insulate the heck out of your trailer. I had this done on the 8.5x24 I bought a couple years ago, and it was well worth the money. Even in direct summer sun, it doesn't become an oven (even with its black exterior).

Your electrician should be involved in the selection of components.

I imagine everyone will agree 48 volt server rack batteries are the way to go. Most KW/hrs for the buck, and easily expandable.

Next look at solar panel costs per watt in various capacities, paying attention to physical dimensions. Then determine how many you can fit on your roof. Figure out your peak solar hours, and do the math to see how much you can produce versus how much you will use. This also will give you a clue as to how much battery capacity you need.

For your solar charge converters, get the hybrid one that allows for grid (or generator) input.

A 7500 watt generator being too loud at a motorcycle track? Now that's damned funny!

Thanks for the advice.

And when it's time to go to sleep and the desert gets cold you gotta keep the heater on. So running a generator isn't really plausible.

Also my trailer is spray foam insulated. I'm currently mounting the walls (1/4 plywood) then plan to do electrical wiring for plug and lights and put another, nicer, wall up. Probably some type of snap boards.

 

[Ekard]

Thanks for the advice.

And when it's time to go to sleep and the desert gets cold you gotta keep the heater on. So running a generator isn't really plausible.

Also my trailer is spray foam insulated. I'm currently mounting the walls (1/4 plywood) then plan to do electrical wiring for plug and lights and put another, nicer, wall up. Probably some type of snap boards.

Gotcha, generator much after 6:00 p.m. is not very neighborly. For heat, you might look at a good old RV propane furnace. It would cost a whole lot less than the battery capacity you'd need to run even the smallest space heater. Same for your water heater - those electric ones are energy pigs.

But since you probably have a diesel truck to pull this trailer full of aviation gas running motorcycles, and the regular gas generator, you may not want to deal with a fourth fuel.

 

[Migh7yMous3]

Gotcha, generator much after 6:00 p.m. is not very neighborly. For heat, you might look at a good old RV propane furnace. It would cost a whole lot less than the battery capacity you'd need to run even the smallest space heater. Same for your water heater - those electric ones are energy pigs.

But since you probably have a diesel truck to pull this trailer full of aviation gas running motorcycles, and the regular gas generator, you may not want to deal with a fourth fuel.

Yeah, fuel is kind a issue lol. 89, 93, and diesel. I was thinking of maybe using a propane heater and just using the small campfire propane tanks. Seen a couple of people run them. I plan to install a fuel system in the trailer to hold my bike fuel so that may clear up having to bring a bunch of jugs.

 

[Ekard]

No desert camping experience but a lot at 10,000+ feet elevation. Same thing - 95 during the day, 40 or less at night. Even got snowed in on 4th of July one year.
I've winter camped in my trailer, and found this little guy, run an hour or so before bedtime is enough.

Portable Buddy® Heater

Mr. Heater Portable Buddy® Propane Heaters are the Most Popular Portable Heaters in America. *ATTN Mr. Heater® Customer – Mr. Heater® has improved the performance of the tip-over safety switch inside your heater. You can now hear the operation of the tip-switch when the unit is shaken, bounced...

www.mrheater.com

For showers, I'd use the cheesy Coleman solar camp showers (laying on the dash of my truck in the winter time), and was happy if the water was so much as 80 degrees.

 

[dcg9381]

Hi. I'm someone in the RV space, a recovering auto-aholic, and can do both PV and residential electrical. Not to knock on your plans at all, but you'll spend a FRACTION of what you're going to spend on this and can have all of that powered (all be it not at the same time) by a single closed frame 3500-4000 watt inverter generator that will be half as loud. Want to get really quiet? Link two Honda 2k inverter generators.

If you want to do this "off grid" - you need to start by doing the math on how much power storage will be required. The equivalent of running a 5KW generator for 6 hours will cost you (minimum pricing) about $12-13k in batteries and inverters (EG-4 products). That's 600lbs of lithium battery. That's the reality. That's without wiring, wire, any of it. Finding someone that can work on AC power and DC power - it can be difficult to do, I'd say you're not going to find someone for under $100/hr, maybe a lot higher. Guys can do this work - the margins are really high and the demand for the work is pretty high.

