Hey Man,
I'm going to assume you've run the Optima and this problem just came up. With this said, Get a battery charger and charge the Optima battery FIRST! No need in killing the battery leaving it discharged. Then when you toss it in and crank it up, be sure to have a volt meter or DVOM and read off the battery what kinda voltage you got going on at the battery.
If that fails or reads <12.8v, then with the car running if you can reach it, go to the back of the alternator and pull the rubber cap off the red cable on the back, that's the main feed to the battery to recharge it. Check the voltage there. Again if it's reading <12.8v then you got a bad alternator, or it's not energizing.
But!
If you got good voltage at the alternator and not the battery ( i.e. Alt: 13.84v and the Bat: 12.7v ) Then you may have a the main 'charging wire' grounded out, or open, or have high resistance. If that's the case, IM me and I'll explain further.
Later