Solar on 27FB Twin

[Totlh]

I have a 27 FB Twin with two A/C units. Anyone put solar panels on a unit similar to mine? If so, what were you able to make fit? Size and brand of solar panels? Thanks in advance for you help and thoughts.

Jerry

[fran&frank]

I have a 27 FC FB with a queen bed and did my own solar install. Check out my post here or just search Frank's solar upgrade: http://www.airforums.com/forums/f448...-a-164507.html
Frank

[Totlh]

Frank, Thank you.
This I exactly what I was looking for. Great write up!

I think what I'm going to do is take two 160-watt panels off my other trailer (Lance) before I sell it. This will return the Lance to original. (It had one 160-watt panel on it from the factory).

Unfortunately, I think the 160-watt panels are too big for the top of my A/S. I need to cut some cardboard and see where I can get them to fit. I have been flopping back and forth between mounting two panels on the roof or just using the two as portables.

Did you mount your panels over the top of the shower and bathroom exhaust fans?

Has your setup effected gas mileage?

Thank you.
Jerry

[fran&frank]

I covered the bathroom fan and plumbing vent. I snapped the cover off the plumbing vent so it would have a lower profile, since the solar panel would now act as a cover. To many other variables for me to know if its affected gas mileage.

[daleyocum]

I was able to get five 100w Renogy Eclipse panels of my FC25. With a 27 you could probably get one more without cleverness like going over vents.

[Totlh]

Nice picture Thanks.

[mtbackpacker]

That picture is super helpful—there are surprisingly few good overhead shots of these layouts. I have a new 25FBT we will be bringing home as soon as the snow melts out on the highways and Renogy 100w panels are near the top of my list. Really want 6... I know 4 is possible easily. Looks like I will have to get creative especially as I have the dual AC model.

[Soonersalt]

Totlh

I was wondering if you have made any progress on this solar update? Im also interested in the 160 watt addition you did on the previous trailer as Im looking to buy a 27 FB with the factory install and would like to upgrade it with another 160 watt panel. Is this a difficult thing to do? Was it a DIY improvement?

[daleyocum]

Originally Posted by Soonersalt

Totlh

I was wondering if you have made any progress on this solar update? Im also interested in the 160 watt addition you did on the previous trailer as Im looking to buy a 27 FB with the factory install and would like to upgrade it with another 160 watt panel. Is this a difficult thing to do? Was it a DIY improvement?

I doubt you’ll find any of the experts on this forum that would recommend the factory solar. Cost per watt is way high and the lifespan of felexible solar panels quite short. You’d be far better off having 400w or more of rigid panels installed and a modern Victron controller.

[stevejones]

Originally Posted by daleyocum

I doubt you’ll find any of the experts on this forum that would recommend the factory solar. Cost per watt is way high and the lifespan of felexible solar panels quite short. You’d be far better off having 400w or more of rigid panels installed and a modern Victron controller.

We got the factory solar on our 27 FBQ Globetrotter. Initially, I thought it was the way to go. Our battery stayed charged when we were in storage. We always had hookups in our first extended camping adventures so we really didn't use the batteries much. Now we have embarked on a full timing adventure and intend to boon dock as much as possible. Our first parking lot overnight stay with the fantastic fan running all night, using lights, exhaust fan, etc. showed us the current factory solar, battery, inverter set up is not going to be adequate for our needs. We are now planning on a robust solar installation, completely replacing the factory installed solar system, before we really hit the road that will give us the ability to run everything off the batteries.

Here are some thoughts on the factory solar and stock electrical system. Like everything else, it all depends on your intended use of the trailer.

1. The main advantage to the factory solar is all the components and wiring are installed during trailer construction. So if the scope of the system suits your needs it is worth considering. You have a small amount of flexibility to augment the system if you want, but that means spending more money of course.

2. The panels that come with the factory solar are only 80 watts each. That is 160 watts total. That is not a lot. However, the roof installed port has three inputs. Only two are used by the two factory installed panels. You can add a third panel with a Zamp connector and just plug it in and it will be integrated into the system. But if you're installing the same kind of panel you will have 240W. Still not a lot.

3. Your trailer may have a port on the trailer tongue for a portable panel. However if your trailer is like mine, this port is wired directly to the batteries. That means whatever voltage is input there is not controlled by the solar controller in the factory system, so you need to use a portable panel that has an integrated controller. But this also means that if you use a portable panel, the two controllers will be interfering with each other. So if using a portable panel to augment the roof top panels is part of your plan, please know this may not work very well.

4. The AGM batteries that come with the factory solar package are only 80AH each. That's 160AH total. However you should only discharge an AGM to 50% so you really only have 80AH total available. That is not a lot of capacity. You could replace these with higher capacity or lithium batteries if you want, but that could be expensive.