There are quiet heat options. RV residential furnaces put out high BTUs and can run all night off 2 group 24 12V batteries. You just need a tank of propane. I see people using diesel heaters (designed for campers, no power requirements) inside with luck, but I'm a little sketched by the solutions. These heaters avoid the battery consumption issues - so they are popular with the camper crowd that is camping in really cold climates w/o grid power.

Not trying to discourage, but I am trying to be realistic. Let us know if you're OK with the reality here, lots of people can help you provide an outline for this system.

 

[dcg9381]

Also my trailer is spray foam insulated. I'm currently mounting the walls (1/4 plywood) then plan to do electrical wiring for plug and lights and put another, nicer, wall up. Probably some type of snap boards.

Curious if you did the spray foam yourself or if you had it done? TigerFoam?

 

[Migh7yMous3]

Curious if you did the spray foam yourself or if you had it done? TigerFoam?

I bought the trailer already spray foamed. The guy who sold it was starting his project but something came up and had to sell it and the stars aligned with the timing.

Also I'm on with the price but I've seen the server rack batteries priced around 1500 each. So I'm guessing around 3k-4500 for batteries. Are you saying that the inverters and charge controllers are going to cost around 9k? If so then I may need to rethink this. I was honestly expecting to spend probably around 6-8k for everything(not including appliances).

 

[Quattrohead]

Chinese diesel heater
Yeah Solar is not going to save money or make financial sense, but it feels great to do if you can.
48(51.2) V is the way to go for efficiency on the DC side but watch out for electricians that know nothing about high current and voltage DC.

 

[Ekard]

Also I'm on with the price but I've seen the server rack batteries priced around 1500 each. So I'm guessing around 3k-4500 for batteries. Are you saying that the inverters and charge controllers are going to cost around 9k? If so then I may need to rethink this. I was honestly expecting to spend probably around 6-8k for everything(not including appliances).

I see you're a brand new member. Watch a bunch of Will Prowse's YouTube videos. You can build a substantial system within your budget.

PM me if you like, and I'll help you with defining your requirements and determining your parts required. You need not buy the highest quality everything since this isn't a full time offgrid endeavor.

 

[Migh7yMous3]

Hi. I'm someone in the RV space, a recovering auto-aholic, and can do both PV and residential electrical. Not to knock on your plans at all, but you'll spend a FRACTION of what you're going to spend on this and can have all of that powered (all be it not at the same time) by a single closed frame 3500-4000 watt inverter generator that will be half as loud. Want to get really quiet? Link two Honda 2k inverter generators.

If you want to do this "off grid" - you need to start by doing the math on how much power storage will be required. The equivalent of running a 5KW generator for 6 hours will cost you (minimum pricing) about $12-13k in batteries and inverters (EG-4 products). That's 600lbs of lithium battery. That's the reality. That's without wiring, wire, any of it. Finding someone that can work on AC power and DC power - it can be difficult to do, I'd say you're not going to find someone for under $100/hr, maybe a lot higher. Guys can do this work - the margins are really high and the demand for the work is pretty high.

There are quiet heat options. RV residential furnaces put out high BTUs and can run all night off 2 group 24 12V batteries. You just need a tank of propane. I see people using diesel heaters (designed for campers, no power requirements) inside with luck, but I'm a little sketched by the solutions. These heaters avoid the battery consumption issues - so they are popular with the camper crowd that is camping in really cold climates w/o grid power.

Not trying to discourage, but I am trying to be realistic. Let us know if you're OK with the reality here, lots of people can help you provide an outline for this system.

Also I can always add solar later and just use the batteries at night to allow silent night running. So that would just be batteries, inverter, wires, etc

 

[Migh7yMous3]

I see you're a brand new member. Watch a bunch of Will Prowse's YouTube videos. You can build a substantial system within your budget.

PM me if you like, and I'll help you with defining your requirements and determining your parts required. You need not buy the highest quality everything since this isn't a full time offgrid endeavor.

I've been watching a bunch of his stuff and that's why I'm hooked on the idea to power my trailer like this. He's a very convincing guy lol. Plus I like the idea of not relying on a hot loud heavy generator that I have to load up everytime.

