@SparWeb,
I found your 2006 document at
http://www.jimic.cl/appv/Congreso/PDF/AXIAL_FLUX_HowItWorks.pdfIt describes the Dan Bartmann Axial PMA Ed is refering to, for which I have all 16 magnets in at the moment.
But in the end you write the following
"At 80 RPM, this alternator will produce 50 Volts, unloaded. When connected to a 48V Battery
system, Dan has recorded 600 Watts at 100 RPM. (Roughly 12 Amps). This is actually a
fairly large PMA, suitable for a windmill size of about 17 feet diameter. At higher wind speeds,
the prop turns much faster and he can capture upwards of 3 kiloWatts."
This is in stark contrast to what I am aiming for. Roughly 52V open circuit at 4 RPM.
@MagnetJuice
What I meant with breaking force ability was inspired by Joestru when he mentioned mechanical resistance and MaryB when she mentioned cogging and how much force it takes to overcome it.
The current charge controller I have will short all 3 phases to slow down the turbine. But if the coil/magnet configuration can't produce enough torque/breaking force then not much breaking will happen.
On the same token, if there turbine is charging the battery bank but not much resistance in the turning is being produced then there will be very little wattage available to charge at.