Chad Heiser

The transfer switch I am using is a small 15 amp transfer switch from Magnum Energy. It is only on the refrigerator circuit. The transfer switch is plugged into my small Magnum CSW 1012 inverter (like the diagram in the link). The breaker for the refrigerator circuit in my sub panel feeds the AC In side of the transfer switch and the AC OUT side of the transfer switch goes directly to the refrigerator plug. My large inverter, my generator or shore power (Whichever is available) energize the sub panel which sends power into the AC IN side and passes it through to the refrigerator. When I don't want to use one of these sources, I turn on the small inverter and it then passes power through to the refrigerator plug. In essence I have three transfer switches in my system. The first is in line between shore power and my generator. The second is built into my large Magnum 3012 Hybrid inverter. The third is the small transfer switch described above. These three switches all work together to seamlessly pass power to my residential refrigerator based on the power source that is available with no intervention from me.

Thanks for the compliment. I did put a lot of thought into the design and components. It really was a natural progression from the previous system I designed and built in my last trailer. To answer your questions: 1. No I did not consider flipping breakers to isolate the refrigerator. Residential style circuit breakers are not really designed to be used as regular on/off switches. The contacts in them can degrade over time with repeated switching. In addition to this, typical RV circuit breaker panels are not usually located in easy access locations. The ones in my current trailer are down low in a cabinet near the floor. I have to get down on my knees to get access to them and to see which breakers are for which circuits. 2. The transfer switch does not draw any power from the system. It simply changes contacts to the appropriate circuit based on which one has priority and whether or not it is energized. It is a passive device only reacting to input from other devices. You do need to be aware of "ghost" loads when you are running off battery power. In order to preserve battery power, you should be aware of what the draws are on the battery bank. I do not use both inverters at once, so I do not have duplicate inverter "overhead". This is also one of he reasons for adding the second dedicated refrigerator inverter. When traveling, there is no need to energize all the appliances in the trailer through the whole house inverter. None of these appliances will be used while running down the road, so why power them just to keep the refrigerator running? This helps eliminate unneeded draws from the battery bank when they aren't needed. It also gives me redundancy in my system just in case.

This time around, I did pay attention to the fans in the PT-100. They never kicked on. The temperatures were fairly cool all weekend though, so the basement compartment where the PT is mounted never got warm.

Day two was a little heavier as far as usage, but there was also more sun that day so that helped. I know we used a lot more than 300 amp hours throughout the day. I used that as a simple math equation of going from 100% SOC to the low 70's% SOC as an example. Really we used that 300 amp hours in the evenings along. We were typically still right at or near 100% SOC until the sun went down. Then we drew down into the 70% SOC range through the evening and into the next morning when the whole process would start over. I was going to reset my amp hour usage counter when we arrived, but I forgot so I don't have the exact number we used (but it was a lot). I am very pleased with the results.

