Set vehicle's usual max power

[TheMr-S]

Is your feature request related to a problem? Please describe.
My vehicles both use way less than 11kW / 3,6kW when fast charging. With the Kia e-soul, it is about 10,4kW in 3p and 3,4kW in 1p. I know that this is a normal behavior, but it comes with problems when using the planner: The charging will always overshoot the planned time as it calculates with the theoretical max power.

Describe the solution you'd like
I would like to have the option to set a value for the usual maximum charge power of a vehicle which then is (only) respected by the planner for calculations. For my use-case, this would have to be seperately for 1p and 3p.

Describe alternatives you've considered
As far as I believe, setting a lower maximum current for the vehicle (e.g. 15A for about 10,4kW), should not solve the problem since this will only result in the vehicle charging even slower.

[andig]

should not solve the problem since this will only result in the vehicle charging even slower.

Did you try? Why should that be slower than it charges anyway?

Closing since max current is the option available.

[TheMr-S]

I was quite sure about that fact, now tried and verified it:

When I set the max current of the vehicle to 15A (which should fit to about 10,5kW), it then only charges at maximum 9,5kW.

For some technical reason, some vehicles tend to draw a certain amount of current less than what the wallbox tells them to draw. In my case this difference seems to be about -1A. So reducing the max current of the Wallbox will reduce the real current even more and not solve my problem with the planner.

[premultiply]

Ultimately, it's a question of the assumed charging efficiency, which is currently assumed to be 90% across the board.

Perhaps this value is still a little too optimistic and we should lower it slightly?

[TheMr-S]

Ultimately, it's a question of the assumed charging efficiency, which is currently assumed to be 90% across the board.

Perhaps this value is still a little too optimistic and we should lower it slightly?

Doesn't really make sense to me in my case. 10,4kW/11kW would mean about 95% charging efficiency. And the planner does indeed overshoot it's goals. Are you sure that there is a 90% efficiency assumed in the plan?

Edit: Here I ignored the efficiency of the OBC - please ignore my objection. Lowering the assumption could be a solution.

[andig]

No, just guessing ;)

[VolkerK62]

@TheMr-S what is the targetsoc if you use the plan?
is there a difference regarding the overshoot if the target is 80%, 90% or 100%?

[TheMr-S]

@TheMr-S what is the targetsoc if you use the plan? is there a difference regarding the overshoot if the target is 80%, 90% or 100%?

Usually 60-80%, but sometimes also 100%. There is no real difference regarding the targetsoc.

[mfuchs1984]

Ther will be no assumption that fits all, temperature, SoH, SoC, battery calibration, self consumption etc. influence capacity and charging efficiency.

The best way to get accurate planning is to adjust the vehicle's battery capacity. In case you set it to a higher value, the planner will begin earlier.

My car also charges with about 10,4 kW, the net capacity is 80,7 kWh, at the moment, the car itself reports a capacity of 79 kWh. In evcc, I use 80,7 and the plans are super accurate.

[andig]

We might make the 90% a user parameter. It doesn't feel right though since we did well without doing so for 5 years now...

[TheMr-S]

We might make the 90% a user parameter. It doesn't feel right though since we did well without doing so for 5 years now...

Thought so too: Why would this be a (quite heavy) problem that happens to me after all that time? But that would be nice, thank you!

[andig]

Seems we don‘t know. Can we get a full debug log of an entire planned session maybe? Just interesten in how the planner/estimator behaves.

[jorisvanpoucke]

should not solve the problem since this will only result in the vehicle charging even slower.

Did you try? Why should that be slower than it charges anyway?

Closing since max current is the option available.

Can I add that I have the same or similar question as the OP, since I am stuck with the capacity tariff in Belgium.
The planner is overestimating its charging speed, but I don't want to reduce it, since it will also reduce the charging speed when it is PV loading (or PV + some net).

Prerequisites
To make it concrete, my charger can do 7.4 kW.
I want to limit the grid usage to 2.5 kW.
I have 9.52 kW PV panels on a 5 kVA invertor.

The behaviour I want:
So when the sun is shining nicely during the day, I can load with about 7.4 kW as in 5 kW from PV + 2.4 from the grid.
If the sun is not shining in the night, I can only load with about 2.5 kW from the grid.

The behaviour I get with limiting the power of the charging station to get the planner right:
If I limit the charging station to a certain amount, let's say 2.5 kW to get the prediction for the night correct, it can not load faster than 2.5 kW during the day anymore...

The planner should take into acount the max power from the grid connection point, and add the (expected) pv power to it and plan with that expected possible charging speed.