I am no expert, but it all depends on your specific needs, expectations, and other factors. What is the AMP rating?. It has to be quite small which limits the max current produced. What is the Weight? How big is the shaft on the motor? If the shaft is big enough, you can go with a bigger prop which can mean better low wind performance than a small 4' mill.
The maximum WATT output would be limited though. You would have to furl early. 12v cut-in would be very low for that motor. (probably around 90-100rpm?)
I just made one out of a similar motor (not quite that low of cut-in though) and it does make a very CONSISTENT low wind/low rpm PVC (3-5) bladed generator.
I will most likely replace it with a nice brushless alternator next year.
I wouldn't do it unless the motor was very affordable and you want something quick and easy. It is something fun to experiment with. But the bigger 7' diameter blade rotor is much more noticable than a small 4' mill.
It is not the ideal thing to do though. Brushless alternators are better for many reasons. I am still testing mine but quite excited with the low wind performance.
(Which happen over 90 percent of the time)
I live in a low wind area (hilly valleys) , and I have a small batt bank. And I can't put up a tall tower. And So I need to try to recharge what I use each day, not every three or four days with a serious big batt bank.
