In stereo mode, the earbud batteries will provide up to 7 hours of play time or 48 hours of standby time (no audio playing). For all-day wear that involves a mix of audio listening and standby, the battery life will vary depending on the proportion of each. For example, 5 hours of audio would leave 10 hours of standby life remaining. And if the battery does run out, a quick 10-minute charge in the case will add up to 2 hours of play time.