Adding a Portable Panel to PV System When in Shade

[Josh41]

Building a PV systems for a small trailer (Dometic CF40, fan, a few lights)
160 Panel on Roof (permanent)
MPPT Controller
100 ah AGM Battery

Can I wire in series or parallel a port on the side of the trailer to plug in a second panel for when I'm in the shade (long cord to put it in the sun).
I'll check wire gauge and length and all that stuff, doesn't need to be a art of this conversation.

 

[jonyjoe101]

another method is get a cheap 10 dollar pwm controller on the external panel and just connect that way. Having 2 controllers won't affect anything, they both will feed the battery as needed. That would solve the problem of using different size panels.

 

[Josh41]

I'm hoping to stay with one controller so that I can add a blue tooth monitor.
It looks like maybe if I stick to parallel, I might be able to do this. If parallel, do I still need to stick with the same size panels?