I am always amazed at the SUCCESS stories about using solar panels...
I guess the way to success is to never get behind the charge curve on your battery bank. The solar panels then become a top-off source of charge energy for the battery bank when in high sun.
My daily schedule routine with all the 120VAC items using an Inverter and 12VDC items direct connected seems to draw around 22 AMPS (appx 300WATS) on my battery monitor meter 300WATTS between the 6PM and 11PM . This includes my parasitic drains. This equates to about 134AHs of battery drain over the one day/night run off the battery bank. This will drain down my 255AHs to its 50% charge state by 8AM the next morning. My trailer is equipped with LED lights and has smart mode charging capability for the batteries.
In my case having a single 120WATT Solar Panel or even two 120WATTS Solar Panels would get behind the battery charge curve real quick.
The 120WATT Panels will only provide 14.4VDC @ around 5AMPS each of DC Current in the high sun. The average time of high sun is around 6 hours and will only give you around 30Ahs of usable charge current per panel. Adding two of these bumps that up to 60AHs... Three panels makes it to around 90AHs. I am still behind the battery charge curve of not being able to put back into my batteries verses what I am taking out if I am using 132AHs a day.
When I get behind the charge curve I have to use my 2kW Generator to do the initial start-up BOOST Charging for around one hour using smart mode charging from my on-board converter/charger being run by my 2KW Generator. My 255AH battery banks initially jumps to around 52-53 AMPS Current demand from my converter/charger and this will slowly drop back to around 8amps of DC Current in about an hour run time as the battery banks starts taking on charge.
Once it gets past the high current demand then I can really use the solar panels to continue the battery bank re-charge to get to the 90% charge state or higher while still in high sun.
It all depends on how one likes to camp off the power grid and use the appliances and lights etc that they want to use. I must start out each day/night run with a good 90% charge state on my battery bank otherwise it goes dark on me around 10-11PM at night.
If I was just running LED lights and a occasional short term higher current draw then YES I can see where I would not get behind the battery charge curve and not have to re-charge in a few days... This just doesn't happen for us the way we camp with all of our toys... Ham Radio guys have to yak on the Radios too as well...
We basically look just like we do at a regular camp ground electric site with the exception of using the air conditioner and high wattage microwave. Just about everything else is up and running... When it gets cold at night this is an another story if the furnace has to run...
We have been very successful camping off the power grid with our 255AH battery bank and recharging each morning using our 2KW generator starting at 8AM when allowed to run it. Just now starting to think about adding solar panels to my POPUP trailer only to supplement the generator run times and hopefully reduce the amount of time I have to run my generator.
just my thoughts based on how we camp off the power grid and using solar panels to supplement the generator run times...
Roy Ken
My Posts are IMHO based on my experiences - Words in CAPS does not mean I am shouting
Roy - Carolyn
RETIRED DOAF/DON/DOD/CONTR RADIO TECH (42yrs)
K9PHT (Since 1957) 146.52M
2010 F150, 5.4,3:73 Gears,SCab
2008 Starcraft 14RT EU2000i GEN
2005 Flagstaff 8528RESS