IOG slots and battery force discharge

[AndySmithers]

I'm sure I must be missing something.
I have just switched to IOG after getting my Zappi connected this morning.
IOG is setup, test charge worked and it has created a schedule.
During the test charge, Predbat recognised the dispatch and switched to battery force charge during that test charge slot.
All seems fine.
But... looking at the Octopus schedule, I have charging slots for 01:30 to 05:00 tomorrow.
However, Predbat has scheduled a battery charge/discharge cycle *to maximize the delta between 7p import and 15p export) during that Agile slot.
This makes no sense to me since there is no point in force discharging while the car is charging.
Now, I do have my i8nverter and Zappi correctly wired so that the inverter cannot 'see' the car charging, but, even so, discharging the battery during this slot will definitely not go to the grid for the 15p export.

What am I missing?
Will Predbat dynamically recognise the IOG slot when it happens at 01:30 and change the plan accordingly?
If this is the case then surely forward planning is kind of pointless at this stage.

[gcoan]

I'm confused by what tariff you are on. You mention IOG but also Agile, is that Agile export?

Predbat will pickup the IOG slots and schedule battery charging in them. If the IOG slots change, predbat will update its plan.

If you want to stop predbat from discharging the battery when the car is charging you need to configure that option. See car charging documentation for details

[AndySmithers]

Sorry, I'm on IOG, read "IOG slot" for "Agile slot". (Too many tariffs considered and used in a short period!).

>If you want to stop predbat from discharging the battery when the car is charging you need to configure that option. See car charging documentation for details<
I'm really not sure what option you are referring to here (and certainly can't see that specific option in the documentation.

I guess what I'm asking is:
Does Predbat plan based on the scheduled future IOG slots or does it only respond to the Off-Peak rate sensor when it happens to adjust the charge/discharge behaviour?
Indeed what sensor actually gives me the scheduled slots?

[gcoan]

If you want to stop predbat from discharging the battery when the car is charging you need to configure that option. See car charging documentation for details<
I'm really not sure what option you are referring to here (and certainly can't see that specific option in the documentation.

I was trying to avoid me having to go and find the specific sensor name. Teach people to fish and all that.

But I failed, you didn't read the documentation.

See https://springfall2008.github.io/batpred/car-charging/#additional-car-charging-configurations

I guess what I'm asking is:
Does Predbat plan based on the scheduled future IOG slots or does it only respond to the Off-Peak rate sensor when it happens to adjust the charge/discharge behaviour?
Indeed what sensor actually gives me the scheduled slots?

If you have read the documentation and correctly setup your apps.yaml and the required switches for IOG then predbat will plan based on your IOG cheap rate AND IOG slots.

Again, this is in the documentation

https://springfall2008.github.io/batpred/car-charging/#octopus-led-charging

First bullet point

Please do read the documentation, its there to help you

[AndySmithers]

Thanks again for your reply.
I did read and re-read the documentation.
I thought I understood it completely.
I have got the switch switch.predbat_car_charging_from_battery set to Off.
And I have got all the options set up correctly, as per the documentation. (I think).

My question was regarding the plan:
The plan clearly shows discharging of the battery during the IOG charging slot tomorrow morning.
Now, the second link you gave me above suggests that the way Predbat prevents discharge form battery when switch.predbat_car_charging_from_battery is set to off and you have a car charge slot is by setting discharge to 0 during that slot.
How do I see this in the plan?
And, more to the point, why does it do it this way rather than plan to set the inverter to charge the home battery during this period???

[AndySmithers]

And, I've just discovered that it was all an unnecessary exercise.
The issue was simply a delay between the Octopus integration picking up the planned slots (and the fact that Octopus changes the slots every 5 minutes, it seems!).
It's all working as expected now.
Thanks for your fast responses.

[gcoan]

Predbat replans every 10 minutes, but as you are discovering Octopus can change the IOG slots very frequently which means Predbat is always in catchup mode. You can set the trigger entries in apps.yaml to force predbat to recalculate when the Octopus IOG sensor changes.

If you've set switch.predbat_car_charging_from_battery then predbat will prevent the battery from discharging into the car, this is done either by setting the discharge rate to zero (or setting battery pause mode to PauseDischarging if your inverter supports that), OR by charging the battery. But predbat won't charge the battery unnecessarily as that costs money. If you've have Predbat set to Charge and Discharge mode, and the rates (after losses) are favourable, then Predbat can charge the battery and then export the stored charge, but it won't charge the battery unnecessarily.

Predbat is not perfect but it does do a pretty good job of optimising your costs, so do try to trust it, and bear in mind that predbat can change its mind about what is the optimal plan!