EG4 18k PV Discharging 10 - 50 times per day

Let's keep this pithy. I've had my EG4 18k PV for a little over 2 weeks now. I've had a great experience in comparison to the Sungold 8k so far, Signature Solar staff is prompt and knowledgable, but there is one giant gap I'm continuing to experience and i'm kind of astonished that it's caught Signature Solar tier 1 and 2 off guard. I've run the question past Markus @ eg4, but he's been out of reach for a week.

Desired State:

PV power to Loads
Excess PV to battery charge
Discharge only between 18:00 and 7:00
Any excess energy after PV can go to grid or not (I don't care).

I've tried every setting combination imaginable with and without Signature Solar's help...nothing changes the behavior below.
I'm on firmware FAAB 1919


Here's 2 different days below. I've tried using Forced Discharge schedules, and I've kept it simple and used no schedules. No matter what, the behavior of the discharge schedule is erratic. I've seen the old threads from last year complaining about problems around peak shaving...but I'm not trying to do anything special here...is the 18k pv capable of one discharge time per day? Or is it going to cycle back and forth between charge and discharge 50 times per day?

the.shining said:

Let's keep this pithy. I've had my EG4 18k PV for a little over 2 weeks now. I've had a great experience in comparison to the Sungold 8k so far, Signature Solar staff is prompt and knowledgable, but there is one giant gap I'm continuing to experience and i'm kind of astonished that it's caught Signature Solar tier 1 and 2 off guard. I've run the question past Markus @ eg4, but he's been out of reach for a week.

Desired State:

PV power to Loads
Excess PV to battery charge
Discharge only between 18:00 and 7:00
Any excess energy after PV can go to grid or not (I don't care).

I've tried every setting combination imaginable with and without Signature Solar's help...nothing changes the behavior below.
I'm on firmware FAAB 1919


Here's 2 different days below. I've tried using Forced Discharge schedules, and I've kept it simple and used no schedules. No matter what, the behavior of the discharge schedule is erratic. I've seen the old threads from last year complaining about problems around peak shaving...but I'm not trying to do anything special here...is the 18k pv capable of one discharge time per day? Or is it going to cycle back and forth between charge and discharge 50 times per day?

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View attachment 219447

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Good morning!

I believe that you were working with Phil at Signature Solar. I'll get with him to get with you to see if there is some time today we can run through some stuff with you to ensure we get this working as intended!

Yes, I had worked with Phil a bit, but it does seem like there's no known solution for this simple problem

this behavior shouldn't even be possible...

the.shining said:

Or is it going to cycle back and forth between charge and discharge 50 times per day?

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Just curious, is the charge from AC or PV?

BKY2003 said:

Just curious, is the charge from AC or PV?

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Can be from either. It'll switch back and forth when the sun is up or down

Does anything change if you put AC charge current 0kw

the.shining said:

this behavior shouldn't even be possible...
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Why not? Your batteries are charging/discharging in a 2.5KW window, which is going to be dependent on your load, pv, consumption.

What is the time zone set on the station, user, and on the maintenance tab of the 18kPV? I typically only see this sporadic reading when the three time slots are not set to the same time on the monitoring system.

BKY2003 said:

Does anything change if you put AC charge current 0kw

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I've tried the .1 it does change charge behavior but inconsistenly...sometimes only for a few hours....it doesn't change discharge behavior though which will still kick on whenever it feels like...then stop...then start dischargingn again

ksmithaz1 said:

Why not? Your batteries are charging/discharging in a 2.5KW window, which is going to be dependent on your load, pv, consumption.

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It's one thing to discharge...stop....discharge...stop....that's not what's it doing.

It's discharging...charging...discharging...charging....this is not desirable behavior in any situation to cycle batteries up and down.

EG4_Jared said:

What is the time zone set on the station, user, and on the maintenance tab of the 18kPV? I typically only see this sporadic reading when the three time slots are not set to the same time on the monitoring system.

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both the web (maintenance tab) and machine (station) display are on the same time (few minutes difference because I didn't take the pics at exact sime time)...I don't understand where/what the USER time is

So what is the load and available PV? If your PV moves around and PV input falls below AC output the unit will grab the power from the battery.

ksmithaz1 said:

So what is the load and available PV? If your PV moves around and PV input falls below AC output the unit will grab the power from the battery.

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if pv falls below load, i want power to come from grid.
it wouldn't make sense to discharge from the battery while the sun is up..which will result in far too many up/down cycles on the battery.
The behavior you describe is inneficient and not desireable

If you put System Charge SOC Limit(%)101. The battery keeps charging. If System Charge SOC Limit(%)100 it charges to the battery to 100% then stops. Check if it’s at 101.

