Want to use auxiliary solar charging

[E2tials]

I think tradewind comes with 600w solar charge on the roof and it also has auxiliary solar input nearby propane.

Does anyone know how to use both of roof solar and auxiliary solar concurrently to combine solar output to charge the battery?

If it is doable, what's the maximum watts auxiliary solar can charge the battery? The manual only says 15amp max.

[Malia20]

You give no details as to what rig you have so I can not get too detailed.
Auxiliary charger panel. Yes, you can use a "suitcase" panel. The standard Zamp plug as installed by Airstream goes directly to the battery, it is right there. The red wire has a 15A fuse, so the charge current is limited to 15 A.

Now will it work with the roof top? Yes, but how well it works very much depends on what gear you have. Guessing that you have a solar controller, maybe MPPT, that transforms the roof top solar to battery voltage. The Suitcase plug has no controller, it depends on what is in the suitcase. Most likely, those two controllers do not talk/work together.
I had that situation: panels on top, Victron MPPT controller and a Zamp suitcase panel with Zamp PWM controller.
During the initial bulk charge cycle, all charge amps were used (nice). But when the battery (FLA) reached absorption voltage and charge current had to be reduced to not over shoot desired voltage, the two controllers competed with each other to control voltage, and eventually the controller that wanted a lower absorption voltage shutdown.
After testing panel voltages, I changed the suitcase wiring so that all panel currents combined before the Victron controller. I lose a little as the various voltage combine, but gain more with the suitcase now going through the more desirable MPPT controller.

A better solution, one that many here use, is to have a second Victron controller (all of the "Smart" version). Multiple Victron Smart controllers will work together (according to Victron), one will tell the others what to do and all panels will feed the batteries as needed. All it takes is money and room for the gear.


Good luck and safe travels.
Fred

[JeffKim]

Yes, a few more details would be nice. If you do have a Tradewind or considering one, I don't know how the Zamp port is wired on the Tradewind since the batteries aren't in the box like all other Airstreams (as described above by @Fred). But it sounds like it's fused to 15A somewhere. It's a much different animal than most Airstreams.

That said, our 2023 GT came with the port wired to the battery. To use this connection a controller is required (also as stated). My strong bias is not to wire both rooftop and external to the rooftop controller since the solar exposure is almost always different.

So we have a MPPT controller like the Victron Smart 100|30 mounted inside (as @Fred suggests). I also replaced the stock Blue 150|35 with a Smart 100|30 for the rooftop panels. This is more work than buying external panels with built in controller but it will take advantage of the VE.Smart Networking to optimize charging with other Victron equipment. The Tradewind has a Cerbo which coordinates charging, but it's a matter of running a communications cable to it from the controller.

To add the controller I ran a 10AWG from the plug to the controller which is wired to the positive bus bar. It is fused at 40A which is good enough for the 10AWG. The wire with the Zamp plug to the battery is something like 12AWG so they fuse it lower. That would only support about 3x100W panels in parallel (~5A SSC/panel = 15A total) if you went with an external controller. For external panels you will need an MC4 to SAE adapter which is on Amazon and likely an extension cable.

[E2tials]

Thanks guys.
I am not super familiar with how these thing work and, I have 2 x 220w ecoflow portable panels.
So what i want to do is to connect those 2 portable solar panels to zamp port of 2025 25ft tradewind to make gross total solar system watt from 600w to 1040w.

I thought the ecoflow 220w solar panels have controller attached, and wondering if this charges battery faster

[Malia20]

Ecoflow. I looked at these on the web and it appears that the panel has a set of MC4 connectors. I do not get an impression that there is a solar controller in the panel, that the panel is meant to feed the Ecoflow "Solar Generator" which has the controller and a battery (and inverter).
So can it be used, assuming I was looking at the correct panel, I would say yes, with a little (or a lot?) work and more gear. I would be surprised if there is a solar controller between the solar plug on the A-Frame and the battery. It is possible that Solar Plug feeds into the roof top solar, but as Jeff pointed out that is not the desirable solution, and it would require a large wire to support the current you are talking about, so I would doubt it. Need to check the manual.

Most likely solution: Add a solar controller between the solar plug and the battery. Hopefully this will be compatible (ie Victron Smart) with the existing roof top solar controller. Get some MC4-to-SAE conversion wires for the panel. And watch the polarity as Zamp SAE plugs are generally wired with reverse polarity to many others.

All this, no doubt, will require you to get on your hands and knees and do some poking around.
Good luck!
Fred

[JeffKim]

You might want to post on the Tradewind thread since as I said the Zamp plug might be configured differently with the Tradewind and others might have come up with a good solution.

If you put the controller before the Zamp plug, with two 220W panels the approximate maximum output is 440/12V = 36A so if it's fused at 15A then you will need different wiring to use all your panels.

Or if you put the controller after the Zamp plug and near the positive bus bar then the SSC from the Ecoflow specs in parallel is 2x12.4A=24.8A, so you're still over the 15A limit and need to run some more heavier duty wire like I did. I spliced it into the Zamp wiring. (As @Fred says note the reverse polarity of the Zamp plug but the MC4 to SAE adapter usually includes a polarity reversal adapter.)

Anyways... I know it should be easier but it's all part of the fun. I came from a point of ignorance about all things electrical and figured most things out and now have enough arrogance to give advice.

[joshjack]

See https://www.airforums.com/forums/f553/solar-port-functionality-250007.html