My Experiement with the Factory Solar

[uncle_bob]

Originally Posted by Imustwander

This is a factory solar question. I apologize if this has been covered in another thread. I've searched and can't seem to find an answer.

I have factory 90W solar on my 2020 23' GTFBT. I also have a 140W Zamp solar suitcase. If I plug the suitcase into the Zamp solar sidewall port, would the batteries be able to receive charge from both panels? Would I effectively have 230W of solar in a sunny location?

Thanks!

Thanks!

Hi

There is a controller in the suitcase and a separate controller in the trailer. They do not "network" together ( = one does not know the other even exists ).

When the batteries are really dead (like below 12V) this isn't a problem. Both controllers go into full blast mode and even if one gets an occasional spot of shade, all is well. You get the sum of the two.

Once the batteries begin to charge up, you get problems. One or the other "takes over" the entire process. This happens when that spot of shade hits one it comes back and decides the process is done. That one goes into float mode and stays there. Net result is that the second part of your charge process only gets power from one controller. There is no way to know which one "wins" the race ....

Net result is that in the most common case ( = batteries are not way run down ) you only get the output of one controller after they have been on for a bit.

Bob

[glcmranger]

absolutely...... that's how I'm set up -- The portable ZAMP has it's own solar controller...

[Imustwander]

Bob,
First, thanks so much for the clarification. I have learned a lot from reading your various posts about solar and everything else.

It sounds like using both panels will be just fine and will work especially well when boondocking in a shady spot. That was what I hoped would be the case.

I watched a 1hr+ long YouTube video walk-thru from Colonial for my exact trailer and in it the spokesman says that if you plug a panel into the side port then the rooftop no longer charges the battery. That just didn't seem right to me.

Thanks again for your excellent advice.

Jill

[smsasf]

I have factory installed Zamp 90W and before my current 50 days trip added another Zamp 90W to roof, changed out the Atkinson solar charge controller with a Victron 100/30 and also put the Victron Smart Battery Sensor at the battery to “talk to” the controller regarding temperature. I also have the Zamp 180W portable suitcase with its own charge controller which is preset to AGM. Recently when dry camping in NF outside of Bryce I had positioned the AS close to a large pine tree. With that in mid afternoon the two roof top 90W solar panel were on getting partial sun. When I looked at the Victron 100/30 display it showed some solar voltage and current but the battery was in bulk (normally in full sun it would have gone to float since I only have refridge drawing significant current). When I hook up the portable and place it in full sun within a couple of minutes it shows 14+ volts and soon my Victron 100/30 shows that the battery is now in float. So while the question of “working together” may be subjective, the Victron 100/30 readouts certainly show the results of the portable Zamp feeding the battery.

[GOUSC]

As the OP I just wanted to update that I did eventually replace the factory controller with the Victron MPPT 100/30. It is a night and day difference. While storing my RV at home I no longer have to keep my RV plugged up to shore power as the Victron does an outstanding job.