Hey guys, just wondering how long these things typically last (lifetime, not in between charges). I have 2 1300mah Spinners and was just curious how long (months, years?) before these things 'crap out' on me. On a related note, can you take these apart and replace the batteries? I received a dud from a bad vendor and am willing to experiment with taking it apart and fiddling with replacing the battery. Has this been done before?