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Trying to decide on 12v now and 48v later or 48v now.

Birdman3131

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Ok so I have a house I am working on. Looking to get 1 room going with AC for now. The issue is I eventually wanna go for a 48V system but don't want to throw much money away now.

What I currently have.
Xantrex ProWatt 600 inverter. Surges to 1200W
5k btu window AC. 450W running
10 530W BYD bifacial panels. (currently just in a pile.) Voc 49.12 ~13A ea
(Not really relevant but I also have a Riden 6018 setup for charging batteries as well if I need to take them to my main house with electricity.)
What I need to get is batteries and a charge controller. My issue is if I go for a 48V all in one now I can't afford one of the good ones so I am looking at a small say 3kw one that I end up replacing later anyways because its likely better to just have 1 18kw than 6 3kw units.


I don't really have any batteries. I was thinking about 4 of these (100Ah 12.8V lifepo4 for $165 ea) so I could parallel them now and series them later. (Yes I am aware of the amount of power an AC uses. This would be enough.

Thoughts? Just trying to spend as little now as possible.
 
Wy pay for 2 times.
The inverter will only work on 12 volt not on 48 volt.
So you have to sel it later (you tell new inverter for the airco unit )

we have a saying
if you do something, do it right the first time.

But i do understand you .
If you are in a budget .

Personal i will save the money and save more to do so.
I have done this for my self to, for i have beult all the stuf in my boat .
I have cost me 2 years savings do so.
 
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If what you have works then use it!
When the time comes to upgrade then go 48v.
 
What are you trying to accomplish in the end? Full electric with heat pump, electric stove, microwave, electric hot water, MargaritaMaster-3000? Those are gonna want 240v power. You'll have to spend a fortune to get 500a of SCC to utilize all those panels, that's not realistic.

The problem with changing voltages is that so much of the expensive stuff is getting chucked. The 600w inverter you have now might run the little aircon and some lights, but it's not going to be able to do much of anything else. Unless you drop the big bucks, the charge controller isn't going to be savable either. The battery is going to cost you either way you go, but there are a few different ways to tackle this.

EG4 3Kw 48v is about $700, gets you 3Kw on a 48v bank, but you need space for 2 of them to get the 240v you'll want later.

EG4 6000XP is about $1500, gets you the 240v right out the gate, and takes up less space than a pair of the 3Kw's. It also includes the breakers and such which helps adjust the cost.

Eco-Worthy 50Ah 48v batteries have been getting really good reviews and are pretty cheap for a 48v battery.

Super tight budget, DIY yourself the battery and put those savings towards a 6000xp. A stack of 16 cells and a decent BMS will run you about $900 for a 100Ah battery, but saves you a few hundred bucks and you can get larger cells if you can afford them. The larger cells is where the real savings is, but it's a more substantial up-front which hurts.

If you want to go super cheap in the other direction, grab a MPP3024LVM or a Growatt 3000-TL for about $400, do a 24v system that will handle many things, and build the battery bank in pieces later. The cells are the expensive part, once you have those converting from a couple of 24v batteries to a 48v battery is a $100 BMS and a couple hours of wiring. A 24v system is not unreasonable for a tiny home or trailer, and 3Kw of 120v gets you a good ways towards comfort. A decent 60a SCC for your 12v will cost you easily $200 which is half the cost of the AIO with its 80a SCC, AC input, inverter, etc.
 
There is nothing wrong with starting with parallel 12 volt batteries now ( if they are good ones) and wiring them 48 volt later.

Just add a balancer when you get that far.

From a practical perspective, I doubt that your existing inverter can run the air conditioner due to motor starter current but the Xantrex units are pretty tough. Maybe find someone who has some batteries near you to try it out first ?
 
6000xp will work great for building as they handle surges and loads very well and can be paralleled later for full house loads.
 
48v now, as I am at 24v, my new place I could really use 48v, but not going to throw out or try and use what I have to go 48v, not optimal.
 
