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luupus avatar image
luupus asked

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

Node-REDSOCbattery
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4 Answers
hominidae avatar image
hominidae answered ·

...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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luupus avatar image
luupus answered ·

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?

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hominidae avatar image hominidae commented ·
...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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nickdb avatar image
nickdb answered ·

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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luupus avatar image
luupus answered ·

Great, thanks for the update.

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

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