I have a dc motor and a propeller. how do i charge the batteries? do i just connect them to it?

Question

I have a dc motor and a propeller. how do i charge the batteries? do i just connect them to it?

Answer 1

yes, if you want the batteries to make the motor turn.

If you want to charge the batteries, you put a diode between the battery and the motor. If the motor starts to turn, then swap (reverse) the diode connections. Use a 1 amp rectifier.

You have to get all of the polarities correct, the motor, the battery, the fan blades, the wind.

But I doubt a wind can spin the motor fast enough to generate enough voltage to charge the battery. Try it. If you have a voltmeter, connect it across the motor to see how many volts you are generating.  The voltmeter will tell you if you have the polarities correct. If the voltage is the same polarity as the batteries, you are correct. If not, swap the motor leads.