@hotrodtodd , Todd, I take it you are talking about a vehicle, year, make and model may help. The battery/alternator light is an indicator of a charging system fault. So for whatever reason when the light comes on, it is because your charging system, alternator, may not be functioning properly. Could be a slipping worn belt that drives the alternator or a seizing belt tensioner/idler pulley,etc.. Possibly bad wire/plug/corrosion/loose connection on the alternator or battery, intermittent problems tend to be because of wiring and connection issues. If all else looks OK, have both the battery and alternator re evaluated/tested using a load test. Some parts suppliers Pepboys, Nappa, Advanced auto, etc. may offer this service for free. If not wanting to diagnose the problem yourself have a good Technician have a look diagnose and estimate repair. Good luck.
I hope this helped you out, if so let me know by pressing the helpful button.