I've been reading up a little on wiring in series vs. parallel. I'm wondering if there is an advantage to one or the other. One gives you more amps and the other gives you more volts I think.
What kind of connections are people using to connect their two panels on the roof?
Most people
don't have two panels...but a few "more-is-better" folks like me do.
And
mine are wired in series.
If wired in series you HAVE TO use an MPPT charge controller, as you have, because in series adds together the voltage of both panels. And only an MPPT charge controller can make use of the ~35 volts that will result.
But you need to make sure that your charge controller specs say that it can handle the input voltage of two panels in series...and make sure that the specs can handle the increased
current that results once the MPPT does it's voltage-to-current-conversion thing.
I have mine in series because that way I can use the existing OEM roof-wiring that came in my FWC without worrying if that wire gauge can handle the current -- since in series the voltage is added together but not the current.
And because I already had an MPPT controller.
I'm not sure...but seems like I remember reading that the two panels should be very similar/identical for this to work best, be most efficient. In my case they
are identical (spec-wise), so I didn't have to worry about it.
One downside to in-series is that the combination is more-prone to the problem of shade falling on the panels. That is, shade on one can reduce the output of
both of them. In parallel they're independent.
As a desert rat, mostly, I don't camp much in places where shade is even available, so the shade problem is usually not a worry for me. When I am in shade I'm usually at the Oregon coast and I'm in a state park with 120-volt hook-up, so when I'm in that deep, dark, shady environment I'm not relying on my solar system.
But...if I had to do it over
I might consider doing it in parallel, even if I had to increase the roof-to-controller wire size to handle double-the-current -- just to reduce the shade effect.
Links about the effect of shade:
Solar Oregon
Renewable Energy World
Solar Choice
