Re: Could I power a car battery with a windmill

Hello Ben, 

Well for your question I must say that car already has battery charging 
mechanism which is charged from alternator. 
If you intended to charge it from wind turbine then there are two aspects
1) Power of wind generator. 2) Charge controller & AH(battery storage 
capacity, measured in "Ampere Hours"). 
Your mentioned speed of wind is much sufficient it is about 20 mps
(meters per second). You didn't mention output of your WT; I guess you
have power curve provided by vendor so check your curve. If your WT output
is for 12V (charge controllers provided by manufacture) then just put the
connection on your battery and enjoy! But note that it is better that your
WT is not more then 200W because car batteries usually have low storage
capacity.

Regards, 
Asif Ali Khan