Thank you for your question. I am planning to explain the production with a video in my next tribune. More than any engineering calculation I am focused on the production with minimum cost. I try to expand the tribunes’ limits in time. Since I am not an engineer it is not for me to answer your questions.
By the way; did you ever tried to fix a car alternator to your motor and try to charge another battery while driving with the first one ?
Probably you will need a cut-off charging circuit to control the charge.