[consultIII]

Did the no start occur the day after the battery replacement or was the new battery ok for a while?

fully charge your battery and then check for parasitic draw.

Its unlikely that 2 batteries are bad but it is possible. New batteries aren't fully charged and may have not been fully charged by just driving.

slow charge the battery for 8hrs. Conductance test the battery if a jobber in your area provides this service for free...maybe where you bought it. This rules out the battery.

If battery ok, check for parasitic draw. Any draw over 50 miliamps is considered excessive.

If draw ok, check alternator output.