2012 Toyota Corolla S won't start

3 weeks ago the car wouldn't start.  There was
corrosion all over the battery and cables.  Battery
tested bad so I replaced the battery, cleaned and
neutralized the clamps and cables and about a
week later, dead battery again.  I replaced the
altenator, charged the battery and still nothing (no
lights, horn, or start.  I replaced the positive battery
cable, charged the battery and nothing.  I can get it
to start when I jump start it.  It will run fine and start
with no jump if it sits for less than an hour, but if
longer will need another jump?  Out of ideas on why
the battery is dead when it sits overnight and what
to replace next?