my ipod warrent expires in two months and id like to kill the battery before then so i can get it replaced and i wont feel like i wasted money on the warrenty then got stuck paying for a new one. Ive been charging it then letting it play till it runs down but one of my friends says it kills the battry faster if you leave it plugged into the wall and playing all the time, so which is the best way to go about doing it?