Starsnav waterproof GPS Tracker can be used when external power is not always available, or when a long standby time is required, such as on motorcycles, boats, caravans, containers, etc. It can be configured to stay in sleep mode. When it is in sleep mode, it can operate for months or 2-3 years using its own backup battery. When external power is connected or turned on, it will not only be back online, but also automatically charge its own backup battery.