Alternator Question

[suprabahamut]

I noticed on the voltmeter in the car sometimes reads 12 to 13 volts. I wanted to know does the alternator have a sleep mode? I use to have a Honda and when the alternator would do a sleep type mode, it would stay at 12 volts until the electrical system demanded more voltage. So I wanted to ask. I am going to check the battery with the car on tomorrow with a DVOM ,but it mostly happens when I am driving. I wanted to check if anyone knows if it is the same type of alternator.