I have an Avion truck camper and due to the rounded roof mounting solar panels has a few challenges. But there are a few spots where I can mount 60-140 watt panels. But another idea is to run panels the length of the camper on both sides of the roof. Basically on the horizontal surface but a little bit into the radius that transitions to the campers sides. Doing some measurements and looking at a few vendors sites I could fit six 20 watt panels end to end for 120 watts on each side.Is there any problems wiring 12 panels together ? I like the idea mainly because it will leave the majority of the roof accessible for the AC and roof vents. Thoughts ?

Forget the 20 Watt Panels, they are next to useless! Just arrange the highest Wattage Panels that You can afford on the Flat surface of Your Roof for Maximum Charging capabilities!To answer the question about using several panels ,there really is no limit to the number that You use other than having a suitable charge controller! That little device is limited by the amperage it is designed to handle.

I would build a very large frame to hold the panels about 16" to 18" above the roof and fill the frame with 230 Watt panels.The roof will always be in the shade.The AC will never shade the panels.The panels will get better cooling than they would if there were no space between them and the roof.

You can wire as many panels together as you like. There's no limit. You do have to do it properly, keeping in mind the voltage and amperage limits of your charge controller. You will also need proper fusing for multiple parallel panels.I don't know if you've done much pricing research but you can probably buy a 120 watt panel for about the cost of 2 or 3 20 watt panels.

KD4UPL wrote:You can wire as many panels together as you like. There's no limit. You do have to do it properly, keeping in mind the voltage and amperage limits of your charge controller. You will also need proper fusing for multiple parallel panels.I don't know if you've done much pricing research but you can probably buy a 120 watt panel for about the cost of 2 or 3 20 watt panels.X2. Find a spot that a single 120 to 140W panel will fit. Morningstar 10amp sunsaver controller. About 200 bucks plus the wire to run. Custom make yourself some mounts to accommodate the curved roof.Multiple tiny panels will work but it is multiple times the cost and more holes in your roof.

solar panel ? is it OK to use several panels together ?

15 Replies

rfuerst911sc
Explorer
Oct 12, 2013
RoyB wrote:
Some folks are using their outside windows for solar mounts to add more needed panels. They hinge down when in travel mode and open up like a window awning when being used... These mounts would make great candidates for portable solar panels as well.

Saw some recent comments on here about this idea.

I have followed various posts about this method and it is in my mix of options. I have to decide if I'm going to use awnings on my camper, if I do then window mount is out the window as the panels would be below the awnings. But if I decide not to use awnings then this is a good mounting option.
69_Avion
Explorer
Oct 12, 2013
rfuerst911sc wrote:
JiminDenver wrote:
You might research the 12v fridges and determine how much power they require in a day. You may need more battery than you think.

You may be right but all the research I have done indicates the Dornfoss compressor is quite frugal in energy consumption. I really don't know how much boondocking we will do we may do the majority of camping in campgrounds so solar a minor point. So I'm not going to go crazy with the solar but will plan on being able to " add to " whatever I go with. I also have a Honda EU3000 generator in the mix.

you need to check out "westend" and his trailer. He has done what you are thinking about doing and he did a great job. It is easier, and less expensive, by learning from his experience.
JiminDenver
Explorer II
Oct 12, 2013
rfuerst911sc wrote:
JiminDenver wrote:
You might research the 12v fridges and determine how much power they require in a day. You may need more battery than you think.

You may be right but all the research I have done indicates the Dornfoss compressor is quite frugal in energy consumption. I really don't know how much boondocking we will do we may do the majority of camping in campgrounds so solar a minor point. So I'm not going to go crazy with the solar but will plan on being able to " add to " whatever I go with. I also have a Honda EU3000 generator in the mix.

Sounds like you are doing a pretty good job of planning then. For occasional boondocking you could just run the Honda a few hours a day if the solar can't keep up.

If some of us sound a bit critical on the numbers, it's because we never ever have shore power. My poor trailer hasn't seen shore power in years and the generator hasn't seen a drop of gas for charging this year either.
westend
Explorer
Oct 12, 2013
I use an electric fridge that draws about 80 watt average with a 1/5 duty cycle in typical summer 85f ambient. This is a 120v unit run with an inverter. I have 320 AH of battery capacity and am using a single 235W module. I have no other significant or parasitic draws in the trailer, basically designed the solar to run the fridge. I figure three days without sun is about my maximum. The good news is that the 235W module harvests some power even in cloudy conditions and throughout the whole day.
The 12v Danfoss compressor fridges draw less power (maybe 20% less) but cost 8-10 times more, initially. I also needed an inverter that cost more than what I could have used just to run entertainment devices.
RoyB
Explorer II
Oct 12, 2013
Some folks are using their outside windows for solar mounts to add more needed panels. They hinge down when in travel mode and open up like a window awning when being used... These mounts would make great candidates for portable solar panels as well.

Saw some recent comments on here about this idea.
rfuerst911sc
Explorer
Oct 12, 2013
JiminDenver wrote:
You might research the 12v fridges and determine how much power they require in a day. You may need more battery than you think.

You may be right but all the research I have done indicates the Dornfoss compressor is quite frugal in energy consumption. I really don't know how much boondocking we will do we may do the majority of camping in campgrounds so solar a minor point. So I'm not going to go crazy with the solar but will plan on being able to " add to " whatever I go with. I also have a Honda EU3000 generator in the mix.
JiminDenver
Explorer II
Oct 12, 2013
You might research the 12v fridges and determine how much power they require in a day. You may need more battery than you think.
rfuerst911sc
Explorer
Oct 12, 2013
Thanks for all the replies. I am just in the " figure this out " stage so everything is on the table for consideration. Yes I have researched the flexible stick on type and they have promise but I'm curious about heat build up to the panel and the camper with no " air gap " ? Plus how do you peel it off if there is a problem ? To be honest I don't know how much watts I need as I'm still figuring out what to do about refrigeration and batteries. I " think " I'm going to purchase a 12 volt compressor fridge and I know I will go with two house batteries. Have not determined 6 volt vs. 12 volt but will be two batteries. Electrical draw will be fridge, LED interior lights,two ceiling vent fans, range hood fan, a platinum cat heater and maybe some TV/stereo. Just the wife and I so based on that I think 200 watts would get us there. I'm going to the Atlanta RV show next weekend and hope to purchase the fridge and look over what is new/available in the solar market.
time2roll
Nomad
Oct 12, 2013
Wire them all up in parallel, good to go.

Have you considered unisolar? Long narrow panels that just stick on the roof.
MrWizard
Moderator
Oct 12, 2013
yes you can use as many panels as you want
as long as they are wired correctly and the 'controller' is large enough for the total power

120w on each side for 240w total can be done

but it means a lot of screws in the roof holding '4" brackets per panel
plus a lot of wire connections

IF you can arrange another way with larger panels, it will be less work

also there are flexible stick on panels available that might be better suited to what you want to do , than using so many small 20w panels

here are some on Amazon 68w 12v for 12v system
http://www.amazon.com/Uni-Solar-PVL-68-PowerBond-112-Inch-15-5-Inch/dp/B002MWDI44/ref=pd_sbs_lg_2

peel & stick to 'CLEAN' roof

yes they work, several members have them on their rv's
i have the old style uni-solar frame mounted thin film panels