alternator slipping, belts squealing,

[upstate240sx]

hey nissan fiens,
heres my problem, im tearing through belts, 2 in 1 week, 2 new belts, they are all snapping. and when i first get the belt, it squeals and squeals and squeals, the squeal slowly gets quieter, and as it gets quieter i notice that i think my alternator is slipping, when i install a new belt my charging system works great, headlights heater radio everything can turn on and stay on and i wont lose the battery, but as the belt goes throughout its life, a couple days later, the battery will die , ill charge it up with a wall charger and it will die again, and it also holds a charge, this is my second alternator. which im sure is good, and the battery im semi sure is good, i have a sr20 running a k/a waterpump pulley and there is a slight angle of the belt when you look down at it, there is a angle in the belt at every spot the belt makes contact, where the belt makes contact with the w/p and the alternator, where the alternator makes contact with the crank pulley, and where the crank pulley meets the water pump. so i notice that the k/a waterpump pulley has a different offset so i think an sr w/p pulley will solve this any ideas?