I have a multiplus II 120v 5000watt inverter and also have a BMV-712 battery monitor. I see both have a programable relay in them. I am off grid. What I was thinking of doing was to set a relay up that would turn on a 120v water heater when the batteries were at 100% and shut off if batteries were below 80%. Is that something I can do? If so what is the voltages and amps these relays can control? Thanks
Yes, you can do what you propose, the BMV relay can be SOC controlled, the Multiplus one can be controlled via the relay assistant.
Go to victronenergy.com, go to the required product page and download either the datasheet or manual for the product, it will have the info.
If you are driving another relay take heed of this FAQ in the diy section.
have you found an acceptable contactor or relay that would suffice to turn on your water heater? I would like to use the BMV-712 to disconnect a 100A breaker panel. So I am looking for a relay/contactor with 50VDC 1A coil with a 100A 120VAC Contactor, and I cannot find one. Grainger had some Schneider options with smaller contactor current ratings that you might like for a 12VDC or 24VDC battery (see attached).
Amazon has contactors with 12v coil, 25a single phase, 40a triple. Should be enough for a water heater.
On my Quattro, I’m planning to use the AC2-out to turn on a heater when the state of charge is greater than 90%. No need for any further equipment.
There are YT videos that show how to do this.