I had my phone charging all night long, but this morning, the battery indicator was in the "yellow" zone, about to go "red." WTF?
I hate it when that happens.
Sometimes I wish I didn't know about phantom loads. The average cell phone charger uses 2.5 watts of electricity when it's plugged in without anything attached to it. That's why I unplug the charger during the day.
Evidently, a corollary to that is: A cell phone gets zero watts of electricity overnight from a charger that isn't plugged in.