Solar setup question

[Cosmo]

My trailer battery (when plugged into the car 2018 Subaru Outback) connects directly to the car battery (positive to positive and negative to negative) just like you are jump starting another car.

The Alternator keeps the car battery topped off which charges the trailer battery at the same time. This bring both batteries up to the same voltage. It brings the trailer battery up to 12.5 volts which is very charged.

The solar panels and solar controller will squeeze more electricity into the trailer battery than the car but in my opinion the trailer battery is 97% charged by the car. It does not bring it up to the 13 or 14 volt float charge (fully charged).

There is a device ( forget the name of the thing) you can add to bring the trailer battery to fully charged while driving but in my case I see no need for the thing.

I have camped and left the care connected to the trailer (no shut off switch) and the result was the trailer battery did not drain very much since the two batteries together has lots more amps available than just the trailer battery. I'm not recommending that just noting my results. Make sure you leave enough charge in the car battery to start the car! The car battery is not deep cycle and should not be used for deep cycle (according to biblical law).

I know a number of people who are not using deep cycle batteries and just use an old spare auto battery for light trailer duty who have not been smited yet at the time I wrote this.

=Cosmo

[Cosmo]

One more thing...
The variables are iendless. For flexibility when I need more power such as for running my power hungry laptop to edit videos I take an additional 30 amp AGM deep cycle battery and one or two 2 amp solar panels. This keeps the energy hog laptop on its own power source. I powered 2 laptops for a week using this method in very cloudy conditions https://youtu.be/ZEd0yjTjRJE?t=491

Its probably no news to anyone here - But Optima Yellow top batteries claim to provide lots of Cold Cranking Amps for the care and to ne deep cycle for long duration power too. The price is high and they have lots of techno-babble about their battery but it seems to provide about the same amp hours as all AGMs.

The advantage I imagine (but have not tested) is if you did want to use the car as an additional power source to add to the trailer battery the Yellow Top may help that setup. For me the additional 30 amp battery was more cost effective and less trouble.

=Cosmo

[GPW]

Going “Solar” now requires a "change in lifestyle” ( and Money ) … Using Solar in addition to what we have already is Fun and pretty easy … For me , I use Solar cookers, solar water purifier, little solar small battery chargers , and modified solar "yard lights" that charge outside during the day and go inside at night …( so Simple, I use them at Home too )
Our intent is Camping ( EVAC) , namely getting AWAY from our social “devices” … NOT bringing them along … ( we’ll be Fishing )
We still feel Solar is still in it’s infancy , Great things to come , like Solid State batteries ( that don’t catch Fire ) ,and smaller more efficient panels and appliances will make Going Solar Much more convenient ..
One of the other problems is, we’re trying now to use new technology to power century old devices which we convert DC to AC and then back to DC again ( not very efficient) … I have a loooong extension cord ( for local mains ) and generator(mobile) for those needs … Right now ( for me ) a “Mix" of technology seems convenient and familiar( and thrifty ) … but ” the future is wide open “ …

I’d sorta’ like a briefcase size folding solar panel (including SS batteries) that would power ALL my trailer power needs ( even AC ) … Soon !!!

[tony.latham]

I’d sorta’ like a briefcase size folding solar panel (including SS batteries) that would power ALL my trailer power needs ( even AC ) …

GPW:

What electrical system do you run in your camper? Solar or no?



Tony

[Burro]

My trailer battery (when plugged into the car 2018 Subaru Outback) connects directly to the car battery (positive to positive and negative to negative) just like you are jump starting another car.

The Alternator keeps the car battery topped off which charges the trailer battery at the same time. This bring both batteries up to the same voltage. It brings the trailer battery up to 12.5 volts which is very charged.

The solar panels and solar controller will squeeze more electricity into the trailer battery than the car but in my opinion the trailer battery is 97% charged by the car. It does not bring it up to the 13 or 14 volt float charge (fully charged).

There is a device ( forget the name of the thing) you can add to bring the trailer battery to fully charged while driving but in my case I see no need for the thing.

I have camped and left the care connected to the trailer (no shut off switch) and the result was the trailer battery did not drain very much since the two batteries together has lots more amps available than just the trailer battery. I'm not recommending that just noting my results. Make sure you leave enough charge in the car battery to start the car! The car battery is not deep cycle and should not be used for deep cycle (according to biblical law).

I know a number of people who are not using deep cycle batteries and just use an old spare auto battery for light trailer duty who have not been smited yet at the time I wrote this.

=Cosmo

I also have a Subaru outback limited. I'm curious what is the tongue weight of your camper and the overall weight of your camper. I was thinking of getting a trailer hitch put on. The tongue weight on my camper is 175 pounds. I'm thinking of putting a second battery on the tongue which would probably increase the tongue weight 2/200 lb.

how does your outback handle pulling your camper? Have you had to pull it through any mountains?

Do you have any pictures of your camper hooked up to your outback?

sorry more questions. When I ask the dealer about installing a 7-pin trailer wiring harness on the car they said that was not possible. It sounds like you have a 7 pin or at least wired up to charge your battery? Was that something you did yourself or were you able to locate a kit?

Did you happen to purchase the hidden trailer hitch or did you go with a factory trailer hitch?

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[Cosmo]

Hello,
Good questions.
I went with the factory Subaru towing package. It costs more than an after market hitch but Subaru says it maintains the integrity of the safety crumple zone. https://www.youtube.com/watch?v=jB60gz7ZvfA

My trailer has a Dexter EZlube axle and Dexter electric brakes it weighs 1500 - 1600 pounds loaded with water, food etc.
Tongue weight is 200 pounds loaded. I have a propane tank on the tongue. Battery is near the trailer axle.

