Any benefit of two (2) smaller AIO units vs one (1) larger?

[Lord Doa]

This may be a stupid question for non-beginners, but I'm working off the saying my dad had about "The only stupid questions are the ones you already know the answers to" and I honestly don't know this. But, is there a benefit to getting two smaller units (2 x EG4 3kw) as opposed to one larger unit (EG4 6.5)? I realize in my example the larger unit has an extra 500 watts, but I'm thinking of other things on top of that.

Something like I see both units have a 500 VOC max input. Does having two smaller units mean I can have two incoming strings of panels; effectively increasing how fast I can recharge my batteries? Also, it seems like with two units I can make two different "zones" if needed allowing me to have different priority grids, though I can't think of why I would want to do that.

So what are the pros/cons of going with two smaller units vs one larger?

 

[G00SE]

Redundancy, split phase depending on if the inverters chosen are only 120v, can have one off/standby for the majority of the time to limit idle draw and still have the output available when needed

 

[rhino]

Backup. If one fails you are likely to still have another one that is working. Importance of that is how dependent you are on having power from one.

 

[Lord Doa]

limit idle draw and still have the output available when needed

Ahhh... good point. Looking at the idle consumption when I was on a single smaller (50w) unit I'd save about 480Wh a day over the larver unit (70w) but of course if I ever have to put the second smaller unit into production I'd end up spending an additional 720Wh.

Time to make a decision if I think I'll ever outgrow 3000w

 

[MichaelK]

Perhaps a different question should be why have AiOs at all? Most of the AiO brands occupy the lower ends of the off-grid strata.

 

[Lord Doa]

Backup. If one fails you are likely to still have another one that is working. Importance of that is how dependent you are on having power from one.

It's for an off grid hunting cabin so it won't see a ton of use, but I'm human so I want things to work when I want them to work. As they say in Contact, "Why only build one when you can build two for twice the cost?" I mean, it's only money... I'll make more

 

[Lord Doa]

Perhaps a different question should be why have AiOs at all? Most of the AiO brands occupy the lower ends of the off-grid strata.

Indeed, and I am asking that question. I'm speccing out multiple different systems including AIO and component systems to figure out which will work best in my application.

 

[G00SE]

Indeed, and I am asking that question. I'm speccing out multiple different systems including AIO and component systems to figure out which will work best in my application.

I’ve been on the same struggle.
The smart part of me says “go Victron or schneider or midnite or Outback”
The frugal part of me says “go eg4, Growatt, or mpp”

I did read that Growatt was the 3rd largest by volume worldwide so while they may not be tier one, they can’t be the worst (at least that’s my poor rationale hah)

But even if I go Victron and start small and expand later, one charge controller alone (not including an inverter) cost as much as a budget AIO.
I could have 2 spare all in one inverters in a box potentially never needed and still save money

On the other hand it could all go haywire and I could piss that money away just to at the end say “shoulda gone Victron”

So I too find it a bit of a catch 22.

But I think I’m coming around to the notion that (let’s say on a smaller scale) 2-3000w eg4 inverters are mere Pennies compared to the modular stuff and I spend more money in groceries in one paycheck than what the inverters cost so it’s not much risk

 

[DIYrich]

But, is there a benefit to getting two smaller units (2 x EG4 3kw) as opposed to one larger unit (EG4 6.5)?

Problems that people are having with the 6.5. don't know if there are similar issues with the 3kw

 

[Johno1066]

I am presently running 2- 3kw EG4 inverters, run 2 from 7am to 10pm powering a well pump, A/C window units, washing machine, refrigerator freezer, 1500watt water heater, and other small appliances. I shut one down every night at 10 pm just to save the idle current and one unit handles the load during the night. I went with 2 small units each now powered by its own PV array so if one fails I could still limp along with the other until I could repair or replace the failed unit. Been running my home since January without any problems and as the units are so reasonably priced I am thinking about purchasing a spare now in case one of them fails.

 

[ArtieKendall]

Perhaps a different question should be why have AiOs at all? Most of the AiO brands occupy the lower ends of the off-grid strata.

