New user - Hybrid 3-phase inverter & 3 batteries + solar + EV

Hi all. I've had solar on the house for almost 10 years, but I've just had the Hybrid 11Kw 3-phase inverter installed along with 3 batteries giving 10.6Kwh storage. I have a Zappi EV charger.

I've recently switched to Octopus and am in the process of switching my export MPAN to Octopus.

Are there sticky posts with links to useful reading material please ? I don't want to be that guy who asks all the dumb questions without reading up first.

Inverter model : GIV-3HY-11
Software version : DA0.007-DD0.007-A0.007
Battery Capacity : 52 Ah | 10.18 kWh | (3 Packs)

The installer told me it would go through a calibration cycle so I left it to do its thing for 24 hours. Yesterday I set a charge window to coincide with my Octopus EV tariff (23:30 to 04:30) and it charged itself up nicely. Today though it has discharged itself almost fully by exporting to the grid - I should have seen that coming and stopped it until I know that Octopus SEG is in place.

The first and obvious question which occurs to me is this - is there a way to "reserve" charge which I'm likely to need for the house, so I only export surplus above that level ?

As I say, I'm happy to be pointed at reading material rather than asking dumb questions. Mostly just wanted to say hello.

Mick J hi, welcome. Unfortunately the forum isn't really set up in a way that makes it useful for browsing old topics for information.

If you are confident with computers, many here use home assistant to control things like matching battery level to expected consumption. (I've gone my own way with lower-level scripting.)

Mick J Today though it has discharged itself almost fully by exporting to the grid

The battery shouldn't have discharged to the grid. The default 'eco' behaviour is to discharge only enough as needed to cover any consumption not covered by solar. It would only discharge to grid if it was configured for timed export, or if it wasn't measuring consumption correctly (not impossible on a new install).

Reading this article ... which is possibly out of date ...

https://community-beta.givenergy.cloud/t/managing-the-inverter-from-the-app/1129

It states ...

_While Charge Mode is set to Solar and Discharge Mode is set to Dynamic, the inverter is put in Eco Mode. _

I can't see anywhere to set a "Charge Mode" or "Discharge Mode" in the "My Inverter" section of the GivEnergy Cloud app, nor in the mobile app. I can see how to enable "Timed Charge" and the 10 time slots associated with it, also "Timed Export" and it's 10 slots.

What I want to happen (for now) is this ...

• During cheap hours, charge the battery to full
• Outside cheap hours, power the house from the solar first, then battery if available, then grid
• Outside cheap hours, charge the battery only from excess solar generation and NOT from the grid
• When there is excess solar and the battery is full, export to the grid

I think I achieve that by enabling Timed Charge and putting my hours into slot 1, set at 100%.

Does that make sense ? Am I understanding things correctly ?

Once I've got that basic config going I can refine, especially once I get my MPAN moved to Octopus SEG.

Mick J Yes the default Eco mode will do most of what you want, and then a timed charge for the cheap rate period will fill the battery. Worth being aware that when the battery is full in the cheap rate charging period all of your electricity will continue to come from grid import until the end of the cheap period

When you program a timed charge the inverter is set to charge mode for that time period

Mick J I can't see anywhere to set a "Charge Mode" or "Discharge Mode" in the "My Inverter" section of the GivEnergy Cloud app

Yes, I think that document is old - they used to talk about the inverter being in one of various modes, but that doesn't really make much sense since they tend to operate orthogonally.

On the cloud page, inverter settings, the top one is eco, and the second one is timed charge.

Obviously it depends on your daily consumption, but if you charge to 100% overnight, excess solar will have to be exported, which isn't ideal if you're not getting paid for it. But of course that's better than not charging enough, and then having to import if you run out of battery before the end of the day. You don't say how much solar you have, but I guess if you've had it 10 years, it's probably going to be a relatively low max power ?

Mick J I have a Zappi EV charger.

Are there sticky posts with links to useful reading material please ? I don't want to be that guy who asks all the dumb questions without reading up first.

