Meaning of discharge mode

Can anyone explain to me please something which seems obvious, but it clearly isn't. I want to occaionally do a forced export of energy stored in the battery. From the app then I would select discharge mode as "schueduled". This then gives me another choice "Meet home demand" or "Full export". The meanings seem obvious. If I select "Full export", then at the alloted time, it exports. No problem there, but at the end of the time then the battery just idles's. It isn't topped up by solar. In order do that I have to return discharge mode to "Dynamic". What this means is that there is little point is scheduleing a timed export if you have to change a setting at the end of it. I feel there must be something I have misunderstood here. Can someone straighten me out please

Richard14 Known problem. Unlike timed charge which reverts to eco (dynamic) after the charge period timed discharge does not.

cluelesscris
Oh I see. Well thanks for your reply. It's quite concerning that they haven't put this issue right. I wonder if there is any kind of work around ?. I can't think of one !!

Do it manually in the app, or get yourself involved in Home Assistant.

TimHutchings OK. Thanks for your reply. I'll check out Home assist

Richard14 if you are gen2 or 3, use timed discharge, not timed export. It should be what you want. Gen 1 I'd different behaviour for the same settings ....lf you are on the app, that's scheduled and meet home demand.

Richard14 thanks. I'll give it a go later but I thought that wouldn't actually export, but just as it says, meet home demand. I'll try it anyway

Richard14 https://youtu.be/DDDd_j8O5s4 explains it very well about half way through…

Dom66 thanks for that. The video does explain it well, but my system does not do that. Full export is as per video, (works but battery just idles afterwards) but "meet home demand" does exactly that and doesn't export (contrary to the video). I've tried looking at the Web based portal and it does the same, except that " meet home demand" in the app is called "discharge" in the portal and "Full export" in the app is called "export" in the portal

Richard14 gen2 and gen3 should work as video explains. If you have gen2/3 maybe your firmware is old? Mine is gen2 and does what I want if I choose Home Demand - a full export during scheduled period otherwise Home Demand (back to Eco mode).

Dom66 Well I know the firmware is up to date, but the inverter is the 3kw ac coupled inverter. I have solaredge for solar. I guess this us the difference perhaps

Richard14 believe AC3 models are all gen1. It hasn’t been fixed for gen1. Not sure if it will be. Maybe. Hopefully?

I have a gen1 and I can confirm that Richard14's experience is exactly the same as mine. The easiest way over it is to manually use the 'play' buttons and 'battery -' buttons in the app, setting phone alarms when you want to be reminded.
Alternatively, if you're computer savvy, Home Assistant appears to be the way to go.

Thanks for confirming. Yes I'd thought that the alarm on the phone is an option. A rather clunky way of doing it, but it is solution. We live in hope that Givenergy might fix it one day !!

I have same setup as Richard14: SE inverter for solar and AC3 to control my batteries (two 8.2 kWh).

I use phone alarms and initiate Full Export to start and Dynamic to end (which seems to turn ECO back on).
Home demand on this set up does just this and does not export.

I have never really got to grips with the difference between the discharge and export modes and I just use export on the portal.

Like many, I am awaiting a firmware update for the AC3.

We all seem to have invented our workarounds. I am just getting into HA and may try to automate this process (I am on flux and use the 4-7pm slot each day). I may go back to Agile and 15p outgoing come winter as solar reduces but Flux is great in the summer months. With Agile, I will actively control import times.

Rob

Hi Rob. Don't know if you have the 'Quick settings' button activated which makes life easier. Top left menu, settings, preferences, show quick settings button. The Play button is Eco/Dynamic button. Just click on the Play button and choose the Battery- button from the selection. This exports at full power, and when you want to stop it, just on that button and pick the play button again.

TimHutchings That's the way I've been taking advantage of the flux peak export for the last week since we finally got export setup and I'd confirmed that the half hour meter readings were coming through. Quick setting / battery minus at the start of the time I want to export (between 5:40 and 6pm) and then quick setting / play button at 7pm to revert to normal mode.

I have gen 1 inverters and was fully expecting it not to go into eco mode at the end but manually controlling via the app it seems to work fine.

