AC coupled recommendation?

Fafrd: If you elected to buy the Victron, you would always be able to sell it in the future if your plans changed. They are very popular with the RV crowd. But, keep in mind they are not certified for use in the US.

I've gotten to the point where I don't trust any written or verbal statements from Chinese manufacturers about certification for use here. In the cases where they claim "Ul Listed" or "Compliant" most of them could not be found, were not tested by a NRTL, were "certified" internally, or "certified" by an unknown agency.

That may or may not matter to you. I do agree that the Huayu units look very appealing.

TexasSun said:

Well fudge. In reading specs in more detail, I realized that the Sigineer model does NOT work with the grid. So it will not produce power onto the grid which is a problem. (I'm surprised nobody mentioned that!). OK, back to the list:

$7k Sol-Ark 12k... full featured
$3k Outback Skybox... 5kW output, only 4kW charging capable
$5k Sunny Island used (2x units)... full featured but no warranty
$3.2k Sigineer M12040D . 12kW inverting, 120A solar charger plus 100A charger. (please verify, but I take that to mean it will charge off it's own panels at a 6kW rate, and additionally charge from the enphase inverters at a 5kW rate at the same time?)

Well that takes out the Sigineer. Next options are the Outback Skybox (yes Ampster) and the Sunny Island (not in love with 'used' units, but new units aren't that much more). OK, first, SolarPrep, can you point to evidence that it is being discontinued? And Ampster, how can I get the Skybox to have more charging capacity? Can it support an external charger that it will control to run in AC coupled mode... or is my only option to get 2 units? And for the Sunny Island system, I've heard where they need a transformer. Can someone point to where I can read more about that?

BTW, again, reading specs more indepth, I read where the Sol-Ark 12k only actually supports 9 kW of continuous output in inverter mode! Gotta read the fine print.
Thanks

Click to expand...

Texas SUn: What about the 5k Sol-Ark? Under $4500

SolarPrep said:

Fafrd: If you elected to buy the Victron, you would always be able to sell it in the future if your plans changed. They are very popular with the RV crowd. But, keep in mind they are not certified for use in the US.

Click to expand...

I believe Victron does now have a Multiplus II certified for use in the US, but it is only a 12VDC model, which won’t work for me.

SolarPrep said:

I've gotten to the point where I don't trust any written or verbal statements from Chinese manufacturers about certification for use here. In the cases where they claim "Ul Listed" or "Compliant" most of them could not be found, were not tested by a NRTL, were "certified" internally, or "certified" by an unknown agency.

Click to expand...

Once they end up on California’s apt river list (like Growatt) there is little to be concerned about.

SolarPrep said:

That may or may not matter to you. I do agree that the Huayu units look very appealing.

Click to expand...

My plans are changing as I’m realizing the new crop of EV will essentially provide a whole-home generator.

So while I was interested in the Huayu or another brand AC-coupled battery charger to dump excess AC solar energy beyond that needed to serve loads onto my LiFePO4 battery, I’m now more interested to find a way to find a way to charge an EV only with excess solar generation (not sure that exists yet).

Using an EV as an on-demand generator to keep a house battery topped-off (or skating just above empty) looks like it is here now (and easy/cheap) so the only remaining piece of the puzzle is how to recharge an EV during daylight hours without importing from energy from grid…

Thank you for all for the additional ideas.

SolarPrep, I tried contacting Huayu, and have not gotten a response from their US rep. I asked who are their distributors in the US. Do you know who to contact?

The Sol-ark 5k is quite appealing. But it's limitation is the AC coupling capacity, at 5kW, that leaves 3kW at risk or he disconnects it. I have the Sol-arc 12k and love it. Yes the 5k is more than the competitors, but I think it's worth it. But I know my buddy will have issues with the shortfall in AC coupling capacity.

And there is the 'flood' of new products due in Q1. No idea what will be available when or at what cost... and that will be when we have another freeze / power outage, so my buddy wants this in place before then. Ah well...

