Portable solar panel(s) plugged into 7-pin connector???

[OCJohn]

Been doing some reading/research about adding solar to our Hymer. So far, I don't believe I've seen anyone wire a portable panel setup into their trailer's existing 7-pin towing connector. Any reason for that? Wouldn't using the #4 and #1 pins for 12V+ and Gound (in the example below) be the same as charging from the vehicle alternator when towing? Assuming you use panels with an included charge controller (like this Renergy suitcase...) why would using a cheap 7-pin vehicle-side connector be different than installing Anderson plugs?

I'm just trying to learn about this whole solar thing. What am I missing?

[Byron Kinnaman]

both will work just fine.

What I've done is put a pg tail on the battery with anderson power pole connectors and anderson connectors on the about 15' of twin 12 awg wire coming from my solar panel. There's several reasons why I did this. One I have a secondary battery in the back of my truck purchased to run Amateur (Ham) radio. With the power pole connectors I can plug it into the house battery to get a bit more in the trailer.

That said, if I need to ditch the extra battery I might just connect to 7 pin connector.

[Huck]

That's what I did at 1st, but decided a mounted solar panel was a better option.

[Byron Kinnaman]

Originally Posted by Huck

That's what I did at 1st, but decided a mounted solar panel was a better option.

I Prefer to park in the shade and I have two batteries in different locations that need to be charged from time to time. The purchase and build of my solar system was done primarily to accommodate my Ham Radio hobby which meant that portable was the best option. It's served me well for the past 10 years.

One thing to be a bit careful about buying a solar panel read the specifications. Some say after 5 years you can expect the output to be at 80% others say that after 20 years you can expect the output to be at 80%. Just a suggestion to be a bit careful on what you pay good money for.

[John in Michigan]

I'm with Byron. Prefer parking in shade and in places like MI, there's plenty of shade. So I have a portable solar panel, "extension cord", removable solar charge controller located near the battery.

We've even stayed in campsites where there is insufficient sunlight (too much shade) to provide power, even with a 25' "extension cord". In those cases, I wish I had a 2nd battery.

On the other hand, we've also camped in western Texas and Gulf coast Texas where we had plenty of sunlight every day, all day ...

[ZachO]

Yeah, no reason that can't work.

Having both mounted and portable solar is the best of both worlds...and I'm leaning that way. I bought portable panels because obviously I want to park in the shade. But sometimes I just camp for a night. Pull into a place near dinner time, then leave in the morning. Not much time for charging. In the meantime I'm in the sun when I run errands in a town, stop to eat, and the entire time I drive.

Right now, the wiring in my truck isn't heavy enough to contribute any real charge to the battery while I drive. So unless I can set out the portable panels, I'm getting no charge. I really hope to get panels on the roof soon. All that time in the sun and no charging...

[Huck]

Originally Posted by Byron Kinnaman

I Prefer to park in the shade and I have two batteries in different locations that need to be charged from time to time. The purchase and build of my solar system was done primarily to accommodate my Ham Radio hobby which meant that portable was the best option. It's served me well for the past 10 years.

I actually wired with 2 y cables, so I have a 100 w panel on the roof and another 100 w panel I can place wherever I want. Where I most often camp, there is no shade anyway.

[OCJohn]

Originally Posted by Byron Kinnaman

One thing to be a bit careful about buying a solar panel read the specifications. Some say after 5 years you can expect the output to be at 80% others say that after 20 years you can expect the output to be at 80%. Just a suggestion to be a bit careful on what you pay good money for.

Good tip. Thanks.

[neparker]

I have a Go Power portable panel and an optional 7-pin plug for use w my Parkliner. The 7-pin conncecction did charge the battery a bit on several trips, but I found that a direct connect (Anderson connector pigtail) to the batteries charged the batteries *much* faster. Not a scientific experiment by any means, but in the direct connect, there was some shade on the panels and the batteries were still charged faster than full sun via 7-pin.

