Hello everyone!
I bought small used boat, it has 2 12v batteries and a 300w 30v solar panel with Steca pwm controller. Solar is charging only agm battery(150ah, used for electric trolling motor only), and engine(18amp alternator) is only charging starter battery.
I was thinking of few ways of charging starter battery from solar too, and dual output controller would be most elegant solution. But, panel has high voc and only mppt controllers can take it(besides this Steca), and 300w 30A dual mppts are expensive and harder to obtain for me.
Another option and much cheaper one is to just install Cyrix ct, so it can transfer extra charge to other battery, be it from alternator or solar.
Since I don’t plan to use start assist function, i was thinking of using smaller diameter wires, wire size calc recommends 4 mm2 for 25amps 1m long, but lets go with 6 or 10mm2 just in case. Now, in that case what to do with a 120A fuse from schematics?