One charge on the band will pretty much last 48 hours. It depends on how many apps you setup on the Band. It looks to me that mine is going to last more than 48 hours. I've been monitoring my sleep. I'll probably stop doing that every night and charge it over night now and than. BTW, I did test voice input and that works pretty well. I just feel a little funny talking to my hand. Doubt that I will do that too much in public, less they think I'm with the CIA or FBI. For those of you who remember, Dick Tracy's technology has definitely arrived.