Community Forums

cricket2386 · 04-16-2019, 04:11 PM

Just bought a national tropical 396 and the solar panel when it was purchase new is bad
want to up grade to a100 watt paper work said it was a 40 watt can I replace it with a 12v 100watt or 18v do I need to put the other 40 watt back or upgrade to a new controller/

WinnieView · 04-16-2019, 04:15 PM

What are the specs of the existing controller?

cricket2386 · 04-16-2019, 05:21 PM

that is my issue it came with it new and I do not have that information except it did say that a 40watt solar was the option it is hooked through the power board but only shows on with a green light

cricket2386 · 04-16-2019, 05:22 PM

I am hoping someone has the information on what rally came with this unit also the panel has too many cells to be a 40 watt may have been replaceced before

BCam · 04-16-2019, 05:28 PM

The critical issue is not the wattage of the existing panel, it's the capacity of the existing controller and the gauge of the wiring. Ten gauge wiring would be the minimum you'll need. I also suggest sizing your wiring and controller for expansion so you can add additional panels if you desire to do so in the future. There is a lot of info on this forum about these issues.

Richard S. · 04-16-2019, 05:29 PM

Take a look at the link below, I would remove the 40 watt panel, I do not think you have a controller from the factory and the existing wiring may not be of the correct size for a larger panel.. I have been very happy with my 100 watt kit.
https://www.renogy.com/renogy-100-wa...-solar-rv-kit/

BOOZE TRAVEL · 04-16-2019, 08:53 PM

If your 07 is like my 02 the panels are on the AC covers and just wired into the 12 volt system in each A/C opening. They have no controller. In my opinion they didn’t do much of anything besides make a spot to leak water where they put the wire under the seal of the A/C units.
We got a leak about 1 month ago at both units and when I pulled them to replace the seals the leak was right where the wire went under the seal.
I cut and capped the wires inside the enclosure and cut the wire on the panel short enough it wouldn’t flap in the wind.
Best of luck!

biggerboat · 04-16-2019, 10:52 PM

I have a 2006 Tropical. The 40 watt panel was toast and I removed it and sealed the mounting holes. If you reinstall any other solar panels, you will need to install a charge controller and abandon the existing wiring. I am in the process of adding a 400 watt system from renogy.

speed racer · 04-17-2019, 05:14 AM

The original solar panel was only a trickle charger to maintain the batteries while in storage.

Isaac-1 · 04-17-2019, 06:52 AM

Given the vintage if there was an original charge controller, chances are it was a simple shunt style unit, modern low end charge controllers are far more efficient PWM controllers, with more and more better setups having even more efficient MPPT controllers.

BCam · 04-17-2019, 10:06 AM

I think you have your answer. And, if you are going to install new panels, wiring and controller, I suggest you install a minimum of 200w as a start. Also, check out Home Depot's prices on solar panel kits but make sure the controller included in the kit is sized to accommodate additional panels. If not, forego the kit and buy the panels and controller separately.