Same as AlleyCat. The battery life span was about the same between my analog and digital hearing aids.. roughly 10-14ish days. shorter the older the hearing aids got. The current pair though don't seem to last a week (I need to pay attention next time one dies). Every hearing aid I've had is maxed out on power and I nearly always had/have them cranked to full volume (a 4 on those volume wheels lol).