2013 Honda Fit MT (CDN) Alternator or something else.
This *might* just be shitty luck, but this is my 3rd alternator, (rebuilt), recently I've had my battery light flickering, staying on for a minute then off again.. but I haven't actually had issues with the battery dying (until a few days ago), after breaking down conveniently a few KM from a parts store, a short tow and a boost I made it home (100km) with the light flickering occasionally but the battery staying charged.
Once home I cleaned all battery contacts, including the alternator side bits, replaced my ground wires,
I've built this little ODB2 voltmeter Do-hickey, expertly duct taped to my console.
Car runs fine (as a 13yr old hatchback will), no squealing from the belt (which is old, but tight). I've not had the battery light come on since getting home, but I attribute this to it not dipping below a certain threshold.
In the clip:
I'm coasting ~20km/h or less. (slowing down for traffic). And I can see the voltage from the alternator stop charging then kick in again. From what I understand, this shouldn't be normal. There's no "smarts" here, it's a 4g wire directly to the battery and it's bolted to ground, I'm monitoring the battery directly (ergo also the alternator output simultaneously), 14.2v steady AF when idling (no load) - 14.1v lights, radio and fans.
But these diiiiiiips in voltage concern me that the year old alternator is already dead/dying.