The resistance of the stator taps ( with no other stator taps cut in ) and small drop wire  is somewhat limiting to the impedance of a battery bank .Make your own bridges from small amperage diodes that total resistance Will keep you running cool  . If you want more control use a pwm to limit the current to average 800 mil per tap the taps with a large resistance will average out with the smaller ones .
The speed taps are usually on the inner stator . The other stator is easy enough to cut in taps 16 or 14 coils. Make note of where the windings finish there is a over top wire that you can cut in leave enough to bring it out. . Every four coils has you bringing 4 more wires out  running 4 to 6  amps there a bouts