Some people talk all day on the phone!  And the muscular strength that
it gave to her jaw . . . .

Four or five years ago I watched my boss burn through a battery charge
in a single morning!  This was an old StarTac 7868W.  He was using his
cell phone because he was away from his desk working on a computer in
our data center and talking to technical support.  If he hadn't actually
been using the phone, the battery almost certainly would have lasted
sixteen hours and maybe even twenty-four.  I don't recall if he had a
spare battery or not but he certainly could have used one that day.