Solar Install for a 16DB

[whitefish]

I put off writing this post until I had some time with this install to have enough experience to discuss the good and the not so good with my system.  I also wanted to help those specifically with a Camplite Trailer, giving an example of solar could be installed in their unit.  As it seems the norm on the net nowadays, I'll give the standard caution that I'm not an electrician or a solar install expert. Use this information with caution and at your own risk.  I don't promote or discourage the use of the equipment that I chose to use, its just what I chose.

My system (summary):
2013 Camplite 16DB
2 @ 100w Greesonic  ETFE  Semi Flexible Panels
2 @ 100w Matrix Monocrystalline "Rigid Panels"
2 @ 6v 235 ah Crown GL2 batteries (in series for 12v 235 ah)
Morningstar TS-45 PWM Solar Charge Controller
Go Power 400 Amp Catastrophic Fuse
Go Power 2000w Pure Sine Inverter
Go Power TS-30 Automatic Transfer Switch
Schneider Electric 60 amp AC Sub-panel
Victron BMV-700 Battery Monitor
Midnight Solar Baby Box with 15 amp DC breakers

My install (summary)
After a lot of debate, I opted to have: 1) the battery bank situated in an existing battery box in the trailer tongue, 2) the catastrophic fuse, solar charger and solar breaker in the small hold area at the front, 3) the inverter in hold next to the hot water tank, and 4) the automatic transfer switch and associated AC breaker in the space under the bench seat/folding bed.  All DC connections are 2/0 wire (DC) except the solar controller which is connected by 4 AWG wire (DC). All added AC connections are 10/2 Romex.

The ingress point for the solar panel combiner box is just above the microwave along the backside left side of the microwave and fridge enclosures. Then the 4 AWG wire is run under the fridge, inside the right storage compartment (under queen bed) to the solar charge controller.  Wires to the combiner box from the solar panels are either 14 or 12 AWG.

All wire sizes chosen were either required (battery to inverter) and/or to minimize voltage drop to 2%.
The location of both the charge controller and inverter were done so to minimize distance to the batteries, as required.
All panels are connected in parallel to maintain voltage but increase amperage.

[whitefish]

Solar Panels


2 @ 100w Greesonic  ETFE  Semi Flexible Panels
The panels were originally mounted to the roof of my trailer using 2" Industrial Velcro.  I placed a strip along each edge and diagonally along the middle of the panel (to prevent sag in the middle of the panel more than anything else).  This worked VERY well – almost too well.  The panels were very hard to remove at times and sometimes the glue gave way before the Velcro.  I ended up bending one panel and cracked a solar cell in the corner trying to remove a panel.  I opted to drop down to half an inch of Velcro, found out this was too little and lost one panel on the road.

Why not just permanently mount the flexible solar panels to the roof? I went with a removable system because I wanted to have the option of moving my panels into the sun. For example, in one particular camping spot I found that placing the flexible panels on the open awning was very effective (maxed out at 12 amps charging with just two panels). This actually exceeded the panel specifications of 5.87 amps each). 

The good: Flexible ETFE panels are very light (3 lbs) compared to rigid glass panels (17 to 20 lbs for 100w), making install and removal a breeze (as long as the mounting system allows for this).  Flexible panels are very mobile. The panels in good solar conditions (high irradiance and moderate to low temperatures) performed above expectation. 

Because of the low profile of the flexible panels, you don't even know they're on the roof.  This makes for a very clean look and install.

The not so good: I found out that panel efficiency really drops when the panels get hot.  This is caused (in part) by the panels sitting directly on the metal roof with no gap underneath for airflow to allow cooling.  I tested this by cooling the panels and then placing back on my roof and saw an immediate increase in amperage by as much as 40%.  I then watched the panels heat up again and the amps go back down to what I saw before the test.

Flexible panels cannot really be tilted, at least not as easily as rigid panels.  It's easier to put them on a tilted surface, such as an awning.  Tilting does make a difference, especially in the winter.

