Optima dead, trying to find problem, help!

[MonzaRacer]

Sounds like you have a drain, get one of the battery disconnect switch for about $8to$10 then you put it on one of the cable ends , run the car, then you hook a DMM(digital Multimeter) with a 10 amp scal and milliamps tooto the wire and the terminal.
then seperate them and read it, if you have more than 250milliamps, or 1/4 of an amp your definately getting a drain, the first thing I would look for are any automatic lights(doors,glove box, alternator)or 12v turned on circuit.
If you have a 10 si alternator unplug it, as some times they will stay turned on, if its a self excited(ie has no 12 volt key on wire or loop overto the other plug terminal) it can stay on.
also you may also have the power wire that the alt feeds power through placed wrong. make an 8 guage wire to the battery positive nad see if system voltage goes up.
also your car needs to run at least 13.9 to 15 volts (actaul indusrty "spec" is 13.9 to 14.6) and the voltage should never drop morethan a volt and the amps should increase as loads go up and figure your car would probably run with anywhere from 10 to 20 amps steady charging.
The thing is you need to use a good multimeter with amps channel, and start pulling fuses and unplugging things till it drops. Have a friend watch the meter.
Also if your battery dies over a period of time you may need a trickle charger to keep it up.
Also if a battery dies and stays down it will be junk pretty quick. Even an optima.