Quote:DC just cannot make up their minds though regarding Superman and how his powers really function!
Quote:removed fully from the sun, does he get weaker quickly, or does it all depend on how much solar reserves that he has charged up, so could go on for days/weeks/ even months?
Quote:same way with red Sun, does he go instatnt weak, as Mon El does, or does he stay super until reserves used up, which could take days?
Take this as what is is - a plot convenience. One of several. The weight of evidence shows that it would take several days without sunlight for Superman to depower significantly, Johns himself previously had Superman thrown into the blackness of The Trench for a number of hours in the Thone of Atlantis storyline, he was fine.
He should remain Super until he fully used up his solar reserves...