TexasSun said:

The Sol-ark 5k is quite appealing. But it's limitation is the AC coupling capacity, at 5kW, that leaves 3kW at risk or he disconnects it. I have the Sol-arc 12k and love it. Yes the 5k is more than the competitors, but I think it's worth it. But I know my buddy will have issues with the shortfall in AC coupling capacity.

Click to expand...

A single Sunny Island could support all 8kW (up to 12 kW) with manual intervention.

One Sunny Island and a 120/240V transformer could have up to 6.8 kW of AC coupled GT PV downstream, and would serve as a UPS with solar. That automatically supports critical loads.
A second AC coupled GT PV inverter could be connected before Sunny Island so it also feeds grid, but doesn't go through the 56A 120V relay.

During a power failure, flip a couple breakers and Sunny Island feeds breaker panel like a backup generator would, and interacts with the second PV inverter as well. It can control up to 12 kW of AC coupled GT PV while off grid; current doesn't go through its relay.

A limit to watch when setting up system with transformer like this is that while power of second PV inverter is balanced across both grid phases, the first PV inverter going through transformer and Sunny Island puts all its power on one phase. Code limits main + PV breaker amperage to 120% of breaker panel busbar.

If both inverters go to grid connected breaker panel they would be balanced. When Sunny Island picks up load as a battery-backed UPS, no PV is automatically used. Once you flip breakers, PV would be available.

Supervstech said:

I’m thinking, in a grid down gas lines down… winter weather situation… 100Ah isn’t unreasonable… the amount of energy electric resistive heaters use is STAGGERING…
Then again, the odds his will happen again is low. Likely whatever took down the gas mains has been corrected. I’m certain MANY homeowners in the area purchased standby generators after the fact…

Click to expand...

I found a sweet 4350kw gas/propane 30 amp generator for $621 one month after that freeze. I've been offered $1000 for it. I have a friend out in Katy who tried what these gentlemen are talking about, and DCPower is correct. It's not worth it for "most people." There are always exceptions.

fafrd said:

I believe Victron does now have a Multiplus II certified for use in the US, but it is only a 12VDC model, which won’t work for me.

Once they end up on California’s apt river list (like Growatt) there is little to be concerned about.

My plans are changing as I’m realizing the new crop of EV will essentially provide a whole-home generator.

So while I was interested in the Huayu or another brand AC-coupled battery charger to dump excess AC solar energy beyond that needed to serve loads onto my LiFePO4 battery, I’m now more interested to find a way to find a way to charge an EV only with excess solar generation (not sure that exists yet).

Using an EV as an on-demand generator to keep a house battery topped-off (or skating just above empty) looks like it is here now (and easy/cheap) so the only remaining piece of the puzzle is how to recharge an EV during daylight hours without importing from energy from grid…

Click to expand...

fafrd: the Victron Multiplus and Quattro in 12v and 24v are UL listed. The 3000va units only.

TexasSun said:

Thank you for all for the additional ideas.

SolarPrep, I tried contacting Huayu, and have not gotten a response from their US rep. I asked who are their distributors in the US. Do you know who to contact?

The Sol-ark 5k is quite appealing. But it's limitation is the AC coupling capacity, at 5kW, that leaves 3kW at risk or he disconnects it. I have the Sol-arc 12k and love it. Yes the 5k is more than the competitors, but I think it's worth it. But I know my buddy will have issues with the shortfall in AC coupling capacity.

And there is the 'flood' of new products due in Q1. No idea what will be available when or at what cost... and that will be when we have another freeze / power outage, so my buddy wants this in place before then. Ah well...

Click to expand...

TexasSun: And the 5k SolArk cannot be stacked. Darn.

SolarPrep said:

fafrd: the Victron Multiplus and Quattro in 12v and 24v are UL listed. The 3000va units only.

Click to expand...

Victron themself told me that only the 12V model of the Multiplus II was UL-certified for use in the US, but if you have other information on the 24V model, please share.

Fafrd: not the Multiplus 2; the original Multiplus in the old fashioned heavy box, and the Quattro. Look on the Northern AZ Wind site, and you will see them. 12v and 24v; not 48v. 3000va only. I was mistakenly told that the 3000va 48v Quattro was also UL, but after I bought it, found out is not. Now, that is an issue.

