Hello everyone, were new here but not new to living in campers, including ClassA, Class C, 5th wheels and bumper trailers from 25ft to 34ft. I am just putting my feelers out to get some advice or help finding good deals before i start pouring $$$$ into this project. We had a 400W solar system on our last Class C motorhome and it was sufficient for everything except the window A/C unit because the 300A battery bank would die after 4-7 hours of running the A/C and the stereo. in the sun on a 85F june day.

Were going to be working on making our park model self-contained and completely solar powered

I have attached a couple pics of the park model im talking about for reference.

What we already have:

4x100W 12V solar panels with tilt mounts.

FlexMax 60 programmable MPPT solar controller 60A (up to 4000W with a 60V Solar array) 

https://www.thesolarbiz.com/outback-flexmax-fm60-charge-controller.html

Cotek 12V 1500 Watt Pure Sine Wave Power with auto power transfer switch/relay from grid or generator power

https://www.wholesalesolar.com/2915319/cotek/inverters/cotek-st1500-112-inverter

2x125Ah Solar AGM deep cycle batteries

https://www.vmaxtanks.com/SLR125-AGM-Solar-Battery-_p_38.html

Aluminum outdoor cabling for the solar array, and 1/0AWG copper stranded cable from the controller to the battery bank.

What I will be adding/purchasing before the end of May:

800W-1000W of additional solar panels final wattage will vary depending on which panels i end up going with (more later on that)
LP tankless heater from camping world ($120)
Solar water heater design
Water collection system with strainer and filter
LED or 12V CFL's 
40-80Gal of fresh water capacity
100Gal waste tank
High effeciency fan to put in the opening when the A/C is removed...
Thinking of a Energystar 800W window air conditioner for just the living area.

If i go with a 24V or 48V battery bank (depending on battery configuration and solar panel selection) i would use one of these to drop down to the 12V DC i need for powering most items, 25A should be plenty as most older campers only came with a 30A converter in the first place and you rarely use it all especially after converting to LED and newer fans:

https://www.amazon.com/dp/B01CUA4QLQ?th=1

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Its got fiberglass insulation and a false ceiling that uses panels like in your house, so hiding wiring and installing shallow recessed lighting would be fairly easy

What are good brands or places to order LED 12V light fixtures or bulbs? ive got some on ebay but i figure if im starting from scratch i would ask around

It only has 120V and 240V hook ups so I would be running the 12V system from scratch and running all lights and outlets, including a couple cigarette outlets and built in USB blocks in every area, kitchen, bathroom, living room, sleeping area.

Im wondering also does anyone here have recommendations on a solar panel company or website i can look into, im ok with 12V 24V or 48V panels because i can series my 12V panels into a 24V or 48V loop so they are compatible.

Also I have been looking at the youtube videos showing putting 100Ft to 500ft of black garden hose in a coil in the sun and getting really hot pressurized water within 10-30 minutes depending on sun coverage and ambient temp, has anyone done that here?

I was thinking of 3 to 6 coils of 3/4" PEX hot water heater tubing or black ABS tubing (whichever is less likely to breakdown in the sun/hot temps) or even place a window film over the coils that blocks only UV A/B ( i think that would still allow heat buildup) that would give us 8-10 gallons based on the tubing calculator i used. and i could easily put in a temp switch or thermostat so that if the temperature exceeded XXX Deg F then it would flip a relay and pump the hot water into a holding tank or just purge it with cool water some how, that design i havent thought about too much yet but brainstorming.

I would put the solar heat water inline before the LP tankless heater and just switch it off if there is hot water up top, and mainly use it as a backup or if its cloudy/cool out.

This camper would still be connected at the duplex most of the time, and about half the time at campgrounds with hookups, but we want this camper to be "bugout" ready for anywhere if the need arises. I am working on flame less/fan less heaters but they are kinda spendy.

Please dont judge it by the mess, i did check for structural integrity where its open on the sides and the tip outs and any previous leaks were already sealed but some new insulation is in order, and alot of cleaning. some minor repairs and a repaint are also in order

ive been looking at Lifepo4 lithium solar batteries and yes they have all the advantages and can be discharged to 0%, more charging current, lighter, smaller,but a stable lithium battery will cost me $600 for 100A of usable energy but i can buy 2-6V Trojan golf cart batteries rated at 225A but only 120A usable(at my average Amp use) for $260 1300 cycles to 50% and if i get the signature trojans then they are rated for 80% discharge and still good for over 700 cycles like that so i would have a emergency reserve of 80ish Amps if i needed it per battery. the lithium batteries cost about $6/Amp hour whereas flooded industrial/golf cart range from $0.90 to $1.34 per amphour but that number is really $2.21 per usable Amphour if i want to maximize battery life to 2000 cycles. but $2.21 per amp is still cheaper than $6 and it seems getting lithiums to charge properly is a tricky bit of work otherwise they shut down or potentially overheat. my controller can do it but it would be a pain programming it. i think for budget reasons im going the classic 6V golfcart route in a vented box lol i can get my target 1000A (500 usable) for $1048 no core charges and free shipping of course, but for $1000 i can only get 200A of usable litium storage. i might upgrade later tho

