Hi Norm,
I think you have the gist of it ,A rectifier on the red wire converts alternating current (AC) from the stator into direct current (DC) for the battery. It also acts like a diode by allowing current to flow in one direction (to the battery) while preventing reverse current from flowing back to the stator, protecting the electrical system.
Yes, using a voltage regulator between the rectifier and the battery is generally a good idea in applications like this.
As we know.
Voltage Regulation: The output from the stator and rectifier can fluctuate depending on the engine speed. Without regulation, this voltage could exceed the battery's rated voltage (usually around 12.6 to 14.4 volts for a standard lead-acid battery), leading to overcharging and potentially damaging the battery.
Cheers
Max.