5. On our trailer the inverter is only 1000W. Because of this, only half of the AC outlets are on the inverter circuit and you are limited regarding what you can plug into an inverter outlet. The outlets in the galley, bathroom, and under the dinette are not on the inverter circuit. You could replace the inverter, but proceed with caution since a higher capacity inverter will draw more current from the batteries requiring thicker cables, higher amperage fuse, etc.

Whether the factory solar system will fit your needs depends a lot on how you will use the trailer. If you will mainly camp where you have hookups, then it doesn't matter much. If you intend to use a generator it doesn't matter much. If you are careful about how much you use the battery at night, it may work fine for you. But if you want to boon dock a lot and do dispersed camping, camp at National Parks where there are no hook ups, use the inverter a lot (particularly to power higher wattage things), it may not suit your needs.

Steve

[NoResults]

I also have a 27fb twin. Can I just wire two panels together on each side and then plug them into the existing plug on the roof. This would still leave one plug available.

[daleyocum]

Originally Posted by NoResults

I also have a 27fb twin. Can I just wire two panels together on each side and then plug them into the existing plug on the roof. This would still leave one plug available.

At an absolute minimum you’d also need to install a solar charge controller. That doesn’t come standard in the trailer. Most people appreciate having a battery monitor as well so you know the state of charge.

The wires from the roof probably terminates under the curb side bed, at least they does on my FC25FBT. They will be labeled “solar” and be yellow and green.

[Totlh]

Originally Posted by Soonersalt

Totlh

I was wondering if you have made any progress on this solar update? Im also interested in the 160 watt addition you did on the previous trailer as Im looking to buy a 27 FB with the factory install and would like to upgrade it with another 160 watt panel. Is this a difficult thing to do? Was it a DIY improvement?

Both trailers are now at home . I can take pictures of the top of the Lance if you like.

[wulfraat]

The Lewster fit 8 panels on our 30’. You should be able to place at least 6 on your 27. Maybe even 7 or 8 depending on where the fridge vent is located - it’s the single biggest speed bump preventing one from laying panels continuously along the sides.

These are AM Solar SP100 panels. 800w total. Puts 56amps @ 14.2v to the batteries mid day in the summer.

We went over the bath and show vents no problem - they still open and vent under 2 of the panels thanks to some extended feet. All gear was from AM solar. More details here:

http://www.airforums.com/forums/f539...-182406-2.html

[Totlh]

Originally Posted by wulfraat

The Lewster fit 8 panels on our 30’. You should be able to place at least 6 on your 27. Maybe even 7 or 8 depending on where the fridge vent is located - it’s the single biggest speed bump preventing one from laying panels continuously along the sides.

These are AM Solar SP100 panels. 800w total. Puts 56amps @ 14.2v to the batteries mid day in the summer.

We went over the bath and show vents no problem - they still open and vent under 2 of the panels thanks to some extended feet. All gear was from AM solar. More details here:

http://www.airforums.com/forums/f539...-182406-2.html

Nice,
Are these panels screwed down or held in place with tape?

[lewster]

Originally Posted by Totlh

Nice,
Are these panels screwed down or held in place with tape?

Taped (3M VHB 4950) and sealed with SikaFlex 221. I never use screws in Airstreams and with their aluminum roofing structure.......none are really needed!

[Totlh]

I have installed two 160-watt Carmanah panels and four 100-watt Renogy panels on my 27 FB for a total of 720 watts of solar. It also has two A/C units, two sky lights, two vent fans, a Fantastic fan, a black tank vent and a gray tank vent on the roof. Needless to say, it was tough to get them all to fit.

While I hate to post a partial update, I have not yet charged up my drone to take a good picture of my installed solar panels. On my last day camping, on a mostly sunny day, I was able to get over 2.3 Kw out of the panels. My batteries (400 Amp-Hours of LiFePo4 Battle Born) were charged by noon. I then entered my testing mode by running my refrigerator off the panels. During full sun, the batteries would charge, and when a cloud would go over, the batteries would make up the difference.

To get them all to fit, I had to bolt one 160 panel and two 100 panels together on the ground and lift them as a unit. Lifting them into place was probably the most nerve-wracking part of the install.

Now that it is all done and I have towed it down the road at 70 MPH, and verified all panels stayed in place, I am very happy with the install.

More testing this winter as we head south.

Questions welcome.

[Garfish]

What size Renogy panel, know 100 watt but there is a longer skinny one as well. Thanks

[daleyocum]

Originally Posted by Garfish

What size Renogy panel, know 100 watt but there is a longer skinny one as well. Thanks

I used Renogy Eclipse 100w panels on my FC25. See picture earlier in this thread. On a narrower trailer that might not work so you’d need the narrow panels from Zamp or elsewhere. I’m not sure.

[GMFL]

Originally Posted by lewster

taped (3m vhb 4950) and sealed with sikaflex 221. I never use screws in airstreams and with their aluminum roofing structure.......none are really needed!

Amen!