What does the ammeter on the Schumacher battery charger tell me?

The ammeter indicates the amount of current measured in amps being drawn by the battery. As the battery charges, it draws less current from the charger, and the meter will show decreasing current. When the current stops decreasing, the battery is fully charged. During engine cranking, the meter needle will be at the extreme right side of the start area. The 2 amp charge rate may show some meter activity, though the meter has limited resolution at this low rate.