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rachelsdad
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# Posted: 7 Apr 2025 04:42am - Edited by: rachelsdad
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My youngest brother bought a remote barn with no electricity and he wants to go solar. Mainly lights...probably 30-40 LED 100W equivalent and 5 AC/DC fans plus fridge. He's working out the math and has tons of room to do the panels on the ground.
Maybe it's just me but it seems 24v is the redheaded step child of the solar world...I went with it years back as I thought 12v was not as efficient.
Anyway, based on what's selling, it looks like 12v is still very popular but I'm suggesting he go 48v.
Yay, nay??
Also, just saw this little package.....
https://www.litime.com/products/48v-3500w-solar-converter-charger?currency=USD&varian t=45466233241820&utm_source=google&utm_medium=cpc&utm_campaign=Google%20Shopping&stkn =a05d7c18f02e&gad_source=1&gclid=EAIaIQobChMIjIntjcHFjAMVHjIIBR3U6i3NEAQYASABEgLS_vD_ BwE
What's everyone's thought on that?
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rachelsdad
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# Posted: 7 Apr 2025 04:59am
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Well Steve_S covered the 24/48 question back on November 4th!!
Tough search engine results...nothing popped up first time. Then of course after I post...up it comes.
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Brettny
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# Posted: 7 Apr 2025 06:15am
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I would be hesitant on an AIO system. They tend to have large standby draws. I also dont like that it dosnt list that spec.
But yes after owning a 12v system for 5yrs I would never built one again nor am I going to add to my 12v system in a way that wont work for a future 48v system I want to build.
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FishHog
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# Posted: 7 Apr 2025 07:05am
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For a small simple system, I love my 12v. See no need to make it more complicated and have wired all my lights, phone chargers, water pump, fridge direct for 12v. The only time I use my inverter is to charge my laptop (could actually get a 12v charger for it as well), and then for some odd power tools or cordless tool charging.
I just don't see that I would have any advantage to move away from 12v, but sure seems like people think higher voltage is better so maybe I'm just strange.
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Steve_S
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# Posted: 7 Apr 2025 07:11am
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Given all things going on now, I would apply KISS and go 48V as this is a fresh build.
The LiTime stuff is "okay" but that AIO is High Frequency and therefore not the best for anything with a motor, like compressor or tablesaw etc... The running draw overhead is always higher with an AIO and worse with the cheapies like LiTime and other discount tier-3 stuff.
The GOTCHA is thanks to the Orange Ogre, in the USA you now have a 54% Tariff on Chinese products. His latest 34% is on top of the existing 20% that was there... This is a FACT and not arguable. They are in effect and so anything coming over the border now gets hit... Maybe LiTime like many others stocked up in the US Warehouses. That will not last BTW.
My suggestion for this type of system is to go independent component. Solar Controller, Inverter/Charger that can take 120V or 240V Genset input to charge if needed (NOTE use Inverter Generator only).
Of the many types of Solar Panels out there, the QCell Panels (Monofacial) are the best combo for shade/cloud to bright sunny day production. The design allows for partial shade on a panel and still allowing it to generate unlike many others. I Highly recomend QCELL panels and they are quite a good $ value as well.
I will look in on this thread. FYI, I pulled back drastically from the DIYSolar gang as that sites "personality" has gotten darker and there are too many attack dawgs... I have no time from that sort of crap, there is enough "real shit" to deal with. IE: Today's Nikkei Market Opening is already another damned bloodbath.
NOTE on Buying stuff... There is little time to doddle if you want deals. Some retailers have already pumped product prices up by Tariff Values even on current stock to profiteer (already hitting news as building material co's and others are doing it). Do NOT underestimate the Greedy !
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paulz
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# Posted: 7 Apr 2025 09:35am
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Quoting: FishHog For a small simple system, I love my 12v. See no need to make it more complicated and have wired all my lights, phone chargers, water pump, fridge direct for 12v. The only time I use my inverter is to charge my laptop (could actually get a 12v charger for it as well), and then for some odd power tools or cordless tool charging. I just don't see that I would have any advantage to move away from 12v, but sure seems like people think higher voltage is better so maybe I'm just strange.
