In my off grid system I use an AC Thor 9S to run two 3kw immersion heaters when excess solar is available which the PV assistant controls by adjusting the charge settings in the inverter however it is very unreliable and the frequency shift to 53hz remains even when the batteries are down at 40%, it’s hit and miss if the frequency goes back to 50hz or not and it will drain my system if I’m not careful.
Battery is currently 60% and frequency 52.6hz, there is no logic to this.
Is there a better way to control this that’s more accurate?