Hi Bill,
There in lies the problem
The regulator sees say 11.5 v , its sole function is to get this up to its cutoout voltage paobably 14,4v
If the alternator is capable of stuffing 30A into the battery it will do this till the battery voltage rises to its cut out point
Basically tha alternators and batteries need to be matched in capacity within certain peramaters
The Kubota or similar permanent magnet alternators are probably not as hard on the batteries as excited rotor alternators but they have antother problem
They have very strong magnets so do not turn over smoothly at lower revs, rather they pulse from one magnetic pole to the next
Early Alltons suffered from this and apparently used to break the (dynamo) drive gear teeth on certain bikes
THeres a guy in USA or Canada who has devloped the Kubota for use on Vincents, I believe it uses some kind of centrifugal cluth
I went through the ups and downs of fitting such an alternator to the A10, but abandoned it due to complexity and the issues mentioned
The thoughts of broken timing gear teeth and then valves hopping off the pistons put me off the idea
The 12v dynamo with belt drive and Podtronics regulator have been 110% relaible so far
So this is what I have recommended to my customers to go with, (DVR2 regs on those)
Cheers
John