Difference "Battery level" and "Battery level (nominal)"

[gsteger81]

Hello,

I'm new to HomeAssistant and this great integration for my Sungrow inverter. I got it all up and running without a flaw thanks to this great integration and the detailed instructions.

The only thing I do not unterstand right now is what the difference is between the two battery gauges in the dashboard displayed. They are called "Battery level" and "Battery level (nominal)". Can anyone explain to me what's up with that?

Thank you in advance!

[hboltz]

Hi,

that's quit simple. Since you can set the max SoC for your battery, the both levels could be different. Let me explain it with an example: to avoid permanent full loading to 100% I set my max SoC to 80%. So if the 80% (Battery level (nominal)) are reached, the battery is loaded 100% (Battery level). I hope this explained the difference between the 2 values.

Have a nice day!

[gsteger81]

Thanks hboltz for the reply!
But as far as I can see from the data it's the other way around. "Battery level" is the actual level of the battery as delivered by modbus. "Battery level (nominal)" is the level of the useable battery range and takes Min SoC and Max Soc into account (template sensor):

(from modbus_sungrow.yaml)

But if I understand correctly Battery level (nominal) should give 0% if the Min SoC level of the battery is reached. This is not the case for me:

Is it a bug? Or am I plain stupid?

Thanks for the patience with a noob!

EDIT: I'm confused right now, I think hboltz is right that "Battery level (nominal)" should be the one that shows the modbus value. The formula should calculate the value of "Battery level". Is it possible that this is a mistake in the yaml file?

[Gnarfoz]

The value from Modbus register 13023 contains the current battery level modified by the user-configurable min- & max SoC limits.
The real, full-range battery level needs to be reconstructed from those 3 values, which is what battery level (nominal) does.
To stick with @hboltz' example, if the Modbus value is 100%, then the nominal SoC (80%) is equal to the configured max SoC (80%).

Battery charge and battery charge (nominal) also take this into account.
Battery charge takes the battery capacity (which is not modified by min/max SoC), adjusts it for min+max SoC, then multiplies it with the Modbus battery level value (which itself is already adjusted for min+max SoC).
Battery charge (nominal) doesn't adjust the capacity, it just multiplies it with the nominal battery level.

It's not the most intuitive setup, but it seems correct.
Battery level should always deplete faster than battery level (nominal) since it is the one modified by min+max SoC. (Unless those are 0 and 100, of course).

[gsteger81]

Thanks Gnarfoz, now it becomes clear to me. Very good explanation.