OK. I sent a text to Jack of ROADSTERCYCLE.com, and he corrected several of my misconceptions. He’s been selling Shindengen kits for years, (11000+ of FH020AA). He corrected me as follows: ( I’d love to paste his email to me, but need to ask permission).
1. FH020AA has a peak current of 50 amps, 35 amps continuous (I’d said 30 amps.). He’s not aware of an RPM limit.
It is a MOSFET unit. It would be fine on my bike.
2. He said SH 775 was originally built for low RPM ATVs, not motorcycles. He quotes 9000 RPM limit, but issues actually
occur somewhere between 9000 and 10,000, so he picks 9000 to be conservative. He quotes rating at 27 amps.
The unit is also fine for my VMAX. This R/R definitely runs cool, and keeps stator cooler than the FH020AA.
3. Jack says SH 847 unit is a 50 amp unit, and he says it is of particular value for very high RPM bikes in keeping stator
much cooler. It’s much larger than FH020AA and SH775.
4. Surprise: He said the SH775 & 847 are indeed series R/Rs, but I was wrong in that they ARE NOT MOSFET
CONTROLLED R/Rs, THEY HAVE DIODES. In all his years of selling SH 775 and 847, he’s received no negative
feedback on stator insulation breakdown due to high voltage open circuit voltages, or other problems, so he feels
my concerns are not warranted. The stators run cooler.
5. The feedback he’s received from customers is the MOSFET FH0020AA R/R runs cooler than the SH 775 and 847
R/Rs, but they’re all very much cooler than the old OEMs.
I wanted to set the record straight, don’t want to leave the wrong information. I think I’ll save a few dollars and buy the FH020AA. I know enough for me.
Jeff.
PS: Shaun, I priced the 96-07 OEM R/R, and it was $230. While easier to install than the Shindengen R/Rs, I’m a fiddler, can’t wait to put in an FH020AA.
PS2: For technuts, the Vmax forum has a great, detailed thread in first generation Vmax, electrical, titled “how stators work”