To fill out the story, my car gave me a "low battery" warning, and was charging at 14.8 all the time, which makes sense if the battery is charging up from a low state. Dealer told me that it is normal to always be at 14.8. Dealer subsequently determined that a prior dealer who had installed new battery for the previous owner failed to re-set the computer to reflect that battery was new, so they re-set it. When I got the car back yesterday, I was seeing 14.2 right after start-up and before getting under way; after I started driving, it would increase to 14.6, and stay there, even when idling at a stoplight. I had the battery checked by a third-party, and checked good (although shows as bad by my CTEK).
So, I'm wondering what others are seeing as normal driving voltage variances--does your voltage drop down into the 12s or 13s during normal operation, or does it always stay in the 14s? As I said, my 981 would drop down--it was supposedly for fuel economy (clutching/slacking the alternator would put less drag on belt/engine). As a side note, when I put the key in accessory position, I have seen as low as 12.2, which is obviously not good, but also doesn't seem to be accurate--the lowest I have measured with a voltmeter is 12.48. I'm starting to wonder if maybe there is an issue with the voltage regulator/charging system, although the car apparently passed all the diagnostics.