Mr. Businessman has just had his bands tightened

Got into my car this morning and noticed the blue LED on the handsfree car kit was illuminated...  just barely.  It immediately struck me that something was wrong.  Sure enough, when I turned the key, nothing happened.  Absolutely nothing.  No radio, no dash lights, no dome light, nothing.  The battery was utterly depleted.

When my SO got home from work, he helped me push the car far enough out of the garage so that I could get under the hood.  He also found the battery charger and I hooked it up to trickle charge overnight.  

I think the problem was the cellular hands-free kit.  When I began pumping power back into the car, the kit began trying to connect to my cellphone, which it shouldn't do unless the ignition is on.  I don't know if it had been on for the past two weeks or if the low battery just caused it to malfunction.

Discharging a standard automotive battery more than about 5% shortens the life of the battery, and I drained this one completely.  It's a damn expensive Optima (red top) battery, so I hope I didn't damage it.  Next time perhaps I'll buy one of the yellow-top Optima batteries, they're designed to survive a full discharge.  I'll find out tomorrow whether the battery is still usable,