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

[Birdman3131]

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.

 

[Suijkerbuijk]

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.

 

[robby]

If what you have works then use it!
When the time comes to upgrade then go 48v.

 

[pollenface]

Pick the voltage that makes best use of the hardware you have and can currently afford.

I have both.

 

[Rednecktek]

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.