battery & starter recently replaced by dealer. alternator recently replaced. on 2002 Lexus ES300

Alternator replaced with NAPA part. Battery warning light continues to come on from time to time. Dealer checked and found alternator OK and clueless as to reason for battery lighy coming on. Any ideas?

Asked by for the 2002 Lexus ES300
ck your power dist box to see if there is a bad alt relay that may be sticking. there should be a relay for charging system.