So I need to move my solar panels around to add a Fantastic Vent over the bed. I always figured I'd add one more panel so I could have 450 watts of Solar. The reason I'd like to add one more panel is..........Just because that's how I roll. If two works fine then three should be even better. Also because I've been kicking the idea about have the RV-Armor Roof Treatment done if/when I moved things around on the roof. So if I move things around I would like to get it all done so I do the RV-Armor Roof install once with the new lay out. So let's say I do this and I have 450w of Solar going through a 30a Samlex controller. I currently have two Interstate 6v in series. Would the 450w be enough to charge four 6v batteries? We boondock for a week or so at a time and like to be able to live off the sun. We don't use any 110v appliances at all. No TV. The 12v system is pretty much used for lights and the Fantastic Vent/s, and two C-Pap machines . We do use the Forced Air Heater off 12v's when it's cold, and by cold I mean when i't like less than 30 degrees. Historically we've had no issues keeping the trailer warm at night and letting the Solar bring things back up during the day. Thoughts?

Vintage465 wrote:So let's say I do this and I have 450w of Solar going through a 30a Samlex controller. I presume those are 12V panels. Don't know anything about Samlex controllers, but as long as total Isc of the panels is less than 27A, you should be fine. Vintage465 wrote:I currently have two Interstate 6v in series. Would the 450w be enough to charge four 6v batteries? It's not just about how many batteries you have. Depends on how much energy you use, especially after sunset. With your energy use - no 110V appliances, furnace being the biggest 12V item - I would say yes. You'll probably go down to 80% by the morning and back to 95-97% by sunset most of the time.Don't know how you can sleep with furnace cycling. I am running Olympian cat heater in chilly winter evenings and mornings in Central Baja, sometimes leave it on the Low through the night - but rarely, since it's never below 40 and that little heater can be too much. Recently bought a heavy over-stuffed synthetic fill duvet, it keeps body temperature in a comfort zone better than a heater. They call it "down alternative", but it doesn't have the same soft cuddly feel as a real down duvet.

Almot wrote:Don't know how you can sleep with furnace cycling.Not sure what you mean. I can barely hear mine.

2oldman wrote: I can barely hear mine.Must be a big rig, furnace far away from the bedroom.

You should be good to go with 450 watts of solar charging approx 450 AH of battery.The general rule of thumb with flooded lead acid batteries is 1 watt of solar per amp hour of battery.

If you plan on FlexArmor....we had ours done this past summer in Mesa,Az. (contact Michael with APR-RV). He re-installed my six(6) panels with my design (I supplied the materials, already cut to size), and did very nice work. My set-up is designed so as, the panels can be angled as to your location and season, for maximum efficiency. Right here in the DIY forum... I have pictures and details on the solar panel brackets mounted to roof. We’re running (6) six 12 volt batteries, if you boondock and can add additional batteries...”the more, the merrier”! We boondock for two to three weeks at a time, in temperatures often near to below zero. With the short days and long cold nights, we have to supplement our panels with a little 2000 Honda almost daily (for a few hours). Especially if the days are overcast... but we do use the satellite system/tv 2 to 4 hours per day/night.

Might add a third panel | Good Sam Community

Lwiddis
Explorer II
Dec 26, 2017
Do you need more amps during bulk charging? If no....doesn’t your current setup supply the max the batteries will accept during the absorption phase?
memtb
Explorer
Dec 26, 2017
If you plan on FlexArmor....we had ours done this past summer in Mesa,Az. (contact Michael with APR-RV). He re-installed my six(6) panels with my design (I supplied the materials, already cut to size), and did very nice work. My set-up is designed so as, the panels can be angled as to your location and season, for maximum efficiency. Right here in the DIY forum... I have pictures and details on the solar panel brackets mounted to roof. We’re running (6) six 12 volt batteries, if you boondock and can add additional batteries...”the more, the merrier”!

We boondock for two to three weeks at a time, in temperatures often near to below zero. With the short days and long cold nights, we have to supplement our panels with a little 2000 Honda almost daily (for a few hours). Especially if the days are overcast... but we do use the satellite system/tv 2 to 4 hours per day/night.
Boon_Docker
Explorer III
Dec 26, 2017
You should be good to go with 450 watts of solar charging approx 450 AH of battery.

The general rule of thumb with flooded lead acid batteries is 1 watt of solar per amp hour of battery.
Almot
Explorer III
Dec 26, 2017
2oldman wrote:
I can barely hear mine.

Must be a big rig, furnace far away from the bedroom.
2oldman
Explorer II
Dec 26, 2017
Almot wrote:
Don't know how you can sleep with furnace cycling.
Not sure what you mean. I can barely hear mine.
Almot
Explorer III
Dec 26, 2017
Vintage465 wrote:
So let's say I do this and I have 450w of Solar going through a 30a Samlex controller.

I presume those are 12V panels. Don't know anything about Samlex controllers, but as long as total Isc of the panels is less than 27A, you should be fine.
Vintage465 wrote:

I currently have two Interstate 6v in series. Would the 450w be enough to charge four 6v batteries?

It's not just about how many batteries you have. Depends on how much energy you use, especially after sunset. With your energy use - no 110V appliances, furnace being the biggest 12V item - I would say yes. You'll probably go down to 80% by the morning and back to 95-97% by sunset most of the time.

Don't know how you can sleep with furnace cycling. I am running Olympian cat heater in chilly winter evenings and mornings in Central Baja, sometimes leave it on the Low through the night - but rarely, since it's never below 40 and that little heater can be too much. Recently bought a heavy over-stuffed synthetic fill duvet, it keeps body temperature in a comfort zone better than a heater. They call it "down alternative", but it doesn't have the same soft cuddly feel as a real down duvet.

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