I operate a solar system with a Fronius GEN24 inverter and a BYD HVS battery. Until now, I was able to read all values reliably via the Fronius integration.
Today, I installed a second BYD HVS battery. It is correctly recognized in the Fronius Solar.web portal and functions as expected. The batteries are running in parallel, and the total storage capacity is now shown as 20 kWh. However, the second battery does not appear separately in the Fronius integration.
I attempted to connect the new battery directly to the network via LAN, but it seems to disable the LAN interface after startup, likely because it is configured as a slave to the first battery.
Since the expansion, the SOC values of the first battery are no longer available in the Fronius integration within Home Assistant – even though the battery remains reachable on the network and its IP address has not changed.
My questions:
– What steps do I need to take to ensure the SOC values of the first battery are correctly displayed again in Home Assistant? – Is it possible to also read the values of the second battery via Home Assistant – perhaps using Modbus or another interface?
that’s quite normal since you don’t have 2 batteries in the end but you expanded the capacity since both battery towers are combined in parallel on the DC side normally by utilitsing that BYD combiner box, and logically they are linked in a master-slave setup.
Means, there’s the master BMU in the battery tower talking to the inverter, the BMU from the other tower sort of wastes it’s life till the end of all days.
And this master BMU recognises that there’s 2 BMS available one from each tower.
The integration isn’t aware of 2 BMS since so no information.
There’s a couple of workarounds
this one if you want to stay on the HA side
that one if you realised things do go wrong in terms of boths SOCs do drift away from each other, Cellvoltages differ a lot and similar effects. This is merely a damn good replacement to the Be Connect Plus app available from BYD. It offers a way better graphical representation, the ability to create logfiles and trace through the recorded period again with an even better graphical representation, and since a while the author of that tool added MQTT publishing which allows to simply publish them to the MQTT broker available as an addon for HA. With the benefit one mustn’t import everything, so one’s not endiing up with hundreds of entites.
Of couse this tool does require an extra hardware either linux or windows where it runs 24/7. Ideal if you own a NAS or have pi running 24/7 for lets say pihole or something like that.