6/12V 10/6/2A Pro-Logix Battery Charger

For a severly drained agm car battery, how long is a typical charging time on the 20 amp setting? thank you.

Does the charger fail to detect parasitic drain depleting a battery when left connected?

Cant i keep this hooked up as a tender/maintainer for long perior storage ?

Once unit starts conditioning the agm battery, is it suppose to turn off