Prior to the Outback we towed with a Forester which has a 150 pound tongue weight. It towed fine but the braking noticed the trailer a little even with the trailer electric brakes. The trailer was at the upper limit of the Forester towing capacity but it worked well.

My trailer is a perfect match for the Outback. The trailer is below the towing capacity of the car. Outback is a 2018 4 cylinder. I think its an SI model. The car. It gets great gas mileage and has 8.75 inches of clearance.
It tows well. Handles good and the brakes on the Outback are larger than the Forester so it stops better and the trailer brakes are a perfect match for this car.

Outback also matches the 200 pound tongue weight of the trailer. I have stuff in the trailer when towing but I don;t fill it with other gear.
When I load the care I pay attention to weight distribution. to help the ride and handling. I put only light stuff behind the car axle if I can.
I drive about 65 to 70 for gas mileage and 75 or higher when I need to cover ground. I had it up to 90 once for a short period just to see. No issues for me. I get 20 to 24mpg towing at 65 to 70. Better mileage if I go slower. I get up mountains just fine but I am not passing everyone or holding anyone up going up mountains.,

My car came with the 4 pin connector, I wanted Subi to install the 7 pin connector. They refused. Then I wanted to know what color the wire was for the brake lights and they would not tell me. They told me I might void my warranty if I touched the harness. I took it to a place that truckers use for trailer work and they did the install including the wire fro the car battery to the trailer so it will charge the trailer battery when driving. Its all working fine,

Maybe put the battery weight on the tongue and see what it weighs before you start modifying.

You can see loads of details on the trailer at the video link below (and you will be helping pay for the trailer if you click on an add). I cant remember which video show the trailer attached to the car etc.
https://www.youtube.com/channel/UC5Sd6k ... _polymer=1

If I can answer any questions - Happy to help.

=Cosmo

[Burro]

Thanks for the info. I usually pull my camper with a Tacoma. But there may be a time where I will need to pull it with the outback. My camper only weighs 1000 pounds unloaded but I don't have trailer brakes. I feel like the tongue weight is a little heavy on the front. My access is a little farther set back.

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[GPW]

Tony , here’s a pic of my electrical system … I went with something simple and interchangeable should something go wrong … With my SIMPLE camping/EVAC needs , it works out fine …
Sorry , I made no attempt to make a Fancy RV style camper trailer … just a portable shelter for times of need … ( viz, every summer )
With these “storms of a lifetime “ happening yearly now , we feel the need for some type of “ bugout” vehicle …

And then we have a small generator , an old Harbor Freight 45 watt solar setup (next to worthless), many solar powered lights and a solar lantern , solar cookers , chargers, batteries .. etc.etc. ( and a AC/DC powered TV ) everything carried in the back of my Pickup truck (with my "paw paw" camper top)

Ps. any electrical cords I can easily thread through the holes in my ribs to any point on the trailer …

[rjgimp]

I’d love to get a battery tray that hangs under the camper near the axel and put in 2 of 3 batteries. I haven’t seen a rugged tray that could hold that weight yet. I’d ultimately like to be able to be free from shore power and a generator for up to 4 or 5 days if possible.

Try looking in the trucking industry. Most truck dealerships parts counters (Freightliner, Kenworth, Mack, International, etc...) will have oem or aftermarket battery trays available that are designed to be suspended between the frame rails behind the cab and hold 2-4 group 31 batteries. If you stop in on a slow day with a smile on your face most parts guys will show you what they have on hand and maybe take you in the back and let you measure things to make a modification plan for putting it in your trailer.

[StrongFeather]

I use a C tek D250SA https://www.ctek.com/products/on-board/d250sa and there are other brands out there - these will lift the voltage to 14.8 v which is needed to charge a AGM deep cycle battery and worse still are the later cars with smart alternators - they just don't charge a battery on your trailer without assistance of a Dc - Dc charger the C tek also has a MPPT solar controller built in and will handle 300 watt of solar panel and they are a 5 stage smart charger of cause the other advantage is when the trailer battery/batteries are full these send power to the cars battery to top that up as well something like this is probably worth looking at if you dont use one

Cheaterparts beat me to it. I'm in the process of building my trailer and when designing the electrical/charging system, I did a lot of research on how to charge from multiple sources, i.e. TV, solar, generator and shore power. I looked at battery isolators like this... https://www.renogy.com/renogy-200a-battery-isolator/, continuous duty solenoids like what FLBOY did on his build http://www.tnttt.com/viewtopic.php?f=42&t=65498&start=2190, and even powering a solar charge controller from the TV alternator. In the end, I decided to go with the CTEK D250SA, which is a pretty slick device. It does seem a little costly at first, but consider you won't need a separate battery isolator or solenoid, you can use the 10AWG wire in your 7-pin and you won't need a separate solar charger controller for your solar panels because the D250SA has inputs for both solar and TV power. It also, as cheaterparts mentioned, is a 5-stage smart charger so it'll take care of your batteries. Really, this was a no-brainer for me. I think the only downside that one might be able to come up with is that it's limited to 20Amps, but to me that's a benefit because I won't have to worry about overloading the 10AWG wire in the 7-pin. If you do want to be able to charge faster, you could upgrade your cables and buy their SMARTPASS device to charge up to 140Amps.

Good luck!

Steve