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diy solar

48V vs. 12V, DIY vs. OTS, Current Connected & More

Over9000

3rd Shift Ass. Manager @ 2nd-Hand Adult Toy Store
Joined
Nov 28, 2024
Messages
464
Location
Michigan
Hello Folks,

I'm looking for some feedback regarding if I should replace my existing 12V setup with another 12V setup (keeping my batteries) or starting fresh with 48V. The key concerns are budget and longevity.

Planned Equipment (regardless of voltage):
  • Solar Input = 500W, no room for additional
  • MPPT = Victron 150/35
  • Other = Victron Cerbo GX

Tentative 12V Setup: $1389, 5.76kWh
  • $0 (Sunk Cost) ==> (1) 12V 280Ah LFP EcoWorthy Battery (Not Self-Heating)
  • $800 = Victron Multiplus 2kVA 12V 120Vac Inverter
    • Plan would be to add (1) extra battery, preferably self-heating, and increase the storage capacity
    • $589 = SGP 200Ah Self-Heating (link) = Best deal I can find right now
    • or DIY ???
Tentative 48V Setup: $2124, 4.8kWh
  • $824 = Victron Multiplus 2kVA 48V 120Vac Inverter
  • (2) x $650 = Renogy 50Ah Self-Heating (link) ~= 4.8kWh
  • or DIY ???

Analysis:
  • Unless I'm missing something, the analysis shows I should go for the 12V setup.
    • I think this makes sense especially since it's such a small system
  • Otherwise, DIY Battery would make the most sense, but that's a lot to play with
  • ==> Does the forum agree?
Other Considerations:
  • I have a crapton of parts in my cart at Current Connected.
  • Does anyone have a coupon code? Free shipping? Anything?
I appreciate the help!
 
Hello Folks,

I'm looking for some feedback regarding if I should replace my existing 12V setup with another 12V setup (keeping my batteries) or starting fresh with 48V. The key concerns are budget and longevity.

Planned Equipment (regardless of voltage):
  • Solar Input = 500W, no room for additional
  • MPPT = Victron 150/35
  • Other = Victron Cerbo GX

Tentative 12V Setup: $1389, 5.76kWh
  • $0 (Sunk Cost) ==> (1) 12V 280Ah LFP EcoWorthy Battery (Not Self-Heating)
  • $800 = Victron Multiplus 2kVA 12V 120Vac Inverter
    • Plan would be to add (1) extra battery, preferably self-heating, and increase the storage capacity
    • $589 = SGP 200Ah Self-Heating (link) = Best deal I can find right now
    • or DIY ???
Tentative 48V Setup: $2124, 4.8kWh
  • $824 = Victron Multiplus 2kVA 48V 120Vac Inverter
  • (2) x $650 = Renogy 50Ah Self-Heating (link) ~= 4.8kWh
  • or DIY ???

Analysis:
  • Unless I'm missing something, the analysis shows I should go for the 12V setup.
    • I think this makes sense especially since it's such a small system
  • Otherwise, DIY Battery would make the most sense, but that's a lot to play with
  • ==> Does the forum agree?
Other Considerations:
  • I have a crapton of parts in my cart at Current Connected.
  • Does anyone have a coupon code? Free shipping? Anything?
I appreciate the help!
I thought you had a tp6048. That is 48v only.
 
500 watts / 12 volts = 41.6 amps
500 watts / 12.8 volts = 39 amps
With a 35 amp scc you could be loosing some energy
 
500 watts / 12 volts = 41.6 amps
500 watts / 12.8 volts = 39 amps
With a 35 amp scc you could be loosing some energy

500W is STC. In reality, each panel nets me 60W = 300 Total. 300/12 = 25A.
 
You definitely need the 150/35 the way your wired and it may be over the 150 volts on a cold day depending on how cold it gets there
Victron has a app for scc recommended setups you might want to check it out
Also you might want to check out Craig’s list or Facebook marketplace and see if you could fit a couple of 250 to 300 watt panels in place of the 100 watt panels that would drop the voltage and it sounds like your 100 watt panels are not producing like they should, correctly setup you should get 80% of rated watts and sometimes more
 
My suggestion to the typical mobile user is to go to 24 volt.

Use as much of what you have as possible.

There is a substantial improvement going from 12 - 24 and it is very easy.

The jump from 24 -- 48 volt is an improvement, but nothing like the first step.
 
My suggestion to the typical mobile user is to go to 24 volt.

Use as much of what you have as possible.

There is a substantial improvement going from 12 - 24 and it is very easy.

The jump from 24 -- 48 volt is an improvement, but nothing like the first step.
dollars to dollars if you are going to go above 12 voltsgo 48... Ignore 24 entirely unless you are in an overlander that is native 24 volts... any other scenario and you are tossing money down the drain.
 
You definitely need the 150/35 the way your wired and it may be over the 150 volts on a cold day depending on how cold it gets there
Victron has a app for scc recommended setups you might want to check it out
Also you might want to check out Craig’s list or Facebook marketplace and see if you could fit a couple of 250 to 300 watt panels in place of the 100 watt panels that would drop the voltage and it sounds like your 100 watt panels are not producing like they should, correctly setup you should get 80% of rated watts and sometimes more

1. I already posted the data from Victron's tool. They recommend the 150/35 even when considering low temperatures.
2. This is a very space constrained area. If I use a larger panel, I can't fit more than 1 and then won't reach the voltage threshold for the MPPT to begin working.

