Ran roof air all day on only solar, batteries still full

[Boatycall]

It's been a long journey, but I'm finally there.

So--the back-story, I have a 2-slide Eagle Cap 1160, when I got it 6mos used, the previous owner ordered it stripped - no AC, gen, not even tvs. I put a 13,5kbtu AC in because my previous Arctic Fox had a 11k and I had days where it didn't cut the mustard.
I put in (6) 145ah AGM batteries and a Magnum Technologies 3KW Hybrid Inverter, and a Honda 2000.
First attempts to run the roof air on the Honda were hit n miss, mostly miss, even using the hybrid function of the inverter.
Then I put 600w of solar on my trailer(The Shotwagon) with (6) of it's own 145ah batteries and ran 4ga to the hitch an Anderson disconnects to the TC.
That worked 'ok'. But at the end of a hot day, I killed about a half of my battery capacity, voltage would be down to 12.1-ish from 13.7 float.
Then I put 800w solar on my TC and tied the two systems via the same 4ga Anderson connectors and just last week installed a Micro-Air soft start.
Yesterday we had a record hot day for May, I hit 87 here. Ran the roof air all day, I ended the day with the batteries still @100% charge. The solar was putting in roughly 80amps charge even though the roof air drew 110amps@12v from the inverter. In between roof air cycles, the solar of course kept charging and kept the batts at 100% I ended up with both solar controllers in Float mode, 13.7v.

Attached a pic of my system design.

[Kayteg1]

"if you have to ask >>> you can't afford it"

[notsobigjoe]

So how much money did all this cost?

[Kayteg1]

I remember couple decades ago to get the battery capacity you'd have to carry about 2 tons of led.
Give or take.
I had 700 lb of batteries in my bus conversion and that would give me about 20 minutes of AC.

[valhalla360]

jimh425 wrote:

valhalla360 wrote:
Yes, you can run air/con off a solar/battery system...just not practical.

Leading edge technology and larger newer TCs aren’t ever practical. That doesn’t stop us though!

Nothing cutting edge about the setup...could have done the same thing a decade or two ago.

[Camper_Jeff___K]

The greater usable current from Lithium batteries is a game changer to run AC. Several RVers doing it with 1200 or so watts on the roof.
I use my TC AC two ways. In the driveway on those really hot days using shore power or camped somewhere using shore power. The third way is altitude, up in the mountains, preferably by a lake or river. Also have two Fantastic Vents that can whip up a good wind inside the TC and not use a heck of a lot of power.
None the less, Impressive...

[Kayteg1]

Now I really would like to hear the story about free batteries. 😉
Batteries went long way in just last years.
I still remember my first laptop, not much more than 10 years ago, where new battery would power for 1 hr and with 12 months warranty, it promptly died on month 14.
Now in 4 yo laptop with 17" screen the battery still powers long movies with power to spare, or 3 hr of forum chatting.

[work2much]

We use electric mattress pad to stay toasty when it gets cold while sleeping. Only uses about 60AH overnight. We set the thermostat low but keeps the camper manageable for the dogs and midnight bathroom breaks. We also have a small 750/1500 ceramic heater with t-stat that we can use on low overnight if we have the battery reserve and good weather the following day, or we can use the electric heater with the propane heater coming on periodically if it's very cold so the electric doesn't run 100%

[time2roll]

Kayteg1 wrote:

time2roll wrote:
.. Run a generator 24/7? No thanks.

So next question would be how much heat you can get from solar system?

Heat in the RV is easy when burning propane. Generator maybe runs near idle 2 hours a day instead of 80+ % throttle near continuous to run the air.

[Boatycall]

Kayteg1 wrote:
So next question would be how much heat you can get from solar system?

