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Need help choosing 48v all-in-one

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donsolarak

New Member
Joined
Aug 23, 2023
Messages
23
Location
Fairbanks AK
I live off grid near the arctic circle. My current system is 12v with 10kwh of lead antimony batteries (5kwh at 50% DoD) with a 2k inverter and a 60amp mppt charge controller. I currently have 800w in panels connected. I'm maxed with the current controller at 12v. I have another 800w of panels brand new ready to install. I have a somewhat undersized manual 12v AC charger. During the winter months I have to use generator power to charge the batteries every 4th day or so due to the lack of sunlight. My daily consumption goes from 1kwh on the low end to 2.5kwh on the high end. My average daily consumption is pretty close to the middle of those two at 1.7kwh.

My system works great, but I'm looking for further refinements.

I want to switch to a 48v system. I recently installed a midnite solar all-in-one for someone local and it works pretty nice. I've been thinking about going with an all-in-one as well.
I've noticed that a huge number of these all in ones are almost identical. The outside sheet metal is exactly the same. Most of the hookups are the same as well. I'm talking about the units from Midnite solar, chins, sungoldpower, powmr, et al. They seem to differ mostly in the color the box is painted and the logo on the outside.

My minimum requirements:
48v battery system voltage
500vdc oc for PV. My voc will be about 388v not accounting for very cold weather
2000w pure sign wave output (my max loads ever are about 1.5kw. typical load is 100-200w)
2000w AC charging via gas generator
lead acid and lithium charging profiles

single phase is fine. I won't ever have grid connection.

I was looking at the EG4 3k:
48v
500vdc oc PV
3000w output continuous
60a or 3.5kw of AC charging
80a pv+ac charging
both lead acid and lithium charging profiles
50w idle consumption, manual states 15w in power save mode
$750 shipped to me
3 year warranty
I can only find through signature solar (this worries me with all the threads with people having issues with shipping, warranty, tax issues?)
signaturesolar.com

EG4 3kW Off-Grid Inverter | 3000EHV-48 | 3000W Output | 5000W PV Input | 500 VOC Input

Signature Solar provides solar panels, off-grid solar systems, grid-tie, and hybrid systems. Quality solar inverters, bifacial solar panels, complete solar kits, solar batteries. Featuring brands such as EG4 Electronics with their solar battery, LifePower4 and EG4 LLifePower4 and EG4 LL
signaturesolar.com signaturesolar.com

I was also looking at this sungoldpower shipped/sold by amazon:
48v
500vdc oc PV
5000w output continuous
40a or 2.3kwh of AC charging
100a pv+ac charging
both lead acid and lithium charging profiles
manual says <50w idle consumption in power save mode
$799 shipped to me
warranty length? No idea

The higher AC battery charging of 60a from the EG4 vs 40a of the SGP is somewhat desirable for me. Other than that both would work from the specs in their manuals. My current inverter consumes about 10w idle. 50w idle concerns me a bit with either of the above. The inverter is off at night and when I'm not at home.

Q: will these units still charge via PV when switched off? I'm not sure if the power switch is just for the inverter circuit or if it kills the MPPT charge controller as well.

I'm looking for feedback of people who are using either unit, people's thoughts with signature solar shipping/warranty/taxes issues, or other recommended products that also meet my minimum requirements.

thanks!
 
donsolarak said:
I live off grid near the arctic circle. My current system is 12v with 10kwh of lead antimony batteries (5kwh at 50% DoD) with a 2k inverter and a 60amp mppt charge controller. I currently have 800w in panels connected. I'm maxed with the current controller at 12v. I have another 800w of panels brand new ready to install. I have a somewhat undersized manual 12v AC charger. During the winter months I have to use generator power to charge the batteries every 4th day or so due to the lack of sunlight. My daily consumption goes from 1kwh on the low end to 2.5kwh on the high end. My average daily consumption is pretty close to the middle of those two at 1.7kwh.

My system works great, but I'm looking for further refinements.
Click to expand...

As a short term solution, a genuine MPPT can typically be over-paneled significantly.

If you were to attach your addition panels in a parallel fashion to your existing array/MPPT, you could place your strings at different facings to get max power for longer through the day.



donsolarak said:
Q: will these units still charge via PV when switched off? I'm not sure if the power switch is just for the inverter circuit or if it kills the MPPT charge controller as well.
Click to expand...

