First try at a build, in over my head more than I thought

[Shred802]

Solar beginner here. Trying to add solar to my off-grid cabin to replace the gas generator being used. Thought I could just buy an EG 3000EHV-48 inverter, EG4 LifePower4-48V/100ah battery, and a few 200W solar panels and have enough to power minimal things -lights, Starlink, charge devices, etc.

First realization was that the cabin was actually wired split-phase using a 4-prong generator plug for the generator, although no appliances are/will be 240V...got around this by wiring the two loads together at the inverter side and works fine enough. Considering returning for the 6000EX-48HV to hook up the split phase properly.

2nd realization is needing 120V minimum solar input...okay so I need to buy more panels. Now I just learned of the high idle consumption of these EG4 inverters which leaves barely any battery capacity when the sun isn't shining.

Getting pretty stressed about this so I'm looking for any recommendations on what I could do. Don't need a crazy amount of power at the cabin- maybe 200-250W max at any given time during the day and that would be with everything turned on. Would be great to still utilize the Eg4 battery as that cost a fair bit to ship plus restocking fees are up to 40%...so wondering what might be compatible for an inverter that has a much relatively lower idle draw. Thank you so much for any thoughts or considerations you can send my way!

 

[BentleyJ]

If you wish to upgrade to a quality 240V split phase inverter with lower idle consumption a Schneider SW4048 would be a good choice. Maybe a little larger than what you normally need but will easily operate a skill saw Etc. or portable air compressor for occasional maintenance and repairs.

Victron is an alternative if you decide to keep the 120V system.

 

[Shred802]

If you wish to upgrade to a quality 240V split phase inverter with lower idle consumption a Schneider SW4048 would be a good choice. Maybe a little larger than what you normally need but will easily operate a skill saw Etc. or portable air compressor for occasional maintenance and repairs.

Victron is an alternative if you decide to keep the 120V system.

Thanks for the suggestions! I was wondering if I should think to convert the panel on the house to 120V single phase and switch the input on the cabin to a 120V/30A plug and then just use an adapter if ever wanting to use the generator. The split phase seems to complicate the solar setup for minimal power needs.

 

[BentleyJ]

IMHO, I would not downgrade the electrical system. You could possibly need/want it in the future or any new owner may.
There is already a 240V panel and a 240V generator available. All you need is a compatible 240V split phase inverter. Literally the only difference between a 120V and 240V inverter is 1 wire for the other leg. If you count the jumper wire you used to tie the legs together in the panel then its exactly the same number of wires. So there is really no complication.
As far as the "solar set up" consisting of PV panels and a charge controller for the battery, this is also exactly the same regardless of the voltage rating of the inverter. Note: the SW4048 is not an AIO, the charge controller is sold separately but again this is a minor detail, not really a complication.
The generator would be connected to the inverter AC input, either direct wire or via a gen receptacle.

 

[panther2200]

I'm curious, if you hook up the 3000EHV-48 to the Victron Autotransformer 120/240V-32A. Couldn't you use the step up feature to create the 240vac instead of stacking EG4 inverters.

 

[Shred802]

IMHO, I would not downgrade the electrical system. You could possibly need/want it in the future or any new owner may.
There is already a 240V panel and a 240V generator available. All you need is a compatible 240V split phase inverter. Literally the only difference between a 120V and 240V inverter is 1 wire for the other leg. If you count the jumper wire you used to tie the legs together in the panel then its exactly the same number of wires. So there is really no complication.
As far as the "solar set up" consisting of PV panels and a charge controller for the battery, this is also exactly the same regardless of the voltage rating of the inverter. Note: the SW4048 is not an AIO, the charge controller is sold separately but again this is a minor detail, not really a complication.
The generator would be connected to the inverter AC input, either direct wire or via a gen receptacle.

That’s a solid point. With that example not having it AIO would be a bit of a bummer in terms of simplicity. And looks like their mppt controller adds another $700+, with the inverter already being almost $1700. Did not realize there would be such a ‘cost’ trying to spec a cheaper AIO inverter ?‍?
All this makes trying to add solar + battery a harder pill to swallow. Doable, but apparently need to increase the budget quite a bit more. Still definitely cheaper than bringing in power almost a mile away.

 

[Shred802]

I'm curious, if you hook up the 3000EHV-48 to the Victron Autotransformer 120/240V-32A. Couldn't you use the step up feature to create the 240vac instead of stacking EG4 inverters.

View attachment 168428

That might help the split phase ordeal but not the high ~50W idle consumption of the inverter. Basically 1/4 of a battery a day goes towards just powering the 3000EHV which was a huge bummer to find out.

 

[Rednecktek]

I'm curious, if you hook up the 3000EHV-48 to the Victron Autotransformer 120/240V-32A. Couldn't you use the step up feature to create the 240vac instead of stacking EG4 inverters.

Which is more cost effective though, another $700 EG4 3Kw unit or anything that says Victron? Plus, with an auto-transformer my understanding is that you need to keep the loads pretty balanced to keep them happy.

Thanks for the suggestions! I was wondering if I should think to convert the panel on the house to 120V single phase and switch the input on the cabin to a 120V/30A plug and then just use an adapter if ever wanting to use the generator. The split phase seems to complicate the solar setup for minimal power needs.

