My bike was doing the same thing - lower than idle charge rates at higher RPMS. I also had weird AC voltage numbers at the time. For reasons beyond my understanding, a new battery cured it. The only thing I could reason was perhaps it was the way the regulator sensed the state of charge off a less than stellar battery? Maybe the regulator gets an attitude and feels insulted to be sending precious voltage up to a wheezing battery?
I wonder if a dealer would let you temporarily swap to a new battery just to test this theory? I'd swing down your way and let you try my apparently good battery, but I have fambly coming to town today, and can't get away 'til they leave.
The "no charge or discharge for X hours" data is perhaps the most relevant to battery health. 12.6X is usually considered the place to be for a 100% battery. As you can see, the charted tests require a digital volt meter.
I bought a battery for my wife's car the other day. It was 12.66 on the dealer's shelf. Sold!
(Doesn't everybody go battery shopping with a digital volt meter? ;-) )
If you do end up needing a battery, the NAPA ones at around $65 allow adding acid at the time of purchase, which one would think would lead to a fresh state of charge. I could be wrong.