Victron always says they are coming out with listed models, and it never seems to happen. Too bad, because it is great equipment. Our market just isn't important enough to them. They still sell a lot to RV people. The Multiplus 2 is really popular for that. I understand that the primary reason for the new "2" versions is saving cost and weight on the cabinet, and the addition of the second input. The inverter is basically the same.

Fafrd: Now I''m only finding the Multiplus 3000va 12/24 that is UL listed....hmmmm...

SolarPrep said:

Fafrd: Now I''m only finding the Multiplus 3000va 12/24 that is UL listed....hmmmm...

Click to expand...

I’m interested in any information you have on a 24VDC Multiplus II that has UL listing.

Here is a direct quote from Rich Shea at Victron US from last week:

‘Please note that the FIRST model MultiPlus that will be certified for these type of systems in North America will be the MutliPlus II 48/3000-35.’

fafrd said:

I’m now more interested to find a way to find a way to charge an EV only with excess solar generation (not sure that exists yet).

Using an EV as an on-demand generator to keep a house battery topped-off (or skating just above empty) looks like it is here now (and easy/cheap) so the only remaining piece of the puzzle is how to recharge an EV during daylight hours without importing from energy from grid…

Click to expand...

What is your cheap/easy solution to using an EV to keep the home battery charged?

As for charging the EV with excess PV, I am set up to due that now with OpenEVSE

400bird said:

What is your cheap/easy solution to using an EV to keep the home battery charged?

Click to expand...

There are new EVs coming next year (Ford F-150 Lughtening, Hyundai Ioniq) that come with integrated V2L capability (essentially a 120V plug output powered by an inverter wired directly to the main battery of the EV):
So that provides an always-on source of islanded 120V power directly from the EV that is ‘free’ (comes with the EV at no extra cost). V2L will probably become standard for new EVs before the decade is out.

Then, a standard extension cord powering a low-cost 10A AC LiFePO4 charger allows the EV to keep the house LiFePO4 battery charger / topped off at very low cost.

If the ‘always on’ aspect wasted too much power, my SCC includes a dry contact (relay) intended to turn on a generator that I’m pretty sure can be used to activate the V2L/AC-charger only when the house battery is sufficiently depleted and needing a boost.

400bird said:

As for [v]charging with excess PV[-b], I am set up to due that now with OpenEVSE

OpenEVSE - Electric Vehicle Charging Solutions

OpenEVSE provides electric vehicle charging solutions worldwide based on SAE J1772 and IEC 61851 standards. Our experts provide components, software and services to accelerate the development of new charging technologies.

openevse.com

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I’ve seen those OpenEVSE platform but found the information surrounding what they so confusing/unclear.

Can you explain more about how you are ‘charging with excess PV’?

What I’m specifically interested in is whether there is any EV charging solution that automatically scales the charge power / current to what power is available, rather than limiting charge power to one out of set of ‘all or nothing’ options (ie: 12 or 16A @ 120V or 16 or 30A @ 240VAC, etc…).

Does your OpenEVSE platform allow you to charge at arbitrary current / power at either 120V or 240V?

If so, will that variable-power capability work with any EV or is there some deciding charging standard that must be supported?

I wouldn't classify buying a not yet released and extremely wait listed EV as easy/cheap. But, I understand.

For the OpenEVSE. Yes, it requires an external current sensor on the mains and something to send that data to the EVSE, but it will ramp up/down from 6 amps (minimum supported by J1772) up to 40 amps (max for my wiring/OCPD) based on excess PV production.

I've got it set up at 240 volts. It does support 120vac, but it can't switch between the two.

400bird said:

I wouldn't classify buying a not yet released and extremely wait listed EV as easy/cheap. But, I understand.

Click to expand...

I was speaking to the trend of where things are headed, not necessarily today / this minute.

Though there seem to be several existing DIY techniques to power islanded 120VAC off of an EV using an inverter (though most I’ve seen use the 12V battery which sacrifices some efficiency).

