Solar panels mounted and portable (hybrid?)

At the risk of being flamed !

You don't state the AH capacity of your battery bank, so I don't know how applicable my method would be.

I have 225 AH of Wet-cell GC 2 battery. When I'm in shade and need to use the portable, I just tie the 100 watt panel directly to the battery. The voltage never rises above about 15 V at about 5 amps.

Doug

The roof panels are poly. It would be real nice if they can produce at least 30 or 40 Amp hours per day when in dense shade to keep up with minimal usage (Fridge, propane detector and LED lighting).

A couple years ago when I was camping in the Adirondacks with my old trailer that had a single 140 Watt panel on the roof, I got essentially zero Amp Hours (according to my Turnigy meter) into the batteries over the course of 10 sunny days. That campsite had serious shading from dense tree cover. I had to use jumper cables from the truck alternator to charge the trailer batteries 2 or 3 times.

It sounds like using a separate pwm controller is the way to go.

The portable panels are in a nice folding kit that includes a cheap pwm controller that I will remove from the kit and mount close to the batteries (after first validating the charging profile is compatible with my agm batteries). If the pwm charger does not have the right charging profile I'll find a cheap 10Amp PWM controller online that does.

My new 5th wheel has a generator so I can easily do rapid battery charging at any time by just pushing the gen start button. But it would be nice to not have to run the gen at all since it never gets hot enough up there to need air conditioning.

Thanks,
Ed

I have three 250w polys. They pull down up to 20-25a in pretty good cloud cover. I also have a portable but it is its own complete system. It's a 230w poly and I have tied it into the system. The Voc on my TS-MPPT-60 constantly hunted up and down a few tenths of a volt, it was also lower since the 230w affected the array.

For the few bucks a small PWM cost, I would keep the portable separate. I also use the portable to keep the truck up, I have loaned it out and use it here at the house.

If the roof panels are poly you may not need the portable at all. Mono would be a different kettle of fish.

Last few days, I have been seeing 4-5 amps (out of 300 watts) in daylight only,...no sun. And even tho that doesn't fully charge, it carries me thru each day.

As long as the Vmp of the panels is within 10% you can just parallel them through breakers to the Tri star. The 250 watt are most likely a much higher Vmp then the portables though.

Do not tap into the 90+ volt connection to the Tristar.

I would even keep the PWM controller portable. Just use battery clamps and keep the portable controller with the suitcase.

You said shade but I think the 750 watt set up will surprise you.

Like stated above, connect the roof mounted panels to the controller. Leave that controller alone to do it's thing.

Connect the portable panels to the battery via it's own controller, probably a PWM at the battery location, not near the panels. This will allow for the voltage drop across the wire going to the battery from the portable panels.

For wiring, I would recommend #10 romex, probably the grey wire solar at Home Depot rated for direct burial and UV protected.

I have never had a problem with my 400 watt roof mounted solar system keeping my battery full, except while in Yosemite Valley, where it is super covered in trees. I don't mine parking in partial sun, as the solar panels cover much of my roof, shading it, and me under the solar panels.

Personally, I would skip setting up the portable pair of panels, and would mount them to the roof, wire them to another PWM controller, and leave them there. If you are in such deep shade, that the extra panels would really help, run a generator once a week for a couple of hours. Much easier than fiddling with the solar panels. And it is only for a couple of weeks a year.

Have fun camping!

Fred.

eb145 are the panels poly or mono?

I use amorphous and get 7 amps in leafy shade at solar noon (max output is about 17 amps).

Connect to controller that exists. No sense throwing extra $$$ at something that isn't needed. Where you may have an issue is if you have it all connected and harvesting because of the module mismatch. The controller will be constantly searching for the best MPP.

For the alternative, a small PWM controller just for the portable panels is inexpensive and will allow for all your modules to be charging with no issues.