Same here. My solar charger, TV, fridge, water pump, modem, inverter are all old stuff, still going, so why mess with it unless needed.
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Grizzlyman
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# Posted: 7 Apr 2025 11:26am - Edited by: Grizzlyman
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I also like my simple 12v. BUT I run 15 ish leds.
With That many lights the amperage draw on wiring gets pretty high with 12v- which means either running really heavy gauge wiring or putting in many separate circuits. also if there are that many lights it’s probably a pretty good size place which means the runs from battery to bulb get pretty long, which again necessitates heavier wiring for 12v. LEDs are also temperamental meaning if they don’t have a minimum they won’t work.
Higher voltage has the advantage of lowering amperage- that would be the advantage of the 24 or 48 IMO
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Steve_S
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# Posted: 7 Apr 2025 11:48am
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There is a point that requires FIGURING which is not as clear as it may seem at first blush. I run 24V so I will use that as my baseline for this. Keep in mind that I am 100% offgrid (grid is over 1km away) so I use Solar & when needed Generator for top up.
If I am "running heavy" such as water pump+fridge+microwave I could be pulling up to 100A +/- a bit from my 24V battery Bank, so I'll work wth the 100A mark for simplicity.
With 24V that will be 100A, on 12V that would be 200A and with 48V that would now be 50A to deliver the exact same amount of VAC. Now this is what is being pulled from the actually Battery Bank ! In my case I have 6x280AH Packs in Parallel, so that 100A pulled is divided by the 6 packs, so it is 16.6A per pack which is NO stress on the packs obvious. Each can deliver 200A or burst to 500A, so 16A is nothing at all.
There is a bit of loss inverting but as I use Samlex which is 97% efficient, nothing to worry about but a 3rd Tier value product will often be 85-88% efficient so it adds up quickly. I use a Samlex EVO4024 Inverter/Charger (tier-1 & $$) which is Low Frequency & High Efficiency.
24VDC systems are indeed an Odd Duck in the pond but certainly not orphaned as some would think. 48V is the Mainstream for Energy Storage and therefore have the most choices & options for products across the board. Having ready access to a large number of products also adds to the "peace of mind" factor because in the Real World "shit happens"... ALL OF US HERE CAN ATTEST TOP THAT ! and there is always the Murphy's Laws Factor on top... gonna happen at the absolute worst time possible.
COSTS are the real bugger in the stew !
Now keep in mind, the addage that "you get what you pay for" is very true with Solar Gear/ That can be quality but also Features/Functions & Capabilities too ! There are some damned good Value 3rd & 2nd Tier products provided you do not expect a Rolls Royce for the price of a 1978 Chevette ! (eeks, cringe).
When your brother is working out what he thinks he will use "immediately" he also needs to think of what he is likely to add in the next 6,12,18 months too ! Then the Golden Rule is add 20-25% load ON TOP of calculations because "EVERYONE" under-estimates.
Now Take inverters delivering VAC: (gross numbers not accounting for efficiency losses)
1000W Inverter can output 120VAC/8.3A.
2000W - 120V/16.6 & 4000W - 120V/33.3A
Divide the Amps out by 1/2 for 240VAC.
Things like Compressors & Well Pumps can have huge surge demands on start, Fridges & Freezers less so but still quite significant and these buggers can add up to a lot of pull collectively.
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rachelsdad
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# Posted: 7 Apr 2025 03:34pm
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I will look in on this thread. FYI, I pulled back drastically from the DIYSolar gang as that sites "personality" has gotten darker and there are too many attack dawgs... I have no time from that sort of crap, there is enough "real shit" to deal with. IE: Today's Nikkei Market Opening is already another damned bloodbath.
Yup!
Thanks for the last post!! You're the best
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travellerw
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# Posted: 7 Apr 2025 04:57pm
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I vote 48V for various reasons.
Cables are smaller and cheaper.. and lets just say its pretty nice to be able to run a welder off a solar system.