You'll probably want to avoid discharging battery into car. It can be done with software, but if you're using Intelligent Octopus Go, that now has a habit of repeatedly changing its plan throughout the night, making it a little hard to anticipate what it's going to do. So ideally you want to hide the charger from the inverter.

I recently posted a photo in https://community.givenergy.cloud/d/6061-adding-an-ev-charger-using-a-harvi-and-replacing-solar-ct-clamp/5

(You can still configure the zappi to use any excess solar, but this prevents the battery from trying to cover car-charging from the battery if you get a bonus IOG charging slot. But once you are getting paid for your export, it's cheaper to just rely on the grid for all your car charging. So you might want to configure the zappi with a large export margin so that it doesn't consume anything you're trying to export while the car is plugged in.)

DD We are lucky enough to have 3-phase power and a large roof which we filled 10 years ago. Total is I think 7.2kW which we spread across the 3 phases 2.4kW each.

I'm sure it won't take too long to get the export MPAN transferred. we've done the final reading and now most of the way through I think.

geoffreycoan That's a good thought and thanks for pointing that out I don't think I would have realised. Our consumption overnight is very low, unless of course we're charging the EV. I want the EV to charge from the grid and not the battery, so by setting a charge period covering the cheap rates it sounds like that will achieve just what I want.

DD Thanks I'll have a read of that. The Intelligent Octopus Go has worked very well with the Zappi so far and of course it might result in charging outside cheap periods, which Octopus will control. If that happens the inverter will I guess draw power from the battery which isn't ideal.

I'll have a word with my installers about hiding both the solar and battery from the Zappi. If that can be achieved so we can only ever charge from the grid that sounds ideal.

DD I had set up a timed export period. I've now removed it. I have a timed charge (23:30 to 04:30, 100%) but nothing else.

DD My Inverter Settings show (top to bottom)...

• Timed Charge
• Timed Export
• Winter Battery Conditioning
• Grid Settings

I've set it so I have 1 timed charge period and no timed exports. Winter conditioning is off.
Under Grid Settings it's set to the default maximum (60kW).

DD I'm not averse to just switching to Go and using timed charging. If I restrict the EV so it can only charge when the inverter/battery is in a Timed Charge period will that prevent the EV from consuming battery ?

[unknown] I'm not averse to just switching to Go and using timed charging. If I restrict the EV so it can only charge when the inverter/battery is in a Timed Charge period will that prevent the EV from consuming battery ?

Yes, that's another way of doing it - during the GE timed charge period, the battery will not discharge.

You can just ask for the car to be ready by 05:30 to prevent any extra slots, but that doesn't really seem to me to be within the spirit of IOG.

Last year. Octopus only paid 8p for export on Go, so it made quite a big difference to qualify for IOG, but they've now removed that differential, so it's not such a big deal.

geoffreycoan Worth being aware that when the battery is full in the cheap rate charging period all of your electricity will continue to come from grid import until the end of the cheap period

When you program a timed charge the inverter is set to charge mode for that time period

And on a related note, if you configure a timed export with a lower limit on SoC, the battery will go idle if that SoC is reached, and grid import will be used to cover consumption, which is not what most people want. It does render the feature a bit limited.

I had a chat with my installer and they had apparently already realised an error had been made with the meter connections on the three phase inverter. They came back in to sort that out and do a couple of additional things. Givenergy tech support were involved to help get the connections right and to test the measurements all round.

It's working perfectly now, exactly as I expected. I have switched to Octopus GO for now, from Intelligent Octopus GO, as it's simpler and I can keep an eye on things for a while. I may switch back at some point. My Export MPAN is also being switched to Octopus and I plan to use the Outgoing SEG for a while.

For the last few days it's been charging the batteries to full on a timed charge starting at 00:30. Aside from that charging the grid import has been basically nil. After 05:30 the load for the house is provided by the solar if generating, or batteries if not. Any excess solar is used to top up the batteries or exported if they are 100%.

Perfect.

When I get the MG EV back from the garage (therein lies a big story) it will be charging via the Zappi on a timed charge in the same 00:30 to 05:30 cheap period, topped up to 80% every night. As I say I may switch back to Intelligent Octopus GO (which gives slightly cheaper off-peak) and I will look at options for Smart Export, but I want a couple of months of simple operation first.