Either unit should work fine. They're very similar with similar features and are both likely made by Voltronics.

The power switch controls the inverter. Most of these units will still act as a charger from either PV or AC when switched off.
 
Upgrading to a 48 VDC could be a good thing, but your power requirements could stay at 12 volts.

What is your max charge rate of your batteries? I can see a need to upgrade those if more panels are added.

Lead acid battery charge rates are typically towards 10%, but can be as high as 30%.

To me, to prevent overcharging off a 1600 watt array, could be good to keep the panels on one SCC. This will be ~1000 watts charging which comes out to ~80 AMPS AT 12 volts, ~40 amps at 24 volts, or ~20 amps at 48 volts.

The limited charge rate of lead acid is one reason I upgraded to lithium. I had three three SCCs rated at 110 amps, that would actually see 72 amps, but my max charge rate on my batteries were 60 amps. The three SCCs even on a Victron network had now way to max output at 60 amps. One SCC can be dialed to a limit less than its rating.

I’ll bet you have some limited charging days at the arctic circle on shorter days. May need to push more than 10% in on those to replenish the batteries?
 
Either unit should work fine. They're very similar with similar features and are both likely made by Voltronics.
Click to expand...
Perfect. Thanks.
The power switch controls the inverter. Most of these units will still act as a charger from either PV or AC when switched off.
Click to expand...
Thanks for the confirmation.
If you were to attach your addition panels in a parallel fashion to your existing array/MPPT, you could place your strings at different facings to get max power for longer through the day.
Click to expand...
Understood. Currently I have about 4 hours of daylight per day. This time of year anything not pointing directly south isn't going to get any sunlight. The summer solstice is another story as I will have 24 hours of daylight and could point panels north and still get direct sunlight. I do understand and appreciate the point you are making though. Good thoughts.

I also want to move my array further from my cabin. That's another reason I want the higher voltage to lower the line losses.
 
chrisski said:
Upgrading to a 48 VDC could be a good thing, but your power requirements could stay at 12 volts.

What is your max charge rate of your batteries? I can see a need to upgrade those if more panels are added.

Lead acid battery charge rates are typically towards 10%, but can be as high as 30%.

To me, to prevent overcharging off a 1600 watt array, could be good to keep the panels on one SCC. This will be ~1000 watts charging which comes out to ~80 AMPS AT 12 volts, ~40 amps at 24 volts, or ~20 amps at 48 volts.

The limited charge rate of lead acid is one reason I upgraded to lithium. I had three three SCCs rated at 110 amps, that would actually see 72 amps, but my max charge rate on my batteries were 60 amps. The three SCCs even on a Victron network had now way to max output at 60 amps. One SCC can be dialed to a limit less than its rating.

I’ll bet you have some limited charging days at the arctic circle on shorter days. May need to push more than 10% in on those to replenish the batteries?
Click to expand...
A 10c rating on my batteries at 48v is 21amps. 1,600w/58.4v = 27.4amps which is fine. Plus they will never actually see that much current.

Two problems with lithium this far north: cold and shipping.

Temps tomorrow will be about -40F and that's air temp not fake windchill temperature. Living deep in the woods far from grid power I cannot guarantee that I could always keep them warm. Shipping is the other issue. None of UPS/Fedex/USPS will ship any lithium batteries over 100wh to Alaska. I posted here awhile back asking for other shipping/vendor ideas with zero useful responses. The only quote I've managed to get so far would double the cost of the batteries by the time they arrived.

Every single solar system that I've encountered in interior AK is using lead acid batteries.
 
donsolarak said:
Q: will these units still charge via PV when switched off? I'm not sure if the power switch is just for the inverter circuit or if it kills the MPPT charge controller as well.
Click to expand...
From my experience with the 3000watt 24 volt Midnite DIY and their 5000 watt 48 volt models, The smaller 24 volt model has a 100 Voc max PV input and will still charge the battery when the inverter is shut down. OTOH, the 5000 watt/48 volt model has a 550 max Voc PV input. It will not charge the battery when shut down. I was told by the good folks at Midnite that the reason is the much higher voltage potential in the larger inverter is too dangerous to have flowing into the inverter when the inverter is shut down where people might think it's safe to open when operation is shut down. Something to that effect anyway.
Using this reasoning, I would think that all/most of the high Voc AIO's follow this model. This would be a good question for the mfg. before purchasing one.
 
