Want to go solar on my 25RR

[Herk7769]

Originally Posted by States02

Hi all, I'm new to the forum and just getting ready to set up solar in our new Winnie 2013. We previously had a Class C with 415 watts of panels on the roof running to a TriStar 45 MPPT controller and feeding three 12 volt AGM batteries. We lived full time on the solar for the last two years (except a few months in the winters) with no problems, of course we didn't use the microwave except for an extra cupboard. We also got a mellita drip coffee pot where you heat water on the stove and then pour through the filter. I'm no expert on this and very challenged with the math, but I'm a little handy and willing to give it a try. We were amazed at how freeing the solar panels were. We bought most of our stuff from Northern Arizona Wind and Sun and bought these panels from Solar Panels, PV Systems and Inverters Distributor we're going with more power on the roof this time, but could probably get by with less. Anyway, I guess I'm just encouraging you and offering to answer any specific questions you may have.

If you ever decide to spend some time in PA or NJ, I would love to sit down with you and pick your brain to put together an "off the grid" system.

[States02]

Originally Posted by herk7769

If you ever decide to spend some time in PA or NJ, I would love to sit down with you and pick your brain to put together an "off the grid" system.

We actually go to Pittsburgh and then usually on up to Northern New York. Don't usually get to the east of PA though. Happy to email or gab on the phone. PM me if you want.

[Rod Johnson]

Originally Posted by apollumi

Below are the solar panels and charge controller I'm looking at.

Panels (2 x 145 Watt)
Amazon.com: DM 145w Polycrystalline Solar Panel (2 Pack): Patio, Lawn & Garden

Charge Controller (30 amp MPPT)
Amazon.com: Morningstar ProStar 30 Charge Controller with Meter: Home Improvement

I'm unfamiliar with doing solar power. How hard will this be to hook up to a 25RR Toy Hauler? I was hoping I could continue to use the inverter that came with the camper.

Thats a decent deal on the panels, did you get a shipping quote for them? You'll still need some way to mount them, I think most people are doing z brackets and flat mounts on the roof. Though I've seen plenty of people just set them in the dirt and lean them up against the tongue while boondocking. Up on the roof, you don't have to mess with them, and they aren't likely to walk off while you're away from the trailer. I used a stud finder to mark the roof trusses, then transferred the locations to the panels. I drilled new holes in the panel frames to make sure my Z brackets ended up directly over the roof trusses for a good solid mount.

I think most people run the wires from the roof mounted panels down through the fridge vent, thats how I did mine.

I have a 400W PSW inverter that powers a 19" LCD and Blu-ray player just fine. Or the laptop I use in the bedroom for movies. Don't know if it'll do both at the same time. Of course, you can go as big as you want. I'd really like to get to the point that the fridge can run off the solar during the day instead of burning up propane.

Where is your inverter mounted? You're not talking about the charge converter are you??

I also use a PWM charge controller and it seems to work fine. The last two or three trips out, we never ran the generator, one trip was 5 days. Lots of tips and ideas on here to lower your consumption rate. LEDs are fantastic. I can turn EVERY light in the trailer on, including the trailer's running lights and the LED strips outside, and the circuit that powers it all has a 5A fuse...

[Rod Johnson]

Also, are you set on the Morningstar controller? I picked up a Sunforce 30A, looks like it half the price of the Morningstar there on Amazon. The Sunforce has #10 screws on the back, so you could connect 8, 6, 4, whatever gauge wire you want as long as you have a ring terminal...

Looks like the Morningstar is limited to 10 gauge, or even smaller, I can't tell. Pretty sure most of the panels all have 10 gauge, as thats as big as the MC4 connecters are designed to accept.

[Rod Johnson]

Originally Posted by apollumi

Here is my big unknown. I understand "Solar Panel --> Charge Controller --> Batteries <-- Inverter <--- Appliance" but I have no idea how the electrical system in a camper works nor where to connect everything. In my mind I put solar panels in and a charge controller connected to the batteries. Then by magic I can use my normal outlets for 120v appliances and everything is hunky dory. So, I'm tarded on getting my nice cheap solar generated electricity going through the existing electrical system of my camper.



I've only done a couple days reading on solar panels, charger controllers, and looking at installs on rv.net (I think that is the site). Still a ways to go but I got a little fundamentals down before I came here to post.

There are lots of ways to get your 110V from your inverter back into the trailer wiring and out to your outlets. The easiest way is to make a pigtail cord that plugs into your inverter and runs around to your shore power plug. You'd plug your trailer back into your inverter like it was a generator. (Remember to turn off your converter as it'll just waste a bunch of energy) I moved the wire for the converter to a dedicated breaker so I can just reach down and flip the breaker off.

I have a wall switch style transfer switch. My setup only powers one AC circuit in the trailer, thankfully all the TV outlets are on that same circuit. Basically, the TV wiring is on the poles of the switch, and the inverter is on one set of throws, and the circuit breaker box/shore power is on the other set of throws.

