I might be getting some unexpected extra money and am considering adding solar panels to my fifth wheel. I currently have a factory installed 50 watt panel that has 10 gauge wire going down through the roof to the controller. I have 4 125 amphours batteries that function mostly to run a 2500 watt modified sine wave Xantrex inverter charger that runs a residential side by side. I've always imagined that if I got 400 to 500 watts on my roof I could travel and camp more like I use to when I had little electrical draw with the old gas frig in my previous trailer. My wife loves the residential's performance and size. Me too! Could one you guys who knows what you're doing (I don't ) give some suggestions as to panels, wiring and controller needs? I'll have between two and three thousand to do the whole thing but would like to do it at the best value point as I have other things I'd like to do with any money left over. Thanks

Have you seen all the solar threads posted recently?household refer and inverter2009 Household refer Class A 2009residential fridge- boondocking 09Residential refer Class A 2010Solar in Heading in tech Issues

Here are some installs to look through:Forum Members Solar Installations With PicsI would assume you want 500w or more.

Far be it from me to discourage solar (I've had panels on all four RVs we've owned over the last nearly 20 years). But 400 to 500 sounds like much/all of the roof would be covered.With your current 10 gauge lead-in you are limited to probably 400 watts (unregulated panels can run to 18 volts, time 30 amps... roughly 400 watts)A good resource is RV SolarPersonally, when boon-docking (summer time) we don't watch TV, we have LED and florescent lights, are careful with power and find that 100 watts is enough.

500w sounds about right. 2 245w or so panels and an MPPT controller sized to handle at least 500w.Since your big desire is to run the fridge buying a kilowatt meter from Lowes and reading what you really use per day would be most of your energy audit to verify these estimates.I think you are talking 6 or more batteries but knowing your usage for the fridge would give a better idea.Camping in sunny Texas or elsewhere? Jim

Seems if I need to, I could use the existing 10 gauge wires to pull a larger wire through the ceiling cavities if I need to but don't really know where it runs. The reply before last indicates I might want 500 plus watts. I have a lot of clear roof space on my Alpenlite. If I do it I'd like to have sufficient power to run the frig and normal florescent bulbs ( we don't watch TV either) for a week or so not hooked up. We like national forests. Is this possible or am I caught up in an impractical idea?

Thinking about a new solar setup for my 5th wheel

14 Replies

howardwheeler
Explorer
May 07, 2013
Thanks. This really seems within reach.
hmknightnc
Explorer
May 07, 2013
With 500 AH of battery capacity something like this would probably be a good place to start. 660watts of solar with Morningstar 60amp MPPT controller. That controller will pass through nominally 800 watts of solar but accept well more than that since is self power regulating by limiting output to 60 amps.

220 watt 24volt panels
Morningstar 60amp MPPT controller

Get 3 of the panels and the controller. About $1,000 plus miscellaneous and self install
time2roll
Nomad
May 07, 2013
I have my 675w going down through #10 wire as the three panels are in series making about 90 volts that the MPPT controller converts to 12v and increases amps for battery charging.

Consider something similar. Panels can be as low as $160 and controller about $500. That is about $1,000 + self install materials.
pianotuna
Nomad III
May 07, 2013
Hi,

Here is a simple flow chart.

Budget-->Energy Audit-->Battery bank size-->number of watts-->PWM or MPPT.

Here is a link to the rather special spreadsheet that N8GS has created to help size solar battery charging systems!
Solar Spread Sheet N8GS
Salvo
Explorer
May 07, 2013
I would be really helpful to know your fridge 24 hour power demand. You mentioned 20A when on, but what is the duty cycle?

As already suggested, you need a kill-a-watt meter to get a good estimate on your fridge power.

kill-a-watt meter

Sal
HiTech
Explorer
May 07, 2013
The partial shade means you need max watts you can fit on the roof and it still may not be enough. 10000 feet means the sun is stronger which helps a bit.

Jim
howardwheeler
Explorer
May 07, 2013
You're right about trees. Our favorite spot has trees all around but the roof does get probably three to four hours of midday high country sun. We are up about 10000 feet. We also need our furnace a little at night.
time2roll
Nomad
May 07, 2013
National forest says "deep in the shade trees" to me. May not be practical unless you are in a sunny site. Although with a large system even two hours of sun can make significant power.
howardwheeler
Explorer
May 07, 2013
Sorry. While I was responding a couple of other posts came through. We like to camp in Colorado high country. I have a Linklite battery monitor that says I draw around 21 amps while the frig is running and a few lights on. Does that help?
howardwheeler
Explorer
May 07, 2013
Seems if I need to, I could use the existing 10 gauge wires to pull a larger wire through the ceiling cavities if I need to but don't really know where it runs. The reply before last indicates I might want 500 plus watts. I have a lot of clear roof space on my Alpenlite. If I do it I'd like to have sufficient power to run the frig and normal florescent bulbs ( we don't watch TV either) for a week or so not hooked up. We like national forests. Is this possible or am I caught up in an impractical idea?