Last edited:
donsolarak said:
air temp not fake windchill temperature
Click to expand...
I love that statement because - science aside, and in spite of me not living in Alaska which is a wholly different level/game than here in Vermont- the focus on “feels like” the last 20+ years just annoys me to death LOL. But I digress.
donsolarak said:
Every single solar system that I've encountered in interior AK is using lead acid batteries
Click to expand...
You understand the initial problem. The follow-up issue is getting enough voltage into the batteries for good life expectancy. Not familiar with ‘lead antimony’ so I don’t know if the low state of charge sulfation issue is of an equal concern to typical lead acid batteries.
donsolarak said:
My system works great, but I'm looking for further refinements.
Click to expand...
donsolarak said:
AC battery charging of 60a
Click to expand...
For a small system with ~5kWh of usable battery bank I would agree that 60A charging capacity is a desirable priority.
sunshine_eggo said:
genuine MPPT can typically be over-paneled significantly
Click to expand...
More on that below…*

In your situation I can see an AIO with other devices in parallel from additional PV could offer the power increase you seek as well as provide a measure of redundancy for circumstances like equipment failure or other unforeseen issues.
That’s actually the approach I arrived at once I compared the risks and benefits of various equipment that would meet my needs.
For me, 2/3? of my daily consumption is keeping my refrigerator/freezer running. So being offgrid maintaining my uptime even in a failure was the top of the flowchart of solutions.
donsolarak said:
want to switch to a 48v system. I recently installed a midnite solar all-in-one for someone local and it works pretty nice. I've been thinking about going with an all-in-one as well
Click to expand...
if a 2000W inverter does not cramp you in meeting your electrical needs I see no ongoing advantage to going 48V other than perhaps a higher VOC tolerance from the PV. While in most typical circumstances 48V has advantages including that most people living closer to civilization norms need way more output wattage. I suspect you do not.

*I initially read this yesterday and hesitated to respond. I was thinking of my own similar but slightly’larger” system and how I use it but didn’t want to project that onto you. With additional posts my thoughts settled and I think the following could be useful.

Your biggest need is more PV. That was where I arrived also with virtually the same daily kWh average, and I even use a 2000W inverter.
I have changes pending me finishing onlining equipment and panels already on hand, but currently I am running with the following equipment and I believe this same/similar setup would meet your three goals you alluded to or called out:
- more PV
- higher string voltage for distance
- at least 60A of utility/generator charging capacity

I have ‘this week’ ? 1500W of panels running ~75’ from mounting to my abode.

900W of PV feeds a 1012LV-MK (its inverter is always turned off) with the AC input being wired to my generator in the shop. It automatically begins charging when/if I start the generator (which is seldom).
600W of PV runs through a 60A mppt SCC simultaneous with the 1012LV-MK.

I have three other mppt’s unused currently but available for speedy hookup in case of failure but two are awaiting connection with ~1000W additional panels.

I have a 2000W standalone inverter (~18W idle) that is always on. If it failed? I have the 1012LV-MK available for a <5-minute swap of wires though I ‘should’ probably wire it with a 3-pole switch. I also have my original 1200W Giandel inverter “in case of.”

My battery bank is 5kWh lithium and irrelevant to you other than knowing it’s a 12V system. I used lead batteries for a number of years because they lived outside- same charging concerns you have with low temperatures.

So basically you can see that I’m doing a virtually same system as you are growing to.

My recommendation would be to do as I have done: the 1012LV-MK can support (iirc) 1000W of solar, is moderately inexpensive, and has a 60A automatic charger built in. The independent inverter you already have might work or you could buy one. Or two ?
donsolarak said:
500vdc oc for PV. My voc will be about 388v not accounting for very cold weather
2000w pure sign wave output (my max loads ever are about 1.5kw. typical load is 100-200w)
2000w AC charging
Click to expand...
How far will your PV cables need to run? My new yet-to-installed approach has provisions for four strings at ~75’ and three of them will be used (I might add 600W to the fourth for optional cloudy day / winter enhancement) for a 2500W system at roughly ~115VDC loaded. “A few more panels” is going to make up way more than the Volts loss over distance. More expensive wire (big gauge) can mitigate “losses” but a few more panels will cost (in practical terms) about the same AND increase overall wattage. More income is generally better than reducing expense (loss) so I don’t worry about a few percent of loss when $300 of panels yields a net increase in capacity.

