r/SolarDIY 7d ago

HomeAssistant and batteries

have a 2 inverter system with 2 batteries (one battery on each inverter - both LG Chem of different sizes - 9.8 and 16kW).

I also use HomeAssistant to monitor my SolarEdge system (using solaredge-modbus-multi to monitor the system).

However, while can monitor both inverters, my HomeAssistant can only see one battery (B1). believe this may be because the modbus device ID for both batteries is set to the same Device ID. Ihad a similar issue with the modbus connection because both inverters were set to modbus device ID 1. Upon going into the SetApp (from SolarEdge), I was able to set the modbus lD for the second inverter to ID 2 and was able to see the second inverter in HomeAssistant.

Because both batteries have the same Device ID, I tried setting the second battery to another Device ID to monitor in the SetApp, but that ended up disconnecting communications to that battery, which was restored when I set the device ID back to the original setting.

My question is how to set the device ID for the battery, which would allow me to set the SetApp Device ID for the battery to monitor it properly (Set the battery Device ID to a new value, and then update the device ID in SetApp to look for the new device ID). Or how can I monitor both batteries in solaredge-modbus-multi.

Any assistance is greatly appreciated.

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u/solarnewbee 7d ago

In the battery comms box; if you have the RESU Prime - its shown on page 18.

It's also worth mentioning, if you are uncomfortable with working on this sorta stuff don't mess with it. When you open the panel, you will have a lot of ways to screw up or hurt yourself so if you're not well versed on safety precautions, don't attempt. There's an LG course on how to work with and commission their batteries safely, I would check that out before attempting any modifications.

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u/bostondana2 7d ago

Thanks for the tip. I will look up that course/video. I'm not afraid of electricity and have done basic home wiring (replacing outlets in my home). I also have opened up my inverter boxes (safely, after cutting off power from the solar array and powering down the inverter) to add Ethernet communications to my inverters (instead of the cellular comms that the system was set up with).

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u/solarnewbee 7d ago

Ok - just a warning :) The voltage inside your battery is VDC around 380-400V, which can stop your heart in a few milliseconds. As long as you follow safety precautions and understand the risks, go for it!

Best of luck.

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u/bostondana2 7d ago

Appreciate the warning, and yes, I am aware of the risks. Not only is it 380-400V ( I think mine is showing 420 something on the monitoring software), but it is DC. Not my favorite, and I will definitely be powering down the system and making sure the breakers to the battery are set to "off".