How long does the battery of ZeRound last after a full charge? May 21, 2016 08:00 Updated The internal battery of your ZeRound provides up to 2/3 days power receive: Talk time: 2:30 min Standby time: 3 days Related articles My ZeRound is not charging, what should I do? Can I charge my ZeRound with a wall plug? How to change ZeRound watch face? How to charge my ZeRound? Where can I find ZeRound mobile App?