Vue's battery will last 3 days on standby, which includes activity tracking and notification forwarding. Vue's battery will last 5 hours during continuous audio streaming (this figure is based on a moderate volume level). If you use Vue for a mixture of activities, they will last between 5 hours to 3 days.
When Vue's charging case is fully charged, it can re-charge the Vue frames up to 3 full times. The charging case charges over USB-C.