Block battery unload at a given SOC with node-Red

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luupus asked Mar 3, '24

Block battery unload at a given SOC with node-Red

Hi, I would like to block battery unload as soon as a distinct SOC state is reached.

I do not want to set it via minimum SOC, as this would trigger the battery life cycle (+ 5%...).

However, this block has to disappear in case of an power outage. How would I implement this best via node-RED? Right now I do it with scheduled charging for one hour, which is continually updated.

I would prefer to send a direct command to do this.

Thanks for your help

Wolfgang

SOC battery Node-RED

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Modifications Space

Node Red Space

Answer 1 · 2024-03-07T10:28:16Z

hominidae answered · Mar 07 at 10:28 AM

...assuming you run an ESS, you should:

at first enable monitoring of grid failure in your GX

...then, in NR:

use NR to monitor the SoC value
use NR to monitor the GridLost alarm value
pass the SoC value messages through a Gate Node (node-red-contrib-simple-gate)
manage the State of the Gate with the status of the Grid alarm (open the Gate while Grid-Alarm is false/0 with a (gate node) control message)
after the Gate, pass the SoC value through a switch node; if the value is below desired level, enable ESS inverter limit/set ESS inverter limit to 0W - if not disable ESS inverter limit
when grid alarm triggers, close the gate with a (gate node) control message AND disable ESS inverter limit

...hope you'll get the picture.

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Answer 2 · 2024-03-09T12:19:58Z

luupus answered · Mar 09 at 12:19 PM

Hi, thanks!

However: if the ESS invertert limit is activated and set to 0W, in the event of grid lost, would there be any power to keep the process alive to de-activate the inverter limit? In my understanding this could cause an immediate power outage.

Basically, is there a hard coded inbuilt switch that overides the setting automatically?

1

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hominidae commented · Mar 09 at 12:38 PM

...the GX and Multi are both connected to (and their electronics driven / powered by) the battery ... but you should give it a try and examine how the system behaves...then adjust the NR flow accordingly.

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Answer 3 · 2024-03-09T12:23:57Z

nickdb answered · Mar 09 at 12:23 PM

Grid loss tends to override most config, with cutoffs set on the inverter.

It is all in the manual:

This limit only applies while connected to AC-in: In inverter mode, the AC loads determine how much power is drawn from the battery.

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Answer 4 · 2024-03-13T09:41:35Z

luupus answered · Mar 13 at 09:41 AM

Great, thanks for the update.

(Ok, I admit, I should read the manual in more detail ;) )

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