Solare panels on a camper van

[winchman]

I bought a 200w panel for my camper, but its a swine to fit and I would have to use adhesive and mechanical fixings as its so big, I have gone off the idea of drilling holes in my roof so looking at fitting two smaller 100w panels as I can just glue them on. So How should I wire them and why?
I have this 20A controller

DuoRacer Dual Battery MPPT Solar Controller 20A - 12/24V

DuoRacer MPPT charge controller is made for charging two batteries at the same time in a solar system. This controller supports multiple battery types, including Sealed, Gel, Flooded, LiFePO4, and Li-NiCoMn. The device recognizes the start battery system voltage automatically, and trickle...

www.sunshinesolar.co.uk

 

[barracuda816]

I fitted a large (house) solar panel to my van. I used ally angle with rivnuts and sikaflex 221.
I also wasn’t keen at first about drilling into the roof, but I also cut a giant hole for the vent so figured in for a penny in for a pound. That was 5 years ago and I haven’t had a drop through. So I wouldnt be put off about drilling a few little holes.

Also solar panels need ventilation under them, they get hot (black things in the sun) and the output and longevity are reduced.

I had a friend that bought a solar kit with some plastic “brackets” that are to be fitted with adhesive. After a year they broke in a storm and the panel was completely loose. The adhesive didn’t fail, it was the plastic. Luckily it didn’t happen when he was driving as I’m not sure the connectors would have held on, I wouldn’t like to imagine a solar panel flying through the windscreen of a car behind. That’s a long way of saying I would never recommend relying on the plastic brackets or just adhesive.

Also just a tip but don’t bother with the flexible panels. They just don’t last long.

What is the voltage for the panels? That will dictate if you can wire them in series. With that controller.

 

[voipio]

If the panels are a similar output voltage rating, they can be wired in parallel, which results in far smaller loss of power when one panel is shaded.

 

[Misterg]

So How should I wire them and why?

Wire them in parallel, as it looks like the maximum that the controller can take is 36V and the panels are likely to be >20V each (open circuit voltage).

 

[indy4x]

Roof rack? When we bought our (badly) converted van, the solar panel was screwed to the roof with added PU adhesive, bloody awful job

Now has a roof rack and the new solar panel is fastened to that

 

[sg66]

With more than one panel do you need to fit diodes to stop them shoving voltage back to the weaker one ?

 

[Misterg]

With more than one panel do you need to fit diodes to stop them shoving voltage back to the weaker one ?

Yes. Many (most?) panels are supplied with a blocking diode already installed.

 

[winchman]

Well the deed is done
One is on Just contemplating spending another £100+ on another panel, the bits soon mount up. So 100w or 200w?
Controller is 20A so should be fine

 

[julianthegypsy]

Well the deed is done
One is on Just contemplating spending another £100+ on another panel, the bits soon mount up. So 100w or 200w?
Controller is 20A so should be fine

I would. More the better, especially in winter when it's dark most of the time and grey the rest of the time.