Rooftop solar plus portable solar

[langforw]

I have factory installed 80 watt rooftop plus a Renogy 100 watt solar portable suitcase. My question is would I replenish the battery quicker if instead of connecting the suitcase to the battery as designed, I connected the suitcase panels thru the factory installed controller and did not use the suitcase controller? I read somewher two controllers would conflict with each other and wonder if it is worth the trouble to combine to one. I would appreciate your insight.

[lewster]

Originally Posted by langforw

I have factory installed 80 watt rooftop plus a Renogy 100 watt solar portable suitcase. My question is would I replenish the battery quicker if instead of connecting the suitcase to the battery as designed, I connected the suitcase panels thru the factory installed controller and did not use the suitcase controller? I read somewher two controllers would conflict with each other and wonder if it is worth the trouble to combine to one. I would appreciate your insight.

2 controllers are never good to use. I would disconnect your portable one and put it thru the in-house controller (although that is not a real solution either). To get a perfect charge all of the time, I would use a small Victron controller in the place of your in-house unit and make an addition for your portable one.

[Pimms]

I also have the factory 80 watt setup on our 2018 23FB. I would like to add one or two more panels in parallel. From what I'm reading thus far on this thread, I should try to come as close to the output voltage as my factory 80 watt panel as possible. The manual package supplied with our trailer has no info on that panel whatsoever so I have no idea as to the specs other than it being supposedly outputting max of 80 watts. Can the solar gurus tell me what would be a good match with the factory panel to get it up to maybe 250-300 watts so that I am still good with the factory installed wiring? I would anticipate replacing the controller and upgrade wiring to the batts when doing this. Also, are packages available for doing panel additions that include mounting hardware for the panels or how is this accomplished? I would be doing all the work myself. Thanks very much!

[billrector]

Originally Posted by Pimms

I also have the factory 80 watt setup on our 2018 23FB. I would like to add one or two more panels in parallel. From what I'm reading thus far on this thread, I should try to come as close to the output voltage as my factory 80 watt panel as possible. The manual package supplied with our trailer has no info on that panel whatsoever so I have no idea as to the specs other than it being supposedly outputting max of 80 watts. Can the solar gurus tell me what would be a good match with the factory panel to get it up to maybe 250-300 watts so that I am still good with the factory installed wiring? I would anticipate replacing the controller and upgrade wiring to the batts when doing this. Also, are packages available for doing panel additions that include mounting hardware for the panels or how is this accomplished? I would be doing all the work myself. Thanks very much!

Really good 100W panels can be had for around $200 ea. so why limit yourself based on what is already installed. I'd replace that 80 watt panel with a 100 watt panel and then add as many 100 watt panels as you would like. If you look at Airmiles posts, he used the factory wiring to supply 400 watts to his controller.

[daleyocum]

You’ll want to deal with the solar controller and the panels so I agree you aren’t really upgrading but replacing. AMSolar has lots of videos, parts and support on their site. The existing panel and controller aren’t worth warping your decision making around, not to be too snotty about it.

[Dave-n-Janet]

I've seen a number of different answers regarding roof solar with portable panels (total of two controllers) so I decided to run a test today. Of course the actual components of the system could have a large impact on results.

I ran my 2 GC2 6volt batteries down to 92%. I have 400 watts of Renogy panels wired in parallel with the SC-2030 controller (PWM) and TM-2030 monitor on my 26U Airstream. With everything turned off in the AS (typically then 0.4-.05 watt draw) the TM-2030 showed 10.4-10.8 amps returned to the battery (net over power draw) from just the roof top panels. When I plugged in my 180watt Zamp portable with its own controller I saw 16.9 to 17.6 amps returned to battery. The Zamp controller showed 6.8 to 7.2 amps.

This tells me the SC-2030 and Zamp controller play well together and in fact for bulk mode the amps are additive which is just what I'm looking for as the portable panels come out generally when the trailer is shaded.

In the fall in full sun I get close to 10amps from the Zamp portables. My rooftop solar panels generally max around 20amps to the batteries. Makes sense to me as the portables can be aimed at the sun while the roof top panels lay flat.

[daleyocum]

That’s a great bit of data and puts to rest a lot of concern about dueling controllers.

Those of us with Lithium batteries, though, are still better off running everything through a single controller, I suspect. That’s because the battery’s voltage remains more or less constant so, at least in high end systems, the solar controller needs to make decisions based on what the battery monitor is saying regarding state of charge. A portable panel can’t do that by itself.

[billrector]

Originally Posted by Dave-n-Janet

I've seen a number of different answers regarding roof solar with portable panels (total of two controllers) so I decided to run a test today. Of course the actual components of the system could have a large impact on results.



I ran my 2 GC2 6volt batteries down to 92%. I have 400 watts of Renogy panels wired in parallel with the SC-2030 controller (PWM) and TM-2030 monitor on my 26U Airstream. With everything turned off in the AS (typically then 0.4-.05 watt draw) the TM-2030 showed 10.4-10.8 amps returned to the battery (net over power draw) from just the roof top panels. When I plugged in my 180watt Zamp portable with its own controller I saw 16.9 to 17.6 amps returned to battery. The Zamp controller showed 6.8 to 7.2 amps.



This tells me the SC-2030 and Zamp controller play well together and in fact for bulk mode the amps are additive which is just what I'm looking for as the portable panels come out generally when the trailer is shaded.



In the fall in full sun I get close to 10amps from the Zamp portables. My rooftop solar panels generally max around 20amps to the batteries. Makes sense to me as the portables can be aimed at the sun while the roof top panels lay flat.

I too am putting 400W of solar on the roof and have a portable panel. I asked AMSolar, who I purchased some of my system from, about the roof top solar working with the portable solar. They said they were designed to work together and there was no need for me to wire the portable panels to feed the roof system controller.