DD

I can see exactly what you are referring to. My Timed Charge period is 00:30 to 05:30. During that period any load is provided by the grid, not the battery, even though the battery is full.

Thanks for pointing that out. I may reduce the window of the charge period. So far it's been fully charged by around 01:00 - ie 30 minutes after starting. The consumption before 05:30 is pretty low so nothing really to worry about but I can try setting it earlier.

Thinking about it, until I get confirmation that Octopus have taken over the export MPAN I could be exporting power to the grid without being credited for it. I could set the Timed Charge to say 60% (of 11kWh) which will power the house for the day and let the solar top up the battery instead of exporting.

[unknown] So far it's been fully charged by around 01:00 - ie 30 minutes after starting.

Could consider charging for longer at a lower power - possibly kinder to the battery than charging at full power for a short time. (I charge 9.5kW battery at about 2kW over 5 hours, rather than full 3.5kW for about 3 hours.)

DD

Interesting - how can I control that ? Against the Timed Charge I can only see start/stop times and maximum SOC ? So I can tell it when to charge and up to what battery %, but not at what power ? Am I missing something ?

[unknown] There's a global register to configure the max charging power - affects both grid and solar charging. I leave it at 2kW since I don't particularly want solar to charge the battery. Can use the API to adjust it between values. (Initially, I had a script which would calculate power required to charge battery from current state to target state over the full off-peak period, but since I now run down the battery at night and charge to 100%, that rarely changes.)

In the remote control, it's in the percentage limits section - "battery charge power". (That said, not sure if 3-phase has the full complement of features ?)

DD

Ok thanks I see it - "Battery Charge Rate" and "Battery Discharge Rate". Both set to 100.

So they are global settings which limit the charge/discharge rate, irrespective of whether the source/sink is solar/grid. Useful to know thanks.

Since the inverter is 11kW I assume that 50% for example would mean the battery charge rate is limited to 5.5kW.

So If I set it to charge at 50% for 1 hour it will add 5.5kWh to the battery, in my case adding 52% of the SOC to whatever was in it to start.

Correct ?

Mick J my system seems to show it in W rather than a percentage. Though I think I'd read on here that it's available as either.
Internally it's stored as an integer 0-50 which is a percentage of battery capacity. So for my 9.5kWh battery, each step is 95W.
Is 11kW the max AC output? There's probably also a limit on the battery power. Eg my 5kW inverter has a limit of 3.6kW on the battery interface.

In short, I don't know, but should be easy enough to experiment - cost is minimal to charge from grid for a few seconds to see what power it's using.

Mick J Oh, I see - I do seem to have two different settings in the remote control: in Percentage Limits there's battery charge and discharge power, in W. But in Battery, I have Inverter Charge/Discharge Power Percentage.

While power is set to 1805W, the percentage is 100%, which suggests they are two different settings. Which is interesting. Reducing power from 1805W to 1710W changes register 111 from 18 to 17, as I expected. Reducing the charge percentage from 100% to 96% changed register 313 from 100 to 96.

My modbus documentation calls 111 the "battery_charge_limit", and 313 the "battery_charge_limit_ac" (in a block "Single Phase New registers". I've not played with the latter, so not sure what it does, or how the two interact.

The battery charge limit applies to both grid and solar charging - at a guess, the charge limit ac would affect only grid charging ?

DD Thanks a lot. Mine is 3-phase but I suspect much of this will be the same.

[unknown] I've done some more experimenting - the percentage ones do seem to be based on max rate. So for my gen-3 hybrid (max charge/discharge rate 3600W), 1% is about 36W.

I've now adjusted my scripts to use this feature - I was previously adjusting the original discharge one between about 2kW when I was exporting, or 3.6kW in eco mode. But now I've just set this _ac one to be 50% and can leave the other one at max, and the inverter now automatically exports at the lower power without the need for dynamic adjustment. So that reduces the number of register writes needed.