I do have an issue that the amount of discharge seems to vary from day to day, sometimes one inverter backs off discharging at full rate and I'm left with more in the battery than I need for overnight. Not sure why this is.
Will move to home assistant scheduling soon

geoffreycoan Are your inverters 5kw or 3.6kw. When my 5kw had a restriction on at 3.68kw, it depended how much sun was shining while exporting . If solar was producing say 2kw, the battery would only export say 1.68kw till as the solar reduced, then the battery would increase it's export to compensate. Likewise, if you have a big solar array with a 5kw inverter, the same thing will happen . If there's 3kw of solar, the battery will only export 2kw until until as the solar reduces, then the battery will gradually increase export to 2600w, it's max with a gen 1.
So depending on the amount of solar being generated, it will affect the battery export.
Don't know if that's the issue with yours?

Tim,
Thanks for this advice. I will try tomorrow when my 3:55 pm goes off on my phone. And again with the 6:55 pm alarm. A nice Solar day today (and yesterday) making up for the dreadful Friday, my worst Solar day since 9th April and my first this summer where I haven’t made a Solar profit..

Rob

TimHutchings I’ve 2x 5kW gen hybrid inverters with no export restrictions.

Yes I understand that if the sun is shining I will discharge less from the batteries as the solar is filling in the rest.

Taking the hour of 6-7pm when I'm on full export, I'd expect export to be minimum 2.6kW (max battery discharge rate) x2 = 5.2kW and maximum of 5kW (max inverter rate) x2 =10kW

Obviously have to take off whatever load the house is generating, but then in addition I've got a 4kW FIT array that's soaking that load up and should be contributing to the export as well.

Looking at the last few days from 6-7pm:

16th 5kw consumed from the battery, 3.8kW exported
17th 3.1 battery, 4.6 exported
18th 4.2 battery, 3.8 export
19th 2.8 battery, 4.6 export
20th 3.9 battery, 2.8 export

All the figures from Home Assistant energy dashboard

Wasn't a lot of solar generated in that hour so that can't be massively reducing the battery discharge rate:

16th 0.4kW PV generated
17th 1.2kW
18th 1kW
19th 1.1kW
20th 0.8kW

It starts off with both inverters ramping up but it doesn't appear to be sustained over the discharge period. I'm not massively upset about it because I'm happy to discharge a bit to get the peak rate flux payment but I want to keep enough in the battery to run me through the night so I'm only starting the discharge at between 5:30 and 6pm.
Worst case I can start the discharge earlier when I've worked out better what I need to keep. It's just not consistent and it's considerably below what I would expect from the two inverters.

geoffreycoan It does seem strange, the differences.
So forgetting any conversion losses (I'll come back to that in a moment), am I getting this right? On 16th between 6-7pm, you consumed 5kw from your battery, which with 2x5kw gen1 inverters is just 200w less than their max output combined and you generated just 0.4kw. How did you manage to export 3.8kw? Looks like it should be 0.2kw from the battery and 0.4kw from generation totaling 0.6kw. I must be missing something.
As for losses exporting and importing, I attach 3 screenshots of the app.taken just 3 minutes apart.
One shows standard background usage which remains much the same between screenshots and at the end.
Another shows max export. Note what the grid actually receives at max export, and how the consumption increases, although background house usage hasn't changed. The difference is the loss on conversion.
Final one shows max import. Note how much extra power is consumed from the grid and lost in conversion. Again background usage hasn't changed.
This may also have a bearing on the figures you quote.

TimHutchings Can you tell me where/how the export restriction is set? I can't see it. Thanks.

John A Morning John. Are you talking about my 5kw gen1 inverter being restricted to 3.68kw AC export initially? If you are, then it's a setting that customers can't see or get at. I believe it's in the installers programme they use to set the system up. It is a software setting rather than a hardware setting as my installer was able to release it while I was on the phone to him.
If you're asking something else about export, please clarify. Thanks

geoffreycoan it's considerably below what I would expect from the two inverters.

What was the grid voltage while this limited export was under way? Even with no export restrictions, the specification for inverters is that they reduce output when voltage exceeds 253V (UK distribution network upper limit). I would expect all three of your inverters to respond correctly to such high grid voltages. If that's not the issue, then I'd be asking Givenergy to have a look, because your inverters should have been capable of discharge battery at 2.5kW + PVkW.

TimHutchings Thanks that was the answer to my question.