underdrive charging woes!!!maybe! lol!

[fast88]

I recently istalled a set of march underdrive pullies on my car and deleted the a/c at the same time.I have been having problems with the battery going dead.The gauge shows that at idle the car isn't charging at what it used to but at speed say1800 rpm the gauge is showing above what it used to (on the second line above the half way on the stock ammeter).I thought at first it may be the battery and it still may be its just a cheap economy from advance but I didn't have any charging problems before the pullies.It takes a couplee of days for the battery to go dead .I have charged the battery today and put it back in the car without driving to see if maybe there is a short killikg the battery.I have heard that sometimes the voltage reg. will stick and drain the battery while the car is sitting,any truth to that??Has anyone ever had this problem??Do I need a bigger alt with the pullies ??