Adding portable solar to existing fixed solar.

Because the performance parameters of the 2 panels are probably different, it would be better for the second panel to have its own controller. That controller will do a better job if it is near the battery, rather than on the panel though.
Check that it is a decent controller and move it to near the battery.
Cheers,
Peter
OKA196 motorhome

Gazz

Did this recently to a mates van.

If the panels are of similar voltage, wire them in parallel through the Redarc only. The Redarc will see them as one and will use the panel with the lowest voltage for its workings.

Regards

TrevorDavid

I have the setup you are contemplating and the advise from Enerdrive was as long as the panels are similar in voltage output just run them all through the one controller and it will sort them out.
I have set up a double adapter Anderson plug to connect my portable panel to.

One of the benefits of a portable panel is to be able to keep it in the sun when the fixed panel is shaded.
Having them on separate controllers will do that better than having then on the same controller.
Cheers,
Peter
OKA196 motorhome

Thanks to all who replied

I rarely spend more than two days in the one spot so the fixed panel does the job but I have a couple trips coming up where I will be forced to sit still for five days lol - so I will take the folding blanket with me.

So now I just need to get my fat boofhead and large hands into tiny spaces for some more wiring lol

Cheers and cold beers
Gazz

Just use 2 controllers and get them in the sun, dont bother trying to achieve theoretical perfection as that is impossible.
When batteries are low or load is high both controllers will go their hardest and when the battery voltage comes up the 2 controllers will switch through their different stages at different times and have an affect on each other but at that stage it doesnt matter as the battery is nearing full, or full enough to last till morning.
I have two seperate systems, the car and the camper, each with their own battery, controller and panel, fridge is in the car.
If the car battery gets low I just link the two together with my 10 metre 6mm(automotive) extention which many here refuse to accept actually works, and let the electrons flow where ever they want. The law of physics sorts that out for me. Both systems charge but the redarc in the car goes into float before the victron in the trailer.
As yet havent run out of power for either the fridge or electric blankets but both of those never get pushed hard at the same time but works for me.
By the way, batteries are an 80ah AGM in the trailer and a 100ah AGM in the car and I consider low to be 11.5 volts while the compressor is running.

If you've ever wondered if it's possible to connect two solar panels to one battery, the answer is Yes... if you do it the right way.

Gazz,

The simplest way is to add an additional MPPT controller, the best are Victron. If you also get the smart controller then you can also Bluetooth to them for data and upgrades, you can also setup a network between them to balance charging needs.
I have two setup like this, one for the permanent panel and one for the external. This way you can get maximum charging from both panels, and if one is in the shade the other will still work correctly (the network allows them to control the charge rate, so if the battery is full they'll start to shutdown).
I'd recommend for a simple setup the 75/15, it'll take up to 260watts, this should be plenty for most requirements.
Not sure if I'm supposed to to recommend, websites but I've brought lots of gear from Outbackmarine. They are a good source of gear and information.

Victron COntrollers

Regards
Andy