I am in the process of building an rv garage, well dealing with the county to see if I can build one.
It will be 30 X 45 X 16 tall I will keep my 5th wheel, Excursion and my 2002 powerstroke in it. neither one get driven very often.
my plan is to put a solar panel or two on the roof and hard wire some outlets to plug in all 3 of them to maintain the batteries.
My plan is to hard wire from the converter to atlest 4 points in the garage and put plugs in and make jumpers to go to everything.
here is the plug I am thinking about. good idea? or bad idea? how many panels? truck and excursion are both powerstrokes with 2 batteries and my rv has 2 batteries.

 

I would not want one solar charge controller charging three different vehicles. You could end up with one very over charged battery in one vehicle and an under charged battery in another. I don't see an easy/inexpensive solution for this. Three solar charge controllers, each with their own set of panels. One solar charge controller charging a separate battery that is connected to an inverter, then three battery chargers plugged into the inverter.

The solar charge controller is necessary because the PV voltage will be higher than 12 volts. If you run those wires too far, you'll see enough voltage drop that the batteries won't get fully charged.

I use similar cables with the SAE connectors on the input side of my solar charge controller where the voltage is around 80 volts. With that many volts I'm pushing only about 8 amps. At 12 volts you could be pushing more amps which might exceed the rating of those cables.

 

Ditto. You can fry the batteries or drain them, either way your batteries wont last.

For each battery, you will need about 300 watts of solar, and you need a separate grid for each battery. You would be better off building a full array, with some storage and an inverter, and then run maintainers on each battery. Here's the thing I discovered with off the shelf battery charging solar panels. When there is no sun, there is still some resistance connected to the battery, which slowly discharges the battery. I had what I though was a good setup to maintain my small trailers deep cycle with Solar over the winter, but wound up killing the battery. Not enough daylight hours coupled with the oblique angle of the sun didn't produce enough current to maintain the charge, and the off charge time slowly discharged the battery. It worked well in summer, but winter, not at all.

 

well that was a great plan that isn't!
maybe one panel and switch between them?
I really don't want to go a big expense to do a full array, if I permit power to the cover that is a $1,000.00 permit.
might be an extension cord and plug the trailer in?
thank both of you for the input.
I haven't messed with solar since the early 90's and I bought a setup from a reputable solar company.

 

You'll also need to take into account the distance. The longer the distance the larger the cable needs to be. A 12 volt DC run of wire will have to be a lot thicker than a 120 volt AC run of wire.

To keep my side-by-side charged, I'm doing almost exactly what you want to do.
PV panels
Solar charge controller
Cables
Circuit breakers

The write-up that I did for my "Board Build" also includes an inverter. You could skip the inverter.

https://diysolarforum.com/threads/board-build.46274/

 

A plug in battery tender may be the best route. We had a 200' cord ran to our TT when we had it. It was dark green and blended into the ground very well.

If you go the charge controller and switch method, keep in mind most CC's need to be told the battery details like amperage, capacity and type. You can get some cheap PWM controllers instead of MPPT and cut your costs.

Sometimes the plans with good intentions are too costly or too much work.

 

How far away from the house is it? If less than 100', you can buy a spool of 10 gauge 3 conductor, put some ends on it and put it on a cable stretched between buildings. Then just have an outlet installed at the house. You can then plug the trailer into it, only need 30 amp circuit, could go 20 if you want, but 30 lets you cycle the AC or water heater. Then tap off the trailer with a couple cords to the other vehicles and plug in maintainers. It is pretty much my summer setup, I run it from the barn which has a dedicated 30 amp to the 5th wheel, I have it draped over some poles. Other than having an RV plug installed outside the house, the rest shouldn't be anywhere near the cost of a couple panels and charger. I think the 100' cable and ends cost me ~$120. I think I spent more on two 25' generator cables than for the RV.

I have a steel cable attached to the fascia of the house with the other end attached to a tri-pole tower that I strung my wireless AP to so I didn't have to bury it, attached it using zip ties.

Some day I may invest in UG 00 and run a 50 amp to the trailer drive and put in an actual pedestal, but that is pretty expensive too. I have a 100 Amp service at the barn that will support it though.

 

I wanted power out to a wood shed in the backyard but did not want to put in electrical.

I went to home depot at the time and they had a very good outdoor 4 guage cord. It is about 100 foot long I think. It is massive.

I plugged into an out in back of the house and ran it along the fence line where it has been for maybe 10-15 years. Once inside the shed, I plugged in several drops to it and has been a good source for many years.