[bbtowns]

You didn't say how fast the battery goes dead, but you've gotten some good advice here. I'd measure the current accross the battery posts with and without any optional electrical accessories connected with the bike off and see whether the current changes. Something is either shorting or running while you park your bike, if it's not an accessory then contine measuring current while you play explore your wiring a bit and watch for changes. You'll need a multi-meter or something similar to do this, but they're really cheap! Good luck.