 

[dcg9381]

I've been watching a bunch of his stuff and that's why I'm hooked on the idea to power my trailer like this. He's a very convincing guy lol. Plus I like the idea of not relying on a hot loud heavy generator that I have to load up everytime.

Happy to help. Like everyone else, 48V lithium is the way to go. Signature solar is a major vendor for Eg-4 products which seem to be the entry price point.

How much power do you think you will need? Lets start there.

 

[Migh7yMous3]

forgot to tag

 

[Migh7yMous3]

Happy to help. Like everyone else, 48V lithium is the way to go. Signature solar is a major vendor for Eg-4 products which seem to be the entry price point.

How much power do you think you will need? Lets start there.

Rough estimate here so don't judge to harshly lol
8 hour track time using tire warmers the whole time plus ac will be roughly 2900 watts per hour. So roughly 23kw for the whole day. Which during the day in cool with running a generator to negate the effects. If I was able to get a small generator to reduce the strain on the batteries I will. Eventually I'll add solar and a small generator. Just trying not to lug around a big generator or spend 4k on 2 small Honda quiet generators. I want to kind of be self sustainable eventually.

 

[dcg9381]

Rough estimate here so don't nudge to harshly lol
8 hour track time using tire warmers the whole time plus ac will be roughly 2900 watts per hour. So roughly 23kw for the whole day. Which during the day in cool with running a generator to negate the effects. If I was able to get a small generator to reduce the strain on the batteries I will. Eventually I'll add solar and a small generator. Just trying to to log around a big generator or spend 4k on 2 small Honda quiet generators. I want to kind of be self sustainable eventually.

Lets say that you need 120% of 23kWh. You don't want to deplete the batteries beyond 80%, that's 27.6K. The 48V battery banks are about 5KW each, so you're ending up at my guess of 30kWh.

You need 6 of these and will need a rack for them. From experience, you'll want 2 racks, as you generally don't want to stack 6 of them in a mobile platform. Better to do two stacks of 3. The inverters offered by the same company are 5-6KW continuous, but only 120V. You'll need one, assuming your AC will be 120V. Expect this to add 600-700 lb to the trailer.

That's a start.. These are not the only solutions, but they are generally the "entry level" solutions for what you want to do.

How'd you insulate that trailer via spray foam? DIY or contractor?

 

[50ShadesOfDirt]

I would approach this design puzzle like so:

1. get rid of all electric requirements that can be served by other means; this reduces the footprint/cost of final solar gear. Propane heat, or other such systems.
2. plan on a smaller inverter-gen, sized to work on reduced loads, and using your fuel of choice. If 7500w doing everything now, might be able to get away with a 3000w inverter-gen. Plan on sound-proofing it, even though it is already somewhat less noisy; build an enclosure for it, somehow tied to trailer and/or truck.
3. now, with those two items out of the way, step through your sizing of solar gear (I'd look at 24v or 48v reference voltage, and skip 12v, but your design effort will tell you which way to lean):
a. at this calculator page, enter in each appliance's values (watts, hours/day you want to run it, etc.):
https://unboundsolar.com/solar-information/offgrid-calculator
b. here, using numbers from above, fiddle with various entries/components, and you'll see in real-time what your system component (inverter, mppt, panel) sizing is:
https://www.altestore.com/store/calculators/off_grid_calculator/
- There are many similar website pages/calculators, but these two pages should help you get through most of the necessary calculations.

Depending on your layout in the trailer, you'll have something like a 24v or 48v All-In-One (AIO) inverter, a battery-bank, and panels on the roof, along with connecting bits & bobs. The electrician will help you get the layout right (I hope, if he understands solar to a degree). given a trailer and tight space requirements. At some point, you'll spend time researching size of components, and how best to squeeze them into your layout; for example, a vertically-oriented rack battery or other layout & inverter end up being a "slim" footprint.

If you can work in propane, that would serve heat, cooking, water-heating, and inverter-gen needs. Run the electrics at night, and if solar not cooperating, fire up the inverter-gen to recharge battery-bank in morning/day ... noise less of an issue at this time, and you can drop a noise-muffling box on it, if designed right for air flow.

