Yea I have a 13 Ford Fiesta 5MT, 150k miles, (drives fine and given it's a 1.6 I pushed it really hard even with daily driving lol)

Last month it's battery light came on when I was driving home from school.

At first it came and go while you drive, but a few days later it's always on.

As a hobbits, I have a OBD scanner on my car so I was able to read the OBD system voltage while the light was on.

From there I see the voltage seems fine so I wasn't worried.

During the time when the battery light came and go while driving, the OBD scanner says 14.1 volts when the light goes away and 13.9 when it's on.

Now the light is always on and says 13.8 to 13.9 while engine running.

Codes that the system is giving are U012D and U049, they are about the smart charge system.

and according to this video: https://www.youtube.com/watch?v=l1am41c7FRA

the guy swapped the alternator because of this fault after confirming that data is being sent thru toward linbus.

I'm just wondering do I actually need a alternator? Could it be just bad connection?

I can steal a oscilloscope form some friend in EE and see if there is data but the connector position on the Fiesta is quite hard to reach.

And I'm assuming the alternator is still charging given what the OBD scanner says, so can I just... let it be? lol 

Also if it's ok to just go without the smart charge for a 5 hr trip for some family matter cuz I almost certainly do not have the time to fix this before going.