dischange schedule

Hi,
I am new to GivEnergy, and am in probably a unique position of having a Giv hybrid system with battery + another PV system (with FIT payments) + Growatt AC coupled battery.
I am finding the Giv battery drains into the Growatt battery, so to prevent this during the day I set a Discharge schedule to stop at 90%; but it is still discharging below this. Could this be because ECO mode is still on? the user guide(s) are very poor in explaining the logic in the inverter as to which modes take precedence and what happens when ECO mode is off.
Anybody any ideas?

How do you envisage this system working? Both batteries sharing the duty of covering house load, or taking turns.
I assume that the givenergy system (in eco mode) peceives the growatt system as a load that it has to try to cover. Both systems are trying to react quickly to house load, and this could well result in chaotic behaviour. Eg if a cloud passes over, there's a small drop in the generation from the FIT system. If givenergy responds quicker than growatt, it will discharge to cover the load that growatt is pulling. It's perfectly possible they don't quite agree on exactly how much surplus there is, so growatt pulls a few mW more, then givenergy increases discharge to cover it, and the system rapidly reaches an equilibrium where growatt is draining the givenergy battery.

Can growatt be configured to leave a small excess of excess AC? Sometimes this is a mechanism that can be used to prioritise power between multiple sinks. If you can configure growatt to leave behind say 50W, then that should introduce negative feedback to break the cycle. [growatt won't consume all the power the givenergy is dischargng, so givenergy will reduce discharge by 50W, which will in turn reduce how much growatt is consuming, until it reaches equilibrium at 0.]

I'm not sure if a givenergy hybrid system will normally charge from AC if it perceives there to be an excess. If not, then one opton might be to use the batteries sequentially. Pause discharge from the givenergy battery until, say, 5pm. And pause charging the growatt battery after that,

I think in latest firmware, the hybrid systems will charge it it sees export, a bit like an AC3. Some people asked for that feature, but now others aren't happy! Not sure if that's just gen 3.

TonyA It sounds as if you want to fully charge the Giv. system during cheap rate and then hold the charge until you want to use it later in the day. In which case just set the cheap rate stop time to the time you want to start using the power, not the actual cheap rate end time.
[https://community.givenergy.cloud/d/3622-battery-discharge-fully-outside-timed-discharge/10](https://)

I was pushing for a simpler system with just a simple inverter on the new panels and one battery on an ac linked inverter. Was told this would not work due to interactions, and that this system would work ha,ha! Neither system seems to be tunable as to what excess wattage there needs to be to switch modes. This is what is really needed. Tried last night using Giv Web page monitoring going into the remote control where it looked like one can set multiple timed modes. But system ignored it all. Any ideas?
The idea I had was to change cheap at night and then have it in battery mode during day with a small charge rate and big 90% SOC to stop it discarging. It seems whatever solution I think of hits a brick wall.

TX200
I also have a new system with 2 Giv energy batteries and 2 inverters, commisioned 4 days ago.
I'm trying to do exactly what you are suggesting e.g. charge at the cheap rate and discharge at the peak time 16.00 to 19.00, if I turn Eco off the batteries both discharge to the house and grid as soon as charging finishes, if I leave Eco on they discharge to the house as soon as they stop charging at 05.00.
Thanks TX200 I going to try your suggestion it seems to be logical.

TonyA what givenergy inverter model and firmware? Different models behave differently, unfortunately.
I'd do an experiment setting growatt to discharge at a fixed rate, exceeding house demand, to see how givenergy responds.
I was about to ask what export tariff you get, but you're on FIT for the original array - how does that work? Do you get paid for export from second system? Are they separately metered?

NUTTY
What kit have you got. I thought GivEnergy did not support twin inverter/battery setup due to cross charging?

Sorry, should be addressing SilverArt

The Inverter is a GIV HY5.0 and the softeware D0.307-A0.307.
In truth I am still waiting for MSC number to get on Octopus FLEX tariff, but experimenting to be ready when can.
Have transferred the FIT payments to Octopus and will cancel the deemed export allowance associated with that and go over to being paid for anything exported at the various time of day rates to take advantage of the extra generation capacity (hope to export at peak rate).
I did an experiment where I had the GivE system doing a 'battery 1st' at a low level during the day, but it was not low enough as it looked like the GroWatt battery was discharging to satisfy the demand, but I am thinking if I set it low then if there is solar it will not charge the battery!
Basically I think I have been sold a pig's ear lemon.

NUTTY
I am thinking that the solution is to get them meeting the demand serially rather than in parallel, which is where I started this post.
ECO just seems really mess things up, but if one turns it off and it is in a 'timed charge', 'timed discharge' or 'timed export' then what logic is it following?
I think that if there is no other mode than it just seems to turn ECO back on, and this seems to override 'timed discharge'!
I will Giv would publish the logic of the modes to allow people to not waste time trying the impossible.

SilverArt
That would probably work at the moment as the small amount of solar would probably be consumed (or might even be saved by the GroWatt system); but what do I do in the summer (when I do not want to use the grid at all) to stop all the power immediate going into the smaller Growatt battery, at which point the Giv Battery will start filling from the new panels but the excess power from the old panels will go to the grid.

I think the basic solution out the box is as already mentioned just set your charge period to extend to when you want the battery to be usable so for NUTTY's @NUTTY example assuming on Octopus Go charge period would be 23:30 to 19:00 leaving Eco on and not setting any discharge or export times

If you want some clever daily flexible solution then your going to need to resort to API and in there you can enable or disable eco, charge period etc on what variable inputs your getting as its always going to be per user basis as GE can't cover for each electric utilities tariffs

TonyA yeah, the timed discharge/export is weird. As far as I can tell, both enable a timed fixed-rate discharge period: timed discharge means turn eco on outside the time window; timed export means turn eco off outside the window. So it's probably timed export you want.