UPDATE: We spent the weekend in the trailer and I put the solar through its paces. We were at a park in a water and power site, but I did not hook up power for this trip. It was a four day weekend trip with my wife and our granddaughter. We were with 5 other couples (some of them also with kids) and we had some other people come out for the day on Saturday and Sunday. In other words, the new trailer had a revolving door on it. Everyone wanted a tour and to see all the new stuff. The kids watched movies, we watched playoff basketball and movies, my DW made coffee every morning, the microwave was used, the dishwasher was run, the heater ran at night, the residential refrigerator was on 24/7, multiple electronic devices were charging, etc, etc. We did nothing to conserve power. I drew the batteries down into the 70% range every night. I have 1040 amp hours of battery so we were using 300 + amp hrs per day (not accounting for the free energy the solar provided as the batteries were charging and once they were fully charged). I tracked usage from 9:00 am (when I got up - it was a nice weekend ) until the batteries were fully charged on day two and day three of the trip (it rained on day four and we packed up and left by 11:00 that morning). Day 1 Time - Ext Temp - Sun Condition - SOC - Charge Status - PV Volts - Batt Volts - Batt Amps - PV Watts 9:00 am 61 Overcast 82% Bulk 60.4 13.0 23.3 290 9:30 am 62 Overcast 83% Bulk 59.9 13.3 36.6 500 10:00 am 63 Slight Sun 84% Bulk 50.4 13.3 42.0 635 10:30 am 63 Partial Sun 85% Bulk 50.4 13.4 44.1 563.9 11:00 am 65 Partial Sun 87% Bulk 56.4 13.6 55.6 751 11:30 am 66 Mostly Sun 89% Bulk 57.0 13.7 64.8 903 12:00 pm 67 Mostly Sun 93% Bulk 55.6 14.1 67.4 939 12:30 pm 67 Hazy Sun 94% Bulk 55.6 15.0 63.2 951 1:00 pm 68 Hazy Sun 96% Absorb 59.4 15.0 51.1 775 1:30 pm 69 Hazy Sun 97% Absorb 63.8 14.9 46.2 703 2:00 pm 69 Hazy Sun 100% Float 68.6 13.7 14.3 198 Day 2 9:00 am 63 Mostly Sun 75% Bulk 52.6 12.7 34.8 441.9 9:30 am 64 Full Sun 76% Bulk 52.7 13.2 48.3 640.2 10:00 am 66 Full Sun 77% Bulk 50.1 13.2 56.5 744.4 10:30 am 67 Full Sun 79% Bulk 49.3 13.4 57.6 774.5 11:00 am 68 Full Sun 82% Bulk 55.0 13.5 69.3 931.5 11:30 am 69 Full Sun 85% Bulk 54.3 13.7 77.2 1060.3 12:00 pm 70 Full Sun 87% Bulk 53.4 13.9 74.8 1027.2 12:30 pm 71 Full Sun 90% Bulk 53.3 14.2 71.6 1008 1:00 pm 72 Full Sun 93% Bulk 54.6 14.5 74.7 1084.6 1:30 pm 72 Full Sun 95% Absorb 60.4 15.0 61.1 906 2:00 pm 73 Full Sun 97% Absorb 62.8 14.9 41.8 621.4 2:30 pm 74 Full Sun 100% Float 68.4 13.6 15.9 276.5 The panels were somewhat dirtier than I thought they would be. It misted the first night and that kind of cemented some dust to the panels. I had my satellite dish up the whole time and was getting some minor shading on one panel from it and one vent cover. The trailer was facing east, which is the best for my panel layout. The eastern sky was clear of obstructions, but there were trees to the west of me that shaded slightly in the late afternoon as the sun began moving toward the western horizon. All and all, I am very happy. I can't imagine us using any more power than we did this weekend without hookups and my batteries were back to 100% every afternoon.

Congratulations on the purchase. I know what you mean about I40 through Arizona. I lost a set of wheel covers along the interstate somewhere in the area last June.

We like our MCD shades in our new trailer much better than our old day night shades in our last trailer. I would never go back to the old style.

I have never heard of these batteries before. I took a look at their website and they don't really have any customer feedback anywhere that I can find. They do have some good information and some nicely produced videos. I don't know how long the company has been around, but it can't have been that long, so it is hard to say what their track record is. My only concern is their claim you can use their batteries with any standard charger. Everything I know about Lithium batteries says do not float them. They say a standard float on their batteries won't hurt them. I'm not sure how to reconcile this. Maybe they have some circuitry in their battery that deals with this, but they don't really explain it anywhere I could find.

That is a nice clean install. My system has more weight in just the batteries (almost 700 lbs). My entire system weighs approximately 1400 lbs (this includes the generator). It is a lot of weight to add to a 5er, but if you have followed my other thread on my weights I am still under my GVWR in my trailer when fully loaded. If I was still in my Montana with this system, I would definitely have been over weight. A lithium bank is a great space and weight saver. You just have to be willing/able to lay out the money for it up front. All this talk about systems is really making me anxious to get mine out again for some more testing.

Oh yeah. I totally forgot about the lithium battery bank when I looked at the picture in your last post. It all makes sense now. I really would like to go lithium one of these days for several reasons. The weight savings and the built in monitoring capabilities of a battery management system are right at the top of that list of reasons. Not to mention the ability to discharge the bank much more deeply than an AGM or lead acid bank while getting full power the whole time. Hopefully when I'm ready to build my next system the prices will have dropped even more than they already have.

Ok, I have to ask. How are you pulling the data for the second screen. Do you have the Mag Web monitoring kit?

With a years experience with the PT-100, what do you think of it. I like mine so far, but I really haven't put it through its paces yet. I have my charge profile linked to the 3012, so I didn't tweak anything there. (This charge profile is a custom profile based on my battery manufacturer's recommendations.) I also have the everything linked to SOC readings from the BMK where I could. Most of the other settings, I left to the defaults. Have you done anything differently with your settings.

Thanks for the feedback. I figured I was in the ballpark with my assumptions, but I am working with limited actual data. Everything up to this point had been based on calculations and printed data. I am looking forward to getting out in the real world and getting a larger actual data set.

Nice. It's always nice to find a good deal on a product you want and/or need. Mine ran my Whirlpool residential refrigerator on and off for two and a half days with no problems on my little test run over the weekend.