Some of us want to start in the lower end before we commit a lot of money. I'm getting my feet wet by building a system just to run my fridge, microwave, and PC. When I learn more, I'll get a whole-house backup, and use my starter system as a backup to the backup.

I think that Will Prowse and Gavin Stone have sold a ton of EG4 3000's with their favorable reviews. In his handcart build video, Will even said it was the best AIO he'd ever reviewed. And it costs less than the shipping charge for a single battery.

 

[Lord Doa]

I am presently running 2- 3kw EG4 inverters, run 2 from 7am to 10pm powering a well pump, A/C window units, washing machine, refrigerator freezer, 1500watt water heater, and other small appliances. I shut one down every night at 10 pm just to save the idle current and one unit handles the load during the night. I went with 2 small units each now powered by its own PV array so if one fails I could still limp along with the other until I could repair or replace the failed unit. Been running my home since January without any problems and as the units are so reasonably priced I am thinking about purchasing a spare now in case one of them fails.

I’m in love with the redundancy idea and being able to “hobble along on a single leg” if one goes out. Plus it will allow me to shift the extra $ to another battery since I can punch purchasing the second unit a little down the road.

 

[Lord Doa]

Perhaps a different question should be why have AiOs at all? Most of the AiO brands occupy the lower ends of the off-grid strata.

This most apparent reason, at least in my use case scenario, is convenience. I don’t have to educate myself deeply on the nuances of solar and instead can sleep well at night knowing that the experts I relied on to size everything did a good job and won’t burn my house down killing everyone in it. No, seriously… my personality type is one that I’m willing to pay extra (in the form of idle consumption) to not have to second guess if I made a mistake.

But, with that said. I am trying to learn the component side of it and have another thread where I was asking if I had the overall theory down correctly. I still may go with components… I’m still learning and getting a feel

 

[Lord Doa]

I’ve been on the same struggle.
The smart part of me says “go Victron or schneider or midnite or Outback”
The frugal part of me says “go eg4, Growatt, or mpp”

I did read that Growatt was the 3rd largest by volume worldwide so while they may not be tier one, they can’t be the worst (at least that’s my poor rationale hah)

But even if I go Victron and start small and expand later, one charge controller alone (not including an inverter) cost as much as a budget AIO.
I could have 2 spare all in one inverters in a box potentially never needed and still save money

On the other hand it could all go haywire and I could piss that money away just to at the end say “shoulda gone Victron”

So I too find it a bit of a catch 22.

But I think I’m coming around to the notion that (let’s say on a smaller scale) 2-3000w eg4 inverters are mere Pennies compared to the modular stuff and I spend more money in groceries in one paycheck than what the inverters cost so it’s not much risk

I just started digging into component inverters but wow! is Victron proud of them when an inverter (with charger) costs as much a an EG4 AIO. I also am bouncing the question of do I want something “that just works” or do I want to spend time and energy tinkering with something and making it work? Honestly, at my age I’m leaning towards an out of the box solution

 

[Lord Doa]

Some of us want to start in the lower end before we commit a lot of money. I'm getting my feet wet by building a system just to run my fridge, microwave, and PC. When I learn more, I'll get a whole-house backup, and use my starter system as a backup to the backup.

I think that Will Prowse and Gavin Stone have sold a ton of EG4 3000's with their favorable reviews. In his handcart build video, Will even said it was the best AIO he'd ever reviewed. And it costs less than the shipping charge for a single battery.

Sunk cost is definitely a factor. And how you mention getting your feet wet and then upgrading later… that’s my learning process. Back in the day mom & dad wouldn’t buy me any games so I went to the library and got a programming book with a bunch of examples. I typed the code in and then started tinkering with different parts to see what the result was with how the program ran. I do the same with computers and anything else really… get something that works and then start changing things to see the resulting changes.

