A stepper motor as a wind turbine?

I brought this little stepper motor from Oatley Electronics.

I had hoped that it would generate a decent voltage as it is rated at 24 volts as a motor.

I set about working out which of the six leads formed each of the two coils. Two leads were center tap ones and can be ignored. I found the two pairs in the end by drawing the following diagram and using a multimeter to record the resistance between pairs.

I hooked the inout shaft up to my battery drill and gave it a spin. I could get about 10 volts out, but only a few milliamps. Multiplying the two it didnt really equate to any decent output in watts.

It would be easy to make a little battery charger to charge very small batteries but I am after a lot more to charge my electric bike and such.

A good experiment.