VERY LONG - My 12V Electrical Modifications and Solar Power System Installation

[Fire Instructor]

WARNING – This post is incredibly long!!!!

Greetings!

I’ve been asked a number of questions about the solar power installation and supporting modifications that we recently completed. (Yea, right…. Is any project ever really completed? I’m already looking at things to add to make it even better!) Anyway, I thought that I’d try to put together a single post that would explain our installation and answer any questions.

First, a little bit about us and why (we believe) solar was the right choice for us. We live in Upstate New York, in the Albany area. Our travel trailer is a 2009 Rockwood 2607, with a large front bedroom, mid-ship galley and living area, and a LARGE rear bathroom (the feature that “sold” us on the trailer)! While it’s a “2009”, it was delivered new in the winter of 2008, so it’s had three camping seasons. Each year, we go to a major RV show in Springfield, MA (plus several other smaller shows), and we have yet to see a RV whose floorplan appeals to us more than the one we already have, which tells us that we made the correct choice, and will likely keep this unit for years to come.

We typically camp in a variety of places, including some very nice RV resorts, private campgrounds, state parks with limited or no utilities, NASCAR races, and an occasional parking lot while in transit more than a day. One of our favorite trips is one that we try to repeat every other year, to Assateague IslandState Park, in Maryland. Camping at Assateague is truly boondocking. There are no services in all but one of the camping loops. Water needs to be hauled in, waste hauled out, and if power is needed, it means “disturbing the peace” by running a generator.

For boondocking, we have a 2400W Yamaha (quiet!) generator, purchased after our first NASCAR camping weekend without one, but using it means that someone needs to fuel it (me!), start it (also me!), keep an eye on it while it’s running (me again!), and then secure it when completed (yup, it’s me!). In spite of the Yamaha being quiet, this activity still requires “attention” – detracting from my camping leisure, burning long-dead dinosaurs whose remains directly fill the bank accounts of a society that includes those who would commit acts of terrorism (I’m a firefighter who worked on The Pile at Ground Zero in NYC post-9-11), and emiting CO and other toxins into my campsite!

So after a 2009 trip to Assateague, DW makes the suggestion that we look at solar. I blew it off as “too expensive” at the time, but started to look at exactly what “going solar” really meant. In July 2010 we, once again, managed to book our sites at Assateague for 10-days in July 2011, so I knew then that I had a year to move on this.

In the Spring of 2010 (after two seasons of use), the original Group 24 marine deep-cycle battery was toast. My solar research and rough consumption calculations had already told me that I needed to get more than 200Ah of capacity, and that I was best-off doing this with a pair of 6-volt golf-cart batteries, which I purchased from Sam’s Club, giving me 220Ah.

By the fall of 2010 I had really gotten into the research. I knew that the first two solar “systems” that I had looked at would never fill my needs. These were the 45W system sold by Harbor Freight, and the Northern Tool 60W system. Both would support most of my daytime use (primary daytime user is the water pump), and would take care of most of the parasite loads (smoke detector, LP detector, refrigerator circuit board), but would never be capable of bringing the batteries back to full charge. This would mean that I’d still need to run the generator every day or two to restore the batteries anyway. So towards the end of the 2010 season, I started asking questions, reading manufacturer’s information, taking measurements, and re-designing my electrical system to integrate solar power.

There are three major subgroups of work involved in my project. These are reducing load, distributing 12v availability inside the living area, and installing the roof-mounted solar collection system.

Reducing Load

For me, the single area where I could most reduce load was with interior and exterior convenience lighting. The unit came from the factory with at least seventeen 921-type incandescent bulbs, and a couple of other individual style of bulbs in various fixtures. I counted what I’d need to replace these with LED’s, and I ordered LED replacements. I found an on-line (Chinese) supplier, ordered one each of what I needed to assure that it was what I really wanted to do, and after trying them out, ordered what I needed. I even replaced the incandescent bulbs in the range hood and the refrigerator. All LEDs were ordered from Virtual Village.com .

