Car battery light ON and then OFF on 1993 Toyota Camry

While I was driving last night about 90 Km/hr suddenly I saw the battery light on. It stay about 4-6 minutes and then disappear. I was scared coz I need to drove about 30 more kms to home and I did it. That time headlight, gps and radio is operating but I switched off radio. would u plz let me know what should i do and cause of this problem.

Asked by for the 1993 Toyota Camry
That mean it not charging if it stays on or the voltage regulator starting to go see if its charging by checking battery with
Volts meter ,should be 14.0 volts with car running...
I also drove today problem till now. is it safe to drive
Yes ,its safe just get it checked out if stays on ':-)
but if it turn on then why suddenly again turned off....
Becausee the voltage regulator is in alternator ,I thin k it could be on its way out..
thanks dude. do you suggest me to replace it? how expensive it is?