Winter supplemental solar

[MrNoodly]

After watching Bob's video on briefcase style flexible solar panels, and seeing how thin and light they are compared to the rigid kind, I thought, hmmmm, I know exactly where I could store one of those in my van. Maybe I could get one to add in winter. I usually have just enough power to get through most short, overcast winter days, but there have been times I had to shut down early. 

The question is, can I just attach the extra panel (which includes its own controller) to my batteries (which are also connected to the existing controller?

 

[B and C]

From what I have read here, yes, they play nicely together.

 

[DLTooley]

Yes. I’ve done something similar when I upgraded my fixed panel. I kept the smaller panel as a supplement - wired into the same controller.

 

[MrNoodly]

But could I run the smaller panel, which has a charge controller, straight to the batteries? Or, if I do it your way, I guess I could save a few bucks and just get the panel without the controller. Yes?

 

[Master Mechanic]

u need a controller fuses ect it is a separate system to same battery

 

[B and C]

From what I remember here, it is not a good idea to mix panels. If you want to use different panels than what you are already using, a second system is needed to employ them.

 

[XERTYX]

I recall this being discussed about portable panels. If I recall Jim said either the panels need to be closely matched into the same controller or use a second controller to the same bank as long as the controllers both had the same settings.

 

[B and C]

^^^ That sounds right to me.

 

[XERTYX]

I found it.
Yes Jim said it's fine as long as both controllers have the same settings. A suitcase panel might not be adjustable though.

https://vanlivingforum.com/showthread.php?tid=37175

 

[MrNoodly]

And I wonder about one controller being an MPPT and the other a PWM.

 

[XERTYX]

Hmm. That would be a Jim question I bet. I remember him saying something about monocrystallines not being as efficient on MPPT as they are on PWM but dont quote me on that bit. I'd imagine again as long as their settings are the same it wouldnt matter. But then again I recall one poster who ran PWM controllers exclusively because he got noise in his system when running HF (high frequency) ham radios. So maybe MMPTs generate noise and it might hurt the PWM? Just a theory. I'd imagine the biggest danger would be to the controller(s) and not your batteries.

 

[jimindenver]

Mono's and poly's differ how they react to cloudy weather. As long as both controllers are set the same and see the same voltage it will be okay