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gcrank1
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# Posted: 7 Apr 2025 09:23pm - Edited by: gcrank1
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My 'legacy' 12v system is adequate for our modest totally off-grid part time cabin. Enough led lights, usb powered stuff and a 300W pure sine wave inverter for our bigger (lol) loads. I have 1K psw inverter in reserve that we have not needed thus far.
For the real heavy stuff, which is all short term use, we run the gen. It has not been a hardship but is certainly not just easy turn-key like a grid house is.
If we were full time Id have wanted a min of 24v (as of 5yrs ago but if younger and starting fresh, especially for a larger structure full time 48v would probably be the way to go. It is pricey but so is running grid in then at the mercy of the monthly billing at whatever rate.
Or maybe buy an EV and plug it in when there to run it all?
For a 'remote barn' I suggest you wire it code compliant for grid power so there wont ever be a question about the wiring being sufficient.
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paulz
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# Posted: 8 Apr 2025 09:10am
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Quoting: gcrank1 For the real heavy stuff, which is all short term use, we run the gen.
Me too. I plan to drill 3/4 inch holes through a bunch of railroad ties today to knock stakes through. The battery bank and inverter might handle a few but the genny is right there in extension cord distance. Plus it’s also plugged into the bank chargers so it will top up while I’m at it.
Also use it to run the dryer which I rarely do but did in the rain last week. The bank will run the washer no problem but the dryer wants more amps.
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MtnDon
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# Posted: 8 Apr 2025 05:43pm - Edited by: MtnDon
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FWIW, I believe that if at all possible it is better to NOT build a new system with connecting LFP batteries in series. It is better, if possible, to use 48 volt batteries if you want a 48 volt system. Use 24 volt batteries if you want a 24 volt system.
Or use individual large cells with a separate BMS for them.
So, as always, determine what storage capacity is required before deciding on anything.
Also FWIW, I am very happy with my 24 volt off grid system that I designed in 2008. Back then 48 volts was really odd and 24 volts was out of the ordinary. It has changed from lead-acid to LFP. Our actual kWh use has fallen as lighting changed from CFL to better and better LED. I have the same old Outback inverter charger but a newer charge controller as the old one was not designed for LFPbztteries.
IF I was designing a new system today I might stick with 24 volts but would consider 48 volts as the cost would not differ all that much and could be more versatile if circumstances changed to want or need more power.
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redwolfguild
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# Posted: 8 Apr 2025 05:49pm
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When I hear barn, I hear lots of equipment and power needed. I think all the points have been made, but keep it simple. If you have constant high loads, 48v, if it is low loads with occasional high loads, 12 volt, and a generator will work just fine.
When shopping, think about expansion, I have both 12v and 48 now, and spent 3x as much getting here as it would have to have just bought 48v when I started.
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Steve_S
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# Posted: 9 Apr 2025 10:40am
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SADLY: As of Today the US has 104% Tariff on everything from China. A huge amount of Solar Goodies from panels to batteries and all things in between will go up. That also includes European Stuff that has Chinese Components too (but lesser rates).
Worst part, there is little true "Domestic" materials for the Solar Sector made in USA (especially without international content) and that also hits the DIY crowd BIG TIME.
China will NOT back down and can certainly weather this Tariff War as their trade with the USA is only 2.1% of their GDP (unlike what some US Left Wing media tries to lie about making it sound like it is more). Globally, Europe, Japan etc do use the REAL Numbers which is proven to be that 2.1%, only USA makes up funky numbers.
IF you can get product from say EG4 right now in USA from USA Stock that has not yet been Tariffed, it would be prudent as next stuff landing at port will be Smacked & hard !
Link to EG4 products at Signature Solar
https://signaturesolar.com/eg4/
NOTE: This is NOT a recommendation or anything, only showing as they are a main dealer for that product line, there are others with stock in USA. !! Soem have already started raising prices preemptively... (aka profiteering while they can).
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Brettny
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# Posted: 9 Apr 2025 10:49am
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For decades we have been drunk on cheap chinese goods..now it's time for the hangover.
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