My mechanic told me a similar story
He said that most of his charging/battery low problems can be remedied by removing the alternator plug and cleaning the connections. If that doesn't help he puts a new set of brushes in. That will be less than 25 dollars for parts. Also put a little grease on the connector to prevent future problems. If you have less than 13 volts at idle, start here.
When I close my eyes, and inhale, I can smell No. 2.