Solar power - Mastermtn or anyone else that has it

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Brother Bear

Well-known member
Joined
Apr 15, 2008
Posts
448
Location
Great Plains
Tell me about your solar application for boondocking. What kind of equipment does it take? How bulky is it? Is it permanently attached to the RV?  How much energy will it generate in direct sunlight? How much in not so direct sunlight? Etc. Etc.

Thanks!
 
BrotherBear said:
Tell me about your solar application for boondocking. What kind of equipment does it take? How bulky is it? Is it permanently attached to the RV?  How much energy will it generate in direct sunlight? How much in not so direct sunlight? Etc. Etc.

Thanks!

Well BrotherBear...you are my namesake on my given name for hiking the PCT!! what a coincidence...


Anyway my setup is pretty simple...and relatively inexpensive...
its objective is to trickle charge the batteries during non-use times...

The system consists of 4 panels, frame, 3 batteries, 1 800w inverter and 1 2000w inverter
plus a 3 stage AGM smart charger with temp sensor.

The batteries are two 80ah deep cycle and one 220 ah AGM battery (the 135 lb one!!)

The panels are 4 ea 12 volt models--
(13.6 VDC nominal when charging) 15W each for 60W total or about 5 amp
DC charging capacity....we hike and
backpack for several days at a time...so in about 3 days = 24 hrs charging if the
sun holds (and sure hasn't this year)  I can recover close to 120 amp hours into the
batteries....since it is not a main-bus type solar system, I connect the panels (in
parallel) directly to the batteries..normally one would use a charge controller
but with such a small system and low charge current I opted for direct battery connection
since it charges when we are away there is no other draw on the panels...

More complex systems (read that expensive on the order of several thousand dollars
could power your lights and heat and tv without a generator...) require a lot more gear and dedicated
controller....home systems such as my neighbors.. take you off the grid per se
--but required almost $30,000 investment.  My total cost including frame for the
panels was about $300...I figure it took about 6 months of charging to recapture
the initial outlay (in terms of purchasing gas for the generator) We also used this
system for car/tent camping to power lights, video player, laptop, tv sat and cells...

The frame is simple PVC pipe with adjustable angle...everything else fits in
the Tundra bed wired up with #4 wire and #12 from the panels...
under a heavy lockable toneau cover.

Main "shore power" during generator hours is an Honda 3000i generator...
the batteries last several evenings of lights,heat and movies before the generator
needs to be run...(depending of course on total power consumed and solar
charge time available)

One warning...if you go with a "bare" panel setup like mine..be careful what you connect
the panels to as the open circuit (unloaded) voltage can be as high as 15-20 volts
in high sunlight....(no regulator there unless you buy one)...and it can blow out things
like the front end to an inverter...always connect to a battery if you do not want to
buy the full controller....

It is connected to the RV only during charging (I put a cutoff switch and charge plug on the
RV battery box for this purpose)....it remains in the truck along with the generator so we
can take it car camping and leave the RV at its site-- power output I guess is fairly
linear with sunlight availability to the panels...be sure to clean your panels regularly
as it can cut down output sometimes over 30% (I monitor charge current with an
in-line amp-meter)...
 
  I recently met Wally from Solar Solutions at Quartzsite. He is brilliant with solar energy and a Forum Member. Hopefully he will read this and offer advice.
  He doesn't work on commision and is a wealth of information.
 
 
Thanks guys. I was hoping maybe it was something attached easily to the fiver, as my TV often goes with me when I'm away from the RV. I suppose it wouldn't be terribly hard to set it up on the ground? All I'd likely care about is keeping the batteries charged during the day. I'm supposing it could be adapted to the regular 12V w/4 6V deep cycle 230 Ah batteries?

My refrigerator is totally electric and runs off an 800 watt inverter when not on the genset or shoreline. Would this system charge enough for my fridge not to drain the batteries, given the sun cooperated?

I suppose I would need some type of voltage regulator to hitch into the coach batteries?

Thanks again!
 
Larry,
There is no simple answer to your inquiry. You need to calculate your daily consumption of 12v power and then provide enough batteries to contain it and enough solar panels to re-charge those batteries. You will need to estimate how long your residential fridge runs each day and the power consumption (via the inverter) while running.

Solar panels are typically mounted to the roof of the RV. Not sure why you would want to have them portable? The panel output is routed through a charge controller to the battery bank.

A typical 80 watt solar panel will generate around 5 amps at 15v in full sun. Depending on season and where you are, you may have "full sun" anywhere from 1-several hours per day. In some locations you will never get direct full sun because of the angle of the sun with respect to the panels. And of course there are trees and such to factor in.
 
RV Roamer said:
Not sure why you would want to have them portable?

Thanks, Gary. I'd rather have the system affixed to the 5er. Mastermtn had said his was in his pickup. That's why I asked that question.
 
Larry,
if you would email us your address at [email protected] I will see that you get a small book that is a primer on solar. or  send us your phone number. I will talk solar anytime. There are so many variables to consider it is easier to do by actual conversations.

Wally
 
Helaine & Wally said:
Larry,
if you would email us your address at [email protected] I will see that you get a small book that is a primer on solar. or  send us your phone number. I will talk solar anytime. There are so many variables to consider it is easier to do by actual conversations.

Wally

Again, ours is portable as we tent/car camp away from TT a lot..
Ditto...call anytime regarding solar.....Five1zero five41 zeroeight41 I love EE and
will talk day or night  (errr...well..depends if the wine, grapes and crackers are flowing or not!)
MSEE and a lot of power work...no charge  for the EE consult except nice fire if we
meet at a CG ;)
 
I looked into this quite seriously and came to the conclusion that it didn't make sense in our northern latitude, especially given that I had hoped to use it mainly for spring and fall trips, when the days are shorter.

The guys who camp in Arizona where there's no tree cover, nights last 10 hours, and there are clouds only 5 days a year obviously come to much different conclusions.
 
I got a 130 watt panal kit from rv solar electric, and two golf cart batteries.  It let's me use the lights and run the furnace all night long. No more cords. I love it.
 
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