Does anyone know if you can control a relay on the Cerbo GX based on the state of charge of a 2nd battery? I am setting up a system on my boat that has a multiplus connectes to a large 24v lifepo4 bank. I have a cerbo gx that will control everything. I want to be able to turn an Orion dc converter on when the house battery starts to get low to supply current to the 12v house system from the 24v battery. The 24v battery is being charged via solar when not connected to the dock.
There are a couple of ways. You could use a BMV on the 12V system which has a relay that is used to start a generator. You could connect that to the remote switch on the Orion.
I haven’t tried this yet but you could connect a second shunt to the system and run it on the 12V. I would have to test if this would even work. You would need to use the USB to Ve.Direct so they are isolated. If it does work and does not cause any errors due to different voltages then you could use a node red flow to control the relay based on SOC of the 12V.
I have 2 spare shunts and some batteries I could test this if you want just let me know its an interesting problem. The BMV should work really well also and be pretty clean install.