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pverga avatar image
pverga asked

Can I send a Modbus TCP command to a Multiplus-II to start charging the batteries from grid

I am at the point of buying and installing a MultiPlus-II 48/5000/70-50 GX with batteries to improve my existing home PV installation. I'm planning to integrate the MultiPlus with my Loxone home automation system using Modbus TCP. The home automation system already has a fairly extensive energy management system. In the darker winter months it's probably beneficial to charge the batteries at the lowest electricity spot prices. I have the automated download of daily electricity spot price information already available, one day ahead.

Is it possible to instruct the Multiplus via Modbus TCP to start charging the batteries either by a schedule that I can submit or at the time the lowest spot prices occur?

I've been exploring the Multiplus and Modbus documentation, but cannot find the answer (other than charging the batteries with a fixed time of day schedule).

Multiplus-II
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1 Answer
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wkirby answered ·

You'll need a GX device (like a CerboGX) which connects to the LAN and performs the ModbusTCP functionality. A RaspberryPi running VenusOS would also work if you have MK3-USB dongle.
There are several writable registers available. The com.victronenery.vebus registers would relate to a MultiPlus. Which one you use will depend upon how your system will be set up.
Check out the Modbus-TCP register list available for download from here:
https://www.victronenergy.com/support-and-downloads/technical-information

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