As others have observed, the ETFE coating on these panels has started to "peel" ever so slightly in some areas.  I don't know whether this is due to wear and tear of moving the panels, expansion/contraction from heating/cooling or both.  Either way, after 6 months I'm not impressed with how the coating on these panels performed.  If one were to install these permanently and then seal the edges with a bead of Dicor (or similar product), I think the ETFE coating would last longer.  I have not seen the delamination/cupping issues reported for PET coated panels.

2 @ 100w Matric Monocrystalline Rigid Glass Panels. 
After I lost one of my flexible panels, I decided to get two rigid panels that I would mount permanently on the roof.  I made my own mounts out of 1 ½ by 2 inch aluminum angle – mounts had a footprint of 2x4 inches each.  I attached the mounts to the trailer using 3M VHB tape and was careful to follow the install instructions to the letter.  The panels were attached to the mounts using 1/4 stainless bolts – I mated the mounts to each other (solar panel mount to trailer mount) using 5/16 stainless bolts.  This way, the solar panels can pivot to angle into the sun.  I have almost 1000km of travel with this setup and haven't lost a panel yet!

The Good: the panels perform to specification and they are far less susceptible to performance loss due to heating than the flexible panels.  There is about 1inch clearance from my roof to the solar panel frame, allowing for lots of airflow for cooling.
With some effort, panels are tilt-able.  I unbolt the side I want to tilt and add a spacer bar to get the necessary angle.  I've opted for a fixed tilt angle of 30 degrees that seems to be optimal. I don't travel with the panels tilted.
These panels are 40% cheaper than my flexible panels and have a far longer warranty (5 years workmanship/25 years solar performance versus 1 year workmanship/10 years solar performance).

Not Good: the panels are heavy (17 lbs each), so moving these panels around to chase sun is not practical.  If you are concerned about adding weight to your trailer, this might be a consideration.
For the future, I plan on a mix of rigid and flexible panels.  I'm going to start with 2 rigid panels as a permanent install.  I plan on having two flexible panels to move into sun as my camping circumstances dictate.  I don't plan on leaving the flexible panels on the roof while travelling, so I won't worry about affixing these to the roof (e.g. Velcro).

Batteries
I decided on using two GL2 (golf) cart batteries in series.  Rather than talking about good and bad about the batteries themselves, I'll talk about options I considered for battery placement.

Option 1 (my chosen option)  – Install GL2 deep cycle batteries in the existing battery box at front of trailer.  This seemed like the obvious option as the box was there and I just need to bring cables to it.  The batteries would also be outside of trailer and properly vented, which is an absolute must for flooded batteries.

The downside to this location is added weight on the trailer tongue.  I already have two 20lb propane tanks at the front and I was worried about overloading the tongue. With this this setup, my tongue weight is around 400lbs.  This is fine for my truck, but may be overkill for some tow vehicles.

Option 2 – GL2 or AGM batteries installed in the "closet" lower cabinet at the rear of the trailer (beside bathroom on the 2013 16DB trailers). The benefit of this option was the ability of putting the majority of the equipment near each other (batteries, charge controller, catastrophic fuse, switches/breakers, inverter and associated wiring all in the same space).  The downside to this option is the loss of this space and the need to contain and vent wet deep cycle batteries. I could use AGM batteries here and not worry about venting, but in the end, I didn't want to give up the space.

Option 3 – AGM batteries in the space under the folding bench/bed. Again, the benefit is having all equipment installed proximal to batteries and the benefit on having all equipment close to each other (e.g. reduced wiring).  However, access to this area is hard unless one were to cut a large access door/panel through the Adzel to access the area without always removing the bench and sheet aluminum. I also debated on how I was going to get the solar feed wires from the roof to this spot.