If 800W is sorta working, your doubling that would be good, and adding a third 800W string eventually would probably feel as miraculous as when I added 600W last summer.
And expense-wise, staying 12V while adding independent charging sources and panels is sorta cost efficient. I’d maybe - probably - likely have a very different recommendation if you were at a lower latitude, but seeing what you are doing and comparing your current situation to mine it makes sense to me.

Does this make sense to you as well?
 
SRNE 10kw split phase, will be all you need ever going forward, and very affordable on alibaba!

I have one as a backup
 
From what I hear the Midnite AIO is solid. Go for the MN5048DIY and dont look back. Having support from Midnite is worth it.

Stellavolta has it on sale right now for $869 with free shipping
 
I am a newbie to solar. I was gifted 1580 watts of solar panels and a Midnite solar Kid charge controller. I have been researching this so I can set up a system on my off grid property in MN (also -40) this spring. The Kid is maxed out with 48 volt battery bank.

I have looked through this thread with interest. I figure I need an inverter that can also charge the batteries from a genny. Stand alone 120 volt AC to 48 volt DC chargers start at about $100 so factor that into cost of your inverter charger. I don't need an mppt charge controller built in for charging from the panels. For you an all in one makes sense.

The Midnite Solar line of DIY charge controllers/inverters are all made in China, not the USA. Tech support and warranty is through Midnite Solar in the USA so that's worth something. The MS DIY units operate down to about 15 degrees f. I have to rule them out. Check the units you are considering for minimum operating temp.

Inverters come in high and low frequency flavors. The low frequency inverters handle the surge when starting up a motor much better. They can surge about 3 times the rated wattage for up to 20 seconds. High frequency inverters double the rated wattage for less than a second. Low frequency inverters are much heavier and more expensive than high frequency ones. Do you plan to run a compressor or table saw? You probably don't need an AC often in AK.

If I hit the lottery I want a Schneider Conext SW 4048.
 
so location. a place that does not allow amazon to replace something that burns up within a reaosnable time frame. so that means either avoid AI's or buy a minimum of three of every AIO component pls as many spare boards as you can afford.

invest in more panels. lead acid is probably the best for you at this level of your knowledge, so you need more panels to get them up to flat as quickly as possible.

this or study about heating systems for LifePo4 and or invest in batteries that can handle it... Winston... -40 ~ +40 no dmage at .1c charging. no damage at -25-+40 for .2c charging, a battery heater needed if you want to exceed either. (not hard look at my examples.) AIO any portion burns up you need a spare and due to your location you probably need two or three spares. its where you live... with individual components you can buy the 1st tier with the knowledge they rarely burn up, and when they do, one or two spare boards can fix them. so one, a spare and two spare boards.... just my advice, where you live is too inhospitable to rely on the best deal through alibabba that day.
 
Daddy Tanuki said:
so location. a place that does not allow amazon to replace something that burns up within a reaosnable time frame. so that means either avoid AI's or buy a minimum of three of every AIO component pls as many spare boards as you can afford.
Click to expand...
Nimrod5 said:
I figure I need an inverter that can also charge the batteries from a genny. Stand alone 120 volt AC to 48 volt DC chargers start at about $100 so factor that into cost of your inverter charger. I don't need an mppt charge controller built in for charging from the panels. For you an all in one makes sense
Click to expand...
I have several different charge controllers on the wall replenishing my batteries (off grid). I use a separate 2000W psw inverter. I have a backup inverter, spare Epever charge controllers.
I also have an AIO on the wall, inverter turned off, solar panels feeding it. So I use it for the mppt, and when I (rarely) fire up the generator the AIO’s 60A charger automatically charges.

So don’t rule out an AIO as part of your plan- my setup works very well for me like this; yours could as well. There are many ways to skin that cat.
 
Nimrod5 said:
If I hit the lottery I want a Schneider Conext SW 4048.
Click to expand...
If the lottery winnings allows you to quit your job then you will have a lot more time struggling to get the buggy and inane software working. I'm not saying you will succeed but you will have more time to try, especially with an AC coupled array.
The hardware is rock solid so putzing around with the software every day will probably not break the hardware.
 