I am specifically looking at the T105RE batteries as the plates are supposed to be slightly thicker to allow a safer DoD while retaining more of the cycle life see here:  

https://www.thesolarbiz.com/media/catalog/product/t/r/Trojan_T105-RE_Data_Sheets.pdf

https://www.thesolarbiz.com/trojan-t105-re-6v-225-ah-battery.html

Also looking to have gutters installed that would channel the water into a collection tank with a filter inside somewhere also.

The front tip out will be retained but the rear one will 95% chance be placed in storage until our move to georiga for the winter months once harvest is over. i would build a very basic 2x2 frame and panels on both sides +extruded polystyrene for insulation secured into the location of the rear tip out

Info on the trailer: all i know is that it has 2 6K dexter axles convertable to the new 8 lug style with new brakes, the rvonline guides and nadaguides list these models as between 5600lbs and 8100lbs from the factory, its 9ft 6" tall outside, only 1 roof vent and the roofAC will be kept by the seller. LP furnace, no water heater currently. 7'10"wide and 36' long

Here is a public link to all pictures i have for now, its currently located 220 miles north of me because its frozen to the ground still: https://www.facebook.com/media/set/?set=a.10210075047525513.1073741850.1016864859&type=1&l=fde0fa212a

Sushidog wrote:

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Greetings Mudigger, welcome to the forum.

Gee, where do I start. First, I'm sure you know that park models are not built to withstand the rigors of continuous over the road use, and this older model looks a little rough from the pictures, so I assume you want to tow it to one place and leave it, or do you plan to move it seasonally? Do you plan or replacing the running gear, as it looks pretty rusty and corroded to me? If it were me, I wouldn't sink much money in this project without first getting it professionally inspected. Definitely get it weighed and look at the data plate (usually on the side of the trailer, or inside a kitchen cabinet do the math to determine its carrying capacity before adding your water heater, water tanks and such, as water weigh 8.35lbs/gallon so just the weight of 100 gallons of water is 835lbs. Add to that the weight of your solar system (batteries are heavy). Remember that 60 amp system is at 60v, meaning you need a 60 volt battery bank. Personally I wouldn't go over 48 volts, for safety sake. There are some nice 48v DC heat pumps that are super efficient that you could power directly off your batteries without the efficiency loss of an inverter. The rest could be run through an inverter for the rest of your power needs. Here's a link: www.geinnovations.net/HSAC_Productline.html If you plan on capturing rain water for potable use, I recommend a reverse osmosis system rather than just filters. Regardless, your plans are going to cost some serious money to do right, and if it were me, I'd look for a trailer in a little better condition to start my build. I'm not trying to discourage you but from the photos of the unit it looks like you might be throwing good money after bad.

Chip

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Ill try to answer all your questions in order lol: 

1. I was under the impression that all parkmodels were designed to be towed seasonally to and from campgrounds/RV parks, left there for 6-9 months depending on the geographic location, for example maybe 6 months in ND, but maybe 9-10 months in florida or georgia, and then towed back home or to storage. Some people leave them at the same location for years on end, but i have witnessed (because i lived in an RV park in a 5th wheel and was the groundskeeper) many people have park models and they set them up only for 8 months then tow them home about 30-60 miles.

2. Our plan is to use it maybe for a weekend here or there, and its main use would be a seasonal trip to central GA from the end of harvest until mid april then come back home to ND, unless we get a good price at the RV park in georgia then we leave it there blocked up.

3. I worked at a shop for 11 months or so (heavy OTR trucks, grain trailers, etc.) So i wll be inspecting the spindles, and axle tube condition, I already contacted Dexter since they manufactured the axles back int he 70's and 80's and they gave me a complete parts breakdown to convert from the old style UTG hubs in the pictures over to the new 8-lug axles that i already have 3,000lb rated wheels and tires for. They also informed me in that email that the axles were factory rated for 6,000lbs, my tires are rated for 3,084 each so im ok there.

