Charge your battery first. 

The voltage regulator regulates the amount of charge current to the battery gets depending upon it's needs. That is why it starts charging initially after startup or when you flash the lights on and when the battery is full up it cuts the charge rate back to zero charge. A cutout on the other hand cuts in when the generator starts charging and keeps charging regardless of battery needs. It will boil the water out of a battery on a long trip. The beauty of the regulator is that when the battery needs no further charge the regulator shuts the generator down. Take a long drive with a cutout, stop and feel the generator and it will be warm, because it has been cooking the battery. Take the same trip with a regulator and the generator will be cool to the touch. The Model T generator needs all the help it can get. 

Ron the Coilman