I have a situation where my batteries reach about 80% soc by 8am on sunny days and the bateies lower thier charge current to say 20A although I may have a potential 100A available, i have a dumpload relay that turns on an immersion heater when the soc reaches 100% and off again when it goes down to 98%, this works well but I know on sunny days I could turn the dumpload on much earlier (at say 75-80% soc) so I was thinking of having the relay triggered by a light intensity sensor connected to an arduino.
Sorry if that was a bit long winded but I'd be interested In hearing people's thoughts or design idea's
Set up is
SmartSolar 150/100
Multiplus 48/3000/35/50
VenusGX
2x pylontech us2000b
8kwp solar