Distributing 12V Availability Inside the Living Area

I carry a cell phone (personal) and a PDA (work); plus my wife has a PDA. All three have cigarette-lighter chargers. We both have cameras that can recharge directly from 12v, plus spare battery chargers for the cameras that also can recharge this way. I have a 12v cigarette plug charger for my laptop. In the past, we had to put these devices in the tow vehicle to charge. This made them unavailable for use, and was inconvenient. So I added five 12v cigarette lighter plug outlets in various locations; one on each side of the bed, one on the exposed wood side of the couch, one on the wall over the kitchen counter, and one on the kick-panel (behind your legs) on a dinette bench. The outlets were Prime Products 08-5010 12 V Standard Plate Receptacle, ordered from Amazon.com .

To wire this, I cut into the primary 12v supply and ground in the pass-through nose compartment, about 3 feet away from the batteries. From this location, I ran a pair of #10 wires about 5 feet to a location inside the pass-through, but easily reachable from the outside. The positive lead is protected at this location with a 30A in-line fuse, which then feeds a 4-fuse fuseblock (purchased at a local automotive supply store). Each fuse then feeds a single circuit (run with #12 wire) and outlet, with one circuit having two outlets to feed. Each of these circuits has an individual 15A fuse.

Roof Mounted Solar Collection

Anyone who has read this far, is likely looking to get to this section. Our solar system is comprised of the following:

Two 150W Suntech Panels (34.4v) – These came from Sun Electric, in Phoenix., as did the wire pigtails necessary to go from the panel to the combiner box. I used pigtails joined to the factory panel connector, as some folks report that cutting the factory connection off and wiring with a crimp connector voids factory panel warranties.

Homemade two axis, four way tilting mounts – Assorted aluminum stock, clevis pins and stainless steel nuts, bolts, and screws came from local Home Depot, Lowes, and True Value Hardware. The stainless steel hinges came from HardwareSource.com . The design attaches (with removable pivot-pins) the panels to the roof of the unit in six points for travel or to use flat. The pivots, one in each corner, allow for the panel to be lifted on either end of the long axis. The hinges, three on each side, allow the panels to be lifted on either side of the short axis. Prop-rods of various lengths, with pin holes drilled every inch, allow for angle adjustment of the panel to accommodate different latitudes, seasons, and whether the unit is oriented N/S or E/W. For example, at my house (near Albany, NY @ latitude 42.6710), in the Spring or Fall I need a 39.5 degree angle. If parked N/S, the panels will be lifted from the North end a height of 43”. If parked E/W, the angle stays the same but the lift to achieve it is 21.5” (so I round up or down for early or late season). It the summer the two lifts are 17” and 8.5”, respectively.

Panel Disconnect – Installed to disconnect power from panels to controller for maintenance, storage, etc. Purchased on-line from Amazon.com is a Perko Marine Battery Switch, Model 9601DP.

Rogue MTP-3024 Controller/Charger – This is the new 3024! In fact, my invoice was 2011-1, which Rogue’s owner, Mark Loring, confirmed was the first of the new 3024’s shipped. I can’t say enough good about working with Marc and Rogue. He answered several questions for me with detailed answers prior to my order, and while discussing via email the progress of my install prior to him being ready to ship the new models, he readily shipped the battery temp sensor and wire so that I could pre-wire.

Roof Combiner Box and Interior Junction Box – These are a matching pair of 4/2 Roof C-Box from AMSolar. Good boxes to work with, with large access points on buss-bars. They mount and seal well, too.

150W catastrophic fuse - Raptor RANL1502 150 Amp ANL Fuses, 24K Gold Plated, 2 Pack and a Scosche EWFH Single ANL Fuse Holder, both from Amazon.com .

#4 Cable - F29740320-A RADAFLEX® #4 AWG Twin Cable from CableYard.com

I also needed to purchase a hydraulic crimping tool to make-up the cables and attach lugs for various junctions. The lugs came from local auto supply stores, but the hydraulic crimp came from Harbor Freight.

