Quick question for the experts here:
I followed this thread, added a Ford regulator with an eBay rectifier and so far everything has been going great.  I have about 600 miles on the bike since getting it on the road a few months ago and haven't needed to touch a battery charger.  Recently I mounted a little LED charge indicator on my bike just as a safeguard to ensure I'm getting >13v when I should be.  For the most part it's been working well, with a "green" LED above 3,000 RPMs, showing that I am above 13.2V.  Here's a thread I posted about that: 
http://forums.sohc4.net/index.php?topic=113261.0I've noticed that at times when I'm at least 10 minutes into my ride, the indicator shows that my charge dips below 13.2V for a short time (less than a minute), and then it switches back to green (which means above 13.2v).  This happens sometimes at 80MPH on the highway while I'm constantly well above 3k RPM.  
So here's my question:  is this expected?  Should the battery voltage fluctuate like this during a ride?  Does the charging system work in cycles when the battery is fully charged?  Is there some other reason why the voltage would dip down temporarily?  
Thanks!
Aaron