Option 4 – AGM batteries, solar controller, etc in space under the fridge. This is completely dead space as there is nothing installed here – the only impediment would be the wheel well which intrudes slightly. In retrospect, this may have been my preferred option, provided that I could get all of the equipment in there and/or minimize my DC cable run from the battery bank to the inverter (4 feet or less ideally).  As with Option 3, access is not easy and would require the addition of a vent or access door. However, getting the solar feed wires to this spot would have been easy.  This also would have minimized the number of cables I had to run under the trailer to weatherproof (just two versus seven).

[whitefish]

Solar Charge System

I chose a Morningstar Tristar 45 amp charger controller based on reading manufacturer manuals and reviews of a variety of products.  After using this charger for about 6 months now, I am very happy with it overall.  It has worked flawlessly.  The charger itself may be overkill for my install, but I felt it was worth it given the "punishment" it would likely take in a moving/bouncing RV.

Right now the solar array is connected by a combiner box (in parallel) which brings power down to the TS-45 by a pair of 4 AWG wires.  The plan is to put the Midnite breaker/combiner box in line and to add 15 amp breakers for each solar panel. This is for fire and short circuit protection when using more than 2 panels connected in parallel.

As required by Morningstar, I have a 60 amp breaker (Blue Sea resettable) between the TS-45 and the battery.

The Good: the charger has an optional display and the unit software can be accessed by an RS232 connection (I use a USB/RS 232 converter).  Using Morningstar's in house software (MSView) I can view live data, look at historical data, change parameters and upload a completely custom charge profile (not to mention upload new firmware updates).  I can also use a Morningstar RS-232/Ethernet converter (EMC-1) to setup an Ethernet connection to the charge controller.

The not so good: The TS-45 (or any PWM charge controller from Morningstar) does not have an Ethernet out or WIFI accessible webpage as a connection option as some other manufacturers do.  The more expensive Tristar 60a MPPT does have these features, but at 3x the price of my TS-45.  For a WIFI connection the only option is to add the EMC-1 and a WIFI router to get the same connectivity as the MPPT-60. Also, as far as I know, Morningstar does not have a linked info system (e.g. battery, charge controller, battery monitor) like Midnite, Victron or Bogart.

As I understand PWM and MPPT more, in some ways I wish I had gone with a MPPT controller (PM me if you want my explanation as to why).  That said, I'm very happy with the system I have, without spending the 2x to 3x more on MPPT.

Catastrophic Fuse and DC Wiring.

I have a Go Power 300 amp T-style fast blow fuse and holder as my protection between the batteries and inverter.  I also use this as my positive bus bar and have connected my battery bank, solar charge controller, converter/charger and inverter.  The negative side has a Blue Sea 250 amp bus bar.
All wire that is not exposed to the elements (the 2/0 and 4 awg wire) is regular welding wire.  The wire is protected by wire loom inside the trailer and on the outside is encased in either Heyco Liquidtite or Carlson Non-metallic Liquid Tight flexible conduit.  Personally, I wouldn't use the Carlson stuff again as its hard to work with in tight spots and short bends, but it matched the existing conduit in the trailer (at least for the AC wiring).

All wire exposed to the elements (i.e. from the solar panels to the combiner box) is 12-14 awg PV wire (I'd prefer 10 awg).  All solar wire connections are MC4.

All wire connections were crimped and protected with double wall adhesive heat shrink.  For the amount custom wiring I was doing, I splurged for a proper mechanical crimper and lugs. A Go Power 300 amp DC connection kit (two 10ft 2/0 cables and catastrophic fuse) was around $350. I managed to find the fuse and holder for $60.00 and spent less than $300 on all wiring, connections and conduit.

[whitefish]

Inverter, Automatic Transfer Switch, Breaker Box and AC Wiring

I got a new Go Power 2000w pure sine inverter for a fantastic price. If hadn't, I'm sure I would have gone with a Magnum inverter as an option (maybe even an inverter/charger combo).  My main criteria were: 1) pure sine and 2) wide voltage operation range.  My Go Power will operate from around 11v all the way up to 16.5 volts.  This way, my inverter will still work when my charger is (sometimes) over 15v in adsorption charge. It would be nice to have a remote display for the inverter, but I don't think it's really needed. I did setup a remote switch that I put in a keystone faceplate along with my USB comm port for the charge controller.

