EG4 18kPV AC Coupling - No voltage on Gen terminals

[BKY2003]

This is what I use, 97% because it the 18Kpv miss calculates it could over charge the battery. Then the BMS will have to step in to stop the charge.

 

[BKY2003]

I see, AC couple start SOC value (mine 95%) is the ac coupled inverter start producing power when the battery gets down to 95%. So anything under 95% the AC coupling is working.

 

[aviateur17]

I see you don’t have a battery?

{
"vbat": 53.400000000000006,
"soc": 58,
"soh": 100,
"Pcharge": 527,
"Pdischarge": 0,
"tbat": 2,
"battypeandbrand": 2,
"batcomtype": 0,
"batstatus0_bms": 0,
"batstatus1_bms": 0,
"batstatus2_bms": 0,
"batstatus3_bms": 0,
"batstatus4_bms": 0,
"batstatus5_bms": 192,
"batstatus6_bms": 0,
"batstatus7_bms": 0,
"batstatus8_bms": 0,
"batstatus9_bms": 0,
"batstatus_inv": 3,
"batparallelnum": 1,
"batcapacity": 280,
"batcurrent_bms": 0.9,
"faultcode_bms": 0,
"warningcode_bms": 0,
"maxcellvolt_bms": 3.339,
"mincellvolt_bms": 3.336,
"maxcelltemp_bms": 21,
"mincelltemp_bms": 21,
"bmsfwupdatestate": 0,
"cyclecnt_bms": 1,
"batvoltsample_inv": 53.6
}

 

[aviateur17]

I see, AC couple start SOC value (mine 95%) is the ac coupled inverter start producing power when the battery gets down to 95%. So anything under 95% the AC coupling is working.

Not my understanding. Any battery SOC % below the AC Couple Start SOC value AC coupling should be disabled. I did test this out and it seemed to work like that as long as the start/end are not 100/255. So far I've only tested "off-grid".

 

[BKY2003]

Test it and see, I was thinking the same way you are and someone on the forum straightened me out, they had a lot of patience with me. Please check that 255% I would not want your battery to get damaged.

 

[aviateur17]

Test it and see, I was thinking the same way you are and someone on the forum straightened me out, they had a lot of patience with me. Please check that 255% I would not want your battery to get damaged.

battery SOC at 60%. AC Couple Start SOC at 65%. AC coupling still running. What does the AC Couple Start SOC mean?

 

[Quattrohead]

255% should be an illegal value, how did that get in there ?

 

[aviateur17]

battery SOC at 60%. AC Couple Start SOC at 65%. AC coupling still running. What does the AC Couple Start SOC mean?

View attachment 247485

AC Couple definitely does shut down when Battery SOC > AC Couple End SOC. So that's good.

@BKY2003, thanks for the tip about overcharging and the BMS having to cut off charging. That is a good tip!

 

[aviateur17]

255% should be an illegal value, how did that get in there ?

That is the value when you reset the inverter values to factory default! Wouldn't a better factory value be 95%?

 

[aviateur17]

That is the value when you reset the inverter values to factory default! Wouldn't a better factory value be 95%?

I think I'm losing my mind. Battery SOC is at 60%. I had start SOC at 5% and end SOC at 95%. Gen port would not put out power. Waited several minutes. Then changed Start SOC to 90% and now the gen port puts out power. WTF? To start AC Coupling the AC Start SOC needs to be greater than Battery SOC?

 

[BKY2003]

AC

battery SOC at 60%. AC Couple Start SOC at 65%. AC coupling still running. What does the AC Couple Start SOC mean?

View attachment 247485

Actually it’s anything under 65% the ac couple will work and the battery will stop charging at AC Couple end SOC value

 

[aviateur17]

I think I'm losing my mind. Battery SOC is at 60%. I had start SOC at 5% and end SOC at 95%. Gen port would not put out power. Waited several minutes. Then changed Start SOC to 90% and now the gen port puts out power. WTF? To start AC Coupling the AC Start SOC needs to be greater than Battery SOC?

There must be some off delay time, where the gen port

AC

once the battery hits 66%, as long as you are off grid. It should stop changing the battery.

Where do you get the 66% value from? 65% Start SOC + 1%? I assume. This is crazy.

 

[BKY2003]

Actually it’s anything under 65% the ac couple will work and the battery will stop charging at AC Couple end SOC value.

I was wrong, trying to work and type at the same time.

 

[BKY2003]

Post in thread 'EG4 18kPV Q+A general thread'
https://diysolarforum.com/threads/eg4-18kpv-q-a-general-thread.61636/post-957960

This is the post where y0bailey explains it to me

 

[aviateur17]

Post in thread 'EG4 18kPV Q+A general thread'
https://diysolarforum.com/threads/eg4-18kpv-q-a-general-thread.61636/post-957960

This is the post where y0bailey explains it to me

Thanks, will read that a bit later.

I wonder if AC Couple Start SOC is the SOC at which to start charging when the battery SOC drops *below* that SOC. So the AC coupling will charge the battery until it reaches the stop SOC and then not charge again until it drops below the start SOC. That seems to fit what I'm seeing. Making more sense now.

 

[Bananaman321]

Thanks, will read that a bit later.

I wonder if AC Couple Start SOC is the SOC at which to start charging when the battery SOC drops *below* that SOC. So the AC coupling will charge the battery until it reaches the stop SOC and then not charge again until it drops below the start SOC. That seems to fit what I'm seeing. Making more sense now.

Now you're catching on

 

[Quattrohead]

That is the value when you reset the inverter values to factory default! Wouldn't a better factory value be 95%?

You would think so, but there are a few factory defaults that are wrong...50hz without a grid connection is another one.

Waited several minutes. Then changed Start SOC to 90% and now the gen port puts out power

Bare in mind there is a default 300 second timer before the switch, this can be changed.....but always changes back to 300 seconds if you change the grid profile.

I wonder if AC Couple Start SOC is the SOC at which to start charging when the battery SOC drops *below* that SOC. So the AC coupling will charge the battery until it reaches the stop SOC and then not charge again until it drops below the start SOC. That seems to fit what I'm seeing. Making more sense now.

Yeah, I think it did not translate well from the dev lab to the general public.

 

[altenergy21]

@altenergy21, I'm not sure what you mean by "chapter 2, Figure B." Can you give the name of the manual you are looking at and the page number? The user manual I am looking at, section 2 is the abbreviation list.

Is that page just a figure or does it actually have the settings needed to make it work? I know it "should" work. The issue is what exactly the settings need to be both for off-grid and on-grid to make AC coupling work.

For example. I am now testing off-grid. I can see the gen port power coming in and charging the batteries. There is nothing hooked to the load port of the inverter. AC Couple Start SOC = 100% and AC Couple End SOC = 255%. Current battery SOC is 55%. How is AC coupling charging the battery when the Start SOC = 100%? That makes no sense in my mind. There is no written, detailed, explanation of how this thing works. I would think that if the current battery SOC is less than the start SOC that the battery should not be charging, otherwise what is the purpose of the Start SOC??

So the issue is not a figure on how to wire it up or whether it should work or not, the issue is the actual inverter settings and how they affect the operation of the unit.

View attachment 247465