Theoretically, the battery light comes on ONLY when the voltage in the instrument panel (and therefore, in general, the electrical system/battery as a whole) is HIGHER than the voltage in the tertiary winding of the alternator. What that means, is that the Alternator cant possibly be charging. Note I did not say it was NOT charging, it is an indication that it can't be charging. Only an ammeter will really show us the charging action of the alternator - but they took such meters off our cars years ago, in favor of giving simple indications that tell us little, other than "there is a problem" - which is not helpful.

What all this means, is that the "Battery Light" is not so much an indicator of the condition of the battery, but of the alternator's charging status. MOST of the time, alternators simply DIE. IN cases where the light comes and goes, I'd suspect slipping belt or, again, a dying alternator.

But again, this is THEORY. There have been a lot of reports of a goofy battery causing the light to come on and off repeatedly. You SURE the battery is OK? I bought a new battery for the SE back in 2016. It lasted four months. "New" does not mean "it's gotta be ok".