I guess north is a relative term, but I'm definitely not sitting in the AZ dessert where I could really make some power. At least I don't have to push snow off my panels like you do.

My trailer is fairly well insulated. The PT-100 is in the basement, which is a large open space. From inside the trailer, I could not hear anything. Quite honestly, I'm not sure if the fans in the PT ever ran or not. I initially had the basement compartment door open to confirm the remote readings were the same as being displayed on the PT. After the first time when I confirmed the readings were the same, I closed the basement and didn't open it again. I can say I never heard the fans, but I can't say whether it ever got hot enough in the basement or the PT itself got hot enough to actually require the fans to run. I will add this to my list to check on the next test.

I am hoping to get some feedback from some of you with solar set ups. I'm curious if my assumption that my system can generate enough power to keep up with moderate to heavy power usage is correct. I realize my current data sample is small, but I'm willing to take some educated guesses. I think I am good and will get a much better idea from my multi-day trip in a couple of weeks, but let me know what you think. Again, considering my panels are flat mounted and cannot be tilted, I think the power I am generating is pretty good for this time of year as far north as I am and should only increase as summer rolls around. I'm still learning the intricacies of the Magnum PT-100 charge controller. It is a relatively new charge controller and there is not much information on the web about it (especially in RV use) or how best to set it up to maximize its output. It seams to be pretty straight forward so far, but there may be some tweaks I can make to improve performance. We'll see as I get more experience with the system.

I finally pulled the trailer out of the shop for the first time since I installed the solar. I did an overnight at an RV park, but pretended I was boondocking. I used no hookups at all. I ran everything as if I had hookups, so I made no attempts at conservation. I actually over used stuff in addition to my normal useage. I did a pretty good job of running the battery bank down. I had the array turned off because I wanted to get the battery bank drained a bit to get an idea of how fast I could recharge. I turned the array on at about noon today. My battery bank state of charge was right around 80% (I forgot to write this value down when I started so this is approximate from memory - it was somewhere between 80 - 83%). My plan was to record my numbers every half hour until my battery bank was recharged. The trailer was oriented facing west. The ideal orientation for my trailer would be facing east, because this would put my satellite dish on the north side of the trailer. For this experiment, I did not put the satellite dish up, so it did not have any shading affect on my panels. All panels were exposed to the sun with no shading. The only thing I had running in the trailer was the refrigerator and one overhead light so I could see what I was doing. The refrigerator was being powered by my small inverter (Magnum 1012). Again, my idea was to see how fast I could recharge my battery bank from the solar. Here are the numbers from my PT-100 meters: 12:00 PM SOC (approximately) 80%, volts from array 54.7, watts from array 1057, amps to battery 75.6, volts to battery 13.9 in Bulk mode 12:30 PM SOC 90%, volts from array 54, watts from array 1080.6, amps to battery 76.1, volts to battery 14.2 in Bulk mode 1:00 PM SOC 93%, volts from array 58.6, watts from array 1105.5, amps to battery 74, volts to battery 15.0 in Bulk mode 1:30 PM SOC 96%, volts from array 61.3, watts from array 742, amps to battery 51.5, volts to battery 14.9 in Absorb mode 2:00 PM SOC 97%, volts from array 63.4, watts from array 630.4, amps to battery 42.7, volts to battery 14.8 in Absorb mode 2:30 PM SOC 100%, volts from array 67.5, watts from array 140, amps to battery 10.4, volts to battery 13.6 in Float mode From the time I turned the array on, it took approximately 2.5 hours to get from (approximately) 80% state of charge to 100% state of charge. All of the meter readings fluctuated up and down slightly as I was recording them. I recorded the highest number I saw within a 15 second window at the time of recording. My Fullriver batteries have a custom charge profile based on the manufacturers recommendations. Considering this is April 2 and I am in Northern California while taking these readings, I am very happy with the results. Based on this sample (which I realize is small), when I have full sun in the summer months, I don't think I can use enough power each day to outpace what my solar system can replenish. That was my goal when building the system, so far so good. This weekend turned out not to be the best circumstances for me to do more in depth testing of the array due to several issues that popped up (not the least of which is that my DW contracted pink eye from our granddaughter). We have another long weekend trip planned later in the month where I will get some more extensive data. For now, it is back to the real world and work for a while. (I'm really looking forward to retirement .)

