Would think it is easily done with software and could be one more program in the load menu. Load comes on when float is reached and shuts off when it cant be held.
Not as crude of an approach to opportunity loads as via voltage and primarily the (lead) batteries are charged which is obviously vital to their health. Ideally also an independant 5V high signal on the RX TX pins can be given out for intermediate builds with Arduino for more versatility while float is active.
Mine is adjusted via voltage to protect the batteries to power the Arduino and the loads which then switches the loads accordingly. To find out whether float is reached I have glued a light sensor on top of the float LED. Works, but could be so much easier with a lot of use for others who want to heat water et cetera.
