Buy one of the ciggy lighter socket plug in volt/amp digital displays to get an accurate idea of what the alternator is doing, and how well the battery is charged. I have one, and it works great.
I also use one of the little trickle chargers to keep the battery up in our less used 1994 164LS. Works well to keep the battery where it should be, confirmed by the little volt/amp plug in meter.
1989 Milano, Shankle Sport
1991 164S, stock
1994 164LS (~Q)
1972 Morgan 27
previously owned since 1964:
62 Morris MiniMinor 850, 67 Austin 1275 Cooper S (Downton 3/4 race), 64 Giulia Sprint GT (1st red one made), 72 Fiat 128 Sedan, 75 Alfetta Sedan, 78 Alfetta Sedan, 78 GTV, 81 GTV6, 86 GTV6