These voltage settings are identified above in the output ratings. Indicators display the battery's condition. The red light indicates that the charger has a 120-volt AC supply present. The yellow light indicates the proper connection to the battery and combined with the red light indicates the charger is charging. The green light indicates a full charge.
Lights alternate when approaching full charge.
This prevents overcharging as the battery reaches its full capacity. The charger has electronic protection against reverse polarity and short circuits. The overload protection is provided by two fully automatic re-settable bimetallic circuit breakers. One protecting against excess current flow and the other from excess temperature rise. All functions are fully automatic.