I have a rebuilt 14668 Denso alternator. it runs at just below 15V pretty much the whole time I'd guess it's a 14.9V set point on the regulator). This is on my old truck though and I don't drive it often, the big battery might not be fully charged.
I've had this alternator on my truck for atleast a year and it's been fine, the battery is fine, I bypassed the Ammeter and installed a voltmeter.

Another thing to think about, the Voltage Regulator set point. Here is one for the same style alternator and it's a 14.6V set point...
https://www.maniacelectricmotors.com/80904406.html


I also found this, notice they seem to set their alternators to 14.9V
https://www.powermastermotorsports.com/why_run_an_alternator_a.html