May I suggest that you have a good idea, but you are looking at it from the wrong direction? If you connect your generator to a windmill and the output across a battery, you have a power source that will keep on working after the wind stops. Chevy alternators only have one connection that goes to the battery. The other lead is the car frame ground.
Your problem is going to be the battery. A car, or even a truck, battery is only good for about three years. After that, it won’t hold a charge.
First, you need to use a stationary battery like the Absolite line that has a 20-year guarantee. The things are expensive, but not over the expected lifetime.
Second, the amp hour rating of a battery is based on a steady discharge over an 8 hour period (with the exception of Gel Cells which use a 24 hour standard so they look better). Discharge a battery in less time and you get fewer amp hours that the stated number. Take longer to discharge it and you get more that specified. Also look at the discharge level specified. A charged led battery will have 2.2 volts per cell output. If on a float charge, the system will read 2.25 volts per cell. Battery specification sheets will give an amp hour rating for a final discharge value of from 1.85 down to 1.75 volts per cell. Discharge below 1.75 volts and there is a good chance the battery will never take a charge again so you have to supply a low voltage cut-off circuit to remove the load to save the battery.
As you can see from the above, your 12 volts are not going to be 12 volts very often. Most of the time it is going to be high or low. That is why most commercial systems connect an inverter to the battery instead of using it directly. There is only one exception that I am aware of and that is the telephone company. They use a 48 volt system of 24 led acid cells plus one CEMF cell connected backwards for a total 50.6 volts. The reverse cell acts as a regulator evening out the voltage. Note, if you try this, they make special cells for this use, don’t try using a regular one or you could have an incident that sprays acid all over everything.
I really recommend that you add an inverter and static transfer switch; then use your 220 system on either the mains or wind power as conditions permit.