Discharging to a very low level can damage, or kill, a battery. But this isn't a level that any phone will let you reach through usage. This is more along the lines of "running the phone until it shuts down and then leaving it sitting in a drawer uncharged for another 6 months".

That makes a lot of sense.

It is beneficial to occasionally run a battery from full down to the level at which the device shuts down without plugging it in in between.

INTERESTING. I usually panic if I ever get down that low because I thought it was a horrible thing. I think after tonight's charge-up, I'll let it do that!