Combined usage of low tariff and plan

[h3llrais3r]

Hi, I've set up some tariffs to only charge during low tariffs.

When I then configure in the UI that it can only charge when the tariff is less than 31ct, it shows the periods when it should only charge. This is working as expected.

I've also defined a plan for my car to be charged until 80% at 6am.

In the current situation, the plan calculates that the charging should only start somewhere after midnight (as it would only take about 5hours to charge it till 80%), but it seems to have started directly at 21h, when the low tariff is active.

I would expect that the real charging would start as a combination of the tariff and the plan, or am I wrong?
It now seems that the tariff has priority over the plan?
If I disable the price limit in the loadpoint configuration, the charging stops as the plan informs it will start after midnight.

Is there a possiblity to use it in a "combined" way?

With "combined" I mean:

• only start during low interval hours (9pm - 6am)
• if the plan informs that it only need to charge from 1am util 6pm to reach the desired SOC, it would actually only start at 1am (as it's within the range from low interval hours)

[UDicke]

That simply means: plan should have higher priority. For which circumstances do you want this? Just take a plan and you are fine.

[h3llrais3r]

As mentioned in our other discussion, I need the tariff setup to make sure it doesn't charge outside the low tarif hours.
Additionally I'm using the plan to charge it up to the required SOC.
If it calculates that it only needs 5h to charge within the available 9h window where it's allowed, I would expect it to only start at the proposed time by the planner.

[mfuchs1984]

You have set a limit of 100%, evcc will charge to this limit by using surplus or when the price is below the configured price limit. This makes sense. I have a plan to charge to 50% on some days with the planner. This is what I want to have as a minimum, the planner ensures the price is as low as possible. But when energy is super cheap or surplus is available, I want it to charge further, so I have a general limit of 80% (better for the battery than 100) and a quite low price threshold. If I want to travel a longer distance, I enable a charge plan with 100% goal, this overrides the general 80% limit.

[h3llrais3r]

Thanks for the feedback.
I'm going to try to change the limit to 80% and see if it still starts charging at 9pm, when the low tariff becomes active, even when the planner says it can start later.

Limit updated to 80% (plan was already set to 80%), will keep you guys informed if it worked or not, as I can only check this evening.

[mfuchs1984]

With a configured price limit, it will, as long as the 80% are not reached. If you don't want this, disable the limit or set it to a very low level.

[h3llrais3r]

Ok, so it won't work in a combined way.
If I use the price limit, it will start (despite what the plan says) to charge in the period that the price is lower than the limit.
I can still use the plan to define the percentage to which I want to load, but the suggested start time displayed by the plan won't be used.

Would it also be possible to share your setup with screenshots, to have an idea how you have set it up?

[mfuchs1984]

Actually, it works in a combined way. Both goals are fulfilled at the same time, it is guaranteed that at least the planned soc at charge plan target time is reached and that very low prices lead to cheap charging. In case the charge plan would override the price limit, the price limit would never become effective with repeating plans since there is always an active plan. This would mean it does not work in a combined way.

In fact, the charge plan was overriding the smart cost limit after introduction of the repeating plans and the behavior was fixed in #17801

[UDicke]

@mfuchs1984 thank you very much for the insightful explanations of this features

[h3llrais3r]

Ok, so it works in a combined way, but not in a way I was expecting it to work.
If I only use a plan to charge my car until 80% at 6am, it calculates for example that it need to start at 1am and it will only start at that time.
If I only define a pricelimit, it would charge between 9pm and 6am, as those as the hours that are a "low" tariff.
I was in the assumption that if I set up both, and the duration of the plan fits within the duration of "low" tariff, it would start when on the hour the plan has calculated (in case above at 1am), but it doesn't.
In fact it will start at 9pm, when the low tariff becomes active and the plan will still be reached, but it will be earlier than calculated.
So my definition of a combined way was wrong. ;)

@mfuchs1984 Thanks for the explanation. It's clear now.

[mfuchs1984]

You're welcome!