I don’t see it any different with this. Start with an AIO and then necessity show that I need something so I have to learn and modify the system to accomplish my needs and goals. Or at least that’s the plan.. we all know about plans and first contact with the enemy

 

[740GLE]

It's for an off grid hunting cabin so it won't see a ton of use, but I'm human so I want things to work when I want them to work. As they say in Contact, "Why only build one when you can build two for twice the cost?" I mean, it's only money... I'll make more

So it won’t be used/occupied? Will you need 120/240 running all the time?

In order to have the AIO charging the batteries that idle is being consumed 24/7. If you go separated you can just run a SCC and shut off an inverter when not there.

For our part time cabin our inverter is off 95% of the time and let the 10ma draw of the SCC keep the batteries full. I then sized the battery to last 4-5 days with minimal solar but enough inverter size for everything we need.

 

[OffGridForGood]

So it won’t be used/occupied? Will you need 120/240 running all the time?

In order to have the AIO charging the batteries that idle is being consumed 24/7. If you go separated you can just run a SCC and shut off an inverter when not there.

For our part time cabin our inverter is off 95% of the time and let the 10ma draw of the SCC keep the batteries full. I then sized the battery to last 4-5 days with minimal solar but enough inverter size for everything we need.

For our cabin I use a portable 24v set up, bring it with me, take it when I leave, use it for camping and in the remote parts of the property & Green House for doing odd jobs. I like a garden cart set up rather than a hand truck/firdge cart set up, just because of the stability of it -4-tires instead of two, works for me. Depending on the price point and power you are trying to supply:
Small set up - I use the MPP 2724, has outlets right on the inverter, simple plug in for the battery comes with the inverter, has some built in MC-4 connectors too, but I never bring the PV with the rig, I just have a spare panel attached to the south wall of the shop run inside to plug in the mobile unit when not in use. I use a DIY 304Ah battery and Daly BMS (if it fails JK BMS will be it's replacement)
A bigger set up (I have not done this, maybe in the future) Use a MPP 6048 which will provide 120 & 240 OR 120 only (you can choose which in settings) in a single AIO, 48v DIY battery(ies) this will be quite a bit heavier then the 2724. Note: The MPP6048 is 6552W output - 27.3A @ 240vAC.
If money is no object go Tier-One if you like. I figure the industry is still in the early stages, better offerings will be coming, I don't mind using the Voltronic line for now, and see what is available in a few more years. Works for me.

 

[Zwy]

Problems that people are having with the 6.5. don't know if there are similar issues with the 3kw

Been there, done that.

MPP replaced the EG4's and did not have those problems, no other changes made to the system.

 

[Zwy]

So it won’t be used/occupied? Will you need 120/240 running all the time?

In order to have the AIO charging the batteries that idle is being consumed 24/7. If you go separated you can just run a SCC and shut off an inverter when not there.

Not true, the units will charge from PV with the inverter off. No need for a separate SCC.

For our part time cabin our inverter is off 95% of the time and let the 10ma draw of the SCC keep the batteries full. I then sized the battery to last 4-5 days with minimal solar but enough inverter size for everything we need.

 

[Zwy]

This may be a stupid question for non-beginners, but I'm working off the saying my dad had about "The only stupid questions are the ones you already know the answers to" and I honestly don't know this. But, is there a benefit to getting two smaller units (2 x EG4 3kw) as opposed to one larger unit (EG4 6.5)? I realize in my example the larger unit has an extra 500 watts, but I'm thinking of other things on top of that.

Something like I see both units have a 500 VOC max input. Does having two smaller units mean I can have two incoming strings of panels; effectively increasing how fast I can recharge my batteries? Also, it seems like with two units I can make two different "zones" if needed allowing me to have different priority grids, though I can't think of why I would want to do that.

So what are the pros/cons of going with two smaller units vs one larger?

I'd determine how large the system needs to be first and that includes if you plan on adding more loads such as a mini split in the future. I'm assuming you don't need split phase. But if you might in the future, you might be better off with 2 smaller units.

These units will charge from PV with the inverter off, so you might be better served by a larger bank that can be charged while you are gone and battery capacity used up by the time you leave.