4. I will be weighing it atleast 2x on a CAT scale on my way home with it and i will post the results but it wont be unfrozen from the ground until early march, however there is no data plate, i opened every single cabinet, the power box, fridge, oven, etc, there is no data sheet or plate anywhere, nor on the outside, no VIN visible on the tongue, or anywhere else. the last owner could not locate one either and filed for a homemade trailer registration because the title and vin could not be located.

5. I do know water weighs alot, and so to the batteries, at 70lbs per battery if i use the T105RE which are optimized for solar use, and atleast 8 to start with, and upgrading to 16 to double the capacity for long nights or rainy days. the RE series can be safely discharged to 80% DoD without reducing the cycle life dramatically. thats 560lbs and double that for the later expansion. i intend to get all of the batteries with 6mo of each other so the date codes will be very close.

6. Regarding the 60A being a 60V system, that is not true at all with my controller, you should take a look at my controllers owner manual, it will allow up to 145V on the solar array and 12V, 24V, 36V 48V or 60V whichever i choose, it downconverts the solar PV to the battery voltage with a limit of 60A, so 60A @ 12V= 720W input, 24V @60A 1440W, 36V @ 60A = 2160W, 48V @60A 2880W, and 60V @ 60A = 3600W. But i dont have the funds for 3600W of solar, so i will only be going around 6- 305W panels for 1800W incoming around 70V then the controller will convert that down to 48V around 38A so i will still have 40% room for expansion later if i want to.

7. I have also been looking into the 30A 48V to 12V DC-DC converters to run LED lighting, fans, and the furnace fan. i havent looked into heat pumps yet, but i should.

8. I am not 100% sure on the rain water collection, atleast not right away, but it is something im looking into for the future if we are boondocking or camping without access to clean water.

9. The 2 main reasons for this trailer is that its large, the frame is much much much larger than even our 1992 34ft bumper pull we had before it was rated for 7500 and the C-channel used was puny in comparison. I am already planning on some reinforacement and removing all the rust and repainting the frame, and the second reason is that Im only spending $150 plus the fuel to get it home.

I could look into other trailers but i have read many many stories of people using regular campers and 5th wheels to live in full time and they are already loaded to the near maximum frame capacity from the factory so they add solar, batteries, equipment, etc then they end up breaking stuff like the frame welds, hitch, bending the C channel running the length of the trailer. I looked up the jr beams they used on our trailer and they use the same rated beams for 18K car haulers and 12K utility trailers at the local trailer plant, so i do not forsee the frame being the weak link but rather the floors and only having 2 axles. I will know how much room i have once its weighed of course, but 12K worth of axles and springs is a good start IMO.

So far my totals that i have estimated:

$150 trailer

$50 diesel

$400 full axle hub upgrade (this in includes new bearings, races, brakes, backing plates and possibly springs too)

$1280 - 8x Trojan T105RE batteries

$50 - cabling to make 48V battery bank

$10 1 gallon of premixed battery acid ( they sell it at the local farm store)

$1800 - 6 305W solar panels 

$500 Aims 5000W 48V MSW inverter. ( can also go up to 60V)

$100 LED light fixtures

$100 3 speed 14"x14" fan

$150 8,000BTU(800W) energystar A/C for just the bedroom

$100- Harbor frieght 800W 2cycle generator for running the AC continuously

Im sure the list goes on and on for all the little misc stuff like USB oulets, DC to DC converter, etc.

It sounds like you've got things worked out. You are definitely getting into it at the right price! If you're moving it seasonally, as you plan and not daily, it may work out for you.

If things prove later not to work out, you could always move your expensive components, like your solar system, to another trailer and not be too much worse for wear.

BTW that 800 watt generator won't run an 8,000 BTU AC. ACs have a large start-up surge which requires much more power for a brief period of time. I have a 1,200/1,500 watt generator that barely runs a 5,000 btu AC, but I'd think you would need something like a 1,700/2,000 watt Champion at a minimum for an efficient 8,000 BTU AC, especially if you want to run it for long periods. It would also be better at charging your batteries too, when there's a stretch of bad weather. You might want to consider a used Honda EU2000 if cost is an issue, as they are much more durable, and will prove cheaper in the long run.

Your Trojans should come filled with battery acid, so I don't think you will be needing any more, unless you plan or ordering them shipped to you. I recommend purchasing them locally if you can find a good vendor.

The point I was trying to make about the controller is that with 1,000 watts of solar that you suggested you might add, it well exceeds the 12v capacity of the controller, necessitating a higher voltage battery bank than 12v - at least 24v. 

Chip

-- Edited by Sushidog on Monday 20th of February 2017 08:12:01 PM