While riding in Georgia, North Carolina, & Tennessee, I noticed that my voltage was fluctuating a bit. The day would typically begin at 14.2 volt. After 30 min. or so of riding, the voltage would drop down to 13.5 volt. I knew I could live with 13.5 volt since it was still charged my battery.
I still was riding the bike as is. No big deal. It's still charging. BUT last week, the voltage meter began showing lower than 13.5. That concerned me.
Last time when I was stranded due to the failed alternator, I pulled out the old alternator and reconditioned it.