System costs – rounded off (what you’ve been hanging on for) are as follows. All costs include shipping, where applicable:

Solar Panels: $756
Pigtail: $26
Controller: $370
Stainless Steel Hinges: $50
Aluminum Stock: $120
Nuts, Bolts, Screws, Pins:$30
Panel Disconnect: $38
Combiner Boxes: $149
Catastrophic Fuse Holder & Fuses: $25
#4 Cable: $79
6-volt batteries: $165
In-line fuse holder: $4
4-fuse block: $7
12v Receptacle Plates: $29
Battery lug crimps: $15
Hydraulic crimping tool: $50
Two tubes of Dicor Roof Sealant: $22
#10 & #12 wire, wire crimps, heat-shrink tubing, clamps, etc: $50

TOTAL SYSTEM COST: $1,985 of this, $425+ is in shipping and handling!

A number of photos showing much of the install can be viewed at: Rockwood Solar Install 2011 pictures by Fire_Instructor - Photobucket

So how does it all work??? It’s all been operational since last Saturday afternoon (June 18, 2011). It brought the battery up to full that day, and has held it there ever since. That said, up until today (June 22), we’ve had sun-filled days, and the trailer has been parked in my driveway. Only parasite loads and short-duration “other” loads (lights, sat radio, water pump) have occurred. Today was rainy and very overcast. The contoller went into sleep mode twice during the day because of lack of panel output in the stormy, overcast sky, yet the times that it was awake, it still maintained a “full” battery, and operated in the float mode. Our Assateague trip starts a week from today, so I’ll know just how good the entire system is in just a few short weeks.

So that about wraps it up. About the only thing left that I haven’t told you is blood-type: (B neg).

My apologies for being so long, but I warned you!!!! I hope that you got something from the read, and hopefully this answered any questions, and gave you some solar meat to chew on for a while…..

Be Safe,

Rick
Fire Instructor

[mikegp1]

That was a very long post. But a great one. I am very interested in possibly doing the same thing to my 5'er. I do alot of camping at NASCAR races and this would be great instead of running the generator. We dont spend to much time in the camper during this time but still need power. I am looking to into LED lighting for the camper as we speak. Would this setup handle a small inverter to run simple things is my question. I am debating my installing a onan generator in the front compartment or going solar. I know the soalr wont run my ac but I could fire the genny for that if it was needed. I currently use a portable one but it is a pain to cart around. I think I'm going to start researching this furthur knowing it worked for you.

I am also a fellow Fire Fighter for 11 years. My company was down at Ground Zero the next day to help with recovery.

Be Safe out their.

[Herk7769]

I stuck the Thread. You are amazing.

On your way down I-95 give us a wave!

[Fire Instructor]

Originally Posted by mikegp1

Would this setup handle a small inverter to run simple things is my question.

Absolutely! That's one of the reasons for so many 12v outlets! I already have two small inverters (a 350w and a 400w). With them, about the only thing that I need to start the generator for is to run the microwave or the Margaritta maker!

One of the "improvements" that I'm looking at is a bigger pure sine-wave inverter. Likely not a "whole house" inverter, but something in the 2000w to 2500w range. This would allow for short runs of either. No sense trying to enjoy a Margaritta on the beach, if I have to start the generator to make it!!!

I've also been checking out small 12v appliances on-line and at truck-stops. Back in the 1800's, Thomas Edison proved that DC was a much more effective than AC for powering the world, it's just that Edison (and his followers) have NEVER been able to develop a way to transmit DC for long distances, like George Westinghouse and his people did for AC. This is why we live in an AC world, rather than a DC world..... Over a short distance (like in a travel trailer system!), DC is more effective! It's just that we now have catalogs and store shelves FULL of 120v AC appliances and very little in 12v choices.

[Acableguy06]

Originally Posted by Fire Instructor

It's just that we now have catalogs and store shelves FULL of 120V AC appliances and very little in 12V choices.

And a lot of these have transformers, power supply's, diodes, rectifiers etc.. bringing 120V AC to a much lower DC level.

[Fire Instructor]

Originally Posted by Acableguy06

And a lot of these have transformers, power supply's, diodes, rectifiers etc.. bringing 120V AC to a much lower DC level.