Originally Posted by apollumi

The 32" TV says 51w (1w standby) and the laptop (alienware M11x netbook) is reported to pull 30ish watts while gaming (much less when streaming a movie or DVD). The laptop has a 65 watt charger. Is my math flawed? I'm thinking 100 watts total draw vs the 1200-1100 watts you mentioned earlier. No problems admitting that there is a good possibility of lack of understanding on my part. Once I know how it all works though I'll stop asking people questions.

Thats 50 Watts at 120V at 12V, its gonna take a bit more amps to make the same watts.

[Rod Johnson]

Originally Posted by herk7769

I found that out the first time I tried to make coffee with my 2400 watt inverter. My 2 battery (140AH bank) was dead before the coffee finished brewing.

I think you mentioned it earlier up in the thread, but some inverters are really inefficient. Look how most of them are covered in heatsinks to get rid of all that wasted energy

Herk, I just broke down and bought a percolator. Just warm that puppy up on the stovetop in the morning.

[BJAY]

Reduce your consumption first.

Install LED lights(90% reduction for lighting)

Use a coffee press, percolator, or drip with heat from propane stove(no inverter req'd)

We have a sheet metal toaster(2 slices end to end) on propane burner(no inverter req'd)

We met a guy in Texas who turned north if it was too hot, and south if it was too cold(no A/C req'd)

Add a bit of extra capacity and forget about fancy tilting solar mounts. 4 years ago we went to Texas for the winter and never went up on the roof. I used 3/4" x 3/16 aluminum angle screwed to the roof trusses and then fastened each panel corner to the angles.(4 brkt's/ panel).

[Herk7769]

Originally Posted by Rod Johnson

I think you mentioned it earlier up in the thread, but some inverters are really inefficient. Look how most of them are covered in heatsinks to get rid of all that wasted energy

Herk, I just broke down and bought a percolator. Just warm that puppy up on the stovetop in the morning.

I now have:

A French Press that I just need to boil water to use
A Filter Cone holder that I can pour boiling water through grounds
A "cowboy coffee pot" similar to yours but blue porcelain

and of course our Tassimo for a hot cup chocolate around the campfire, a Cappuccino for breakfast, or Espresso after dinner (when we have hookups or the generator is running).

I can NOT camp without coffee.

[BJAY]

MPPT controller is the way to go.

They allow using higher than 12v panels but convert and deliver 12v to the battery bank. I have two 115 watt 24v panels. Higher voltage=lower amperage so you can use smaller gauge wire from panels to controller. Smaller wire is cheaper and easier to manipulate down thru the fridge vent etc.

The manufacturers claim up to 30% more power when using MPPT.

Mount the controller close to the battery bank because you need heavy(expensive) wire between the controller and battery bank. I have 3 group 27 batteries(300 A/H) over the axles under the dinette seat in a sealed box which is vented to outside. The controller is outside the battery box but still close to the batteries under the seat. The original plywood under the seat cushion is now lexan so I can easily do a quick visual check by lifting the cushion.

[BJAY]

My trailer had one group 24 battery behind the propane tanks and no room to add so I went with the 3 battery setup under the dinette seat. The positive feed from the orignal battery(no disconnect) ran along the frame and up into the converter. I was able to reroute this to a disconnect near the new battery bank. The new bank goes to a second lug on the same disconnect, and then I installed a new line going to the converter. I can now a)disconnect all batteries, b)connect only the original, c)connect only the new bank, d) connect all batteries with one multi position marine style switch. I will have the original battery charging from the truck in the event I have trouble with the solar system.

[Rod Johnson]

BJAY, have you had any issues with using dissimilar batteries? IE, some not charging, some overcharging, irregular discharging?

[BJAY]

Rod - I just installed 3 new batteries in July and havn't used them much yet, so I don't know how well it will work. I don't like lead battery cable clamps and havn't been able to find cables with the stamped sheet metal clamps that they use on new cars so I flattened 1/2" copper water pipe and drilled 3 holes to fit down over the studs and fastened with wing nuts. An old guy who lives near me has about a dozen batteries connected this way for a few years now for his off the grid home system. My son works for Exide so it didn't cost me retail prices to try this. On my previous trailer I used 2 group 27's for 2 years without problems. We hope to go to Texas after xmas so I hope it works because we don't carry a generator. Two years ago we plugged in 2 nights out of 93 and the 2 nights were just to check out a park.
Bill

[apollumi]

Originally Posted by Rod Johnson

There are lots of ways to get your 110V from your inverter back into the trailer wiring and out to your outlets. The easiest way is to make a pigtail cord that plugs into your inverter and runs around to your shore power plug. You'd plug your trailer back into your inverter like it was a generator. (Remember to turn off your converter as it'll just waste a bunch of energy) I moved the wire for the converter to a dedicated breaker so I can just reach down and flip the breaker off.

