I have a permanent magnet motor that is rated 100v at 2500 rpms. I Would like to know is if I use it as a generator, will it produce altenating current or direct current if I use it in a wind turbine to charge a 12v battery.
It depends. You didn't say what kind of motor it was. Is it an AC motor? DC? What configuration is it? If its armature has a commutator, then it can be configured as a pulsed DC generator and you will need to do the filtering of that waveform. But you may have to make changes depending on the configuration. You need to be more specific. Surely there is model number and manufacturer plate.
As the longer answer infers it may produce negligible power, dc or ac or some of each. You need a bridge rectifier for best results if it produces ac, but a small half dead 1.5 volt cell (measure cell voltage before and after) and a diode in series will do for a test. 100 RPM for one minute will probably charge the cell a bit, if the motor is producing current. It will need to turn faster to charge a 12 volt battery but a few hundred rpm is likely enough for a very slow charge. Neil
If it has a commutator, it will produce DC. If it does not have a commutator, it will produce AC, but internal electronic circuitry pay prevent the motor from acting as a generator.