400bird said:

For the OpenEVSE. Yes, it requires an external current sensor on the mains and something to send that data to the EVSE, but it will ramp up/down from 6 amps (minimum supported by J1772) up to 40 amps (max for my wiring/OCPD) based on excess PV production.

I've got it set up at 240 volts. It does support 120vac, but it can't switch between the two.

Click to expand...

Wow, you’ve made my day. I’ve been searching for a zero-import / zero-export AC charger and from what you’re saying, I may have finally found one.

I’m not sure what options their are to charge home batteries rather than EVs using that OpenEVSE charging platform, but the fact that it communicates with an energy meter on the mains in order to smoothly modulate charging power to maintain zero-export until the battery exits boost charge (CC) and enters absorb charge (CV) means a zero-export-through-load-control solution exists today.

Did you put that charger kit together yourself and how difficult was it?

Any idea what lowest DC voltage it can be used to charge or whether there may be easy ways to adapt it to charge lower-voltage batteries?

The kit assembly I did with my 6 year old on the kitchen table. It wasn't too bad if you've got a good small screw driver set.

Maybe I misunderstood the other part of your question, but this is an EVSE. It's basically a relay and some control circuitry to allow an EV to charge. The EVSE doesn't care what DC voltage the car uses. All it sees is AC voltage.


I missed one detail on the charging that seems obvious, but it's worth saying.
Charging range is 0 amps and 6-40 amps.
It will command no charge when there isn't enough PV when to do 6 amps charging.

I think I understand now, you want to use the EVSE to power a battery charger?
I think you'd be better served with a solution meant to do that. An inverter meant for the purpose (Outback, Victron, Sol Ark, Schneider, or one of even more cheep options) would be a better solution.

I've got a Schneider XW6848. The same external control system commands both the EVSE and Schneider charging. The EVSE gets priority of excess PV first.

400bird said:

The kit assembly I did with my 6 year old on the kitchen table. It wasn't too bad if you've got a good small screw driver set.

Click to expand...

Cool.

400bird said:

Maybe I misunderstood the other part of your question, but this is an EVSE. It's basically a relay and some control circuitry to allow an EV to charge. The EVSE doesn't care what DC voltage the car uses. All it sees is AC voltage.

Click to expand...

You’re right, I forgot EV’s integrate their own DC-battery chargers and that ‘EV chargers’ send in AC, not DC power (except for some of the fancy new high-voltage DC Chargers).

So what this means is that the battery charger in the EV will self-adapt to whatever AC current level the EV charger sends into the car.

I assume that is probably the case for any/all EVs, but just case, what EV do you have?

400bird said:

I missed one detail on the charging that seems obvious, but it's worth saying.
Charging range is 0 amps and 6-40 amps.
It will command no charge when there isn't enough PV when to do 6 amps charging.

Click to expand...

Yeah, that I understood. Minimum of 6 amps of AC current needed before charging will start (so maximum of 6A of AC export while EV battery remains in Bulk).

The key thing for me is that I was told by a family member that has a Tesla that charging is only possible at a discrete set of AC amperage/power levels and cannot be modulated smoothly/continuously as you are saying this charger achieved with your EV.

400bird said:

I think I understand now, you want to use the EVSE to power a battery charger?
I think you'd be better served with a solution meant to do that. An inverter meant for the purpose (Outback, Victron, Sol Ark, Schneider, or one of even more cheep options) would be a better solution.

Click to expand...

No, I’m actually most interested in an EV charger that can charge using excess AC-coupled solar energy.

I don’t have an EV yet and so when I started thinking about purchasing one of these OpenEVSE kits in advance, I got sidetracked thinking about whether I might be able to use it with my existing 24V LiFePO4 house battery (forgetting that EV chargers put out AC and not DC power).

400bird said:

I've got a Schneider XW6848. The same external control system commands both the EVSE and Schneider charging. The EVSE gets priority of excess PV first.

Click to expand...

Yes, so the XW6848 decides how much AC power to make available to EVSE, EVSE passes that amount of power on to the EV (assuming at least 6A), and it is the EV’s integrated battery charger that self-adapts to that level of power for variable-current DC charging (such as is the case when a DC-coupled solar array charges a battery using an SCC).