Go big or go home. I started with 12V jumped to 48V with 3K inverter. Wish I would have bought the 6K. Same money in the long run.
FYI 3K runs mini split and fridges just fine but nothing else so no complaints.

Except I WANT MORE, AND I WANT IT NOW!
 
So I never really understood the solar mini split over just going with an all in one and a normal mini split for the same price or slightly cheaper.

So I am probably going 48v. Between having my money situation change. (I was scrounging everything for a tax real estate auction that was today. Ended up getting nothing so going to pay off some credit cards and do some solar) and just not finding any 12v mppt that could handle much current it seems best.

So at this point gonna see what I can manage for 1200-1500 as far as batteries and inverter goes. Just gotta figure out how I am mounting my panels. (Got 10 530W bifacial BYD panels for $1200). Standard mounting does not seem a great option. Probably building some sort of carport style one.
 
So I never really understood the solar mini split over just going with an all in one and a normal mini split for the same price or slightly cheaper.

So I am probably going 48v. Between having my money situation change. (I was scrounging everything for a tax real estate auction that was today. Ended up getting nothing so going to pay off some credit cards and do some solar) and just not finding any 12v mppt that could handle much current it seems best.

So at this point gonna see what I can manage for 1200-1500 as far as batteries and inverter goes. Just gotta figure out how I am mounting my panels. (Got 10 530W bifacial BYD panels for $1200). Standard mounting does not seem a great option. Probably building some sort of carport style one.
Well… In Texas we have regular day long or multi-day outages and so a backup to grid is almost a necessity these days as the Texas grid is unreliable and at max cap in severe cold or heat. Houston at the moment with the Hurricane, there is a post with hundreds of comments and 17+ thousands of views, We had a Tornado here in Temple and power was out for 4 days. It was 95 and 90% humidity, so the only place we could cool down was our office space with… the solar mini-split as the house AC could not run on the generator due to amps required, and the soft starter failing. This is why you should have both. I plan to put a 24k in my living room space not on solar, but as I have 2 trackers, I can put them in parallel to run it if needed, so plan B for cool or heat. And also they are so efficient it will give me an 2 zone setup reducing my need of the whole house unit in the living/dining/kitchen space. Our pipes in Texas are/were never planned for hard freezes so bursts are common when the temp hits the teens, so warm home is needed.
 
So I never really understood the solar mini split over just going with an all in one and a normal mini split for the same price or slightly cheaper.

So I am probably going 48v. Between having my money situation change. (I was scrounging everything for a tax real estate auction that was today. Ended up getting nothing so going to pay off some credit cards and do some solar) and just not finding any 12v mppt that could handle much current it seems best.

So at this point gonna see what I can manage for 1200-1500 as far as batteries and inverter goes. Just gotta figure out how I am mounting my panels. (Got 10 530W bifacial BYD panels for $1200). Standard mounting does not seem a great option. Probably building some sort of carport style one.
Solar hybrid mini splits allow solar pannels to be plugged directly into the unit. No batteries or charge controller needed for when the sun is shining. It can also automatically switch to 120v power for night time use.
 
Solar hybrid mini splits allow solar pannels to be plugged directly into the unit. No batteries or charge controller needed for when the sun is shining. It can also automatically switch to 120v power for night time use.
What he said OR plugged into your Solar Generator for grid as I do.
 
I guess I could understand it if you're not running batteries at all, but outside of that an inverter and equivalently sized mini split seems cheaper and gives you an inverter on top of the mini split.

Just ordered a 3000EHV-48 from signature solar and four 100 amp hour 12v batteries from temu.

Now to figure out solar strings. I have 10 panels that run a 49.12 VOC. I'm thinking possibly putting them all in a series string. But that is right on the very edge of the 500 volt that that inverter will take.

The other issue is there is likely to be a fair amount of shade on and near the panels. Each panel has three bypass diodes so I'm thinking it will be okay.

The panels are 535w byd bifacials.
 

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