I got charge regulator (homemade) I built few months ago, and it's working very fine untill now. I even sold few of them to the people around here, and they too seem to be satisfied.
I have just one problem with that. I set it that it charges the batteries all the time, and when battery voltage raises to 14.4 volts, it turns the shunt load on. (I use 4 H1 car bulbs (55 W each) connected in series/parallel, so it is 24V/220W, and it performs quite well. 12V setups were burned when the alt is spinning high rpm's)
My problem is in the fact that charging voltage (from the alt to the batteries) is allways higher than the actual battery voltage. Alt's Voc (without the batteries, open circuit) can go as high as 40+ volts at moderate winds. It seems that battery (three in parallel, but performing as one because they're the same) allows a few volts higher voltage to come into than it's own actual voltage (state of charge).
From that fact, when my regulator is switched to dump the power to bulbs (dump load), voltage on battery terminals (measured by regulator) is 14.4 volts. But when I disconnect the alt and all the wiring, and than measure the voltage on the battery terminals, I get only 12.5 volts.
It's obvious that I need to allow higher charging voltage if I want to have 13.8 volts in fully charged battery. How high can I go? I have some circuits that are swithing off the charging current at 16.5 Volts. My batteries are lead acid, 80 Ah each (allmost new, 6 months old).
Can I go to 16.5 volts? Regulator is easy to set up to any desired voltage.