Thats not true at all even back in the day you would almost never get 14.6V which is the peak the voltage regulator allowsThe short answer is yes.
You can check this in vehicle status on the dash and switch it to batter voltage. If it's charging anything other than 14.4 then you can confirm it's a smart battery. Make sure no AC or radio is on.
No offense to them, but they won’t have a clue.