RV System for small camper

Greenhorn · May 2010

I am considering installing a rv solar system in the next couple of weeks. I have debated on this as I own a small (14 ft) travel trailer, and would prefer to use sustainable systems, but am thinking that for my annual use: 4-5 trips a year dry camping. is it worth the cost?

I dont really know how much capacity I need. I haven calculated any consumption formally. We only use lights maybe 1hr/nite, shower (water Pump) and a few dishes. no ac, no microwave, refer is gas, and the heater fan (i hate it) if she is cold..not an issue in northern california during june.

Im willing to purchase 1 quality panel (200 watts or so) and a couple of decent deep cycle batteries, charge controller. What is typical consumption. Where do I begin to run some basic calcs?

My past trips have been complicated by running my battery down, changing to a charged battery (both marine, and I dont think deep cycle). Then, the last trip I really ran them down to nothing :grr and my wife said: lets go; two days early. Im looking at a 4 night dry camp in the next month with great sun exposure. I can purchase a honda generator for sure, but it runs against my grain, and peeves people off with good reason.

Is there a 1-panel system you could suggest which will keep us running (with reasonable conservation-using led lights (I just ordered two for the camper and an led lantern) and maybe a gravity feed outdoor shower) for more than 2 nights? I dont really have room for two panels on the roof.
Please advise me if you can.
Best Regards,
Charles

edited by niel with the word peeves as a replacement. family type forum.

BB. · May 2010

Re: RV System for small camper

Charles,

There is a thread with lots of links and information that covers a wide variety of solar topics--You may get some ideas in there.

Working Thread for Solar Beginner Post/FAQ

Also, there is thread from Kevin in Calgary about his journey to add solar to his small trailer:

nice thread with video

The short answer, usually, is that solar power is expensive and unless used for nearly 9 months of the year--it is very difficult to justify the costs from a pure economic point of view vs just buying a small Honda eu1000i gasoline genset for your few trips a year, plus for emergency use around the home.

Anyway, take a look at the trailer thread and let us know what you think/what questions you may have.

-Bill

Kamala · May 2010

Re: RV System for small camper

Charles,

Lacking a concise load analysis I can only guess that they are quite small. I think you would do just fine with a 200W panel and two 6V 220AH batteries in series. You might want an adjustable mount for the panels so they can be pointed more toward the sun. If the batteries are installed inside the trailer they should be AGM (no outgassing of explosive hydrogen.) I would also include a battery monitor. Try not to discharge the battery bank more than 20%. Never let it go below 50%. It would be a good idea to have a generator to charge the batteries if the skies are cloudy. The Honda eu series is really quiet and you can run it during the daytime (less offensive to others than running it at night.)

Is the cost justified? Only you can decide. What are those 2 lost camping days worth to you?

Good luck!

Craig

Greenhorn · May 2010

Re: RV System for small camper

Hey guys,
Thanks for the input. That is is something go with. I'll purchase the Honda Eu and probably do the solar project as time permits just for the project and learning, and eventually I'll have more time to use the camper and can "justify" the expense. And Bill thanks for the links...helpful..

On the Honda. Ive been reading here and there about people using a xantrex controller (or others). Is this something I need to pickup with the eu1000? And is the 7. 5 amps of the 1000 sufficient for charge? What would the charge time be for a 20-30 percent discharge. I'm guessing I have probably done some damage to my marine batteries (one is from my boat) by running them down to nothing. I like the charge display I saw in Craig's camper. Where do I get something like that? NAWS?

I'll write more later. I'm full of questions. I am going to add solar to my home hopefully by next spring. Gotta take advantage of the rebates.

I find it interesting that Ive been perusing solar distributors on the net for about 6 months off and on trying to educate myself. The NAWS site has the products l've been considering for my home (SolarWorld panels and Enphase microinverters) at good prices, and a lot of information to educate myself..and a forum to boot! The last project I did was build a guitar tube amplifier from scratch using old parts from an old Hammond organ and I found fantastic help from a supplier with a forum.....invaluable to me.

Hopefully you guys can offer some guidance when I get going on that. I'm currently taking insolation data with a unit from microcircuit labs. Is it possible to post my excel spreadsheets here for some review? Ok Im rambling, gotta get to work.
Best regards to all.
Charles

BB. · May 2010

Re: RV System for small camper

The DC output from the Honda euX000i family is unregulated 12 volt output that is really only good for emergency use. Also, the Honda has to run at high speed (eco throttle off) if using the DC output (not fuel efficient).

You will want a 20 amp 12 volt AC battery charger... There are lots of options out there, but for small generator systems, I really like Power Factor Corrected (PFC) battery chargers.

Some Inverter/Chargers have PFC battery chargers (combination unit--sort of like a UPS with an external battery bank).

Also, Xantrex has the TC-2 family of battery chargers. NAWS is listing the 20 amp version on their site (new product, availability has been spotty)--also has a battery temperature sensor--which is really nice too.

If you already have an AC battery charger in the RV, and it is not too big for the eu1000i--getting the Xantrex may be overkill for now.

-Bill

Greenhorn · May 2010

Re: RV System for small camper

Bill, Thanks for the advice. I am wondering if my built in converter/charger is sufficient to just plug in my generator to the ac outlet outside the trailer. Will this device provide sufficient charge to the battery? I'll have to take a look at the make and model specs this week.
Charles

BB. · May 2010

Re: RV System for small camper

Two questions... 1. will a Honda eu1000i drive your converter... You can get a Kill-a-Watt meter and measure both Watts and Volt*Amps with the meter. The battery bank should be at least 25% discharged (or even near 50%) to ensure a good load on the converter. Knowing the Converter's input rating will help validate your measurements too.

If neither of them (Watts or VA) go over 800-900 watts--then the genset can drive the converter (at least at the loads you are looking at.

The other question is will the Converter properly charge your battery bank... Normally, to fully/quickly charge your batteries, you want ~14.0-14.5 volts (bulk and absorb mode) or so (also depends on battery type and temperature).

Once the battery is fully charged, you want a 24x7 charger to cut back to ~13.6 volts or so (float). Obviously, for a genset, you are going to turn it off when the battery bank is fully charged--so float is not a big issue there (just when the RV is in storage and connected to a utility outlet).

You can read about the issues in the Battery FAQs:

Deep Cycle Battery FAQ
www.batteryfaq.org

-Bill

RV System for small camper

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