Nimrod5 said:
The Midnite Solar line of DIY charge controllers/inverters are all made in China, not the USA. Tech support and warranty is through Midnite Solar in the USA so that's worth something. The MS DIY units operate down to about 15 degrees f. I have to rule them out. Check the units you are considering for minimum operating temp.

Inverters come in high and low frequency flavors. The low frequency inverters handle the surge when starting up a motor much better. They can surge about 3 times the rated wattage for up to 20 seconds. High frequency inverters double the rated wattage for less than a second. Low frequency inverters are much heavier and more expensive than high frequency ones. Do you plan to run a compressor or table saw? You probably don't need an AC often in AK.
Click to expand...
If moving away from AIO - I would recommend an Aims LF inverter charger. I have personally tested a 24v/4000w one for several years and in sub zero temps. It even powers up at those temps, not just "stays on". Yes they are manufactured in China but the support is in Las Vegas and decent to work with. The charger feature is really simple and takes any generator i throw at it. Low idle consumption, no programming needed and adjustable charger output. I think it weighs about 65lbs! They cost about $1100

Staying with a stand alone MPPT is going to have to parallel more strings to keep the Voc down. I like the Midnite Classic 150-sl (it has voc protection if you bump into that limit accidentally) those are coming down in price to about $470.

At the end of the day, i still have a stand alone ac charger, a spare mppt and a stand alone inverter i can wire in if something fails. Never needed any of it, but i do like playing with the charger

At some point someone is going to get on here and say Victron everything but i think its more techy than the OP wants. Maybe their CC but not the rest. I only say that for simplicity sake.

Oh and Trojan SPRE-06-415 are kicking butt in the cold. The solar premium line has some sort of coating to prevent sulfation on the plates as they are likely spend time half charged. If you have batteries inside living space, go with Full River sealed.
 
The Aims 24 volt 4000 watt inverter charger is 120 volt output and 120 volt input from the grid or a genny. When you move to 48 volt the 2000 watt inverter charger is 120 volt in and out but the 4000 watt is 120/240 out and 240 only in. My genny is 120 and I'm off grid. I can't hook up my genny to the 4000 watt unit. I don't think the 2000 watt unit can start a compressor or the table saw. The 3000 watt genny can't.

Aims seems to be decent quality. Magnum makes a unit comparable to the Schneider. Any thoughts on quality reliability?
 
Nimrod5 said:
3000 watt genny can't
Click to expand...
What generator?
What tablesaw?

I’ve actually welded exhaust with a 2000W QZRELB. Not heavier stuff. It also runs my small craftsman portable tablesaw, small compressor, and makita compound mitre, but not the delta tablesaw or big compressor. I have three parallel 100Ah 12V batteries feeding it, though.
The champion “6250” inverter generator will run everything including a 120V Lincoln Mig and its twin Lincoln with fluxcore, but it doesn’t want anything to do with the 240V compressor, or the TiG on high amps.

If you’re not challenged with insufficient panels maybe looking at a 6048 split phase makes sense. High idle draw though.
 
Nimrod5 said:
The Aims 24 volt 4000 watt inverter charger is 120 volt output and 120 volt input from the grid or a genny. When you move to 48 volt the 2000 watt inverter charger is 120 volt in and out but the 4000 watt is 120/240 out and 240 only in. My genny is 120 and I'm off grid. I can't hook up my genny to the 4000 watt unit. I don't think the 2000 watt unit can start a compressor or the table saw. The 3000 watt genny can't.

Aims seems to be decent quality. Magnum makes a unit comparable to the Schneider. Any thoughts on quality reliability?
Click to expand...
magnum is light years ahead of AIMS in regards to quality. lower idle draw, better in regards to its peripherals though its not as good as the smurf patrol in regards to infrastructure.
 
One year in on a 48/3000 AIO - 1001 KWH hours solar in ... 591KWH grid in .. connected a 48v battery I built.
(not final form - missing fuses and switches)

48vSolarPlan-Rev31.jpg

The AIO is a Sigineer M4830NC. $900 at the time of purchase. Flawless operation. installed in a lower bay of my Class A RV
(bench mode pic)
RVN_4174-SMall.JPG
 
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