Newbie - battery 100% power being drawn Octopus

Borisburgh

Hello sorry for what is probably a very basic question. I have recently changed to new supplier - Octopus Flux Import and Export with a smart meter installed. Previously no issues with battery being used but an old meter (circular disc) which went backwards (along with meter readings) when solar charging.

I have tried going into SHINE phone settings - but not sure what parameters to change to benefit from the Ocropus peak export, import rates.

However my guess is before scheduling this I need to have the battery discharging when required and not drawing from the grid!

Below should be screenshots from my app and Octopus rates and times

Any help much appreciated.

admin

Borisburgh Grid First is basically for forced discharging from your battery.

Battery First is charging your battery from the Grid. So you would schedule that between 02:00 - 05:00.

And perhaps have an optional schedule to run prior to the 16:00-19:00 peak to top your battery up a bit so you can avoid using the grid at the peak rate.

You can make this conditional charging easier by using our cloud service. :-)

Borisburgh

admin

Thanks battery now being used.

However when I try to add a second charge schedule I get a “Modification Failed” message.

Grid first set to use all day.

admin

Borisburgh Grid First is forced discharging/export. You don't need this (unless you explicitly wanted full rate discharging). Growatt by default will discharge batteries based on Load first.

Borisburgh

I revised settings as per above suggestion. However whilst battery is fully charged overnight at the cheap rate it is now again not being used despite morning kettle, lights etc on

The app suggests it is discharging to grid and smart meter is showing electricity being used from grid.

Octopus smart meter was installed in October 2024. Solar panel and battery installed June 2023.

Sorry for what are basic query but I am confused!

Borisburgh

Borisburgh update - now some sunshine and this going straight to home.

09:40 Further update (Sorry!) - tumble dryer put on and 2.09 kWh being exported to grid, 0.07 from solar, 0 from battery. - previously ((old meter) battery would be used at this point.

10:00 used grid first to force a discharge from battery - now doing so.

It seems that this is not therefore a default for my inverter - is there a way of amending this?

admin

Borisburgh I wonder if your CT clamp has been installed the correct way. Without (hardly) any solar, you should not see 'export to grid' when you're putting the dishwasher on.

Might be worth asking in the general Growatt FB group too: https://www.facebook.com/groups/723997255660985/

Something doesn't sound right.

Borisburgh

admin

I think my update may have passed your reply in the ether 😀 …

10:00 used grid first to force a discharge from battery - now doing so.

It seems that this is not therefore a default for my inverter - is there a way of amending this?

admin

Borisburgh Why would you want to Force Discharge? Default is as it said in the Shine app, "Load First". As from your own screengrab:

Your battery should discharge based on house load automatically. Without requiring you to use a Forced Discharge schedule.

So I would disable the Forced Discharge schedule, and your battery should be used to service the house load.

Note that there is a 5 min interval before the app/data refreshes, and that you are looking at a snapshot in time.

Borisburgh

admin

Yes that seems to be the problem- the battery only appears to discharge to the house
when I force it to do so.

admin

Borisburgh Well, it would also flow grid side if your house load was less than Solar yield plus Battery max discharge (3kW).

But main point is, that's not the mode you want for 'normal' self sufficient operation, you want to leave it in "Load first" by disabling your forced discharge schedule.

Borisburgh

Even though that seems to be the only way of forcing the battery to be used?

admin

Borisburgh It isn't though.

I have mine set as Load First and the battery is discharging fine.

Borisburgh

admin
Thanks for your responses and patience 😀.

Ok I have reverted to on grid mode, load first. The washing machine is now on. There is no load power going to the house and there are 6kw exporting to grid.

This does not seem right ? (It was not how it worked before the smart meter installation in October) meter

admin

Borisburgh Have you got other inverters on this system?

Post in the Growatt FB group I linked, because this does not look right. I reckon some CT clips have been incorrectly installed after the smartmeter installation, which is why your values look off, and why the inverter/battery doesn't seem to recognise your house load.

My installer colleague:"The DNO / smart meter installer has likely installed a new isolation switch, they have probably removed the CT and it’s either installed at the wrong point or pointing wrong direction"