Thanks for your reply. Do you know anyone who makes a 12v or greater hub dynamo? I understand that most dynamos can output 12v depending on the speed; however as you correctly say dynamos rated for a certain volt are capable of attaining that voltage easily at 10 KPH. I want the highest voltage I can find at relatively low speed, as I am aiming for high voltage and low amp output. I know that Busch & Muller do a 12 volt bottle dynamo, but does anyone know if there were any 12v hub dynamos that were ever made. Even far eastern copies?