# Solar Power



## JSSML (Aug 16, 2010)

Okay I have some Solar questions. We have a 29 foot tt and would like to do more dry camping as most electrical site in PP are full or are too far out. We recently went to Bon Echo which is our favorite place to camp, Anyways we needed to use a generator as the battery would only last 24hrs. That is without using lights. Only water pump and of course the stereo clock always stays on as I can't find the fuse and the fridge uses power for a fan and electric monitoring. So does anyone use solar to recharge batteries?? If so what size for a 12V deep cell. Anything i should avoid??? 

Any help would be great!


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## happiestcamper (Mar 6, 2008)

24 hours? Your battery must be bad, unless you're running all kinds of fans.

Anything with a motor in it will drain the battery quickly - water pump, fans, vcrs or dvds, etc. Things like lights and stereo aren't that hard on them. Make sure your water pump isn't set too high - each additional PSI it has to get to takes it toll.

I have two 6 volt batteries in series (the hot wire goes to one battery, the ground to the other, then a wire connecting the remaining + to -). They are both 270 amp hours (I think, been awhile since I bought them). You can also hook up more than one 12 volt in parallel (you hook all the + together and all the - together). If you are planning to use more than one battery, it is important to get the exact same kind at the exact same time - do not mix old and new batteries. Be sure they are all deep cycle (don't make the mistake of getting cranking or combo cranking/deep cycle, get deep cycle only).

Take care of your batteries when you are at home. At least once a month, be sure they get charged, and be sure the charger will gear itself down to a trickle charge as needed. You didn't state the age of your trailer - if it's older than 5 years or so it may not change to trickle charge as necessary, so if you leave it plugged in, it can boil your batteries - that's even worse than letting them lose all their charge and sit for awhile.

My favorite place doesn't have electric, so I use solar. It's kind of shady there, so I am not at my most efficient. I try to get one of their sunnier sites. I have two 60 watt panels. I have those connected in parallel, and hooked up to a 30 amp charge controller. We just did a week there without running out - though since we weren't getting many hours of sunlight, they weren't at peak at the end, but still functional. As a backup, I bring along the 12 volt that came with the camper, just in case. Anyway, what I do is my first day there, I try to aim the panels directly at the sun around noon or 1:00. You want to make sure that when you use them, that they are in the sun, not partially blocked by shade. A panel not in the sun will try to draw power back if it can - so two or more hooked up don't work too well if one is in the shade (that is another function of the charge controller - not only to change to trickle charge as needed, but to also prevent the panels from drawing from the battery at night).

Hope this helps - again, your battery should last more than 24 hours even without solar.


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## JSSML (Aug 16, 2010)

My Trailer is a 2011 Passport 2910BH, The battery however is off our previous trailer and is in its 3rd season. I will be taking it this week for a load test. 

What size of panels do you recommend ? i.e Watts!!!


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## happiestcamper (Mar 6, 2008)

Here's a worksheet http://www.sunvoltenergy.net/BodyPages/Other/RV%20Power%20Worksheet.pdf


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## l2l (Jan 27, 2008)

That's a great worksheet thanks for posting that :thumbup1: :10001:


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## Jordan (Aug 13, 2010)

happiestcamper said:


> Here's a worksheet http://www.sunvoltenergy.net/BodyPages/Other/RV Power Worksheet.pdf


thanks happiestcamper for the the pdf file, great link as it makes such great sense

:thumbup1::thumbup1::thumbup1:


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## vernastorm (Jan 3, 2011)

Great worksheet! I have been using a 12 watt solar panel simply to keep my engine battery charged after the alternator died. And I'm happy to report that it did a wonderful job. I always thought solar could be no alternative to a generator, but with led lighting and new energy efficient appliances, it's worth another look.


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## SMOKEY2348 (Jan 4, 2011)

First you need to figure your wattage use through out the day. For a point here you go. 

Say you use 2kwatts during the day so you have 
2kwatt hours of energy used. 
Say you have 200watts worth of panels it would take 10hrs worth of direct sunlight to recharge the batteries. 

So you used 
2kw's in a day and only have 200watts worth of energy production per hour. 

At most you have 6hrs of sunlight worth of energy so be safe and say 5hrs at 5hrs 200watts worth of panels MIGHT make 1kw leaving you 1kw short to recharge your batteries. 

So for 2kw's worth of energy being used during the day and at night you need at least 400 watts of power generation during the day. Assuming 5hrs of good usable sunlight.


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## happiestcamper (Mar 6, 2008)

fincsher said:


> Just wonder why it has battery even though it is running because of the solar power?


Battery(ies) store the excess solar power to be used when solar is not available - cloudy conditions, night time, etc. :icon_smile_sun:


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