I'll go 12V.

Does anyone have a coupon code for Current Connected?
 
Make a free account and log in. There member pricing is good enough you don't need a coupon code. You could also pick up the phone and call them tomorrow.

I called them Friday and they said they didn't have any coupons or promos. I figured I'd ask if anyone had one that was a referral coupon or something. The member pricing is good though!
 
dollars to dollars if you are going to go above 12 voltsgo 48... Ignore 24 entirely unless you are in an overlander that is native 24 volts... any other scenario and you are tossing money down the drain.

I mostly work with mobile power systems vs stationary and have used many of the voltage options at one time or another, all the way up to 270 volt DC.

For stationary, in general I agree with you.

When it comes to mobile applications where the bulk of the loads are DC ( fridge, pump, lights, etc ), there are a lot of end use devices that can run native 24 volts right off the battery pack very efficiently.

There is a good chance that he already owns some breakers, fuse blocks, etc in that 12 volt system that can be reused in the 24 volt system.

Literally all of the components to build / support 12 or 24 volt can be purchased from any marine store or looking at the blue sea web site. Spare parts can be purchased anywhere in the world for 12 or 24 volt when on the road.

Almost nothing for a 48 volt system is available at the typical marine supply store.

Safety wise, for people who don't build many systems, 24 volt is a much safer setup than 48 volt.

A lot of the battery packs that people use for stationary applications are not really mobile rated.

Mobile rated items, and items rated for extended temperature use like in a van or similar are always more costly than otherwise, no matter the voltage.

That is my logic.
 
I mostly work with mobile power systems vs stationary and have used many of the voltage options at one time or another, all the way up to 270 volt DC.

For stationary, in general I agree with you.

When it comes to mobile applications where the bulk of the loads are DC ( fridge, pump, lights, etc ), there are a lot of end use devices that can run native 24 volts right off the battery pack very efficiently.

There is a good chance that he already owns some breakers, fuse blocks, etc in that 12 volt system that can be reused in the 24 volt system.

Literally all of the components to build / support 12 or 24 volt can be purchased from any marine store or looking at the blue sea web site. Spare parts can be purchased anywhere in the world for 12 or 24 volt when on the road.

Almost nothing for a 48 volt system is available at the typical marine supply store.

Safety wise, for people who don't build many systems, 24 volt is a much safer setup than 48 volt.

A lot of the battery packs that people use for stationary applications are not really mobile rated.

Mobile rated items, and items rated for extended temperature use like in a van or similar are always more costly than otherwise, no matter the voltage.

That is my logic.
yes that why I said unless it is a native 24 volts... then it makes sense. think diesel truck or bus or boat with 24 volt systems.
 
Had those on ebay with coupon for under $360. I bought 2 of them.

they had the same battery "ebay refurbished" for $300. I bought 2 of those. they looked like brand new batteries.
I actually asked them once if refurbished meant anything and if they fixed stuff and they said no, basically returned/open box only. what was slick about "ebay certified refurbished" was that ebay gives you a free 2 year allstate extended warranty, I feel like if there was a massive failure that would cover you more than any ebay seller a year or so into the future...
 
IF there’s a cheaper, simpler, or better way to do it I haven’t figured it out yet…. The wiring was the biggest hassle making 12v to 24…..but overall, I’m really happy with how it turned out. So far they are staying balanced with no balancer. I still might add one but I’m hesitant to increase the complexity of the system.

Right now, the batteries mentioned and that I use are on sale for $335 each (12V, 280Ah), which is a great deal almost feels free compared to a few years ago. I’m even considering grabbing two more as backups at this price.
My Setup:
• Batteries: 4x 12V 280Ah (Eco-Worthy w/ Bluetooth) – $335 each
• Configuration: 2S2P to make 24V (14,336Wh total) – $1,400
• Inverter: LV2424-hybrid – $600
• Solar Panels: 4x 360W bifacial – $120 each locally ($480 total) mounted vertically on my deck. I bet I barely harvest 1000w in the peak hours of the day.

• Total Cost: ~$2,500-2700(including wiring & fuses)
• Backup Generator: Champion 4000W – $900 (for winter charging)

My cabin gets very cold in the winter, and I didn’t have any battery issues this year. The Eco-Worthy batteries are rated to cut off charging at 19°F, which I think helped them stay operational longer than my previous SOKs. Most of the winter is around 32°F, but I’d say half of it drops to 19°F or below, so that extra charging window made a difference.
This setup easily powers my entire cabin 8 months out of the year, with the generator covering the darker months (Dec–Feb).
 
I have a 12v system I built 4yrs ago. It works well but falls a bit short in the cloudy snowy central NY winters. That being said I would never build a 12v system again. For the simple fact that when you spend a bit more on a 48v system you can input way more PV wattage typicaly with the same charge controller. But since you state you only have room for 500w of pannels that's really limiting. Is this a weekend cabin? Why do you need a 2,000w inverter?
 

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