Battery getting drained/alternator is fine

I had a penny stuck in my cigarette lighter and thought nothing of it. I wound up yanking it out and the problems began. I first noticed that the clock light stayed on. Then the car started dying. I was having to charge it daily until I realized that if I turned off the radio and a/c fan, I wouldn't have to charge it unless I didn't drive it for a full day. (I had gone through 3 batteries and kept getting the alternator checked before I had that brilliant idea)
I need my radio and a/c, and I'm not sure if the cigarette lighter is on one of those fuses. (I don't have the manual) I don't even know if removing the fuse would help the situation, or if it's caused a short somewhere requiring more effort/cost than I'm willing to take on. My electrical knowledge is limited. As is my car knowledge. I have made assumptions that the constant drain has to be from the penny incident. Any suggestions? I don't mind getting a little dirty to not have to charge the freakin car at least once a week.
Thanks so much for your suggestions

ps.. I think I posted this wrong after reading the thread I was supposed to read before I posted. Please forgive me.

keep in mind a bad battery can kill an alternator, and a bad alternator can kill a battery, sometimes both need to be replaced at the same time or one will just keep killing the other, also, those 3 batteries youve gone through, did you buy them at wal mart?? if so, that is your problem right there, i bought a battery from wal mart new years eve night, 12-31-06, i took it back and exchanged it twice, until yesterday (time number 3) when i said fuck it and just took it back and got a refund, i went to an actual auto parts store, bought a name brand battery, and havent had any problems since,