And the reason for that is as I stated... DC is a more efficient way of living! It just can't be pushed long distances!

[Shawomet3]

Hi-
Just to add to the thread, I installed a simple home-made system. In the pic, panel on left was bought (80watt) and one on right is homebrew (160 watt). I don't have any elevation brackets-just flat roof mounted. Average charge rate is around 9 amps into my battery. I have 2 12vdc batteries. As an experiment, I have been running my ref, 2 fans, 2 led interior lights for a week. We have had some nasty, dark weather, yet I still have power to the units. Like you, when we want coffee or start the blender, the genny goes on- but not that often.

Bottom line is store bought 80 watt panel- $125; homebrew 160 watt- $210; new 20 amp charge controller (ebay)-$80; #10 stranded wire- $40; asst hardware and sealants- $30 for a total of $485 or $2/watt. Not too bad.





We'll be down at Assateague also around July 5 for a week. Hope we can hook up.

Ps.- I'm a volunteer fire chief in RI- Be safe.
Rick

[Fire Instructor]

Chief,

Sounds like a great system, especially at the low cost! Very interested in seeing your "homebrew" 160W panel. We'll be on G-loop, we (collectively) have the last 7 or 8 sites on the loop. I think that I have the only Rockwood TT of the bunch (there will be a new Rockwood PUP in the group), so look for the Rockwood with the rooftop solar!

We can compare notes over a cold, adult carbonated beverage!

[Shawomet3]

We'll be in the I loop, July 7 - 12. I'll have a solar palm tree.

[toshu]

Chief,

I am wondering whether the homebrew panel was made using parts obtained from EverbrightSolar on ebay??

I will also look you up on Assateague. I live nearby

[toshu]

Fire Instructor,

I am curious what made you select the SunTech panel, over other brands? Cost appears to be above $2/watt, although shipping can be a lot.

Was this brand specifically recommended for RV mounting, or was it recommended by Mark at Rogue, etc????

As far as your Brackets for roof mounting and elevation, I think I understand them now. From picture closeups, it looks as though you use a cotter pin mechanism to attach the panels to the TT roof.

For your wiring run, it looks like you just ran straight thru the roof, right at the roof combiner box, to enter the TT closet above the bed??

My recollection is that this model Rogue allows PC data logging.....have you tried that yet, and will you be testing/using that during your Assateague trip??

How are you monitoring your battery level??

Tnx

[JNelson]

Rick, I'm 65 and work in Home Depot's corp office in Atlanta. I'm a month or so from getting my first popup. I'm a ham radio operator and astronomer, so electronics is always interesting to me. I really enjoyed your article about the solar power you have set up. Probably too big for my popup, but a smaller setup....hmmm... thanks again. I'll look for future articles about how you like it.

[Fire Instructor]

Lots of good questions here! Sorry that i didn't notice them whan you posted them!

Originally Posted by toshu

Fire Instructor,

I am curious what made you select the SunTech panel, over other brands? Cost appears to be above $2/watt, although shipping can be a lot.
It was the right size panel, with the right output, at the right price. Was looking at the Kyocera's, but price and the extra 15w / panel were the deciding factor.

Was this brand specifically recommended for RV mounting, or was it recommended by Mark at Rogue, etc????
I already had the panels on order when I began my dialog with Mark at Rogue.

As far as your Brackets for roof mounting and elevation, I think I understand them now. From picture closeups, it looks as though you use a cotter pin mechanism to attach the panels to the TT roof.
Correct! It's a pin and key system. A little clumsy (I've found that it's easier to manipulate with a pair of needle nose pliars), but cost and use efficient.

For your wiring run, it looks like you just ran straight thru the roof, right at the roof combiner box, to enter the TT closet above the bed??
Correct. Ran the cable right down the corner of the closet, and installed the shut-off in the lower corner of the closet.

My recollection is that this model Rogue allows PC data logging.....have you tried that yet, and will you be testing/using that during your Assateague trip??
The data-logging is a feature to come. The controller has the remote connection for data logging and for a remote panel, but Marc said that they won't be released until likely the Fall. I have the conduit already run for mine, as it was easier to do during the initial install.

