1. A longer tail will help you stay in the wind.
2. You need a dump load on your battery... definitely not a regulator... you don't want to unload a windmill, as it will run out of control if the load is released. You need a comparator or similar to turn on a load and use the excess voltage that would otherwise overcharge your battery... ie when the voltage approaches 14.7v, turn on a load that pulls the voltage back down to 14.5, then release, then pull in then release etc etc. and hold the voltage around the 14.5v for battery that you are going to cycle each day. Float would be around 13.7v, but for playing with , 14.2-14.7 is fine. Your car will run around 14.5v because it is cyclic in nature. Full time will be lower maybe 13.7v.
A Ghurd controller will help you do this, inexpensive but useful.
3. You need to google diode, and understand what it is and how it works. Then you will need to get a feel for your max current you expect, and buy one with at least double that current at at least 3 times the expected voltage.... or use an old alternator's diode block, and rewire that . ( should be 2 banks of three in there to play with)
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4. Once you hook the motor to the battery, the mills voltage will come down to match the battery voltage, as it has a low internal impedance.
The open circuit voltage of your motor is a function of the rpm/volt . If you have say 50 rpm/volt, then 250 rpm will be 5v. The faster the thing runs, then higher the voltage proportionately.
5. Under load, the motor output will be a function of the rpm and the synchronous impedance of the motor...... a big word, but thats the facts. Once generating under load, the impedance ( incorporating the resistance of the wiring and brushes etc) and the inductive reactance as a function of frequency, coupled with the armature reactance and state of charge of the battery, will dictate the output...... but as a given, it will be pulled down to the terminal voltage of the battery. The current will be governed by the synchronous impedance of the motor at that frequency ( and battery impedance at that voltage). It is complex magnetics, and there is no simple way of making firm predictions, and is best found by bench testing into a load to get an idea of how the current increases and the voltage increases/droops , and the relationship with the state of charge of the battery.. not simple to explain, but easy to see on a bench test ( your drill driving the motor driving the battery and taking voltage and current measurements at different rpm with different state of charge of the battery..). This is not a simple subject, but can be fun to suck it and see.
6. Once you have grappled with the magnetics and their characteristics ....re power at what rpms, then you can wrestle with the correct TSR and size of blades to use for best effect of that motor and expected battery bank voltage.
Very difficult to give concrete advise with what you have there.
...............oztules