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Author Topic: Solar Panel  (Read 16044 times)

Solar Panel
« on: May 14, 2012, 08:44:02 PM »
I have a tent trailer with one 12v battery.  What size watt solar panel should I get to maintain my battery while camping?


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Re: Solar Panel
« Reply #1 on: May 15, 2012, 02:04:22 PM »
If you are talking of only maintaining the battery, as opposed to using it to power up other items at the same time, then I would suggest something along the line of a 45 watt panel with voltage regulator.  This would charge the battery at approx. 3.75 amps depending on available sunlight.  About $180-200 bucks at Harbor Freight.

Type, condition, and size of your house battery also play into this.  It depends on what you are expecting out of it.
Hope this helps.

1994 Jayco Eagle 370FB on 24 acres of paid off paradise in Michigan.

You have brains in your head. You have feet in your shoes. You can steer yourself any direction you choose.
Dr. Seuss


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Re: Solar Panel
« Reply #2 on: July 04, 2012, 11:10:49 PM »
I've been searching the same question.....similar that it is. I have 2 - 6v batteries for my tent trailer and agree a 45 watt panel would do ok to maintain the battery (depending on how much battery power you use during the day / night i.e. lights, fans, pump)
i'm looking to get a panel between 80 - 100 watts to maintain my batteries.

but i have some related questions

1. how do you maintain the battery during long storage (more then 1 month). Do you use the charge controller you typically have and the 80 watt panel i'm looking and forget it....???

2. speaking of charge controllers is there one that tells you different info on your batteries i.e. watts remaining, amps being used (not sure what things i want to see)


3. are there better solar panels better than others.??? what makes a good solar panel

Gary RV_Wizard

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Re: Solar Panel
« Reply #3 on: July 05, 2012, 08:35:13 AM »
If you can plug the RV in during storage, you can let its own charge system keep the batteries alive. Just make sure there is water in the cells. If no electric available, solar is a good alternative if there is adequate sunlight.

A solar controller is a regulator, whereas a charger is both a power source and a regulator. Sophisticated charging systems monitor the flow of current (amps) in and out of the batteries and can keep track of the net amount remaining but they typically run $1000 or more. However, you can add a monitor such the Xantrex Linklite for under $250 (plus install)
Gary Brinck
Summers: Black Mountain, NC
Home: Ocala National Forest, FL


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Re: Solar Panel
« Reply #4 on: July 05, 2012, 09:52:46 AM »
I am no expert on these matters but here is my 2 cents worth.  From everything I read it is advisable to match the amp hours of your battery to the watts of your solar panal.  Say you have two 105 amp hour batterys giving you a total of 210 amp hours then you need 200+ watts of solar panal or two 100watt panals, plus a controller and and inverter.   
2007 Coachman Aurora 36FWS
2006 Mini Cooper S


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Re: Solar Panel
« Reply #5 on: July 05, 2012, 07:07:33 PM »
I just completed a solar installation on the rooftop of my class c RV.  I installed 2 120 watt panels, for a total of 240 watts.  I have a battery bank consisting of 2 batteries, 180 amp hours total.  I figured the panels, mounted flat, on the roof top I'd loose some efficiency.  So far, it's great!  The panels top off my batteries each day to a full charge in the evening.  I feel like I don't even need to plug into power anymore. 


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Re: Solar Panel
« Reply #6 on: November 18, 2012, 08:05:06 PM »
An 85W panel should be fine for normal camper use. If it's late in the Fall and you plan to run your furnace fan a lot, then increasing the wattage would be wise as well as getting a second battery in series with the original.


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  • Dave - Okanagan Valley, BC, Canada
Re: Solar Panel
« Reply #7 on: November 19, 2012, 01:36:44 AM »

PLEASE do not connect a second 12V battery in series with your existing battery.  Your tent trailer will not appreciate the 24V that results.
1997 Southwind 32H


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Re: Solar Panel
« Reply #8 on: November 19, 2012, 08:04:52 AM »
Quote from: COcamper
a second battery in series with the original.

Check this illustrated file in our forum library on the correct way to add batteries.
« Last Edit: March 08, 2013, 07:53:59 PM by Tom »
Tom.  Need help? Click the Help button in the toolbar above.

Shadow Catcher

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Re: Solar Panel
« Reply #9 on: March 08, 2013, 07:41:28 PM »
How much solar power is needed is a balancing act with a number of considerations. Conservation is a big part part of the equation i.e. use of LEDs. How much you need/want is dependent on what you plan on powering, anything using resistant heat is a power sucker, we do not even use an electric coffee maker, the french press makes great coffee. but we do run the XM sat radio, TV and Waeco refrigerator and all LED lights.
How much is dependent on where you camp and how much direct sun you will get, if it is in the trees...
We have a 185W high voltage panel which feeds a Morningstar MPPT controller and it will generate usable current in low light situations I also have a Unisolar 140W flexible panel I can unroll out in the sun, which I have yet to use as the 185W has met our needs.
The Harbor Freight panels are low efficiency and the cost per watt too high. I am seeing 100W panels for $150 on ebay with shipping with out doing much of a search.
Home work, one of the best if a bit opinionated, sources of information is Handy Bob http://handybobsolar.wordpress.com/


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Re: Solar Panel
« Reply #10 on: April 21, 2013, 09:27:42 AM »
Here are two excellent links that will provide all the information you need and more.  Well worth reading before you purchase and start setting up solar.


Regards, Bruce, Lin An, Kenji & Suki
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Gone But not forgotten:
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Shadow Catcher

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Re: Solar Panel
« Reply #11 on: October 21, 2013, 07:35:59 PM »
There are a number of factors involved, conservation is the first one. Our trailer is set up for serious boondocking, all LED lights computer case fans... Out of ignorance I bought a solar panel meant to be used for a grid tie system and it is a 66 cell 185W that required a MPPT solar controller and I chose a Morningstar SunSaver. I have seen open circuit voltage in excess of 70V and even in a shaded camp site I see 35+ volts.
What this means is that it gives us usable current from sun up to sun down. We spent eight days in a shaded camp site on the north shore of Lake Superior and the trailer. I am powering LED lights the case fans (much less power than a Fantastic Fan) XM radio, TV/DVD and the big drain a Waeco 12V refrigerator. I use a Vectron battery monitor and we lost a bit of ground each day but at the end of eight days were at 64% state of charge.
We often camp in shady sites, this works very well.
For expertise http://www.wind-sun.com/ForumVB/index.php