My family and I are taking an extended trip into Yellowstone NP and I was curious about using solar panels to keep our trailer batteries charged but don't really know how they hook into the trailer's electrical system nor what I'd really need.
Does anyone out there have experience and information with this sort of thing? I'm not looking to power the whole trailer. We aren't staying at Fishing Bridge so I'm going to need enough battery power every day to run the furnace, fridge brain, and the water pump on occasion. I plan to make everyone use the provided bath-houses for showers and the like, plus there'll be no AC, microwave, or TV (yes, I'm a meanie).
The thing I'll really need to conserve the TT batteries for will be the running of two CPAP machines at night via an inverter. I know this will be a huge drain on the batteries at night so what I'll need the solar panel(s) to do is to recharge them enough during the days that the CPAPs can be run all night.
Any info for "solar panels for rv dummies"? I am not technologically inclined (rather technologically challenged, actually), so please try to speak in small words for me.
Thanks!
* This post was
edited 04/16/07 12:02pm by TomNLauraWA *
'99 Silverado 2500 4x4
'04 Skyline Nomad 250LT
2 cats who don't travel well
Umpteen sheep who don't travel at all
If you plan on moving the RV daily, perhaps the batteries can get topped off, but I know someone with a CPAP machine and he can only dry camp for 3 days with 4 batteries - and only 1 machine. My guess is you will drain 4 batteries nightly with 2 machines - especially if you need to use the humidifier.
The CPAP machine I tested used about 85 watts, while the humidity heater consumed about 200 watts for short durations, like 10 minutes per hour.
I am guessing my 6 volt golf cart batteries will hold about 1,000 watts each. With a load of 200 watts per hour (for both machines) for 8 hours, this is about 1,600 watts. More than should be removed from 4 batteries per night. To replace that much power in one sunny day will require 4 (or more) - 120 watt solar panels, and no shade on them between 9 am and 3 PM. This will cost something like $4,000 to purchase the parts, and another $500 - $750 to install. You would still need some extra power to the batteries - even with this 480 watt solar system.
You will be much better off buying a Honda 1 KW or 2 KW generator and recharge with the built-in battery charger in your RV. Plan on running the generator about 5 hours per day to recover the 250 amp hours used nightly. Make sure that your battery capacity is over 400 amp hours, and the charger is minimum 50 amps - more than 70 is better.
If you don't have 4 batteries, plan on not running the CPAP machines the whole night. They take that much power. Normally I would be happy to recommend a solar system, I have a 400 watt system on my RV, but in this case, I know that it is impractical. Unless you REALLY don't want to hear a generator run, and are willing to spend $6,000 + to make the solar system happen, then I can not tell you that the solar system will recharge your batteries.
Yes I did install a solar system on my RV, along with a 1,500 watt inverter, satellite TV antenna on the roof, E-Meter, and many other things. I even installed a inverter for someone with a CPAP machine.
I install air conditioners for a living, so this installation is no big deal, except for the power requirement that you will need will dictate a very large system, much larger than a normal RV would use.
I can answer any questions that you have for me.
Fred.
Money can't buy happiness but somehow it's more comfortable to cry in a Porsche or Country Coach!
Yea- you need a generator, even if you put some solar on. Keep in mind at Yellowstone they don't allow generators to run after 8pm till next morning, so you'll need to be sure your batteries get topped up during the day.
Hmm, yeah, running the figures you all have provided me, it does seem that a generator is going to be a better solution for making sure my sister and her husband can breathe all night. It beats listening to them snore on my sofa all night, too.
Second question...how long will I need to run the generator in order to charge the batteries during the day? It may be the cheapest solution of all would be for them to get a room at one of the lodges there.
That's going to depend on how much you take out of the batteries each day/night, and how fast your converter (battery charger) in your trailer can put it back- can't tell you without knowing how many amps your converter charges at. If you were to book a site in advance can you not get a power site? I couldn't get power when I was there but I landed in there in the middle of August and hadn't tried booking anything. The campgound we were in did have power sites.
Yes, I could have booked at Fishing Bridge, the only campground with hook-ups, but my siblings would not have been able to join me there as one has a pop-up and the other a hybrid. Fishing Bridge is strictly off-limits to any form of trailer with any canvas areas due to the local feeding area for the bears. There is a natural migration and feeding corridor nearby that the bears use so the park service is trying to avoid attracting the bears unnecessarily into that campground by restricting it to hard-sided units only.
Sooooo, I'll be roughing it for their sakes; woe and alas. They better appreciate my love.
As far as the amperage my converter uses; I have no clue. I raise my own food, weave my own cloth, sew my own clothes and will likely survive the demise of technology when others don't but when it comes to technical crap, I'm a doofus.
Hmm, this is an interesting thread. I'm one of the sisters. I also use a CPAP machine at night, though I can go without it for perhaps a night if I have too. We are just now trying to figure out what we need to power the CPAP. And the TV--we have to use the DVD player nightly for youngest son(he's autistic,can't leave home without the requisite daily movie).
We do not have a generator. Do you think we really need one? Yellowstone is the only park we plan to go to that we won't have electric so I kinda hate to make that investment. But I can't go 4 nights without the CPAP.
"Those who dwell...among the beauties and mysteries of the earth are never alone or weary of life."--Rachel Carson, environmentalist, 1956
I have a Remstar auto w/cflex and it is rated 3 amps max at 12 Volt. I believe that would only be 36 watts at maximum power. It is adjustable from 4 to 20 cm H2O. Would I be wrong in thinking that at 3 amps using it for 8 hours would only be 24 amp hours or 288 watt for the night? On a recent motorcycle trip a friend used his connected to a lawn mower battery and it lasted all night. I don't remember if he used his humidifier or not. I seldom use my humidifier.
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