No they dnt

 

I am inclined that Your serpentine slips then. It isn't tensioned well enough or its surface is oiled.
Technically speaking, excessive excitation current of Your alternator could create a higher drag load (and battery voltage), but since it is not overheating, I'd assume it is OK. Measuring the currents could confirm that, but doing that ain't easy task.
Get a clean rag, soak with alcohol and swipe over the serpentine surface. See what You'll get.

 

Here is a photo of how the markers are aligned on a tensioner pulley with a new serpentine. While it wears and gets longer, the marker moves with the arrow direction. What are Your markers at?

 

I didnt know this. Thanks!

 

Cool tip, did not know this either. Thanks.