[Byron Kinnaman]

Originally Posted by neparker

I have a Go Power portable panel and an optional 7-pin plug for use w my Parkliner. The 7-pin conncecction did charge the battery a bit on several trips, but I found that a direct connect (Anderson connector pigtail) to the batteries charged the batteries *much* faster. Not a scientific experiment by any means, but in the direct connect, there was some shade on the panels and the batteries were still charged faster than full sun via 7-pin.

Guess for why the difference. There's corrosion someplace between the 7 pin connector and the battery. Don't worry about it, it will make it's self known at some point in time.

[John in Santa Cruz]

also wire length and gauge from the solar panel to the actual battery will impact how effectively it will charge. the optimal setup has a temp sensor taped to the side of the battery, and a pair of voltage sense wires connected to the battery terminals in parallel to the main charge wires.

[ZachO]

Exactly why my alternator doesn't charge my camper battery. That's a long run from the engine to the camper, and the way my brake controller kit is wired, the gauge is too small to carry enough current.

[redbarron55]

I found that the factory wiring kit for my 2016 Town & Country was grounded at the firewall near the battery 20 feet from the hitch!
While the hitch may provide a ground the extra 20 ft of wire doesn't help the voltage drop situation any.
To be sure of a good ground that wire should also be paralleled with a ground near the hitch. (IMO)

[Wayne Collins]

When we had our Scamp, I installed a 12V "cigarette Lighter" socket just inside the door, and spliced it to the 12V wires feeding the fridge.
The small solar panel has a mating plug on the end of its wire.
Also bought a volt meter (battery monitor) that plugged into that same socket.
It could be left in there all the time, except when the solar was plugged in.

[WaltP]

I'm with Zach, both roof mounted and portable, the best of both worlds. Actually I got the idea from Jon V.
I had a 100W Renogy suitcase with my previous trailer. When I ordered my Escape I opted for the 160W roof panel and had a Zamp connector installed for the Renogy.

Walt

[kootenaigirl]

Yes, we did the plug in to the 7 pin connector on a past trailer and it seemed to work well.

[Mary F]

Originally Posted by OCJohn

Been doing some reading/research about adding solar to our Hymer. So far, I don't believe I've seen anyone wire a portable panel setup into their trailer's existing 7-pin towing connector.

That's how we set up our 1999 Casita, and I did post about it in this old (2008) Solar Charge Controller thread.

[patrick crawford]

i use two 100w panels. one permanently mounted on the roof of my casita which stays connected to it's controller and the other mounted on the truck's topper roof that's connected to it's controller via cables that are connected when sitting still. of course if the trailer's in the shade i can chase the sun by moving the truck. while underway my two 6v agm golf cart batteries (225ah total) are being charged by the trailer's panel and the truck's alternator. if there's sunshine i always arrive at the evening destination with fully charged batteries. this arrangement was put to the test with last winter's nearly 4 month trek west. according to my victron battery condition meter the batteries seldom dipped below 90% full charge. i did not try to minimize my 12v consumption and kept all my devices charged, used lights (led's), water pump and radio just as i would if plugged in at a campground. i do have a failsafe honda 2000i permanently mounted atop the trailer's tongue and hard wired directly to the trailer's converter in the event of prolonged inclement weather. the only time the honda was pressed into action was to occasionally use the electric toaster oven. i was so encouraged by the 12v performance that i returned home and promptly installed a 12v/120v (no gas) fridge, but...that's another post.

p@

[Scamper Jim]

John,

Your idea is fine if you plan to disconnect the 7-pin connector from your tow vehicle when at the campsite. You could then insert a blade connector into the #4 power slot of the plug on the camper side from your solar panel.

However, if you plan to just tap into that power line somewhere and leave it plugged in to charge full-time, you will create a problem with your TV battery. This would happen because the solar power is going to the TV battery at about 17 volts or higher because it is not going through a controller. It will be charging at too high of a rate and charging it for too long of a time. Short battery life!

[ZachO]

My ideal setup would be similar, minus the generator. Somewhere around 100w on the roof, 100w portable, and 2 6v batteries. But for now I'm working on the rooftop solar. I'm not ready to alter my battery tray and spend the money on new batteries.