the pulley works fine and there is no noticable electrical problem.

One time while sitting at idle, I was on the phone and charging it , heater going, heated seats, lights and radio and after 20 mins, the car started to sound like it was going to stall, so a little tap on the gas and problem solved. Has not happened again.

My car, at idle, makes ~13 volts with electricals off. Before the pulley it was ~14.5.

at speed, it now makes ~14, and before at speed, ~15.

All that i have noticed, after buying a new battery, is that if I leave the lights on for ~15 mins, or play the radio for ~45 min, the battery has a hard time starting the car and some times does not.
If I drive a little, it is not noticeable, and the car seems to recharge it, until I do it again.
However the performance gains far outweight any issues.....