> Next day I put my digi-meter on the batt
>> and got 12.96v reading..Poke the starter and it cranks very weakly for a
>> very short time.  Back to the multi meter and I see 12.4 volts.

Something to keep in mind is that to use battery voltage as a measure
of battery charge, the electrolite must be uniform.  That isn't the
case during or just after a charge.  The acid level is higher
close to the plates.  Standard battery recommendation is to
wait several hours, preferably 24, and then measure the voltage.

See II at http://www.trojanbattery.com/BatteryMaintenance/Testing.aspx

When I pull the battery maintainer off my aux batteries, the
voltage will be 13.3 or so, falling steadily over several
hours to 12.6 or so.

Another factor often overlooked is temperature.  This is seldom
mentioned.  "All voltages are at 20 �C, and must be adjusted -0.022V/�C
for temperature changes (negative temperature coefficient - lower
voltage at higher temperature)."  This from:
http://en.wikipedia.org/wiki/Automotive_battery

This page also has
"After full charge the terminal voltage will drop quickly to 13.2 V and
then slowly to 12.6 V
Open circuit voltage is measured 12 hours after charging to allow
surface charge to dissipate and enable a more accurate reading."

Richard