i suppose it could be used for such a purpose
voltage being linear generally
it should charge a battery at rotor speeds i would think.
the main issue might be the fact that it is a brush type motor
with the power being taken off the armature (rotating part) and you
are limited to around 7amps max.
seems like one could make better power with something else for less money?
i passed up a 300+lb, 50 hp dc permanent magnet motor some years ago
because it was 180 volt and limited to around 30amps if i recall,, might have been more..
but i could not see trying to lift a 300+ lb motor now generator up on a tower
for a result of around 30amps.
be interesting to see the results if you decide to go with it.
bob g