I ordered the DRV with the Magnum 3012, BMK, ARC and AGS installed by the factory. The factory also installed the sub panel as part of the inverter install. I also had them run 4 AWG solar wire from the roof to the battery compartment (it was the largest wire they would run). Knowing I was going to install my own batteries, I had DRV just put in one basic 12 volt battery for delivery. I knew my batteries wouldn't fit in the factory battery compartments due to their size, so I planned to put them along the front wall of the basement compartment (as my pictures show). For ease of my installation/modifications I also had DRV run all the trailer 12 volt connections to the door side battery compartment. Their normal way of running the 12 volt wiring is to put the slide, jack and 12 volt panel connections in the off door side battery compartment and the inverter connections in the door side battery compartment. This would have made what I wanted to do with my install much more difficult, so I had them change it. My off door side battery compartment is now just a regular storage compartment and I use it to store my sewer hose currently (until waste master comes out with their new permanent mount hose carrier). Im happy to answer any questions you might have and share other modifications we made to our 40KSSB4 order if you like. PM me and I'll give you my number if you like.

That's it as Tahoe Shark said. They seem to be nice little inverters and are perfect for running the residential fridge (especially with the accompanying automatic transfer switch from Magnum and the remote on/off switch from Magnum).

I found an open box deal on e-bay (actually two of them - one for me and one for a friend). There are deals out there, you just have to be patient and willing to hunt for them.

I didn't add the second inverter because I was worried about the "idle" draw of the 3012. I did it for two reasons. The primary reason was for use while on the road. I do not want all my electronics (TV's, satellite boxes, stereos, dishwasher, clothes washer, microwave, etc.) powered while my rig is bouncing down the highway. I see no reason to take the chance of creating an issue with sensitive items in a moving environment. I am probably being overly cautious on this, but this is my primary reason. My secondary reason was as a back up to keep the fridge running in boondocking situations where I was trying to conserve as much energy as possible. For example, multiple days in a row of cloud covered, rainy days where the solar isn't going to be able to keep up with high electrical usage. In these situations, if I am not using any other 120 volt appliances, why power them with the big inverter when all I really need to do is keep the refrigerator running. I can turn the big inverter off and use the small inverter to help conserve energy and minimize generator run time. I kind of look at like my last trailer with the RV type fridge that I would switch to propane and only turn the whole house inverter on when I actually needed it (not exactly the same circumstances, but similar). Again, I am probably being overly conservative here, but I figured I was building a system from scratch so why not do it the way I wanted to do it. It also didn't hurt that I was able to source the small inverter for about half price, so why not.

I'm happy to supply the ice in exchange for "refreshments". If you have any questions about the diagrams or the system let me know. I'm happy to help in any way I can.

I see a select group of RV'ers who are passionate about solar and go the extra mile on their solar systems. I don't really see it as a trend in the industry yet. I really do not see it coming from manufacturers. The best you are going to get from a manufacturer in most cases is pre run solar wires from the roof to a compartment (unless you go custom). Even then, those wires are often too small to use on a large system. It really comes down to cost and segment price point for the manufacturers. They want to sell units and to the vast majority of RV buyers, that means keep the price as low as possible. I think the Escapees community is a skewed sample of the RV community as a whole. Generally, Escapees get that glitz and low price are not how an RV should be marketed. Really, substance or infrastructure in the RV is what matters. Unfortunately most RV buyers are weekender types and don't really know what they don't know. Solar is nice to have, but it is not really a must have for a lot of RV'ers. If you spend most of your time with hookups, solar isn't a necessity. When you start spending time without hookups, then it becomes more necessary if you don't want to be dependent on a generator. As you start adding more and more residential comforts to your RV life while off grid, then the size of your solar system becomes more important. Many people can get by with smaller systems and be perfectly happy. My system is probably over kill for my needs, but the price was right so I went for it. Roof real estate is also a typical limiting factor of systems. The larger the RV, usually the more real estate you can scrounge. But also, it usually means more stuff is getting put on the roof like AC's and vents and skylights and etc that are eating up that real estate. A custom built RV with a nice flat, empty roof would be the ideal platform for a large solar system, but this is an anomaly in the industry. It means going to basement AC systems or mini split residential types AC's and giving up vents and other typical RV accoutrements. I have heard Jack Mayer is leaning toward a design like this for his next RV, but again this is not the norm and I don't think it will be any time soon.

Nice write up. I really need to get better at taking pictures along the way when I document my stuff. We head out April Fools weekend for our first shake down trip with the new solar. We will be at an RV park, but I'm going to play with no hook ups to try to get some ideas on performance of the system. Problem is, I know there are lots of trees around the site I will be in, so it won't be the best measure of the system. Later in the month we will go out again to a place where trees won't be an issue.