BKY2003 said:

If you put System Charge SOC Limit(%)101. The battery keeps charging. If System Charge SOC Limit(%)100 it charges to the battery to 100% than stops. Check if it’s at 101.

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it's at 101. Must've been done by SS because I never touched that. But my battery is getting nowhere near 100% or top voltage right now. It's closer to 30% battery capacity because my loads consume most of the pv right now.

I don't know If I totally understand your situation, but I would try
Forced Discharge 18:00 -07:00 Stop SOC% 20%
Discharge Setting On-Grid Cut-off soc% 100%
And please check the apps time to make sure its correct also. Let us know if that worked.

Hoping the 100% On-Grid Cut-off will not let the battery be discharged and the18Kpv Forced to discharge to 20% from 18:00-07:00

BKY2003 said:

Hoping the 100% On-Grid Cut-off will not let the battery be discharged and the18Kpv Forced to discharge to 20% from 18:00-07:00

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I can try the 100% On-Grid Cut-Off setting. I've always had that low (10), not high...so curious to see what happens. I've certainly tried forced discharge with and without schedules but that hasn't solved the problem. Mobile app, the machine, and web app all show the same time.

BKY2003 said:

Hoping the 100% On-Grid Cut-off will not let the battery be discharged and the18Kpv Forced to discharge to 20% from 18:00-07:00

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I get error code 3 when trying to set On-Grid Cut-off SOC to 100....it did take 90...



But as of right now, with Forced Discharge ON...and schedule to begin at 20:10...pv is charging battery (instead of going to loads)...
Changing to 90% On-Grid Cut-Off didn't change behavior. Still charging to battery 5 min after changing that setting.

The On-Grid Cut-Off SOC can only be set in a range of 10-90%. However, feel free to DM your serial number and I can take a look at the time settings. Below you can find pictures on where the other two are located:

My User/Station was set to GMT-5 with daylight savings time on which gave me the right time....I set to GMT-4 wiht daylight savings time off which also gives me the right time.

Here is today with the On-Grid Cutoff SOC to 90. I have battery being charged first all morning.
and I switched back to Batt Discharge Control (Volt) instead of SOC, because the SOC is unreliable (i'm not using closed loop comms with eg4 battery, i'm using lifepo4 prismatic cells 16s configuration...where volts is the more reliable measurement with 56v for high, 48v for low

I'll dm you Jared with my station id.

Well, Jared@EG4 gave it a good shot, got imaginative with trying to leverage Peak Shaving as a means of controlling AC GRID's ability to power loads between 18:00 and 7:00, but as you'll see below, the 18k pv has a mind of it's own and as of 21:05 is powering loads...from AC GRID...and not Force Discharging from battery despite being enabled to do so.

My conclusions: EG4 and Signature Solar are both prompt and courteous. That's not the issue. The issue is that the inverter doesn't do what its programmed to do. Unfortunately, no sane/reputable installer will bother incorporating a product into their workflow that will produce inconsistent behavior.

Several eg4 owners have reached out to me on pm's and tried to help...so the eg4 community is also responsive, another big plus. But, for the people out there, like me, who need to hear the bottom line:

the 18k pv doesn't seem to be capable of this priority:
1. powering loads from pv first
2. charging battery with any excess pv
3. power from grid (not battery) when pv power is insufficient
4.. only discharging batteries overnight

If this isn't your use case, then the 18k pv might be for you. If you need 1, 2, 3, and 4...which is a common priority desired, then the EG4 18k pv seemingly can't do it, or no one knows how to make it do it. And from the research I've done, Solark 15k is supposed to be the magic bullet that solves this issue. But, as a person who likes industrious startups, and I believe in the EG4 vision, I want EG4 to realize they aren't in the end zone yet. Great teams score touchdowns, not field goals.

Achieving goals 1, 2, and 3 is possible. However, for goal 4, it seems that the Battery Backup logic might be conflicting with the Peak Shaving logic, which instructs the inverter to refrain from using the battery unless it's the sole power source detected. I plan to discuss this with our engineering team to determine the necessary steps to align with your preferred mode of operation.

the.shining said:

the 18k pv doesn't seem to be capable of this priority:
1. powering loads from pv first
2. charging battery with any excess pv
3. power from grid (not battery) when pv power is insufficient
4.. only discharging batteries overnight

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I'm curious about the "discharging batteries" requirement.

My 18Kpv does exactly what you're saying above except I don't consider it "discharging" the battery, it just consumes power as needed from the battery. I guess that does, in fact, discharge the battery but not as a forced thing, but as an as-needed thing. I have disabled the "Forced Discharge" setting and this still gives me the behavior I desire.

I am sure that EG4 folks and everyone else understands this better than I do. Can you please tell me what you mean about discharging? Are you trying to force a discharge or just want the inverter to use the batteries at night? If it's the latter, my situation is working exactly like that.