Charging about 10 or 15 minutes a day is enough. The charger has a brilliantly designed magnetic connection to the inner side of the Band, and snaps on without fumbling. I keep a charger on USB on my desktop at the office, and one on a wall charger at home on the nightstand.
If you don't care about GPS, each charge lasts about 2.5 days. With GPS enabled via one of the fitness apps, about 1.5 days. I use the built-in steps recorder, similar to my Fitbit, without GPS. I also use the workout monitor sometimes. I start it at the beginning of my workout, and it monitors my heart rate throughout.