Just finished a solar install with Marvin Braun of Precision RV. I had met Marvin last year when I did an install for my FC25. It worked out that for him to be in the Denver area and I store my trailer in a neighbor’s hangar so he would have a place to do the install out of the weather which was a good thing since we had rain, rain and then some more rain for most of the time he was here.
I had gotten a blueprint drawing of the roof of the 2015 Classic from Airstream. Scanned that and brought it into the drawing program Visio. Checked the scale and was able to play with laying out a mix of 100w and 135w AMSolar panels.
Ended up with 4 – 135w and 2 – 100w panels for a total of 740w of panels.
Controller is a Blue Sky 3024il with a Magnum 3000w Hybrid charger/inverter. The Hybrid allows a mix of solar, battery and any type of shore power to be mixed together and is strong enough to power one of the AC units.
For batteries I went the lithium route. Marvin had experience with the folks at Elite Power Solutions and their GBC based batteries. GBC/Elite offer a 200ah 4 cell which had a form factor that would allow me to mount them under one of the dinette seats.
With 320ah usable with the Elite cells (80% of 400ah) I would have needed to put in 650ah of AGM’s to get the same amount of capacity. That amount of space for 6 Lifeline GPC-4CT’s would have been a challenge. I would have probably lost the under seat storage on both dinette seats and the cable runs would have been longer. And the weight of the AGM’s would have totaled 400# rather than 110#.
Two other factors played into my decision to use Elite rather than AMSolar for the batteries. One was simple. Elite can ship lithium’s while AMSolar is still working on setting up their shipping process since lithium’s are considered a hazardous material. The other is the battery monitoring system (BMS) that is important to have long cell life. Elite puts a BMS on each battery cell. In my case I have a total of 400ah of batteries. 2 – 200ah packs. Each pack has 4 – 200ah 3.2v cells. So a total of 8 BMS sensor boards. This allows each cell in the pack to be monitored and charged accurately. Based on my experience with lithium batteries for UAV’s (drones), each cell should be measured for best life of the battery. It is more expensive than only measuring a group of cells as a bundle. And the Elite BMS system also outputs data to an expensive video monitor with lots of data on the health and status of the battery system.
For mounting I followed a similar path to what BAB (Barry) did for his install. The batteries and Magnum went under the dinette seat under the TV (rear seat). The drawer was removed from the face and the face was screwed to the frame. So we lost that one storage drawer. The Blue Sky went on the wall under the forward dinette seat where the old WFCO inverter had been mounted. Subwoofer was also moved under that seat.
This kept all of the cable runs as short as possible and ended up being a compact installation.
The 50amp sub-panel fit into the compartment under the hall closet that has the heating vent. The original panel now only powers the rear AC and the electric heater for the water heater. Everything else in the coach is on the new sub-panel.
There was ample room in the wire chase from the roadside to curbside where the shorepower cables are installed to bring power to the main breaker panel and back for the new sub-panel and wiring to the Magnum.
Total install was over 4 ½ days. Marvin is meticulous. Wiring is neat, fully bundled and a work of art. He was able to pull all of the cables, both power and data to the Magnum and Blue Sky controllers without additional holes. No need to remove the refrigerator. Tip, in the space behind the TV on the roadside wall where the power and antenna plugs are located, that panel can be removed which helps with running cable up that roadside wall pretty neatly.
We pulled the trailer out on a semi cloudy day and were getting the full 40amps out of the Blue Sky with some shading going on the roadside panels from the A/C units.
Couple of items to note on Lithium’s. They can take the full output from your controller that you can throw at them on a charge cycle. They stay in bulk mode until they are in the high 90% range (usually about 98%) and then go into a slower absorption charge mode. AGM’s go from bulk to a slower absorption rate at a much lower percentage of being full. Thus Lithium’s will charge much quicker than the equivalent AGM/Lead Acids since they will take the full 40ah output from the Blue Sky controller for a longer period of time.
The other item of interest is turning on the A/C unit. Mine is a 15K. With my FC25 there was a definite sag in AC voltage when that type of load was put on the system. With lithium’s the AC voltage did not change. Didn’t even budge on the Elite BMS display.
I like boondocking, lots of BLM and USFS places here in the west. And solar opens up lots of camping sites in general that don’t have power without giving up your power hungry lifestyle. I work from the road, so need internet access. Solar keeps it quite, though I do also carry a 2K Honda as a backup. But I don’t need a 3K unit or a pair of Honda’s to run the A/C when needed.
I’ll post a follow up to see that the affect of the changes had on weight. Removed 102# from the front battery compartment. Added lithium (110#), Magum (60#) and panels (111#) mostly just in front of the axels. So I think tongue weight will go down. Not sure how much. Scales will tell the tale.
As for cost, yes at the front end lithium is more expensive. Comparing this install to my last install the overall price was the same with a delta for the difference in the lithium batteries compared to 4 AGM’s. Long term the jury still seems to be a bit cloudy but even some of the more pessimistic predictions show that properly maintained lithium’s will in the end be the same cost as AGM’s since they should get more charge cycles.
And I highly recommend a pro do the work. Marvin has a wealth of knowledge on how to wire all of the pieces together to give you solid solution. Lots of experience installing solar on Airstreams. He did all of the roof work without walking on roof. Sincere kudos for that. All of the components are the same price but Marvin has the tools to build the cables and all of the other bits and pieces that most of us would have to chase down, borrow or buy. He is very thorough in explaining the system, will help you really understand how to make it work and keep it running.
And for me the plus, besides having Marvin do the install, was that I didn’t have to travel to get the work done. Made it very convenient for me since I am about a 100 yards away from my storage location and I didn’t spend time traveling to get the install completed.
Photo 1 - Batteries, Magnum, main fuse, Elite Power BMS CPU on top of the Magnum
Photo 2 - Side wall, shunt at the bottom and breaker for the input from the Blue Sky
Photo 3 - Blue Sky, Solar disconnect, sub-woofer and cables to the DC Pos/Neg Bus and battery disconnect at the front of the trailer behind the couch
Photo 4 - New sub-panel
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