TonyA I had assumed you'd gone for this setup so as to not disturb your FIT / deemed export scheme. It does seem over-complicated. AC coupled solar and increasing battery size of a single ac-coupled battery might have worked better. Nevertheless, need to try to make the best of what you have.
You have slightly newer firmware than me. I tried battery-first the other day, but it seemed to ignore it. There is a pause interval you can configure on the portal (not available from app). Can pause charge, pause discharge, or both. That might be a better way to stop battery discharging to cover demand, without requiring that you charge from grid. I don't know if pause takes precedence over timed export or not.

Is growatt battery big enough to cover daily demand, so that the givenergy battery is just for extra export during peak export? (Did you mean flux tariff, rather than flex tariff ?)

SteveCook
2x 9.5 Giv batteries and 2x hybrid inverters GIV-HY5.0
I'm beginning to think I'm an experiment.

TonyA are all panels in the same orientation. If the growatt battery is smaller, will it fill first, so that by the time the GE battery is full, the growatt cannot charge any more. If it's east/west split, presumably it's the original ones that are west.
If necessary, could the panels be swapped (new on growatt, old on givenergy) ?

TonyA ECO just seems really mess things up, but if one turns it off and it is in a 'timed charge', 'timed discharge' or 'timed export' then what logic is it following?
I think that if there is no other mode than it just seems to turn ECO back on, and this seems to override 'timed discharge'!

You get more control using the remote-control section (gears icon) on the web portal. If you enable (timed) DC discharge, toggling the eco flag moves you between 'timed discharge' and 'timed export' (or on the app, 'scheduled discharge - home demand' and 'scheduled - full export'. If you use the "friendlier" interface, I don't think you can turn off eco without enabling timed dc discharge, but you can disable both on the remote control section. (Or possibly, via API.)

On my system (firmware 305), a timed pause-discharge does seem to take precendence over a timed DC discharge,

TonyA but what do I do in the summer (when I do not want to use the grid at all) to stop all the power immediate going into the smaller Growatt battery, at which point the Giv Battery will start filling from the new panels but the excess power from the old panels will go to the grid.

Then you need to stop the FIT system being a load on the grid, perhaps it needs to go into an Export or pause mode. That way the Giv. system if it is getting sufficient Solar/battery power it should ignore it. The challenge is if the Giv. system runs out of power and presents itself as a load on the grid in which case the FIT system could be a source, however, as it has the smaller battery it should have run out first anyway.

So thinking about it, I'm not sure why the solution I suggested wouldn't equally work in the summer.

TonyA I wonder if there's any mileage in changing the way the systems are wired together. It's more typically used for ev chargepoint, but maybe it would help... Do you have separate consumer units for the different systems?
A picture would be clearer, but visualise the tails from your meter. What if the growatt and old solar panels are attached first, and then the givenergy and finally the house. Now the CT clamps for givenergy can be attached to the cable after the old system, rather than straight after the meter tails.
The effect is that givenergy doesn't see any power consumed by growatt - just perceives it as export to the grid. (But growatt will grab any surplus exported by givenergy, when it's battery is full.)
For an EV this arrangement prevents givenergy discharging to the car. I'll have to ponder a bit more to find downsides here.

DD
the panels are in the same orientation (south). total battery capacity is enough to cover me for a complete day's power.
In summer I should be exporting quite a bit and it does not really matter from which system this is from.
Did not think I would have the problem of batteries draining into each other.

DD
thanks this is useful information

DD
The old panels feed into the consumer unit (via the generation meter).
Between the Smart meter and the consumer unit is a new junction box to which the Giv Inverter and Growatt inverter are attached.
There are 2 monitoring clamps between the junction box and the Smart meter, and another on the old solar output to the Growatt.
If the wiring could be changed so that it was Smart - Giv - Growatt - consumer and the growatt clamp could be put between the Giv and the Growatt then the Growatt would see energy from the Giv as from the grid and would use the battery instead. Giv would see less demand and back off. Would not matter if the Growatt gets drained 1st.
Need to think it through to see if there are downsides in the sunny seasons.

TonyA hmm... Don't know much about ac-coupled systems. Didn't realise the growatt had a monitor on the old PV output. So when it's draining the givenergy battery, it knows the power isn't coming from solar.
I had just assumed it was simply grabbing any AC in excess of the house load, assuming it would otherwise get exported.

DD
That is just one of the funny things. Initially they put the Growatt clamp back to front so the graph of the solar use showed 10W overnight and the zero during the day. They fixed this last Friday, but it did not stop the immediate drain into the Growatt battery if I part charged them up to 5:00.
So not sure how much the Growatt using the solar output in its decision making (if at all). It would mainly just seem to be is juice going to the grid rather than from it.
Sleeping on the solution the only possible problem would appear to be if both batteries are trying to satisfy the load which one wins? is this decided by voltage? Whatever it is if there is excess and some gets exported and the Giv system will rein back (which is desirable behaviour).
Thanks DD for the time you have spent on my puzzle, I am really happy now that there seems to be an easy solution. Just got to convince the installers.

SteveCook Extending the charging period to 16.00 worked thanks however overnight the discharge schedule was disabled and on both inverters although only one was discharging and then at a nominal 6w.

NUTTY See if this helps explain. [https://community.givenergy.cloud/d/3622-battery-discharge-fully-outside-timed-discharge/10](https://) obviously ignore the timed export comments. The only things that should be enabled for you are ECO and the 'Timed Charge' settings.