Im not here to notoriously complain about bad battery drainage, defend good battery capacity, or whatever. I was just wondering where I can find a good clear and concise list of things to keep an eye out for to indicate a bad battery that would warrant getting it replaced or checked by Apple. What to look at, tests that I can do, numbers, etc. that I can apply to multiple phones. I realize batteries vary, but just even a general margin would be helpful. Thanks.