I had to replace a 2 year old battery but because of my own fault.
What I did is: (DB that is why a while back on MSN I told you to make sure to unplug the battery and main socket when working with headlights, cause now I am paranoid)
About half a year ago when I soldered in my new PIAA heavy duty light bulb sockets I didn't unplug my battery and main headlight switch socket. So guess what? All the extreme heat from the Soldering Iron fuc#$#ked up my Battery. I went to start my car right after that and I got.... flashing lights in instrument panel and the sound CLICK CLICK CLICK CLICK.
At that point of time I thought one word "FUCQQQQQQQQQQQQQQQQQ !!!"
disconnect your neg. battery terminal. use a volt meter, put in 20amp fused mode. connect the one lead from the meter to the neg. batt. terminal and the other lead of the meter to the neg. batt. cable you disconnected. this is testing the system for a drawl. the meter should read .03 amps or less. if it is any higher you probb. have a drawl somewhere. possible trunk light, glove box light,or hood light not properly shutting off when it should. that would drain your battery. hope this helps.
Sounds stupid but did you leave a dome light on by chance? 2 year old battery shouldn't be that beat. Try charging the battery up and see if it will hold it's charge. If it doesn't you may want to buy a new battery. Rather be safe than sorry...being stuck far from home b/c of a stupid battery is now fun.