The inverter is directly wired to the Go Power TS-30 Automatic Transfer Switch using 10/2 Romex. As required, I added an AC subpanel with a 15 amp breaker in order to isolate the converter wiring from the inverter.  This is simple to say, but took some rather complex wiring (at least for me).  I mounted the sub panel on the inside wall of the bench seat "enclosure", just to the right if the access point for the water pump.  If the breaker blows, just pull off the access cover and reach in and reset. In 6 months of use, I have never had this breaker blow.

Battery Monitor

I operated my solar system most of this year without a battery monitor and I can say that it's really shooting in the dark without one.  I could get some instantaneous information from a handheld meter and the charge controller, but I wouldn't know how many amp hours I used until the next day (from the TS-45 logged history) and only if I had fully charged the batteries. This was too much work and guess work for me.

I looked at the Trimetric TM-2030, the Victron BMV-700 and a host of cheap alternativeS found on Amazon, Alibaba and Ebay.  I settled on the BMV-700 because it was on sale and I just preferred the look of the head unit to the Trimetric.  I think the Trimetric really shines when paired to the mating Bogart charge controller or for those who want to dabble in the advanced P3 and P4 parameter setting.  I stayed away from the cheap units because they seemed to require constant re-calibration.

A battery monitor (as I'm learning), does requires some tinkering based on your individual system setup. No monitor is going to be able to be 100% accurate, because no monitor (yet) can anticipate changes in temperature and battery efficiency (both of which affect charge time and efficiency, which affect how the monitor "decides" when the battery is 100% charged).

However, I do see a monitor as an absolute must if you want to ensure that you do not drain your expensive deep cycle batteries below 50% (or the absolute floor of 20%).  It also helps if you are curious on the efficiency of your system and if you want to know what devices are draining "x" amount of amp hours from your battery bank.  For example, I learned that (from a fully charged state), I can make a full pot of coffee using my cheap 800w coffee maker and this only uses about 15 ah from my battery bank (about 93% from 100% charge).  I can use this information to decide if I want to make camp coffee or use my perk, depending on how much reserve I have in the battery bank.

The monitor can also help decide if/when you would need to use a generator.  A generator is best used (most effective), when you are bulk charging your batteries. 

This represents somewhat of an "all in" solar system.  One can certainly omit components, scale up or down to their needs and look at cheaper or more expensive equipment and technologies.

I hope this is helpful to anyone looking into solar.  Feel free to PM me if you have any questions.

[DavidM]

That is quite a comprehensive but no doubt expensive system. What do you do with all of that power- both DC direct from the batteries and AC from the inverter?

The reason I ask is that we can easily go three days on just one Group 24 battery and stay above 50% state of charge on the battery. If we upgraded to two GC batteries like yours we could go more than a week. We don't use fans or the furnace which are big power users and we have no need for AC.

David

[whitefish]

By comparison to some, we are power misers.   

I know from experience that a Group 24 battery would never last more than a cold day in the mountains, and that's even without the electric coffee perc. In addition to the water pump, fans, furnace and lights, I have teenage kids and a wife that like to charge their devices and want to watch the occasional movie. My trailer came with all of this stuff, so I use it. A tent would be alot cheaper.

I sized the system to go multiple days with no generator and to not excessively draw down the batteries (50%), and to do it in less than optimal solar charging conditions. That way, I can make it through a long weekend and never touch the genset. 200w of solar would work if always in the sun. 400 watts gives me insurance for shady trees and cloudy days. And I can do it anywhere, miles from a plug in campsite.

The system, all said and done was marginally more expensive than my Honda generator. I wish I hadn't bought the generator. If someone had all of this equipment installed by an RV center, then yes, it would be 2 to 3x more expensive then what I paid.