More batteries rather than more solar panels?

[CountryFit]

i remember reed's son built the system with higher voltage lfp batteries, 48 or 96v, that makes a big difference.

[Blackhat6mike]

Originally Posted by CountryFit

let's see how many batteries do you have...

a typical 13000 btu ac will draw 12 amps running on 120 vac. that is 2160 - 2400 watts starting, and 1440 watts running. assuming no more than 85% efficiency (have to consider inverter loss and msw incompatibility), so you would be drawing about 1700 watts whenever the ac is on, or 142 amps at nominal 12 volts!! assume no more than 50% state of draw-down on your batteries, you said you use it several hours per day, let's take 5 hours for a simplicity, it would require 1440 amp hours of battery capacity. that' about 7 typical rated 8d batteries. wow, you have a BIG system!!

I never assume anything, I check it directly at the power panel and transfer switch with a Fluke. I don't know where the "85% efficiency" came from, but the actual draw on the AC is 1320. My industrial grade 5,000watt inverter is rated at 95% efficiency, but that is never carved in stone. Also, I don't assume that the 600 watt panels through 60amp controller is sitting around doing nothing while I run my AC. Living in SE Georgia affords me a lot of overhead direct sun and during the summer months, long [12 hrs] of total sunlight.
I don't have a "magic system", just one that I went to great expense and planning to keep the efficiency high, IE 4/0 cables with the longest one being 2 ft. and a MPPT controller.
My bat bank is 500 amp hr and I have run the AC for three hours without depleting it to a dangerous level. These are actual reading and not assumed calculations. Theory and application don't always agree.
I'm a retired pilot and if I used the listed maximum limitations on takeoff weight, I would have never left the ground many, many times.
Also, those figures "assume" the AC compressor is engaged constantly and not cycling on and off. Unless you have set the temp very, very low or have terrible insulation, the AC compressor will not be drawing max amps 100% if the time. Mine stays off longer than it stays on.

[Reed Cundiff]

The system son put together is 90V from panels: two sets of three 235 W panels of approximately 30V each in series. The battery bank is 4 x 12V nominal batteries (each battery is 4 x CALB cells of 3 V nominal or 3.4 V actual at charge) in series for a 48V nominal system (54.6 V actual approximately at full charge). On vacation for 12 weeks in South America at present and do not have actual figures at hand. Return tomorrow night to US. Head out in rig on Thursday. Will be spending time with kids for two months and then probably NE Canada. O alas, had to leave pickup at dealer when we left for new cylinder heads. It is ready now. That required a bit of change

[Reed Cundiff]

If you want an autonomous RV lifestyle, then more solar and more/better batteries. Tesla batteries will probably be the answer

[Blackhat6mike]

Originally Posted by Tony Lee

Yes, the devil is in the detail, except of course for those owners who managed to find one of those magic solar systems that always have the batteries up to full charge by morning coffee time. They had sold out when I asked about them.

One minor - well, not so minor - point about running AC from the batteries (as I have done a few times) is that if the ac is on, it is probably because the sun is shining so the solar panels will likely be delivering full output so this will be supplying say 30% of the power and that will reduce the level of discharge of the batteries somewhat.

The other thing I have been looking for for a long time is an airconditioner that will cool the next room just by having the door open between the rooms. They were sold out too.

We use the larger AC in the main area during the day, which is duct through the ceiling throughout the Flyer. We have the option to open or close vents depending on which rooms we want to cool.
We use the BR AC at night with the door closed. If we want to cool the entire unit at night, we just use the main unit and leave the BR door open.
The Aviator has as much as 5 inches of block [not blown fiberglass] styrofoam in the walls and ceiling. Much more than any of the 4 units I've owned before. As I said before, the entire TT can be cooled just by leaving the BR door open. OBTW, yesterday was over 13 hrs of sunlight.

[Imurphy907]

I want a coach with walls that thick. Holy crud. Mine are like 1.5"

[Reed Cundiff]

Spending the Mothers' Day Weekend with friends and family at Elephant Butte Reservoir (near Truth or Consequences, NM). No clouds whatsoever and have been running fridge on AC. Even so, we were at float by mid-day and wanted to see how much we could "harvest", so turned the water heater to electric and the solar kept the batteries close to full charge while pulling in 1300 W. The end of day tally was 7800 W-hrs on the TriStar remote meter.
Reed and Elaine

[Imurphy907]

960 watts 13.5c X 5.5hrs 391AH