How are you monitoring your battery level??
With the el-Cheapo "Micro-Monitor" (very unreliable) that came with the Rockwood. However, any time that I'm reporting the battery as "full" in these posts, it's when it's switched over from MPPT charging to "Float".

Tnx

[Fire Instructor]

I boilded water today with my TT microwave!

I know.... It doesn't sound like any kind of great feat, but I wasn't plugged into grid power when I did it! I did it to "test" my installation of a new Xantrex PW2000 pure sine wave inverter.

I had previously mounted the unit and the remote switch, so today, I just had to finish the wiring. Ran about 5' of 1/0 (#0) cable from the batteries to the inverter, put a 250A in-line fuse in the hot leg, and turned it on. I had an extra foot or so of cable, so I also replaced the #6 wire connecting the two 6-volt batteries in series with a short section of the 1/0 that I crimped ends onto. To test the installation, I just ran the TT cord into my front compartment, and plugged my 120v ststem into my 12v system.

Next step will be to run 120v Romex from the inverter to a spot next to the TT cord, and install a 120v outlet there, powered by the inverter. Once done, I'll just have to plug in my dogbone adapter into the adjacent outlet.

Our next two planned camping trips are both boondocking, so I'm looking forward to seeing how it all works!

[toshu]

Rick
That's awesome!!!

What has been your high in terms of amphrs from your panels so far?

[Shawomet3]

toshu-
Sorry I didn't get back to you...just got back from an extended trip. Yes, I got the cells from EverbrightSolar. The system worked wonderfully...we only started the generator for good coffee in the morning.

[Fire Instructor]

Toshu - Highest Ah day thus far was July 3, where the panels produces 35.4Ah. We had watched a movie the night previous, and had been inside most of the evening due to the bugs. That's also the day where I received peak watts from my panels, peaking out at 292 Watts. I was amazed at that, as th panels are only 300W, so it must have been a very "efficient" day!

Now I can experiment some, and see just how much use I can actually get, using things like the toaster and Margaritta maker. I'll likely limit the microwave use, at least until I install a second pair of 6v batteries.

[TimeFurnace]

I just got back from a week long trip. I didn't run my microwave off of my inverter on this trip. I can count on 20-25AH out of my meager 160W array during a typical day here in California. It is an estimate because I always end up with a "full" battery according to my LinkLite during the afternoon. I haven't been deliberately draining the battery to lower levels to see what I can make up the next day. That isn't bad performance when the parasitic draw is 1 Amp. (I am not sure why the refrigerator takes 0.9A when running on Propane. My previous TT frig didn't have a draw on propane.

I have run the microwave off of the inverter and IIRC correctly, the LinkLite reported about 140-150A draw. With your much larger solar array (and future larger battery bank), 10-15 minutes of micro use a day might be easily accommodated.

As for wiring, I placed my inverter on the forward wall of the through storage at the front of my trailer so that it would be within about 3-4 cable feet from the battery bank. I used 4/0 wiring to/from battery and upgraded connection between the two 6-V batteries to 4/0 cabling per Xantrex recommendation. To wire up the trailer, I ran 12/2 wiring through flex conduit under the trailer to the converter's distribution panel to power the outlets and microwave.

[BackInAction]

Which 921-style replacement LEDs did you "like" from virtual village? There are so many to chose from.

[Fire Instructor]

For the double overhead fixtures, I went with these: White SMD 36-LED Light Panel with Festoon Bayonet Wedge Connectors

The reading lights got these: 2 Xenon White LED T15 Car Bulbs with 9 LED's in Each

The range hood: 2x25 SMD LED White Wedge Auto Bulbs Lamp Car T10/194

Outside porch light: 36 White 12V LED Circuit Board RV Boat Light Bulb 1156

Refrigerator light: Interior Car Lights - 2 Festoon White 9 LED 12V 42mm Bulbs - 6411 / 4411

Hope that this helps!