question

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Force charge/discharge of Multiplus using VenusGX & Node-Red

What am I trying to achieve?

Charge the battery, or discharge the battery based on external input (via MQTT, but ultimately based on variable electricity tariff status)


I am up and running in Node-Red on the Venus GX 'large' image and am able to set the Multiplus to the following modes;screenshot-2021-02-09-at-140652.png

However if I set the multiplus to 'charger only' it obviously won't charge if I'm not in a scheduled charge slot.


If I set up a scheduled charge slot to be active at all times, then I can charge / not charge on demand by setting the 'Disable Charge' flag to either 0 or 1.screenshot-2021-02-09-at-142013.png

However when in the 'don't charge' state, it also won't discharge the battery as I'm in a scheduled charging slot.

I've tried setting the AC power setpoint instead of charging within a scheduled charging time, but it doesn't seem to do anything if I try the following;

screenshot-2021-02-09-at-142437.png


Can anyone offer any recommendations on how I can switch between charging or discharging to meet my requirement?


Multiplus-IIVenus GX - VGXbattery chargingNode-RED
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homestorage-77 answered ·

So I appear to have arrived at a solution by setting the ESS Grid Setpoint appropriately depending on my charge or discharge requirements.screenshot-2021-02-10-at-092905.png

If I want to charge, I can set this to 20,000 (which will charge my battery up to the 70A DC limit, assuming my AC loads are less than around 17kW - which is usually the case)


If I want to discharge the pack, I can set the variable to 0 and the system will behave in a normal way in that it discharges to match AC consumption.


It also gives me extra flexibility if I ever want to export energy, I could set it to -5000 and the system will do so, local usage aside.


It doesn't feel like the most elegant solution so would welcome any other suggestions, but looks like this will meet my needs.



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Exactly what I want to do..

But no ess until I replace my multiplus with multiplus II.