How to hook up solar panels

[AggieStream]

I have a 2019 Flying Cloud 25 FB that is "solar ready". What is the best budget option for hooking up panels on the ground next the battery for a charge while boondocking? I'm just looking to run the TV and a small fan to keep the air moving. Also....is this easy to do? I've never messed with solar.

[uncle_bob]

Hi

The "easy way" is to buy a solar suitcase setup and just run it in through the Zamp connector on the tongue of the trailer. You have the gizmo to pull out and set up each time, but not much in terms of install.

Running the TV involves ( normally ) firing up the inverter. Both the inverter and the TV pull power. A "small fan" can cover a wide range of devices. A really little DC fan might pull a half amp. Something that is still small and runs on AC might pull 4 or 5 amps off the battery.

What that all adds up to ... who knows ....

A 4 amp fan running 24 hours a day is a really big deal ( = close to 100AH). Solar of any sort will have a hard time keeping up with that sort of load. So will the typical battery setup in a trailer.

You TV *might* pull 100W when turned on. By the time that runs back through the inverter That could be 12A, Watch TV for 5 hours each evening, you are at 60AH. Even that would be tough with a fairly fancy solar setup.

What's reasonable?

If you get a 100W suitcase, figure 50W for 10 hours under very good conditions. That's 500WH and it converts to about 40 AH You could easily be at half that ( 20AH a day ).

20AH a day gets you an hour a day on the TV plus a couple hours on a reasonable fan.

Bob

[richard5933]

I agree that the folding suitcase panels are the easiest to use. They usually have a controller built in and should be plug & play. Just make sure you get one (or more) that are compatible with the solar port on your trailer and that have the controller already on them. Many trailers come with a Zamp port installed and connected to the batteries, meaning you just plug in the panels and they start charging when the sun shines on them.

The Zamp panels are great, but they are not always budget friendly. So if your goal involves finding an option which fits a tight budget you might have to look at panels other than Zamp. Some of them will require different wiring than the Zamp port on your trailer. Not a big problem to overcome, but you need to confirm before plugging in so you can make the necessary wiring changes.

How easy is this to hook up? If your "solar ready" trailer has the necessary port to plug in your solar panel, then it's as easy as getting a compatible panel, unfolding it, and plugging it in. If by "solar ready" it's meant that you have the wiring installed but it's not connected to anything yet, then you'll have some additional work cut out for you. Your manual should provide the information.

As far as running devices off solar...

You don't actually run anything directly off the solar. The solar is there to charge your batteries. Everything you'll be running is actually running from your 12v battery system. If you need 120v power for household devices you'll have to use your inverter to make the 120v power from your 12v batteries.

You'll get much better efficiency if you use 12v devices as much as possible. Your roof vents run on 12v and will provide good air flow without having to run the inverter. You can also get 12v fans which plug into the 12v outlets in the trailer.

There are also 12v TV sets which you can use without the inverter. If you have a 120v TV, the inverter will be necessary. When you look at the current rating on a 120v appliance like a television, keep in mind that it will draw 10x as much off your batteries as the 120v rating. For example, if your television draws 1 amp at 120v, it will draw 10 amps from the batteries via the inverter.

Like Bob was saying, this is all about doing the math. Figure out how much battery capacity you have, how much power the solar panel(s) actually produce and how much they'll recharge the batteries, and how much the devices you want to run will draw from them. Then you'll know how long you can/can't run things.

[SteveinAZ]

I use a DIY suitcase set up with two 100 watt Renogy panels, they're a bit heavy, but still manageable for my wife to move them around once they are out of the truck. I had these from our previous trailer set up, so I have a Renogy MPPT charge controller that I lay on top of the propane tanks and run the cord from the panels to the controller, and then another cord into the Zamp receptacle mounted on the side of the battery box. These panels are about $95 each and the charge controller is about $140 with the bluetooth module. I used a continuous hinge from Home Depot to connect the panels, some 16ga "extension" cord to go to the controller, and a "SAE" cord off Amazon to go from the controller to the Zamp receptacle.



For under $400, Renogy has the whole thing in the suitcase bundle, you can check how much a Zamp runs, but maybe buying one all set up is easier for you.


Also, when calculating battery capacity, if you are using standard lead-acid or AGM batteries, you only get half the rated amp hours that is stated on the battery label. You have to go to lithium batteries to use all of the amp hours stated on the batteries.

[Mollysdad]

Originally Posted by richard5933

Many trailers come with a Zamp port installed and connected to the batteries, meaning you just plug in the panels and they start charging when the sun shines on them.
... if your goal involves finding an option which fits a tight budget you might have to look at panels other than Zamp. Some of them will require different wiring than the Zamp port on your trailer.

For whatever reason the Zamp port is wired backwards on the battery box.
It's a standard SAE-2 connector but with +/- reversed. I use mine to power the TPMS repeater, but had to flip the leads.

[Vantair]

For a super 130w portable that is slightly bigger than a large laptop, check out this Aims folding model. This will easily fold and fit into any side hatch weighing a few pounds. You will need to add a charge controller which Victron Has many smaller MPPTs for this at around 150.00.

We tested this on a five day dry camping on the California coast and it powered everything we needed and kept the 2-6v 220ah AGM batteries fully charged by each afternoon. Little flimsy but no heavy, bulky metal frames but it truly works well and super small package.