Do you have any 240v devices at the cabin like a well pump or oven? If not then there's really no need to provide split phase and you can just jumper it over. If you do, are you within your return window and can see about swapping it for a EG4 6000 that will already be split phase?

That might help the split phase ordeal but not the high ~50W idle consumption of the inverter. Basically 1/4 of a battery a day goes towards just powering the 3000EHV which was a huge bummer to find out.

Yeah, that's the bummer part of AIO's is the standby draw. Some people will say to use Low Power Mode but the minimum draw to wake up the AIO is usually more than the light bulbs you need to turn on to pee at night which makes it pretty useless. You may find out though that while the standby is 1/4 of your battery, everything else may also be 1/4 of your battery which will still work out OK, but most likely you're going to need another battery. Fortunately you don't NEED to buy an EG4 battery, you can get many other batteries from many other sources and still use them as long as they're LFP and 48v, or you could get wild & crazy and roll your own.

 

[Shred802]

Which is more cost effective though, another $700 EG4 3Kw unit or anything that says Victron? Plus, with an auto-transformer my understanding is that you need to keep the loads pretty balanced to keep them happy.


Do you have any 240v devices at the cabin like a well pump or oven? If not then there's really no need to provide split phase and you can just jumper it over. If you do, are you within your return window and can see about swapping it for a EG4 6000 that will already be split phase?


Yeah, that's the bummer part of AIO's is the standby draw. Some people will say to use Low Power Mode but the minimum draw to wake up the AIO is usually more than the light bulbs you need to turn on to pee at night which makes it pretty useless. You may find out though that while the standby is 1/4 of your battery, everything else may also be 1/4 of your battery which will still work out OK, but most likely you're going to need another battery. Fortunately you don't NEED to buy an EG4 battery, you can get many other batteries from many other sources and still use them as long as they're LFP and 48v, or you could get wild & crazy and roll your own.

There aren’t any 240V appliances/individual circuits in the cabin. I think it got wired that way based on the gas generator output to supply the whole cabin off one 30a cord. Or that maybe one day they might add a well pump, etc. Who knows.

I was noticing the lights having a bit of a very slight constant fade in/out (not quite a flicker so not a real issue) and thought that might have been due to combining the load lines. Barely had anything else on. Thus I did go look to buy a 6000 but then seeing 115W idle, then equaling half a 100ah battery each day. So over time and over a couple/few days of low PV generation and the one battery is depleted. This is in New England and don't have an huge clearing, surrounded by some decently tall trees, and at the bottom of a hill so maybe 4hr sun in the winter, TBD. And this is not even taking into account inefficiencies. Seems like saving money on the inverter leads to a much worse cost on battery capacity as opposed to the inverse.

At this point I’m feeling like I’d rather buy a more expensive inverter so my battery doesn’t get drained so quickly as opposed to buying another $1400 battery just to give a bit more buffer. Decisions…feels crazy I have to build out such a system for what is relatively low power usage.

Hah yes I have seen that for the battery saving modes minimum draw, not really practical for smaller normal load systems unless I’m trying to blind myself with a halogen light or the like in the middle of the night.

In regards to adding more batteries of differing 48V makes, is that not an issue? If you’re trying to use BMS? Clearly did not do enough research when I came across the whole ‘easy plug and play’ EG4 components and thought this would be a simple and fairly cost-effective install. Definitely has been tough trying to work with this setup and not throwing in near max PV input and a handful of batteries, then that idle draw would be marginal to everything.

 

[400bird]

That’s a solid point. With that example not having it AIO would be a bit of a bummer in terms of simplicity. And looks like their mppt controller adds another $700+, with the inverter already being almost $1700.

Victron has lots of MPPTs at different price points based on capacity. I'm pretty sure $700 gets you high up into the range. How much solar do you have?

Also, the Multiplus 3k is less than $1700

Victron 48V MultiPlus-II 3kVA 120V Inverter 35A Charger | Current Connected

Discover the power of efficiency with the Victron 48V MultiPlus-II. Unmatched performance and reliability for all your energy needs.

www.currentconnected.com

They also make much smaller inverters if you only need that 2-300 watts you mentioned (and no AC charger)

Victron 48V Phoenix 1.2kVA 120V Inverter | Current Connected

Trust the Victron 48V Phoenix Inverter for unparalleled reliability, advanced features, and precise configurability. Power your world with confidence!

www.currentconnected.com

Yes, you'll pay more for tier 1 equipment with lower idle consumption. But you also open up more possibilities to customize it exactly how you want.

 

[Rednecktek]

Yeah, there's no reason to go for a 240v setup with that wiring. A 3Kw would be just fine, if anything replace that 4-prong plug with a 3-prong, run the two Hot leads to the same terminal and call it a day.

The BMS is part of the battery so no issues there. About the only thing you lose is inverter-to-battery communications which I don't really see as a deal breaker.

Being where you are you're going to need a LOT of panel to handle the weather and lack of sun. Fortunately panels are much cheaper than bateries.

As to the replacing the $700 AIO with a "more efficient" inverter and SCC will cost you a significant chunk towards the cost of another battery and isn't going to make that huge a difference. You're spending 50w/hr on the AIO, or you can spend thousands of dollars now to get down to 30w/hr later? The inverter alone from Victron would cost you as much as another battery. Plus you'll need to have a component system with all its extra parts, wires, and fuses? Those extra parts come at a significant price premium. Kinda rules out "simple" in my book.