So, supposedly you can tell if your phone's battery is bad by putting it on a flat surface and trying to "spin" it (as if you were playing spin the bottle). If it spins, supposedly the battery is swollen and needs to be replaced. Is this for real? And if so....why? I haven't seen one result on Google that says "this is why this test is useful." I ask because my phone's battery seems to be draining a lot faster than usual (despite the fact that I have the brightness down, auto-sync off, etc) and I don't want to buy a new one if I don't have to. Thanks in advance!