The battery lasts up to 15 days. Of course, that depends on how intensively you use the smartwatch. As with any other smartwatch, GPS and the display are the biggest power consumers. The more both are used, the shorter the battery lasts. Here are some selected scenarios: NO ALWAYS ON DISPLAY: 1. watch worn 17 hours a day, small number of notifications, no automatic display activation, no sports activities --> 15 days 2. watch worn 24 hours a day, moderate number of notifications, no automatic display activation, no sports activities --> 11 days 3. watch worn 24 hours a day, moderate number of notifications, no automatic display activation, 1h indoor activity per day with 50% display on --> 7 days 4. watch worn 17 hours a day, moderate number of notifications, no automatic display activation, 1h GPS outdoor activity per day with 0,5h display on --> 4 days 5. watch worn 17 hours a day, moderate number of notifications, no automatic display activation, 5h GPS outdoor activity per day with 1h display on --> 2 days DISPLAY ALWAYS ON: 1. watch worn 17 hours a day, moderate number of notifications, no sports activities --> 3 days 2. watch worn 17 hours a day, moderate number of notifications, 1h indoor activity per day with 10% display on full power --> 3 days 3. watch worn 17 hours a day, moderate number of notifications, 3h outdoor GPS activity per day with 20% display on full power --> 1,5 days