This depends on the way the device is used. For example, a tracking device that is monitoring the whereabouts of a valuable asset may only need to report once a day on battery save mode, and the battery will last for months. Should you require your device to report every ten seconds, this will reduce the battery life. The Prime 3G GPS Tracker's battery lasts for approximately ten days on a five-minute reporting schedule. Your device will 'communicate' with the Tracking Panel every four hours, even if the item has not moved. This ensures you are always confident the device is working correctly. This feature is only disabled in battery save mode.