I have a 110v in-wall house heater I mounted in with a digital thermostat. I went with a Braun 110v heater because the heating element can be split with a switch, 750w and 1500w. I rarely have had to set it to 1500 watts, 750 has been sufficient down to upper 30's.
.
So-- "could" I run it off battery at night, and solar charge back up during the day, ya, I suppose I could, but I haven't tried. It'd be tough - I'd kill most of my battery potential, and it'd have to be pretty darn sunny out to make up for it the next day. It was slightly overcast when I ran the roof air Saturday, enough to knock my output down by about a third. I was getting 45-ish amps out of the TC, 30ish amps out of the Shotwagon. In 'ideal' conditions I've max'd out both solar controllers, 60a and 45a respectively, but that's pretty rare to get max power.
.
The two biggest reason I went through all this--one, I got all the batteries for free. Long story... But two, I absolutely hate generator noise when I'm camping. And even though my Honda 2000 can now run the roof air with the Soft Start installed, I hate the noise and dislike the hassle--unpacking it, gassing it, bringing extra gas, securing it, packing it back up... And didn't want to chance leaving my dog in the TC when I'm not close to camp and the gen running out of gas and/or dying. As long as I got good sun, I have a roof air. If there's no sun, I likely don't need the roof air.

[Kayteg1]

time2roll wrote:
.. Run a generator 24/7? No thanks.

It all depends what you do.
In the years when I was spending days water-skiing, regardless small wet-suit, I was appreciating hot weather. When temperatures dropped at 90F in the afternoon, and California nights are always cold even in August, I was sitting close to campfire at the end of the day.
But then on day when you don't sit in the water, you need to run AC and in South temperatures don't drop much at night, so 24/7 AC is a standard even in September.
Still remember vacations in Victoria BC.
Beautiful waterfronts, but everybody sits behind the glass. Not too many will last in the open and they need heaters in the middle of the summer.
So next question would be how much heat you can get from solar system?

[work2much]

We run our a/c when it's hot. How long depends on how warm it is, how much sun the panels get etc. Our panels make about 70AH in good sun and the A/C uses about 100 with the compressor running and 30 with just the fan motor blowing. Mid 80's and sunny it will run all day with good reserve cycling the compressor. 90's with the compressor on 100% still all/most day but low battery heading into the night.

We don't run it that often. When it gets that warm it's time to head into the mountains. These rv roof units are not the pinnacle of efficiency, nor are campers well insulated to begin with.

[towpro]

Boatycall wrote:

dwrat wrote:
With an outside high of only 87 degrees, I would guess you mostly only ran the fan and very little compressor usage.
Still pretty amazing use of solar.

Ha!
You're in Phoenix, I'm near Seattle.... 'Only 87' is warm for us... I lived in Phoenix for a couple of years straight--though summers, didn't 'snow-bird' it, I get it when you say 'only 87'...
.
I'm hoping I can maintain battery voltage past 90. The roof air is oversized for a TC, I had the stat set to 70, so it was only at about a 50/50 duty cycle during the hottest part of the day.

and phoenix, with its average humidity 37. I don't think I have even see a low of 37 in dead of winter.

[noteven]

delete

[PNW_Steve]

Another option would be a more efficient form of air conditioning.

I will be installing 19 SEER mini splits on my rig. They are "soft start" and consume significantly less power than a typical roof air.

[RoyB]

I just want to add a couple of panels to my roof area to trickle charge batteries during the high sun time... Where we camp is not all that extreme both cold and hot camping...

Something like this...


google image

My new TORKLIFT battery box has a small 10-watt solar panel one end and I am installing a second one for the other end for my two GC2 6V golf cart batteries groups... MY four Duracell 6V batteries are rated at 215AHs... This gives me 430Ahs to play with from 6PM to 11PM and then keep alive until 8AM the morning... Keeps us all lit up when we want it and do our home entertainment things and play with my Ham radio things... This even includes the wife sitting around with a 12V lap blanket when it gets cool...


Google image

We can really cool down at nights with our roof mounted fantastic fan pulling in cool night air through the windows where we like to camp off-grid...

I also have car radiator thing with a fan behind it with two long water hoses and can pump cold creek water thru it for cool air as well...

I am seriously thinking about removing my roof mounted air conditioner and having more room for additional solar panels installed... I can't remember the last time it has been used...

I still expect to run my 2KW Generator each morning starting at 8AM when allowed to get my batteries back up to their 90% charge state so we can do this all over again the next day/night run off my batteries...

When I am running my generator I can make my Cuisinart grind and brew coffee for the day and store it its thermos carafe... This only takes five minutes of the generator run time...

It is definitely in all the planning... Just can't show up somewhere and expect the best haha...

All of this lets us wake up in the mornings to good coffee and watching the fish jump in the creek haha...

Roy Ken