You are in the cutting-edge, 400bird, and I believe there will be over a million solar customers in California following down your same path as their existing solar systems under NEM grandfather out to the new Successor Tariff that is likely to be decided in January…

I’m just happy to hear all of these technologies ‘on the horizon’ are actually already here in early form .

I’ve been thinking about whether this EVSE charger will offer me anything while my NEM agreement is still in force, and I think it will.

Once we have the EV, we’ll be consuming more electricity and my plan had been to add more DC-coupled solar to offset that increased consumption once the time comes.

That would allow me to charge the EV at any time off-peak but would require offsetting that consumption by driving my consumption to zero overnight rather than just to the end of our peak period at 9pm.

With one of these EVSE chargers, I’d be able to charge with excess solar energy from sunup to the beginning of peak period at 4pm that I’d otherwise be exporting.

Consuming my own energy (but no more) to charge up the EV means that I don’t need to worry about continuing to offset consumption after peak period ends at 9pm.

To do this, all I’d need is a timer controlling charge hours (if the EVSE doesn’t already include controls to set on and off times..

Telsa does Tesla stuff
Everyone else follows the standard, J1772
J1772 allows for charging from 6-80 amps with 1 amp steps. 120 or 240 volts (probably 208 also, but whatever)

The EVSE doesn't limit the actual current flow, but it does communicate with th car to relay the available current. Typically this is just a stagnant value based on wiring, OCPD, etc. With the OpenEVSE, and some fancy load sharing set ups, this max current limit is adjusted as needed.

Doesn't matter if the car is in bulk, whatever part of the charge cycle, the EVSE sets the max and th car's onboard charger takes what it needs.

DC fast charging isn't new. Been around a long time.

The XW is not in charge of th EVSE.
I've got a current monitoring program set up controlling both the EVSE and XW when charging either battery.

400bird said:

Telsa does Tesla stuff
Everyone else follows the standard, J1772

Click to expand...

Tesla uses the J1772 protocol. For the fist few years I used a J1772 EVSE to charge my Tesla with a simple adapter.

400bird said:

Telsa does Tesla stuff
Everyone else follows the standard, J1772
J1772 allows for charging from 6-80 amps with 1 amp steps. 120 or 240 volts (probably 208 also, but whatever)

The EVSE doesn't limit the actual current flow, but it does communicate with th car to relay the available current. Typically this is just a stagnant value based on wiring, OCPD, etc. With the OpenEVSE, and some fancy load sharing set ups, this max current limit is adjusted as needed.

Click to expand...

Cool, meaning the current limit is adjusted dynamically depending on net excess current (solar power - other loads), right? Any idea how often the EVSE updates the max current limit?

400bird said:

Doesn't matter if the car is in bulk, whatever part of the charge cycle, the EVSE sets the max and th car's onboard charger takes what it needs.

Click to expand...

Yes, but once the EV battery nears full SOC and can no longer be charged at max current, the car charger will no longer use the full max current and will begin to taper (Constant Voltage Charging Mode typically called 'Absorb').

400bird said:

DC fast charging isn't new. Been around a long time.

The XW is not in charge of th EVSE.
I've got a current monitoring program set up controlling both the EVSE and XW when charging either battery.

Click to expand...

Yes, I understand the XW is not controlling the EVSE.

The XW may be deciding what amount of available AC solar power to consume charging a battery (assuming it has a battery), but the EVSE is controlled by it's current meter on the mains, correct? It only consumes the excess AC current/power that would otherwise be getting exported to grid, right? (assuming it has been programmed to function in that manner and that available excess AC current/power is between 6 and 80 amps...).

Where does your 'Current Monitoring Program reside and what does it do?

fafrd said:

I’ve been searching for a zero-import / zero-export AC charger and from what you’re saying, I may have finally found one.

Click to expand...

An EVSE is not a charger. It is just a contactor with communication protocol that tells an onboard charger on an EV how much current it can draw.