2010 Chevy 1500 4x4 Gauge Reading

chevrolet
1500

#1

Since last spring the battery/alternator(?) gauge occasionally rides at about the 11 o’clock position, into the discharge. Normally it rides at the 1 o’clock position; charging. I replaced the alternator on the suggestion of auto parts store employee after he told me the alternator was fluctuating, but the problem still persists. Any ideas?
Thanks!