I have the Red top Optima, its a few years old, just unhook it and left it in the car this last winter, come back 3 months later and hook a charger up to it, no need, was still fully charged.
Boy they aren't cheap thou...got mine from Sears after their Die Hards Golds kept dieing every year. Took it in their shop too so they could check the charging system, guy said get the Optima...was cool I got credit for my old battery.