Never thought about the pigtail solution but it's sounds much easier than what I was thinking. I like simple solutions. How do I turn the converter off? I guess I need to pop out some paneling and see what's back there.

[apollumi]

Originally Posted by Rod Johnson

Also, are you set on the Morningstar controller? I picked up a Sunforce 30A, looks like it half the price of the Morningstar there on Amazon. The Sunforce has #10 screws on the back, so you could connect 8, 6, 4, whatever gauge wire you want as long as you have a ring terminal...

Looks like the Morningstar is limited to 10 gauge, or even smaller, I can't tell. Pretty sure most of the panels all have 10 gauge, as thats as big as the MC4 connecters are designed to accept.

Yep, looked at the sunforce. I want the MPPT charge controllers but $500 seems a little expensive right now with other things I'm looking at so the MTTP charge controller may have to wait. I'm no big coach, just a little ole 25' toy hauler. I just need something to move forward with the project. I plan on mounting the charge controller where I can change it out fairly easily.

[Rod Johnson]

Originally Posted by apollumi

Never thought about the pigtail solution but it's sounds much easier than what I was thinking. I like simple solutions. How do I turn the converter off? I guess I need to pop out some paneling and see what's back there.

Once you get the power center cover off, and out, you'll be able to see whats going on. The power center takes regular breakers, you can add a dedicated one for the converter, or move the wire to one of the other breakers.

[Herk7769]

Since my power center is "full," I actually have two circuits on one breaker.
Not sure if that was "legal" under RIVA, but it is what it is.

One of those is my converter and the other feeds all of the outlets in the main living area. To turn off the converter without powering down the living area, I would have to move the black wire from the converter to the bathroom/bedroom outlet circuit.

[Rod Johnson]

Originally Posted by herk7769

Since my power center is "full," I actually have two circuits on one breaker.
Not sure if that was "legal" under RIVA, but it is what it is.

One of those is my converter and the other feeds all of the outlets in the main living area. To turn off the converter without powering down the living area, I would have to move the black wire from the converter to the bathroom/bedroom outlet circuit.

I found mine installed the same way. Actually, a short pigtail with a wire nut right there in the circuit breaker panel. You can see I doubled up on the 2nd breaker down. I can't remember which breaker that is...

[apollumi]

Let me see if I understand the whole RV electrical system.

Connected to shore power:

• power comes in via shore power (big heavy 30a power cable)
• All of the 110v circuits are powered directly from the incoming 110v connected to a metal bar (buss) (Not necessarily clean power)
• The convertor is connected to the 110v and outputs 12v which powers the 12v devices such as overhead lights and heater as well as charges the battery.

On battery:

• Convertor isn't getting 110v so it's not powering the 12v devices and 12v devices pull directly from battery (lights, pump, heater, etc)?
• Convertor doesn't turn 12v into 110v so I have no 110v TV, Laptop AC adapter, etc because that is what the inverter is for?
• My brow wrinkles because I wonder why my lights dimmed a little after disconnecting main power

Solar to batteries: (by way of charge controller)

• Battery takes charge
• 12v devices work and battery takes charge
• during good sunlight there is little draw on the battery and 12v devices work
• I go to turn on my TV and bam! Nothing..!

Solar to batteries with charge controller and inverter connected to 110v bus:

• All 12v works.
• Moderate use of 110v devices works after turning on inverter.
• I turn on on disco ball and my Bose 901 speakers and the sides of my batteries bow inward from the suction?

Am I closing in on understanding? So what I need to do is....

1. Get solar panels (done, check)
2. get a charge controller and probably violate the virginity of the fridge vent running cables from panels to it.
3. Run cables from charge controller to batteries
4. Run heavy cables from batteries to 12v devices and inverter?
5. Either wire output from the inverter to the 110v bus or make a pigtail that runs to the shore power connection?

<big stupid grin on face with drool running from the corner of my mouth>

[BJAY]

Looks like you've got the idea. I used fuses at the panels on the roof in case of a short in the wires between panels and controller, a fuse on the positive wire going to the converter,and again at the battery in case of short in the heavy wire to the inverter. I think most inverters are fused internally but with my 1000 watt inverter the wire carries about 100 amps at 12v so I wanted that protected as well. By using a rotary marine style battery disconneet you can shut everything off quickly if something goes wrong, or if you need to do any maintenance. In my case the original battery mounted on the tongue can be left out of the system and then turned on as a backup if needed.
I ran the power line from the panels down thru the fridge vent, across behind the stove, down thru the floor, across under the trailer, and back up thru the floor to the battery bank in the space under the dinette seat. By using 24v panels( lighter gage wire) this task was relatively easy.
Bill

[RPAspey]

get yourself a calculator for voltage drop. use a maximum of 3% voltage drop to maximize output from the panels. you'll be surprised how big of a wire you'll need to keep the drop that low.

I found that auto stereo installers have large gauge wire reasonably priced. Get only pure copper!!