Hope this helps!

 

[Migh7yMous3]

I would approach this design puzzle like so:

1. get rid of all electric requirements that can be served by other means; this reduces the footprint/cost of final solar gear. Propane heat, or other such systems.
2. plan on a smaller inverter-gen, sized to work on reduced loads, and using your fuel of choice. If 7500w doing everything now, might be able to get away with a 3000w inverter-gen. Plan on sound-proofing it, even though it is already somewhat less noisy; build an enclosure for it, somehow tied to trailer and/or truck.
3. now, with those two items out of the way, step through your sizing of solar gear (I'd look at 24v or 48v reference voltage, and skip 12v, but your design effort will tell you which way to lean):
a. at this calculator page, enter in each appliance's values (watts, hours/day you want to run it, etc.):
https://unboundsolar.com/solar-information/offgrid-calculator
b. here, using numbers from above, fiddle with various entries/components, and you'll see in real-time what your system component (inverter, mppt, panel) sizing is:
https://www.altestore.com/store/calculators/off_grid_calculator/
- There are many similar website pages/calculators, but these two pages should help you get through most of the necessary calculations.

Depending on your layout in the trailer, you'll have something like a 24v or 48v All-In-One (AIO) inverter, a battery-bank, and panels on the roof, along with connecting bits & bobs. The electrician will help you get the layout right (I hope, if he understands solar to a degree). given a trailer and tight space requirements. At some point, you'll spend time researching size of components, and how best to squeeze them into your layout; for example, a vertically-oriented rack battery or other layout & inverter end up being a "slim" footprint.

If you can work in propane, that would serve heat, cooking, water-heating, and inverter-gen needs. Run the electrics at night, and if solar not cooperating, fire up the inverter-gen to recharge battery-bank in morning/day ... noise less of an issue at this time, and you can drop a noise-muffling box on it, if designed right for air flow.

Hope this helps!

Thats a lot of info. Thank you! Give me sometime to process all this electrical non sense. (Electricity to me is pfm). Seriously I'll check these sites out tonight.

Lets say that you need 120% of 23kWh. You don't want to deplete the batteries beyond 80%, that's 27.6K. The 48V battery banks are about 5KW each, so you're ending up at my guess of 30kWh.

You need 6 of these and will need a rack for them. From experience, you'll want 2 racks, as you generally don't want to stack 6 of them in a mobile platform. Better to do two stacks of 3. The inverters offered by the same company are 5-6KW continuous, but only 120V. You'll need one, assuming your AC will be 120V. Expect this to add 600-700 lb to the trailer.

That's a start.. These are not the only solutions, but they are generally the "entry level" solutions for what you want to do.

How'd you insulate that trailer via spray foam? DIY or contractor?

Oof that's a lot of batteries... I wonder if I'm buying of more than I can chew.

 

[50ShadesOfDirt]

Once the reduction work is done, and then the design work is done, you may not need nearly as much solar gear as initially discussed ... a prime reason to do the first steps!

 

[Ekard]

Once the reduction work is done, and then the design work is done, you may not need nearly as much solar gear as initially discussed ... a prime reason to do the first steps!

I agree.
Tire warmers (had to google them, had no idea), must they be run all weekend, or for like two hours before you start racing, and then between runs? Maybe you need them for like a total of 5 hours per day at 2Kw/pair (10KwH production)? And only during daylight, when no one would complain about your loud generator?

As for AC, why would you run AC in an empty trailer, rather than crank it up a couple of hours before you go inside, then let the cold desert night do the rest?

You have to map out your real needs and go from there.

 

[dcg9381]

Oof that's a lot of batteries... I wonder if I'm buying of more than I can chew.

Solar will help reduce it, but even in Texas solar is often unavailable for days due to overcast.. Not rain days (not at the track) but clouds kill it. It's not a source you depend on short term. It's more like a power bonus. Or perhaps something you can calculate for longer term (like living off grid).

My SWAG is pretty indicative of what you'll need for your indicated power consumption. As others have mentioned, reduce the consumption and cost goes way down. First thing to go on my list would be the concept that you need to heat (the air) with electrical power.