Catalytic converter=dead battery?

I have an interesting situation. I have been smelling my catalytic converter off and on for a couple weeks now. The muffler shop tells me there is nothing wrong, it just smells when it gets hot.

Now, it seems that every time I turn off my vehicle and smell the cat, I try to start it up and the battery is dead. Now I'm not a mechanic, but this just doesn't seem logical. What's going on?

well most likly they hooked a computer up too it and checkd ur O2 sensers to make sure ur cat is accually doing something... most shops will do that and just call it good but some dont run a back pressure test on them.. try running a back pressure test on it and if it shows that there is a large amount of back pressure then ur cat is getting pluged... ask them to make sure they did that no point in haveing it done twice... the dead battery could be ur alternator... check the output with a voltage gauge it should read around 14.0v+ with no lights or aux. on. and a min of 13.7v loaded. if it reaches past 15.0v it is ur voltage reg inside the alternator. still replace the alternator