Powering AC unit built into travel trailer with solar?

48 volt dc air conditioners do exist. They are not cheap.

I've been able to run roof air since 2009.

I wish I had redone the solar instead of caving into running a generator. In the long run, it would have been cheaper.

Where are you going to find a mini-split that only draws 4 amps? I installed the smallest one I could find (12,000 BTU) in my cabin and it draws about 6.5 amps at 120 volts.
Even if you're unit draws 4 amps that's basically 500 watts. Overnight would be about 12 hours so you need 6,000 watt hours of storage. Using something like a Simpliphi PHI-3.8 you would still need 2 of them to just barely have enough. That's around $6,000 for the batteries. An inverter will cost you another $1,000 to $2,000. Then you need cables, lugs, etc. I'd say figure $8,000 minimum for just the inverter and batteries. If you can get 1,000 watts of solar panels on the roof that would be quite helpful. That's about another $1,000 for the panels, brackets, and wire. A charge controller will be another $500 to $1000.
I, like most people, would love to have this in an RV but the space it takes up, the weight it adds, and the money it costs are all prohibitive for most people. You can find a few Rvers on Youtube and where ever that have installed systems like this.

Lwiddis wrote:
Seems like an awful lot of trouble, spoon, to avoid getting an adequate solar system which is essentially an “install and forget” project. And who wants to move every day? For A/C? Not me.

I'm beginning to think about my cross country trip with the family when I retire in 4 years. When I was 12, my family did a cross country trip. I remember times where we stayed in dry campgrounds for a night, just while on the move. I'm thinking that having a charged battery bank that could power an AC for a night would make that MUCH more bearable!

I am almost 100% certain that I will be installing a mini-split heatpump on my next camper. I am not at all pleased with the noise, inefficient cooling and electric load of 2 15K roof mounted AC units. It seems that a minisplit could more quietly and efficiently cool my camper, with significantly less strain on my electrical system. Even in a campground, I'd rather pull 4 amps with a minisplit than 30-40 amps with 2 roof mounted AC units.

Also, we would like to do some legit dispersed camping in BLM type lands out west. If I had sufficient batteries (and charging was a relatively quick endeavour), we could use the battery bank overnight, spend the day out exploring, come back to camp for dinner, fire up the generator for 2 hours and recharge the battery bank, turn off the generator overnight and rely on the battery bank again for overnight AC.

Again, not at all sure if this is something that is doable. I'm educating myself on solar, but it seems that it would be in the several thousand dollar range for a solar setup. There are certainly benefits to a solar setup, but I wonder if it makes financial sense for people that don't fulltime, or only fulltime at full hookup locations.

Perhaps an efficient mini-split and a small quiet invertor generator are the best option, but then it limits me to staying at places that either provide power or will allow overnight generator use. I'm hopeful that we can not have a strict itinerary when we take this trip, maybe plan out some longer stops, but then take some stuff day by day. If we get somewhere and like the local sites, have the ability to be self contained for a couple days and stay, or else find a new place to go while we meander towards the pre-planned stop.

I'm also curious about a Harvest Hosts or Boondockers Welcome subscription during our trip, as that would give me more options for more creative camping, outside of traditional campgrounds.

I like the idea of a charged battery bank that can get us through a night if we are someplace that we can't get electrical hookups or run the generator though. It might be camping... but I don't want to be roughing it!!!

I think cheap is relative term when it comes to A/C capable solar.
I have a built in Onan 5500 lp genset. I also have 80#'s of lp on board. Push a button and I can have A/C anytime anywhere! No set up, no genset to haul no gas cans. That genset was a 7K factory option.
You could save a few grand with a after market DIY install. But still you will pay 5-6 grand for push button power for A/C anytime anywhere.
With that in mind $7K is not an unreasonable figure a solar package that can provide push button A/C anytime anywhere. Solar will also give you the ability to escape genset rules.
You can have A/C in places where gensets are not allowed.
You can book non electric sites or boondock with ease.
If I were to do it again I would stronly consider a large A/C capable solar package vs. a large built in genset.

Every inch of your roof will need a solar panel. And a 4kW inverter as well as at least 4 if not 6 LifePo batteries. It can be done and is very possible, but it won’t be cheap.

One of the biggest disadvantages of using roof-mounted solar panels for AC is that it forces you to park the RV in a spot that exposes it to full sunlight for most of the day.

So, you end up trying to cool an RV that wouldn't have been as hot in the first place, if you had parked it in shade.

And many campsites don't even have full sunlight exposure all day.

Very few of the folks capable of running their A/C with solar have enough capacity to run it for more than a few hours per day - which means that they either have to do without A/C for the rest of the day and night, or resort to running a generator.

Is running a generator 18 hours a day (with solar) really that much of an improvement over running it 24 hours a day (without solar)?

Solar panels run nothing ! Solar panels will charge your batteries . To run a rooftop air would take many , many batteries and a way to charge them . Solar panels would do that IF you cover your whole roof with them and spend several thousand dollars on batteries , maybe ! You need to spend some time studying this before committing ! Six to ten thousand dollars should cover it !

Certainly it's possible and expensive. If I were going that route I'd use a 48V system composed of 48V solar controller (output), 48V charger/inverter, 48V lithium batteries and 48V to 12V DC to DC convertor for the standard house loads, ie eliminate the 12V house battery. One forum member has that arrangement and he uses 3 2000W gens as needed.

I'd look into either a very large alternator and wire upgrade from the alternator to the TT battery bank, or a second 120V AC alternator if possible.

Todays common trucks likely don't have hood room for a much bigger or second alternator.

Seems like an awful lot of trouble, spoon, to avoid getting an adequate solar system which is essentially an “install and forget” project. And who wants to move every day? For A/C? Not me.

I'm no solar expert. But it is possible to run A/C off batteries.
The cost is still relatively high but it is doable.
It will require 4-6 Lipo batteries for starters.
You then need a means to recharge those batteries which means covering your entire roof with solar panels.
While in general price are dropping I priced a ac capable system at $6000.00 grand or so for a DIY install. Keep in mind a genset can be had for less than a grand! Also know a built in Onan 5550 genset is a 7000.00 factory option for units that have the built in option availabe.
As to just installing batteries with no solar panels it is certainly doable.
Only the end user can decide if it is practical. But if one night gets you through it maybe something to consider? Recharging batteries via genset instead of solar defeats the purpose of having expensive batteries if your going to run genset anyway. However if the no solar panel set up meets your needs it is doable.